0001868941-25-000081 | 10-K | XBRL Viewer

Summary of Significant Accounting Policies and Estimates (Policies)

12 Months Ended

Sep. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The accompanying consolidated financial statements include the accounts of Fluence Energy, Inc. and its subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

Non-Controlling Interest

As the sole managing member of Fluence Energy, LLC, Fluence Energy, Inc. operates and controls all the business and affairs of Fluence Energy, LLC and, through Fluence Energy, LLC and its direct and indirect subsidiaries, conducts the Company’s business. Fluence Energy, LLC is a variable interest entity, of which Fluence Energy, Inc. beneficially owns a 71.81% interest as of September 30, 2025. For accounting purposes, Fluence Energy, Inc. is considered the primary beneficiary and therefore consolidates the results of Fluence Energy, LLC and its direct and indirect subsidiaries.

Use of Estimates

The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the accompanying consolidated financial statements and accompanying notes. Actual results could differ materially from those estimates. Items subject to such estimates and assumptions include: the relative fair value allocations to contingencies with multiple elements, the carrying amount and estimated useful lives of long-lived assets; impairment of goodwill, intangible assets, and long-lived assets; valuation allowances for inventories; deferred tax assets; revenue recognized under the percentage-of-completion method; transaction price estimates with variable consideration; accrued bonuses; and various project related provisions including, but not limited to, estimated losses and warranty obligations.

Cash, Cash Equivalents, and Restricted Cash

Cash and cash equivalents include cash on-hand and highly liquid investments readily convertible to cash, with an original maturity of 90 days or less when purchased.

Cash restricted for use as a result of financing or other obligations is classified separately as restricted cash. If the purpose of restricted cash relates to acquiring a long-term asset, liquidating a long-term liability, or is otherwise unavailable for a period longer than one year from the balance sheet date, the restricted cash is included in “other non-current assets.” Otherwise, restricted cash is included as a separate line item on the Company’s consolidated balance sheets.

The Company typically retains cash for operations within one or more bank accounts. Our U.S. bank accounts may hold cash in excess of the FDIC limit of $250,000. As a result, we are subject to concentration risk associated with the underlying custodial banks with whom deposits of cash and cash equivalents in excess of the FDIC limits are held. If access to these accounts is delayed or suspended indefinitely, it could have a material adverse impact on the Company’s ability to meet its financial obligations required for operations.

Receivables

Trade receivables represent actual billings that are generally due within 30 days from the invoice date, and do not bear interest. Unbilled receivables represent the excess of revenues recognized over billings to date on certain contracts. Receivables are carried at amounts billed, less any reserves for credit losses, if any. The Company periodically assesses collectability of accounts receivable and records an expected credit loss for the estimated uncollectible amount when deemed appropriate. As of September 30, 2025 and 2024, reserve for credit losses was approximately $0.7 million and $2.9 million, respectively.

Advances are given to suppliers based on the contract terms of respective agreements and are presented on a separate line on the consolidated balance sheets. These advances are recovered through the receipt of goods and services mainly used in the production of energy storage products.

Leases

The Company accounts for its leases in accordance with ASC 842, Leases. The Company leases offices, warehouses, and production lines. Leases are categorized at their commencement date and lease-related assets and liabilities are recognized for all leases with an initial term of greater than 12 months. The Company evaluates renewal options at commencement and on an ongoing basis and includes options that are reasonably certain to exercise in its expected lease terms when classifying leases and measuring lease liabilities. The Company’s incremental borrowing rate is used to determine the present value of the lease payments over the lease term for leases, as these leases typically do not have a stated borrowing rate. The Company’s lease agreements do not contain any material residual value guarantees or material restrictive covenants.

ASC 842 requires lessees to recognize assets and liabilities for most leases. The Company determines if an arrangement is a lease at contract inception. A lease exists when a contract conveys to the customer the right to control the use of an identified asset for a period of time in exchange for consideration. The definition of a lease embodies two conditions: (1) there is an identified asset in the contract, and (2) the customer has the right to control the use of the identified asset. Lessees are required to classify leases as either finance or operating leases. This classification will determine whether lease expense is recognized based on an effective interest method or on a straight-line basis over the term of the lease.

The Company’s right-of-use assets and lease liabilities primarily relate to offices, warehouses, and U.S battery module production lines in Utah. On May 31, 2025, the Company entered into a finance lease agreement for the U.S. battery module production line in Utah. The production line is classified as a finance lease under ASC 842. The Company’s leases generally have remaining lease terms of one year to nine years. Certain of the Company’s leases contain renewal, extension, or termination options. The Company assesses each option on an individual basis and will only include options reasonably certain of exercise in the lease term. The Company generally considers the base term to be the term provided in the contract. None of the Company’s operating lease agreements contain material options to purchase the leased property, material residual value guarantees, or material restrictions or covenants.

The Company does not recognize a lease liability or right-of-use asset on the balance sheet for short-term leases. Instead, the Company recognizes short-term lease payments as an expense on a straight-line basis over the lease term. A short-term lease is defined as a lease that, at the commencement date, has a lease term of 12 months or less and does not include an option to purchase the underlying asset that the lessee is reasonably certain to exercise. Leases (with terms greater than twelve months) are recorded on the consolidated balance sheets at the present value of the minimum lease payments not yet paid. As the Company’s leases do not provide an implicit rate, the Company generally uses its incremental borrowing rate based on the estimated rate of interest for collateralized borrowing over a similar term of the lease payments at commencement date to calculate the present value of future lease payments. Certain leases include payments that are based solely on an index or rate. These variable lease payments are included in the calculation of the ROU asset and lease liability and are initially measured using the index or rate at the lease commencement date. Other variable lease payments, such as payments based on use and for property taxes, insurance, or common area maintenance that are based on actual assessments are excluded from the ROU asset and lease liability and are expensed as incurred. In addition to the present value of the future lease payments, the calculation of the ROU asset also includes adjustments for lease incentives, deferred rent, lease prepayments and initial direct costs of obtaining the lease, such as commissions.

Certain lease contracts contain nonlease components such as maintenance and utilities. The Company has made an accounting policy election, as allowed under ASC 842-10-15-37, to capitalize both the lease component and nonlease components of its contracts as a single lease component for its right-of-use assets. This election applies at the asset class level.

Foreign Currency Transactions

An entity’s functional currency is the currency of the primary economic environment in which the entity operates and is generally the currency in which the entity generates and expends cash. The reporting currency of the Company is the U.S. dollar. For all Fluence subsidiary entities whose functional currency is not in U.S. Dollar, the balance sheet is translated into U.S. Dollar using the rates in effect at the end of each period. The income statement is translated using the exchange rate in effect on the transaction date. Translation adjustments are included as a separate component on the consolidated statement of comprehensive income (loss). Foreign currency transaction gains and losses are a result of the effect of exchange rate changes on transactions denominated in currencies other than the functional currency of the respective subsidiary entity. Transaction gains and losses are recognized in “Other (income) expense, net” in the consolidated statements of operations.

Business Combinations

A business combination is an acquisition of a business from an entity not under common control and is accounted for using the acquisition method. Identifiable assets acquired and liabilities assumed are recognized at fair value on the acquisition date. Goodwill is calculated as the excess of the fair value of the consideration transferred over the fair value of the net assets recognized and represents the future economic benefits arising from the other net assets acquired that could not be individually identified and separately recognized. Fair value measurements may require us to make significant estimates and assumptions. A measurement period, which could be up to one year from the date of the acquisition, exists to identify and measure the assets acquired and liabilities assumed. During the measurement period, provisional amounts may be recognized, and those amounts may subsequently be prospectively adjusted to reflect any new information about facts and circumstances that existed at the acquisition date that, if known, would have affected the measurement of these amounts. At the end of the measurement period, any subsequent changes would not be recognized under the acquisition method but would instead follow other accounting principles, which would generally impact earnings.

Revenue and Cost Recognition

The Company’s revenue recognition policy included herein is based on the application of ASC 606. As of September 30, 2025, the Company’s revenue was generated primarily from sale of energy storage products and solutions, providing operational services related to energy storage products, and digital applications. We may refer to our energy storage products as “energy storage solutions” throughout these consolidated financial statements and use this term interchangeably as it is more reflective of the full offering available and provided to our customers.

Revenue from Sale of Energy Storage Products and Solutions: The Company enters into contracts with utility companies, developers, and commercial and industrial customers to design and build battery-based energy storage products. Our projects have a lead time from date of contract execution to substantial completion, typically ranging from approximately twelve up to eighteen months. Generally, we must design the project, as each storage solution is customized depending on the customer’s energy needs, procure the major equipment, obtain manufacturing slots from our contract manufacturers, coordinate the logistics, and assemble the solution prior to delivery and installation at our customer project sites. These actions must be completed timely to adhere to customer schedules and milestones. Depending on the scope of the project we may be responsible for the installation of the equipment. After the equipment is installed, we are responsible for commissioning. The Company recognizes revenue over time when we have enforceable right to payment for work performed to date and the solution, in its completed state, does not have any alternative use to the Company. Revenue is recognized using the percentage of completion (“POC”) method based on actual cost incurred as a percentage of total estimated contract costs. Standard inventory materials (including batteries, enclosures, chillers, and others, which are assembled into “integrated systems”) are included in our measure of progress when they are restricted to a specific customer’s project such that we no longer have the ability to direct their use for other purposes. Contract costs include all direct material and labor costs related to contract performance. As the cost of the assembled integrated systems comprise a substantial portion of the total estimated contract costs, our pattern of revenue recognition may vary materially from period to period. Our judgment on when costs should be included in the measure of progress may have a material impact on revenue recognition.

Since the revenue recognition of these contracts depends on estimates, which are assessed continually during the term of the contract, recognized revenues and profit are subject to revisions as the contract progresses to completion. The cumulative effects of revisions of estimated total contract costs and revenues, together with any contract reserves which may be deemed appropriate, are recorded in the period in which they occur. Due to the uncertainties inherent in the estimation process, it is reasonably possible that these estimates will be revised in a different period.

The Company determines the transaction price based on the consideration expected to be received which includes estimates of variable consideration that are included in the transaction price in accordance with ASC 606. The transaction price identified is allocated to each distinct performance obligation to deliver a good or service based on the relative standalone selling prices. For our energy storage products and solutions, services, and digital applications contracts where there are multiple performance obligations in a single contract or we sign separate contracts at or near the same time with the same customer that meet the criteria for combination, the Company allocates the transaction price to the various obligations in the contract based on the relative standalone selling price. Standalone selling prices are estimated based on estimated costs plus margin taking into consideration pricing history and market factors. Generally, our revenues recognized are not sensitive to the Company’s determination of standalone selling prices.

We assess any variable consideration using an expected value method which computes a weighted average amount based on a range of potential outcomes. Variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty is resolved. Estimating variable consideration requires certain estimates and assumptions, including whether and by how much a project will be delayed or if we will not meet certain performance specifications per the contract.

Our contracts generally provide our customers the right to liquidated damages (“LDs”) against Fluence in the event specified milestones are not met on time or equipment is not delivered according to contract specifications. Liquidated damages are accounted for as variable consideration and the contract price is reduced by the expected LD amount when recognizing revenue. The existence and measurement of LDs may also be impacted by our judgments about the probability of favorable outcomes of customer disputes involving whether certain events qualify as force majeure or the reason for the events that caused project delays. Variable consideration for LDs is estimated using the expected value method.

Fluence may incur additional costs to execute on the performance of a contract. When this happens, we typically attempt to recover these costs via a change order with the customer. When this fact pattern occurs, it can create a timing difference between when we have incurred the cost versus when we record the proportionate revenue, since costs are recognized immediately when incurred and the revenue is recognized based upon the transaction price, which is usually increased upon signing a respective change order with the customer. For the fiscal years ended September 30, 2025 and 2024, we recognized $5.5 million and $11.0 million, respectively, in revenue from changes in transaction prices during the period, in which the performance obligations were substantially satisfied in previous periods.

When shipping and handling activities are performed after the customer obtains control of the product, we elect to account for shipping and handling as activities to fulfill the promise to transfer the product.

Revenue is recorded net of any taxes assessed on and collected from customers, which are remitted to the governmental authorities.

Customer payments are due upon meeting certain milestones as defined in the contract, which are generally consistent with contract-specific phases of a project.

Pre-contract costs with no future benefit are expensed in the period in which they are incurred. Generally, pre-contract costs are not material.

Revenue from Services: The Company also enters into long-term service agreements with customers to provide operational services related to battery-based energy storage products and solutions. The services include extended warranty, maintenance, monitoring, and other services. The Company accounts for the services as separate performance obligations from the battery-based energy storage products and solutions. The extended warranty services are typically considered a separate performance obligation from the maintenance, monitoring and other services. We typically recognize revenue ratably over the terms of the services using a straight-line recognition method. The Company believes using a time-based method to measure progress is appropriate as the performance obligations are satisfied evenly over the terms of services. Revenue is recognized for each of the performance obligations by dividing the allocated transaction price over the service period.

Some of the agreements also provide a commitment to perform augmentation activities which would typically be represented by installation of additional batteries, and other components as needed, to compensate for partially lost capacity due to degradation of batteries over time. The obligation to perform augmentation activities can take the form of either maintaining battery capacity above a given threshold for a stated term while others provide a fixed number of augmentations over a contract term. Augmentation arrangements that require us to maintain battery capacity above an established thresholds for a given term may be considered service-type warranties depending on the contract terms. These represent a stand-ready obligation in which the customer benefits evenly over time, of which we recognize revenue for these arrangements using a straight-line recognition method. Alternatively, augmentation arrangements that require us to perform a fixed number of augmentations over a contract term follow the percentage of completion revenue recognition method. Since these arrangements require a fixed number of augmentations we must perform, we use the pattern of cost as a proxy to identify when our obligations are satisfied and to recognize revenue.

Revenue from Digital Applications: The Company provides access to proprietary cloud-based Software-as-a-Service (“SaaS”) offerings through several market facing applications. These applications currently include Fluence Mosaic and Fluence Nispera. Fluence Mosaic is an intelligent bidding software for utility-scale storage and renewable assets, helping to enable customers to optimize asset trading in wholesale electricity markets. Fluence Mosaic is currently available in the NEM (Australia), CAISO (California), ERCOT (Texas), and Japan markets. Fluence Nispera is an asset performance management software that helps customers monitor, analyze, forecast, and optimize the performance of their renewable energy assets. Fluence Nispera is an AI-driven utility-scale asset performance management platform that supports portfolios of energy storage, solar, and wind assets. Customers do not receive legal title or ownership of the applications as a result of these arrangements. The use of the Fluence digital software applications is separately identifiable from other promises that the Company offers to its customers. As such, Fluence digital applications are accounted for as separate performance obligations when combined with other Fluence products, solutions, and services. We consider access to the platform and related support services in a customer contract to be a series of distinct services which comprise a single performance obligation because they are substantially the same and have the same pattern of transfer. We recognize revenue over time using a straight-line recognition method.

Deferred Revenue: Deferred revenue represents the excess billings to date over the amount of revenue recognized to date. The timing and the amount we bill our customer is based on achieving milestones as defined in the contract with the customer.

Loss Contracts: A contract becomes a loss contract when its estimated total costs are expected to exceed its total revenue. The Company accrues the full loss expected in the period a loss contract is identified which is recorded in “Accruals and provisions” and “Cost of goods and services” on the Company’s consolidated balance sheets and consolidated statements of operations, respectively.

Cost of Goods and Services: Cost of goods and services consists primarily of product costs, including purchased materials and supplies, as well as costs related to shipping, customer support, product warranty and personnel. Personnel costs in cost of goods and services includes both direct labor costs as well as costs attributable to any individuals whose activities relate to the transformation of raw materials or component parts into finished goods or the transportation of materials to the customer. Cost of goods and services are recognized when services are performed or when goods are included in our measure of progress as progress relevant costs, which is when they are restricted to a specific customer’s project.

Inventory, Net

Inventory primarily consists of integrated systems, batteries and related equipment, enclosures, inverters, and spare parts which are used in ongoing battery storage product and solutions projects. Inventory is stated at the lower of cost or net realizable value with cost being determined by the specific identification method. Costs include cost of purchase, costs of conversion and other costs incurred in bringing the inventories to their present location and condition. The Company periodically reviews its inventory for

potential obsolescence and write down of its inventory, as appropriate, to net realizable value based on its assessment of usefulness and marketability conditions.

Software Development Costs and Intangible Assets

Our software development costs primarily relate to three categories: (i) internal-use software development costs, (ii) hosting arrangements which are service contracts, and (iii) external-use software development costs. We capitalize costs incurred to purchase or develop software for internal use and software to be sold or leased externally.

Internal-use software development costs are capitalized during the application development stage in accordance with ASC 350-40, Internal-Use Software. These capitalized costs are reflected in “Intangible assets, net” on the consolidated balance sheets and are amortized over the estimated useful life of the software. Our internal-use software relates to our (i) SaaS customer offerings and is amortized to “Cost of goods and services” and (ii) internally developed solutions and are amortized to “Depreciation and amortization.” The useful life of our internal-use software development costs is generally 3 to 5 years.

As of September 30, 2025, 2024 and 2023, the Company capitalized $8.8 million, $8.9 million, and $6.4 million respectively, of internal-use software.

Software development costs associated with hosting arrangements are capitalized during the application development stage. These are generally cloud-computing arrangements that are service contracts. The capitalized costs are reflected in “Other non-current assets” on the consolidated balance sheets and are amortized to “General and administrative” once ready for intended use over the estimated useful life of the hosted software. The useful life of our software development costs associated with hosting arrangements is generally the period the Company expects to benefit from its right to access the hosted software plus consideration for any renewal or cancellation periods, which is generally 5 to 7 years.

As of September 30, 2025, 2024 and 2023, the Company capitalized $12.7 million, $37.4 million and $0.0 million respectively, of software development costs related to hosting arrangements.

External-use software development costs developed to be sold or leased externally are capitalized upon the establishment of technological feasibility for a product in accordance with ASC 985-20, Software to be Sold or Leased Externally. These software development costs are reflected in “Intangible assets, net” on our consolidated balance sheets and amortized to “Cost of goods and services” on a product basis by the greater of the straight-line method over the estimated economic life of the product or the ratio that current gross revenues for a product bear to the total current and anticipated future gross revenues for that product. The useful life of our external-use software development costs is generally 5 years.

Intangible assets are stated at their historical cost and amortized on a straight-line basis over their expected useful lives. Intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable.

Impairment of Long -Lived Assets

The Company evaluates the recoverability of its property and equipment and intangible assets whenever events or changes in circumstances indicate that their carrying amount may not be recoverable. The assets are considered impaired when their future undiscounted cash flows are less than the carrying value and fair value is less than their carrying value. Impairment charges are calculated as the difference between the discounted expected future cash flows, or other accepted valuation techniques to determine fair value, and the assets’ carrying amount at the date of the triggering event.

Operating Expenses

Operating expenses include research and development, sales and marketing, general and administrative expenses, and depreciation and amortization. Research and development expenses consist of personnel-related costs across our global research and development (“R&D”) centers for engineers engaged in the design and development and testing of our integrated products and technologies and costs of materials and services procured for research and development projects. Sales and marketing expenses consist primarily of personnel-related expenses, including salaries, stock-based compensation, employee benefits and factoring discounts on receivables sold. General and administrative expenses consist primarily of personnel-related expenses, including salaries, stock-based compensation, and employee benefits, for our executives, finance, human resources, information technology, engineering and legal organizations that do not relate directly to the sales or research and development functions. General and administrative expenses also consist of travel expenses, facilities costs, information technology costs, bad debt expense, and fees for professional services. Professional services consist of audit, legal, tax, insurance, information technology, and other costs. Depreciation consists of costs

associated with property, plant, and equipment (“PP&E”) and amortization of intangibles consisting of patents, licenses, developed technology and capitalized software over their expected period of use.

Advertising Costs

Advertising costs are expensed as incurred.

Income Taxes

Fluence Energy, LLC is treated as a partnership for U.S. federal income tax purposes. As such, the members are individually liable for their own distributable share of taxable income or loss. The Company is subject to U.S. federal and state income taxes with respect to our allocable share of any taxable income or loss of Fluence Energy, LLC, and taxed at the prevailing corporate tax rates.

The Company is subject to foreign income taxes with respect to our foreign subsidiaries. Foreign subsidiaries of the Company account for income taxes and the related accounts in accordance with ASC 740, Income Taxes. Under ASC 740, deferred tax assets and liabilities are determined based on differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse.

The Company recognizes the tax benefits from uncertain tax positions if it is more likely than not that the position will be sustained on examination by the taxing authorities. The Company recognizes interest and penalties related to unrecognized tax benefits as a component of income tax expense.

The preparation of income tax returns requires the use of management’s estimates and interpretations which may be subjected to review by the respective taxing authorities and may result in an assessment of additional taxes, penalties, and interest.

Government Incentives and Grants

The Company is entitled to AMPC tax credits provided by the IRA (which went into effect in 2023), as modified by the OBBBA (which went into effect in 2025). The Company recognizes the production credits as a reduction to the related cost of goods and services, when there is reasonable assurance that the Company will be able to claim the credits (i.e., upon recognition of revenue and cost of goods services related to the sold eligible equipment).

Fair Value Measurements

The fair value of the Company’s financial assets and liabilities reflects management’s estimate of amounts that the Company would have received in connection with the sale of the assets or paid in connection with the transfer of the liabilities in an orderly transaction between market participants at the measurement date. In connection with measuring the fair value of its assets and liabilities, the Company seeks to maximize the use of observable inputs and to minimize the use of unobservable inputs. The following fair value hierarchy, defined by ASC 820, Fair Value Measurements, is used to classify assets and liabilities based on the observable inputs and unobservable inputs used to value the assets and liabilities:

Level 1—Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis.

Level 2—Pricing inputs are other than quoted prices in active markets included in Level 1, which are either directly or indirectly observable as of the reporting date. Level 2 inputs include those financial instruments that are valued using models or other valuation methodologies. These models are primarily industry-standard models that consider various assumptions, including quoted prices, time value, volatility factors, and current market and contractual prices for the underlying instruments, as well as other relevant economic measures. Substantially all of these assumptions are observable in the marketplace throughout the full term of the instrument, can be derived from observable data or are supported by observable levels at which transactions are executed in the marketplace.

Level 3—Pricing inputs include significant inputs that are generally less observable from objective sources. These inputs may be used with internally developed methodologies that result in management’s best estimate of fair value from the perspective of a market participant. The Company does not have significant recurring Level 3 fair value measurements.

The Company’s cash equivalents include cash on hand and highly liquid investments readily convertible to cash, with an original maturity of 90 days or less when purchased. Fair value of cash equivalents approximates the carrying amount. The carrying amounts of trade receivables, accounts payable and short-term debt obligations such as current portion of borrowings against note receivable - pledged as collateral, approximate fair values due to their short maturities.

The fair value of the Company’s foreign currency derivatives is measured on a recurring basis by comparing the contracted forward exchange rate to the current market exchange rate. The foreign currency derivatives are categorized as Level 2 in the fair

value hierarchy, as the inputs to the derivative pricing model are generally observable and do not contain a high level of subjectivity. Refer to “Note 21 – Derivatives and Hedging” for details regarding the Company’s derivatives and hedging activities.

The Company estimates the fair value of its 2030 Convertible Senior Notes (defined below) using commonly accepted valuation methodologies and market-based risk measurements that are directly observable, such as unadjusted quoted prices in markets that are not active (Level 2). Refer to “Note 13 – Convertible Senior Notes, Net” for further details.

Short-term Investments and Marketable Securities: We obtain pricing from level 1 inputs which includes information from quoted market prices, pricing vendors or quotes from brokers/dealers. We conduct reviews of our primary pricing vendors to determine whether the inputs used in the vendor’s pricing processes are deemed to be observable. The fair value of U.S. Treasury securities and government-related securities, corporate bonds and notes and common stock is generally determined using standard observable inputs, including reported trades, quoted market prices, matrix pricing, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets and/or benchmark securities. Marketable securities are presented on the balance sheets at fair value at the end of each reporting period. Gains and losses resulting from the change in fair value of these securities is included in “Other (income) expense, net” in the accompanying statements of operations.

Derivatives and Hedging

The Company records all derivatives at their gross fair values on the consolidated balance sheets. The accounting for the gains or losses resulting from changes in the fair value of derivatives depends on the intended use of the derivatives, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting.

Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. The gains or losses from designated cash flow hedges are deferred in accumulated other comprehensive income and subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The gains or losses will be presented in the same income statement line item as the earnings effect of the hedged item. The effectiveness of cash flow hedges is assessed at inception and quarterly thereafter. The change in fair value of the components excluded from the assessment of effectiveness are recognized in current period earnings. The changes in fair value of derivatives that are not designated for hedge accounting are recognized in current period earnings.

Convertible Senior Notes, Net

The Company accounts for its 2030 Convertible Senior Notes as a liability in their entirety, measured at amortized cost. Debt issuance costs incurred in connection with the issuance of the Company’s 2030 Convertible Senior Notes are reflected in the condensed consolidated balance sheets as a direct deduction from the carrying amount of the outstanding 2030 Convertible Senior Notes. These costs are amortized using the effective interest rate method over the terms of the 2030 Convertible Senior Notes and are included within interest expense on the condensed consolidated statements of operations.In connection with the issuance of the 2030 Convertible Senior Notes, the Company entered into privately negotiated capped call transactions with certain counterparties. The capped call transactions are generally expected to offset the potential dilution to the Company’s Class A common stock upon any conversion of the 2030 Convertible Senior Notes and/or offset any cash payments the Company is required to make in excess of the principal amount of converted notes, with such reduction and/or offset subject to a cap.

Recent Accounting Standards Adopted and Recent Accounting Standards Not Yet Adopted

The following table presents accounting standards adopted in 2025:


Standard	Description	Date of adoption	Effect on the financial statements and other significant matters
Accounting Standards Update (“ASU”) No. 2024-04: Debt—Debt with Conversion and Other Options (Subtopic 470-20): Induced Conversions of Convertible Debt Instruments	ASU 2024-04 clarifies the requirements for determining whether certain settlements of convertible debt instruments should be accounted for as an induced conversion.	As of the three months ended December 31, 2024.	The new standard was early adopted by the Company and applied for the Company’s 2030 Convertible Senior Notes. Refer to “Note 13 – Convertible Senior Notes, Net” for further details. The new standard did not have an impact on the condensed consolidated financial statements.
ASU No. 2023-07: Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures	ASU 2023-07 requires disclosure of incremental segment information on an annual and interim basis for all public entities to enable investors to develop more decision-useful financial analyses. The update requires other specified segment items and amounts, such as depreciation, amortization, and depletion expense, to be disclosed under certain circumstances. The amendments in this update do not change or remove those disclosure requirements. The amendments in this update also do not change how a public entity identifies its operating segments, aggregates those operating segments, or applies the quantitative thresholds to determine its reportable segments.	As of the three months ended September 30, 2025.	The Company only has one reportable segment. The Company adopted this standard in the fourth quarter of 2025, which did not have a material impact on the consolidated financial statements and related disclosures. Refer to “Note 1 – Organization and Operations” for further details.

Recent Accounting Standards Not Yet Adopted

The following table presents accounting standards not yet adopted:


Standard	Description	Required date of adoption	Effect on the financial statements and other significant matters
ASU No. 2023-09: Income Taxes (Topic 740): Improvements to Income Tax Disclosures	ASU 2023-09 adopts certain amendments to improve the effectiveness of income tax disclosures, including jurisdictional information, by requiring (1) consistent categories and greater disaggregation of information in the rate reconciliation, and (2) income taxes paid, disaggregated by jurisdiction.	ASU 2023-09 is effective for the Company’s annual report for fiscal year ending September 30, 2026.	The Company is evaluating the impact this guidance will have on income tax disclosures.
SEC Final Rule Release Nos. 33-11275; 34-99678: The Enhancement and Standardization of Climate-Related Disclosures for Investors	SEC Final Rule Release Nos. 33-11275; 34-99678 requires registrants to provide certain climate-related information in their registration statements and annual reports, including climate-related risks that have materially impacted, or are reasonably likely to have a material impact on, its business strategy, results of operations, or financial condition. In addition, certain disclosures related to severe weather events and other natural conditions will be required in registrants’ annual reports.	SEC Final Rule Release Nos. 33-11275; 34-99678 is effective for the Company’s annual report for fiscal year ending September 30, 2026.	The Company is evaluating the impact this guidance will have on climate-related disclosures.
ASU No. 2024-03: Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses	ASU 2024-03 requires disclosure of qualitative and quantitative information about certain costs and expenses in the notes to the financial statements on an interim and annual basis. ASU No. 2025-01: Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date, was subsequently issued and clarified the effective date of ASU 2024-03.	ASU 2024-03 is effective for the Company’s annual report for fiscal year ending September 30, 2028.	The Company is evaluating the impact this guidance will have on its disclosures.
ASU No. 2025-05: Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets	ASU 2025-05 amends ASC 326-20 to provide a practical expedient (for all entities) and an accounting policy election (for all entities, other than public business entities, that elect the practical expedient) related to the estimation of expected credit losses for current accounts receivable and current contract assets that arise from transactions accounted for under ASC 606.	ASU 2025-05 is effective for the Company’s annual report for fiscal year ending September 30, 2027.	The Company is evaluating the impact this guidance will have on its disclosures.
ASU No. 2025-06: Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software	ASU 2025-06 makes targeted improvements to ASC 350-40 and amends certain aspects of the accounting for and disclosure of software costs under ASC 350-40. The amendments supersede the guidance on Web site development costs in ASC 350-50 and relocate that guidance, along with the recognition requirements for development costs specific to Web sites, to ASC 350-40.	ASU 2025-06 is effective for the Company’s annual report for fiscal year ending September 30, 2029.	The Company is evaluating the impact this guidance will have on its disclosures.

Income (Loss) per Share

Basic (loss) income per share of Class A common stock is computed by dividing net loss attributable to Class A common stockholders by the weighted average number of shares of Class A common stock outstanding during the period. Diluted (loss) income per share of Class A common stock is computed by adjusting the net (loss) income available to Class A common stockholders and the weighted average shares of Class A common stock outstanding to give effect to potentially dilutive securities. Shares of our Class B-1 common stock are not entitled to receive any distributions or dividends. When an LLC Interest of Fluence Energy, LLC is redeemed for cash or Class A common stock by a Founder who holds shares of our Class B-1 common stock, such Founder will be required to surrender a share of Class B-1 common stock, as the case may be, which we will cancel for no consideration. In the event of cash settlement, the Company is required to issue new shares of Class A common stock and use the proceeds from the sale of these newly-issued shares of Class A common stock to fully fund the cash settlement. Therefore, we did not include shares of our Class B-1 common stock in the computation of basic loss per share.

Schedule I Condensed Financial Information of the Registrant - CONDENSED BALANCE SHEETS (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Current assets:
Cash and cash equivalents	$ 690,768	$ 448,685
Accounts receivable - related party	272,820	216,458
Other receivables	200,748	362,523
Taxes recoverable	15,186	23,962
Total current assets	2,064,256	1,680,443
Non-current assets:
Total non-current assets	292,744	221,745
Total assets	2,357,000	1,902,188
Current liabilities:
Accounts payable	321,004	436,744
Accruals and provisions	246,235	338,311
Taxes payable	30,317	57,929
Other current liabilities - related party	20,590	24,246
Total current liabilities	1,370,369	1,258,835
Non-current liabilities:
Convertible senior notes, net	390,804	0
Other non-current liabilities - related party	37,449	29,100
Total non-current liabilities	437,783	36,214
Total liabilities	1,808,152	1,295,049
Commitments and Contingencies (Note 3)
Stockholders’ equity:
Preferred stock, $0.00001 per share, 10,000,000 shares authorized; no shares issued and outstanding as of September 30, 2025 and 2024	0	0
Treasury stock, at cost	(10,213)	(9,460)
Additional paid-in capital	627,956	634,851
Accumulated deficit	(199,762)	(151,448)
Total stockholders’ equity attributable to Fluence Energy, Inc.	429,595	472,104
Total liabilities, stockholders’ equity	2,357,000	1,902,188
Related Party
Current assets:
Other receivables	26,615	92,183
Current liabilities:
Accounts payable	4,985	3,410
Accruals and provisions	6,353	6,099
Other current liabilities - related party	301	428
Non-current liabilities:
Other non-current liabilities - related party	0	1,507
Parent
Current assets:
Cash and cash equivalents	371	267
Other receivables	68	443
Taxes recoverable	49	0
Total current assets	6,952	710
Non-current assets:
Long-term notes receivable - related party	400,000	0
Investment in subsidiaries	727,297	802,606
Total non-current assets	1,127,297	802,606
Total assets	1,134,249	803,316
Current liabilities:
Accruals and provisions	2,625	74
Taxes payable	0	1,955
Total current liabilities	9,702	4,906
Non-current liabilities:
Convertible senior notes, net	390,804	0
Total non-current liabilities	390,804	1,507
Total liabilities	400,506	6,413
Commitments and Contingencies (Note 3)
Stockholders’ equity:
Preferred stock, $0.00001 per share, 10,000,000 shares authorized; no shares issued and outstanding as of September 30, 2025 and 2024	0	0
Treasury stock, at cost	(10,213)	(9,460)
Additional paid-in capital	939,433	965,562
Distribution from Fluence Energy, LLC	10,213	9,460
Contribution to Fluence Energy, LLC	(17,811)	(15,641)
Accumulated deficit	(187,879)	(153,018)
Total stockholders’ equity attributable to Fluence Energy, Inc.	733,743	796,903
Total liabilities, stockholders’ equity	1,134,249	803,316
Parent \| Related Party
Current assets:
Accounts receivable - related party	6,464	0
Current liabilities:
Accounts payable	6,657	2,803
Other current liabilities - related party	301	0
Non-current liabilities:
Other non-current liabilities - related party	0	1,507
Parent \| Nonrelated Party
Current liabilities:
Accounts payable	119	74
Class A common stock
Stockholders’ equity:
Common stock	1	1
Class A common stock \| Parent
Stockholders’ equity:
Common stock	0	0
Class B-1 Common Stock
Stockholders’ equity:
Common stock	0	0
Class B-1 Common Stock \| Parent
Stockholders’ equity:
Common stock	0	0
Class B-2 common stock
Stockholders’ equity:
Common stock	0	0
Class B-2 common stock \| Parent
Stockholders’ equity:
Common stock	$ 0	$ 0

Cover - USD ($) $ in Millions	12 Months Ended
Cover - USD ($) $ in Millions	Sep. 30, 2025	Nov. 20, 2025	Mar. 31, 2025
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Current Fiscal Year End Date	--09-30
Document Period End Date	Sep. 30, 2025
Document Transition Report	false
Entity File Number	001-40978
Entity Registrant Name	Fluence Energy, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	87-1304612
Entity Address, Address Line One	4601 Fairfax Drive,
Entity Address, Address Line Two	Suite 600
Entity Address, City or Town	Arlington,
Entity Address, State or Province	VA
Entity Address, Postal Zip Code	22203
City Area Code	(833)
Local Phone Number	358-3623
Title of 12(b) Security	Class A common stock, $0.00001 par value
Trading Symbol	FLNC
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 309.2
Documents Incorporated by Reference	Portions of the registrant’s Definitive Proxy Statement relating to the 2026 Annual Meeting of Stockholders are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. Such Definitive Proxy Statement will be filed with the Securities and Exchange Commission within 120 days after the end of the registrant’s fiscal year ended September 30, 2025.
Entity Central Index Key	0001868941
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Amendment Flag	false
Class A common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		131,369,447
Class B-1 Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		51,499,195

Debt - Pledged as Collateral (Details) - USD ($) $ in Millions			1 Months Ended		12 Months Ended
	Dec. 27, 2024	Sep. 16, 2024	Apr. 30, 2023	Dec. 31, 2022	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Line of Credit Facility [Line Items]
Financing receivable, amount transferred	$ 30.9	$ 24.3	$ 30.9	$ 24.3
Proceeds from borrowing against note receivable - pledged as collateral			$ 27.0	$ 21.1
Interest income, operating					$ 0.5	$ 4.4	$ 3.4
Interest expense					0.5	4.1	2.4
Asset-Backed Securities, Securitized Loans and Receivables
Line of Credit Facility [Line Items]
Interest expense (income), net					$ 0.0	$ 0.3	$ 1.0

- Definition

Amount of operating interest income, including, but not limited to, amortization and accretion of premiums and discounts on securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 830
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479168/946-830-55-10

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 310
-Name Accounting Standards Codification
-Section S50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479255/942-310-S50-4

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 310
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.H.2.Q1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478116/942-310-S99-2

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(1)(e))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-22

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 48
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-48

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 320
-Name Accounting Standards Codification
-Section S99
-Paragraph 6
-Subparagraph (SX 210.12-14(Column E)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 320
-Name Accounting Standards Codification
-Section S99
-Paragraph 6
-Subparagraph (SX 210.12-14(Column E)(Footnote 4))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 830
-Name Accounting Standards Codification
-Section 45
-Paragraph 39
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477346/946-830-45-39

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(1)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 946
-SubTopic 320
-Name Accounting Standards Codification
-Section S99
-Paragraph 6
-Subparagraph (SX 210.12-14(Column E)(Footnote 6)(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6

+ Details

Income Taxes (Tables)

12 Months Ended

Sep. 30, 2025

Income Tax Disclosure [Abstract]

Schedule of Income Before Income Tax, Domestic and Foreign

The following table presents the components of income (loss) before income tax (in thousands):


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Domestic	$	(121,163)	$	(33,983)	$	(100,356)
Foreign	76,091		73,556		87
Income (loss) before income taxes	$	(45,072)	$	39,573	$	(100,269)

Schedule of Components of Income Tax Expense (Benefit)

The major components of income tax expense/(benefit) were as follows:


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Current income tax expense:
Domestic	$	165	$	1,948	$	—
Foreign	14,343		13,700		1,349
Deferred income tax expense (benefit):
Domestic	—		—		—
Foreign	6,293		(6,719)		2,541
Withholding income tax expense:
Domestic	—		—		—
Foreign	2,115		277		659
Total income tax expense	$	22,917	$	9,206	$	4,549

Schedule of Effective Income Tax Rate Reconciliation

The following table summarizes a reconciliation of the U.S. statutory federal income tax rate to the Company’s effective tax rate.


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Statutory rate	21.0	%	21.0	%	21.0	%
State taxes	2.9	%	(1.9)	%	3.1	%
Rate change	(34.2)	%	52.6	%	(15.5)	%
Flow-through losses	(15.2)	%	3.3	%	(9.3)	%
Foreign rate differential	(13.0)	%	14.3	%	2.2	%
Withholding taxes	(4.7)	%	0.7	%	(0.7)	%
Valuation allowance	1.4	%	(118.6)	%	(12.9)	%
Permanent differences	(13.1)	%	(12.2)	%	7.8	%
U.S. tax on foreign earnings	2.0	%	50.6	%	—	%
Return to provision adjustments	3.7	%	14.2	%	(1.0)	%
Other items, net	(1.6)	%	(0.7)	%	0.8	%
Effective tax rate	(50.8)	%	23.3	%	(4.5)	%

Schedule of Deferred Tax Assets and Liabilities

Deferred income tax is generated by Fluence Energy, Inc. and its foreign subsidiaries and is comprised of the following:


in thousands	September 30,
	2025		2024
Deferred Tax Assets
Inventory	$	147,457	$	129,341
Investment in Fluence Energy, LLC	311,957		333,489
Deferred revenue	35,804		27,374
Tax loss carryforwards	66,641		47,765
Unrealized foreign exchange losses	5,301		5,270
Share-based compensation	3,450		3,843
Other deferred tax assets	4,957		2,047
Total deferred tax assets	575,569		549,129
Valuation allowance	(367,323)		(377,218)
Net deferred tax assets	208,246		171,911
Deferred Tax Liabilities
Trade receivables	(8,698)		(20,043)
Intangible assets	(3,676)		(3,697)
Accrued and other liabilities	(192,983)		(140,401)
Unrealized foreign exchange gains	(7,950)		(5,612)
Other deferred tax liabilities	(423)		(392)
Total deferred tax liabilities	(213,730)		(170,145)
Total net deferred tax assets (liabilities)	$	(5,484)	$	1,766

Supply Chain Financing

12 Months Ended

Sep. 30, 2025

Payables and Accruals [Abstract]

Supply Chain Financing

The Company has provided certain of our suppliers with access to a supply chain financing program through a third-party financing institution (“SCF Bank”). This program allows the Company to seek extended payment terms up to 120 days with our suppliers and allows our suppliers to monetize their receivables prior to the payment due date, subject to a discount. The Company does not pledge any assets as collateral under the program. Once a supplier elects to participate in the program and reaches an agreement with SCF Bank, the supplier chooses which individual invoices to sell to the SCF Bank. The Company then pays SCF Bank on the invoice due date. The Company has no economic interest in a supplier’s decision to sell an underlying receivable to SCF Bank. The agreements between our suppliers and SCF Bank are solely at their discretion and are negotiated directly between those two parties. Our suppliers’ ability to continue using such agreements is primarily dependent upon the strength of our financial condition and guarantees issued by AES and Siemens. As of September 30, 2025, AES and Siemens Corporation, a subsidiary of Siemens, issued guarantees of $50 million each, for a total of $100 million, to SCF Bank on our behalf. The Company’s outstanding obligations confirmed as valid under its supplier financing program for periods ended September 30, 2025 and September 30, 2024, are as follows:


In thousands	September 30, 2025		September 30, 2024
Obligations outstanding at the beginning of the period	$	81,289	$	30,001
Invoices issued during the period	63,316		243,655
Invoices paid during the period	(144,605)		(192,367)
Obligations outstanding at the end of the period	$	—	$	81,289

As of September 30, 2025, two suppliers were actively participating in the supply chain financing program. All outstanding payments owed under the program are recorded within “Accounts payable” on the consolidated balance sheets.

The Company entered into a new $150.0 million supply chain financing arrangement (the “New SCF Facility”) with a third-party financial institution (the “New SCF Bank”) on August 8, 2025. This New SCF Facility allows the Company to seek extended payment terms with our suppliers and allows our suppliers to monetize their receivables prior to the payment due date, subject to a discount. Such sales are at the sole discretion of the supplier, and on terms and conditions that are negotiated between the supplier and the New SCF Bank. The Company is not a party to the arrangement between its suppliers and the New SCF Bank and the Company has no economic interest in a supplier’s decision to sell an underlying receivable to the New SCF Bank. The Company does not provide secured legal assets or other forms of guarantees under this arrangement, nor do any of the Company’s affiliates. Under the New SCF Facility, we are required to maintain a liquidity ratio of 2:1 as of the last day of each calendar month. Liquidity ratio is defined as the ratio of (i) liquidity to (ii) the sum of (x) the aggregate outstanding notional amount of all receivables, bills of exchange or similar negotiable instruments purchased by the original SCF Bank under the existing supply chain financing arrangement described above and (y) the aggregate outstanding notional amount of payables outstanding under this New SCF Facility. Liquidity under the New SCF Facility includes the Company’s cash and cash equivalents and aggregate availability under the Company’s committed credit facilities, including the 2024 Revolver. As of September 30, 2025, no suppliers participated in the New SCF Facility, and the Company had no outstanding payment obligations to the New SCF Bank.

(Loss) income per Share - Narrative (Details)	Sep. 30, 2025 class
Class A common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of classes of common stock	2
Class B-1 Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of classes of common stock	2

Revenue from Contracts with Customers - Geographical Regions (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Total revenue	$ 2,262,830	$ 2,698,562	$ 2,217,978
Americas (North, Central and South America)
Disaggregation of Revenue [Line Items]
Total revenue	1,305,941	1,593,003	1,645,107
APAC (Asia Pacific)
Disaggregation of Revenue [Line Items]
Total revenue	348,573	579,255	266,077
EMEA (Europe, Middle-East and Africa)
Disaggregation of Revenue [Line Items]
Total revenue	608,316	526,304	306,794
United States of America
Disaggregation of Revenue [Line Items]
Total revenue	$ 877,300	$ 1,442,000	$ 1,495,000

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-5

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

+ Details

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-4

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-14

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-41

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-42

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-7

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 270
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482964/270-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (ee)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 8: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 9: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 924
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479941/924-10-S99-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-5

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-30

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-22

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 40
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-40

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-22

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-4

+ Details

Summary of Significant Accounting Policies and Estimates - Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 690,768	$ 448,685
Restricted cash	23,862	46,089
Restricted cash included in “Other non-current assets”	0	23,932
Total cash, cash equivalents and restricted cash shown in the statements of cash flows	$ 714,630	$ 518,706	$ 462,731	$ 429,721

Summary of Significant Accounting Policies and Estimates - Revenue and Cost Recognition (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Revenue Recognition, Milestone Method [Line Items]
Revenue recognized on change order	$ 5.5	$ 11.0
Minimum
Revenue Recognition, Milestone Method [Line Items]
Contractual period	12 months
Maximum
Revenue Recognition, Milestone Method [Line Items]
Contractual period	18 months

Cybersecurity Risk Management and Strategy Disclosure	12 Months Ended
Cybersecurity Risk Management and Strategy Disclosure	Sep. 30, 2025
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	We manage our cybersecurity risks through an information security management system (ISMS) that falls under our overarching integrated management system (IMS) for quality and safety. Our cybersecurity risk management program and supporting ISMS focus our efforts on reducing residual risks to our critical corporate assets. The materiality of these risks drives the selection of appropriate controls and the prioritization of the projects and operational tasks of our cybersecurity teams. Our approach to controlling these risks is designed and assessed based on our selection and implementation of certain controls from the National Institute of Standards and Technology (NIST) Cyber Security Framework (CSF). This does not imply that we meet any particular technical standards, specifications, or requirements, only that we use NIST CSF as a guide to help us identify, assess, and manage cybersecurity risks relevant to our business. These controls are implemented to help us identify our critical assets and systems, protect them through preventative measures, detect attempts to compromise their confidentiality, integrity, and availability, respond to attacks by containing their progression and notifying relevant parties, and recover effectively if successfully compromised. Key elements of our cybersecurity risk management program include but are not limited to: authentication and authorization procedures, employee security awareness training, logging and monitoring procedures, network segmentation requirements, in transit and at rest encryption of certain data we deem sensitive, periodic vulnerability scanning, periodic control validation through penetration testing, periodic phishing attack simulations, production change control requirements, periodic tabletop exercises, and written incident response plans. We also use external service providers, where appropriate, to assess, test or otherwise assist with aspects of our security processes. We maintain a third-party risk management process for key service providers based on our assessment of their criticality to our operations and respective risk profile. To date, we are not aware of any risks from known cybersecurity threats, including as a result of any previous cybersecurity incidents, that have materially affected or are reasonably likely to materially affect Fluence. We face risks from cybersecurity threats that, if realized, are reasonably likely to materially affect us, including our operations, business strategy, results of operations, or financial condition. For more information on potential cybersecurity risks, please see Part I, Item 1A “Risk Factors” for the risk factor entitled “Our business depends on our ability to implement improvements to and properly maintain and protect the continuous operation and data integrity of our information technology infrastructure, data, and other business systems and the inability to do so may have a material adverse effect on our reputation and harm our business prospects, financial conditions, and operating results.”
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	We manage our cybersecurity risks through an information security management system (ISMS) that falls under our overarching integrated management system (IMS) for quality and safety. Our cybersecurity risk management program and supporting ISMS focus our efforts on reducing residual risks to our critical corporate assets. The materiality of these risks drives the selection of appropriate controls and the prioritization of the projects and operational tasks of our cybersecurity teams.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	false
Cybersecurity Risk Board of Directors Oversight [Text Block]	Our cybersecurity program and supporting ISMS are governed by our Cybersecurity Steering Committee, which is includes our Chief Information Officer (“CIO”) and is comprised of other members of our management team, including individuals from our finance, supply chain, product, information technology (“IT”), and legal departments. The Cybersecurity Steering Committee convenes quarterly to review the ISMS, identify new material risks and potential treatment plans that are recorded in our cybersecurity risk register, and review the overall health of security key risk indicators, technical key performance indicators, and roadmaps for the expected delivery of new and updated controls.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	board of directors oversees all enterprise risks, the Audit Committee of our board of directors has primary responsibility for overseeing cybersecurity risks and management’s implementation of our cybersecurity risk management program.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	Our cybersecurity program and supporting ISMS are governed by our Cybersecurity Steering Committee, which is includes our Chief Information Officer (“CIO”) and is comprised of other members of our management team, including individuals from our finance, supply chain, product, information technology (“IT”), and legal departments. The Cybersecurity Steering Committee convenes quarterly to review the ISMS, identify new material risks and potential treatment plans that are recorded in our cybersecurity risk register, and review the overall health of security key risk indicators, technical key performance indicators, and roadmaps for the expected delivery of new and updated controls. Cybersecurity oversight and related risk-management activities are currently led by the CIO, who has more than 20 years of experience in information technology, cybersecurity governance, and enterprise-risk management. The CIO has implemented defense-in-depth cybersecurity frameworks and controls aligned with industry standards such as COBIT and ITIL and has regularly reported on cybersecurity risks and mitigation activities to boards of directors and audit committees throughout his career. Management is informed about cybersecurity risks through ongoing monitoring and reporting processes, including real-time incident dashboards, periodic risk assessments, and collaboration with internal and external cybersecurity experts. The CIO provides updates on cybersecurity risks, incident response readiness, and mitigation efforts to executive leadership and Fluence’s board of directors through the Audit Committee as part of the Company’s enterprise-risk-management program. We have a written cybersecurity incident escalation process overseen by senior leadership, and when senior leadership deems appropriate, a materiality committee is convened comprised of certain members of management who assess whether incidents must be reported to the SEC and/or the appropriate authorities. While Fluence’s board of directors oversees all enterprise risks, the Audit Committee of our board of directors has primary responsibility for overseeing cybersecurity risks and management’s implementation of our cybersecurity risk management program. The Audit Committee receives quarterly updates from CIO. These updates typically cover topics such as: overview of material cybersecurity incidents that have occurred since the last update, overview of residual cybersecurity risks to our critical business assets, recent investments in our cybersecurity program, and relevant cybersecurity operational metrics. The Audit Committee will report updates regarding cybersecurity to the Board, as it deems appropriate.
Cybersecurity Risk Role of Management [Text Block]	Our cybersecurity program and supporting ISMS are governed by our Cybersecurity Steering Committee, which is includes our Chief Information Officer (“CIO”) and is comprised of other members of our management team, including individuals from our finance, supply chain, product, information technology (“IT”), and legal departments. The Cybersecurity Steering Committee convenes quarterly to review the ISMS, identify new material risks and potential treatment plans that are recorded in our cybersecurity risk register, and review the overall health of security key risk indicators, technical key performance indicators, and roadmaps for the expected delivery of new and updated controls. Cybersecurity oversight and related risk-management activities are currently led by the CIO, who has more than 20 years of experience in information technology, cybersecurity governance, and enterprise-risk management. The CIO has implemented defense-in-depth cybersecurity frameworks and controls aligned with industry standards such as COBIT and ITIL and has regularly reported on cybersecurity risks and mitigation activities to boards of directors and audit committees throughout his career. Management is informed about cybersecurity risks through ongoing monitoring and reporting processes, including real-time incident dashboards, periodic risk assessments, and collaboration with internal and external cybersecurity experts. The CIO provides updates on cybersecurity risks, incident response readiness, and mitigation efforts to executive leadership and Fluence’s board of directors through the Audit Committee as part of the Company’s enterprise-risk-management program. We have a written cybersecurity incident escalation process overseen by senior leadership, and when senior leadership deems appropriate, a materiality committee is convened comprised of certain members of management who assess whether incidents must be reported to the SEC and/or the appropriate authorities. While Fluence’s board of directors oversees all enterprise risks, the Audit Committee of our board of directors has primary responsibility for overseeing cybersecurity risks and management’s implementation of our cybersecurity risk management program. The Audit Committee receives quarterly updates from CIO. These updates typically cover topics such as: overview of material cybersecurity incidents that have occurred since the last update, overview of residual cybersecurity risks to our critical business assets, recent investments in our cybersecurity program, and relevant cybersecurity operational metrics. The Audit Committee will report updates regarding cybersecurity to the Board, as it deems appropriate. Our management team takes steps to stay informed about and monitor efforts to prevent, detect, mitigate, and remediate cybersecurity risks and incidents through various means, which may include: briefings from internal security personnel; threat intelligence and other information obtained from governmental, public or private sources, including external consultants engaged by us; and alerts and reports produced by security tools deployed in our IT environment.
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	Our cybersecurity program and supporting ISMS are governed by our Cybersecurity Steering Committee, which is includes our Chief Information Officer (“CIO”) and is comprised of other members of our management team, including individuals from our finance, supply chain, product, information technology (“IT”), and legal departments. The Cybersecurity Steering Committee convenes quarterly to review the ISMS, identify new material risks and potential treatment plans that are recorded in our cybersecurity risk register, and review the overall health of security key risk indicators, technical key performance indicators, and roadmaps for the expected delivery of new and updated controls.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	Cybersecurity oversight and related risk-management activities are currently led by the CIO, who has more than 20 years of experience in information technology, cybersecurity governance, and enterprise-risk management.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	We have a written cybersecurity incident escalation process overseen by senior leadership, and when senior leadership deems appropriate, a materiality committee is convened comprised of certain members of management who assess whether incidents must be reported to the SEC and/or the appropriate authorities. While Fluence’s board of directors oversees all enterprise risks, the Audit Committee of our board of directors has primary responsibility for overseeing cybersecurity risks and management’s implementation of our cybersecurity risk management program. The Audit Committee receives quarterly updates from CIO. These updates typically cover topics such as: overview of material cybersecurity incidents that have occurred since the last update, overview of residual cybersecurity risks to our critical business assets, recent investments in our cybersecurity program, and relevant cybersecurity operational metrics. The Audit Committee will report updates regarding cybersecurity to the Board, as it deems appropriate. Our management team takes steps to stay informed about and monitor efforts to prevent, detect, mitigate, and remediate cybersecurity risks and incidents through various means, which may include: briefings from internal security personnel; threat intelligence and other information obtained from governmental, public or private sources, including external consultants engaged by us; and alerts and reports produced by security tools deployed in our IT environment.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Inventory, Net (Tables)

12 Months Ended

Sep. 30, 2025

Inventory Disclosure [Abstract]

Schedule of Inventory, Current

Inventory consisted of the following:


In thousands	September 30, 2025						September 30, 2024
	Cost		Provision		Net		Cost		Provision		Net
Integrated systems, enclosures, batteries and other equipment	$	463,493	$	(30,891)	$	432,602	$	200,171	$	(25,012)	$	175,159
Spare parts	22,415		(2)		$	22,413	7,572		(130)		7,442
Total	$	485,908	$	(30,893)	$	455,015	$	207,743	$	(25,142)	$	182,601

Revenue from Contracts with Customers - Contract Liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Nonrelated Party
Deferred Revenue [Roll Forward]
Deferred revenue beginning of period	$ 274,499	$ 273,164	$ 273,073
Additions	587,933	224,423	273,164
Revenue recognized related to amounts that were included in beginning balance of deferred revenue	(221,975)	(223,088)	(273,073)
Deferred revenue end of period	640,457	274,499	273,164
Related Party
Deferred Revenue [Roll Forward]
Deferred revenue beginning of period	38,162	110,274	300,697
Additions	71,710	37,382	98,891
Revenue recognized related to amounts that were included in beginning balance of deferred revenue	(29,956)	(109,494)	(289,314)
Deferred revenue end of period	$ 79,916	$ 38,162	$ 110,274

Stock-Based Compensation - Option Activity under Non-Qualified Stock Options (Details) - Non Qualified Stock Option - $ / shares	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Number of options
Outstanding, beginning balance (in shares)	187,379
Granted (in shares)	310,422
Vested (in shares)	0
Forfeited (in shares)	(27,908)
Outstanding, ending balance (in shares)	469,893	187,379
Weighted average exercise price per share
Outstanding, beginning balance (in usd per share)	$ 21.70
Granted (in usd per share)	16.07
Vested (in usd per share)	0
Forfeited (in usd per share)	19.28
Outstanding, ending balance (in usd per share)	$ 18.12	$ 21.70
Weighted average remaining contractual term, outstanding (in years)	8 years 10 months 17 days	9 years 3 months 14 days
Weighted average remaining contractual term, granted (in years)	9 years 2 months 19 days

Related-Party Transactions

12 Months Ended

Sep. 30, 2025

Related-Party Transactions

Related parties are primarily represented by AES and Siemens, their respective subsidiaries, and other entities under common control, and other entities in which Siemens and AES have significant influence. As of September 30, 2025, AES holds 51,499,195 shares of Class B-1 common stock of Fluence Energy, Inc. and Siemens holds an aggregate of 51,499,195 shares of Class A common stock of Fluence Energy, Inc.

Sales and Procurement Contracts with Related Parties

The Company signs back-to-back battery-based energy storage product and related service contracts with AES, Siemens, their respective subsidiaries, other entities under common control, and other entities in which Siemens and AES have significant influence (collectively referred to as affiliates) in relation to execution of the affiliates’ contracts with external customers and also signs direct contracts with affiliates. The Company also signs consortium agreements to partner with affiliates to deliver battery-based energy storage products and related service contracts to external customers. When performing our obligations pursuant to such contracts, we may, from time to time, enter into related change orders or settlements with our related parties and their affiliates.

The Company also provides consulting services to AES whereby Fluence will advise and in some cases provide support to AES on procurement, logistics, design, safety, and commissioning of certain of their projects. Revenue from consulting services is classified as “Revenue from sale of energy storage products and solutions” in the Company’s Disaggregation of revenue table in “Note 3 - Revenue from Contracts with Customers.” Revenue from the consulting services is primarily recognized ratably over time based on a project specific period of performance in which we expect the performance obligation to be fulfilled. For the fiscal year ended September 30, 2025, 2024 and 2023, we have recognized $7.7 million, $8.0 million and $12.3 million, respectively, in revenue from consulting services with related parties.

Revenue from contracts with affiliates is included in “Revenue from related parties” on the Company’s consolidated statements of operations.

In addition, the Company purchases materials and supplies from its affiliates and records the costs in “Cost of goods and services” on the Company’s consolidated statements of operations.

Administrative and Service Agreements

For the fiscal years ended September 30, 2025, 2024 and 2023, the Company has received a limited scope of consulting services from Siemens Advanta, a subsidiary of Siemens AG, and limited treasury services related to executing trades for derivative contracts from AES.

The costs of consulting services are recorded in “Cost of goods and services” or “General and administrative expenses” depending on the scope or nature of the underlying project. The other administrative service agreements are recorded in “General and administrative expenses” on the Company’s consolidated statement of operations.

Guarantees

Fluence paid performance guarantee fees to its affiliates in exchange for guaranteeing Fluence’s performance obligations under certain contracts with Fluence’s customers, which are based on the affiliates’ weighted-average cost for bank guarantees and their per annum cost with a reasonable markup. These guarantees are provided pursuant to the Amended and Restated Credit Support and Reimbursement Agreement, dated June 9, 2021, with AES and Siemens Industry whereby they may, from time to time, agree to furnish credit support to us in the form of direct issuances of credit support to our lenders or other beneficiaries or through their lenders’ provision of letters of credit to backstop our own facilities or obligations. The guarantee fees are included in “Cost of goods and services” on Fluence’s consolidated statements of operations.

Refer to “Note 19 - Supply Chain Financing” for details of the related party guarantees associated with the supply chain financing program.

Balance Sheet Related Party Transactions

The following table presents the components of receivables from related parties and payables to related parties on the Company’s consolidated balance sheets:


in thousands	September 30,
	2025		2024
Accounts receivable	$	26,615	$	92,183
Unbilled receivables	174,133		270,340
Total receivables from related parties	200,748		362,523
Advances to suppliers	9,603		32,074
Accounts payable	4,985		3,410
Deferred revenue	79,916		38,162
Accruals and provisions	6,353		6,099
Other current liabilities	301		428
Other non-current liabilities	—		1,507

Receivables, deferred revenue, accounts payables, accruals and provisions and other current and non-current liabilities with related parties are unsecured and settlement of these balances occurs in cash. No provision has been made related to the receivables from related parties.

Revenue and Expenses

The following table presents the related party transactions that are included the Company’s consolidated statements of operations for the periods indicated:


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Revenue(a)	$	557,621	$	1,096,999	$	653,809
Cost of goods and services(b)	80,482		50,653		15,925
Research and development	31		192		912
Sales and marketing	—		123		135
General and administrative	2,061		6,113		5,215
Other income, net(c)	(1,206)		(571)		—

(a) Revenue from AES and its affiliates was approximately $555.1 million, $1,082.3 million, and $642.7 million for the fiscal years ended September 30, 2025, 2024 and 2023, respectively.

(b) Represent purchases from related parties that are included in cost of goods and services and are not associated with the revenue listed in the table above.

(c) For the fiscal year ended September 30, 2025, represents impact on other income as a result of a reduction of our Tax Receivable Agreement liability. For the fiscal year ended September 30, 2024, represents factoring income from a subsidiary of AES related to receivables sold under the Master Receivable Purchase Agreement (“MRPA”). The corresponding cost paid to the purchaser was $2.1 million and is recorded in “Sales and marketing expense” and is not considered a related party transaction. Pursuant to the MRPA, Fluence Energy, LLC may sell certain receivables for any of our customers that choose to participate in the program. Refer to “Note 20 - Sale of Receivables under Master Receivables Purchase Agreement” for more details. This is offset by $1.5 million of expense due to estimated payments due to related parties under the Tax Receivable Agreement

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-5

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-6

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(e))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/850/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-6

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-1

+ Details

Goodwill

12 Months Ended

Sep. 30, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill

Goodwill is assessed for impairment annually each year on the first day of the Company’s fourth quarter, or when impairment indicators exist. No impairment was recognized for the fiscal years ended September 30, 2025, 2024 and 2023.

The following table presents the goodwill activity:


In thousands	September 30,
	2025		2024
Goodwill, Beginning of the period	$	27,482	$	26,020
Foreign currency adjustment	1,102		1,462
Goodwill, End of the period	$	28,584	$	27,482

- Definition

The entire disclosure for goodwill.

+ References + Details

Accruals and Provisions (Tables)

12 Months Ended

Sep. 30, 2025

Payables and Accruals [Abstract]

Schedule of Current Accruals and Provisions

Accruals and provisions consisted of the following:


In thousands	September 30,
	2025		2024
Accruals	$	203,410	$	287,566
Accruals with related parties	6,353		6,099
Accruals for software development costs	23		10,903
Provisions for expected project losses	15,684		14,652
Current portion of warranty accrual	20,765		19,091
Total	$	246,235	$	338,311

Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Sep. 30, 2025
Retirement Benefits [Abstract]
Employee Benefit Plan	Employee Benefit Plan The Company maintains a 401(k) plan covering all eligible U.S. payroll employees. The 401(k) plan provides that eligible employees may make contributions subject to IRS limitations. Under terms of the 401(k) plan, the Company matches an employee’s contributions at a rate of 100% up to 5% of the employee’s annual eligible earnings as defined in the 401(k) plan. For the fiscal years ended September 30, 2025 and 2024, the Company contributed approximately $6.1 million and $5.9 million to the 401(k) plan, respectively.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (o)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (p)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (q)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 60
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480266/715-60-50-3

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480126/715-20-S99-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480794/715-70-50-1

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480482/715-20-55-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(03)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (l)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/715/tableOfContent

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Summary of Significant Accounting Policies and Estimates - Convertible Senior Notes, Net (Details) - Convertible Senior Notes, 2030 - Convertible Debt - USD ($)	Sep. 30, 2025	Dec. 31, 2024
Line of Credit Facility [Line Items]
Principal amount	$ 400,000,000	$ 400,000,000
Stated percentage		2.25%

Stock-Based Compensation - Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 19,650	$ 23,875	$ 26,920
Cost of goods and services
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	2,597	4,079	4,164
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	972	2,309	5,062
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,792	1,486	2,024
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 14,289	$ 16,001	$ 15,670

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(v)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iv)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (l)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 1D
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480483/718-10-35-1D

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480483/718-10-35-3

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(01)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(02)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(03)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(02)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(03)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

Income Taxes - Components of Loss Before Income Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Domestic	$ (121,163)	$ (33,983)	$ (100,356)
Foreign	76,091	73,556	87
(Loss) income before income taxes	$ (45,072)	$ 39,573	$ (100,269)

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-4

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-21

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-14

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478671/942-235-S50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-05(b)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477314/942-235-S99-1

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-22

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 48
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-48

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-30

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 270
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482964/270-10-50-1

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (ee)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 12: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(11))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 14: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-31

Reference 15: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(10))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 16: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(15))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1

+ Details

(Loss) income per Share (Tables)

12 Months Ended

Sep. 30, 2025

Earnings Per Share [Abstract]

Schedule of Dilutive Securities

The following table presents the potentially dilutive securities that were excluded from the computation of diluted (loss) income per share:


	Fiscal Year Ended September 30,
	2025	2024	2023
Class B-1 common stock	51,499,195	—	58,586,695
Shares underlying the conversion option in the 2030 Convertible Senior Notes	18,738,880	—	—
Outstanding pre-IPO options issued pursuant to the 2020 Unit Option Plan	2,211,860	511,756	5,351,585
Outstanding phantom units	—	—	256,935
Outstanding restricted stock units (“RSUs”)	2,232,320	1,103,968	1,843,570
Outstanding performance share units (“PSUs”)	901,516	300,387	—
Outstanding non-qualified stock options (“NQSOs”)	469,893	162,419	—
Outstanding restricted stock (“Nispera equity”)	—	49,171	354,134

Schedule of Basic and Diluted (Loss) Income Per Share

Basic and diluted (loss) income per share of Class A common stock for the fiscal year ended September 30, 2025, 2024 and 2023 respectively, have been computed as follows:


	Fiscal Year Ended September 30,
	2025					2024					2023
In thousands, except share and per share amounts	Income		Shares	$ per Share		Income		Shares	$ per Share		Income		Shares	$ per Share
Basic (loss) income per Share
Net (loss) income attributable to Fluence Energy, Inc.	$	(48,314)	130,307,162	$	(0.37)	$	22,716	126,180,011	$	0.18	$	(69,620)	116,448,602	$	(0.60)
Effect of Dilutive Securities											—		—
Class B-1 common stock	—		—			2,105		52,835,363			—		—
Pre-IPO options	—		—			—		3,799,239			—		—
Phantom units	—		—			—		105,468			—		—
RSUs	—		—			—		826,469			—		—
PSUs	—		—			—		71,535			—		—
NQSOs	—		—			—		318			—		—
Nispera equity	—		—			—		216,429			—		—
Diluted (loss) Income per Share
Net (loss) income attributable to Fluence Energy, Inc.	$	(48,314)	130,307,162	$	(0.37)	$	24,821	184,034,832	$	0.13	$	(69,620)	116,448,602	$	(0.60)

Debt

12 Months Ended

Sep. 30, 2025

Debt Disclosure [Abstract]

Debt

Revolving Credit Facility

On November 1, 2021, the Company entered into a credit agreement for a revolving credit facility (the “Revolver”), by and among Fluence Energy, LLC, as borrower, Fluence Energy, Inc., as parent guarantor, the subsidiary guarantors party thereto, the lenders party thereto and JP Morgan Chase Bank, N.A., as administrative agent and collateral agent (as amended, the “Revolving Credit Agreement”). The aggregate amount of commitments was $200.0 million. The Revolving Credit Agreement was terminated effective November 22, 2023, in conjunction with the entry into the ABL Credit Agreement (as further described below) and at such time, the Company prepaid all amounts outstanding under the Revolver and terminated all commitments thereunder. No penalties were required to be paid as a result of the termination.

Asset-Based Lending Facility

On November 22, 2023, the Company entered into an asset-based syndicated credit agreement (the “ABL Credit Agreement”) by and among Fluence Energy, LLC, as parent borrower, Fluence Energy, Inc., as parent, the other borrowers party thereto, the other guarantors party thereto, the lenders party thereto (the “ABL Lenders”), and Barclays Bank PLC (“Barclays”), as administrative agent, which was amended by the Master Assignment and Assumption and Issuing Bank Joinder, effective December 15, 2023 (the “ABL Joinder”), Amendment No. 1, dated April 8, 2024 (“Amendment No. 1”), and Amendment No. 2, dated May 8, 2024 (“Amendment No. 2”), which provided for revolving commitments in an aggregate principal amount of $400.0 million (the "ABL Facility"). The ABL Facility was secured by (i) a first priority pledge of Fluence Energy, Inc.’s equity interests in Fluence Energy, LLC and (ii) first priority security interests in, and mortgages on, substantially all tangible and intangible personal property and material fee-owned real property of Fluence Energy, Inc., Fluence Energy, LLC, and Fluence Energy Global Production Operation, LLC, in each case, subject to customary exceptions and limitations. Borrowings under the ABL Facility were scheduled to mature, and lending commitments thereunder would terminate, on November 22, 2027, which remains the maturity date of borrowings under the 2024 Revolver.

Borrowing availability under the ABL Facility was determined by a borrowing base calculation based on specified percentages of U.S. eligible inventory, net orderly liquidation value of most recent inventory appraisal, and U.S. eligible in-transit inventory, as well as potential borrowing base qualified cash, less the aggregate amount of any reserves.

The ABL Credit Agreement set forth that (i) loans comprising each ABR Borrowing bore interest at the Alternate Base Rate plus an additional margin ranging from 1.00% to 1.50%, (ii) loans comprising each Canadian Prime Loan Borrowing bore interest at the Canadian Prime Rate plus an additional margin ranging from 1.00% to 1.50%, and (iii) the loans comprising each Term Benchmark Borrowing bore interest at the Adjusted Term SOFR Rate, the Adjusted EURIBOR Rate or Adjusted Term CORRA, as applicable, plus an additional margin ranging from 2.00% to 2.50%, in each instance subject to customary benchmark replacement provisions. Fluence Energy, LLC was required to pay to the ABL Lenders a commitment fee on the average daily unused portion of the commitments through maturity, which accrued at the rate of (a) until the last day of the first full calendar quarter following the closing of the ABL Facility, 0.450% per annum, and (b) thereafter, 0.450% per annum if average revolving loan utilization was less than or equal to 50% and 0.375% per annum if average revolving loan utilization was greater than 50%. The ABL Facility also provided for a letter of credit sublimit in the amount of $200.0 million, if certain conditions were met. Each letter of credit issuance was conditioned upon, among other conditions, the payment of certain customary issuance and administration fees, as well as payment of a fronting fee to each issuer thereof and payment of a letter of credit participation fee payable to the ABL Lenders. Capitalized terms used in this paragraph that are not otherwise defined are defined in the ABL Credit Agreement.

The ABL Credit Agreement contained customary covenants for this type of financing, including, but not limited to, covenants that restricted our ability to incur indebtedness; incur liens; sell, transfer, or dispose of property and assets; make investments or acquisitions; pay dividends, make distributions or other restricted payments; and engage in affiliate transactions. As of the time of our entry into Amendment No. 3 to the ABL Credit Agreement (as discussed below), there were no outstanding borrowings under the ABL Facility or letters of credit outstanding.

2024 Revolver

On August 6, 2024 (the "Amendment Effective Date"), Fluence Energy, Inc. entered into Amendment Number Three ("Amendment No. 3") to that certain ABL Credit Agreement by and among Fluence Energy, LLC, as parent borrower, the Company, as parent, the other borrowers party thereto, the other guarantors party thereto, the lenders party thereto, and Citibank, N.A., as administrative agent (as successor to Barclays Bank PLC) (such agreement, as so amended, the "2024 Credit Agreement") in order to (i) convert the existing ABL Facility to a senior secured cash flow revolving credit facility in an initial aggregate principal amount of up to $500.0 million (the "2024 Revolver"), (ii) replace Barclays as administrative agent under the 2024 Credit Agreement with Citibank, N.A., and (iii) make certain other modifications to the 2024 Credit Agreement as set forth therein. Capitalized terms used in this subsection that are not otherwise defined are defined in the 2024 Credit Agreement.

The 2024 Revolver is secured by (i) a first priority pledge of the Company's equity interests in Fluence Energy, LLC and Fluence Energy Global Production Operation, LLC, (ii) first priority security interests in substantially all tangible and intangible personal property of the Company, Fluence Energy, LLC, Fluence Energy Global Production Operation, LLC and certain of its foreign subsidiaries, in each case, subject to customary exceptions and limitations, and (iii) a pledge of the Company's equity interests in certain of its foreign subsidiaries and security interests in certain assets of such foreign subsidiaries.

The 2024 Credit Agreement sets forth that (i) loans comprising each ABR Borrowing shall bear interest at the Alternate Base Rate plus 2.00%, (ii) loans comprising each Term Benchmark Borrowing shall bear interest at the Term SOFR Rate or the Adjusted EURIBOR Rate, as applicable, plus 3.00%, and (iii) the loans comprising each RFR Borrowing shall bear interest at the Daily Simple RFR plus 3.00%, in each instance subject to customary benchmark replacement provisions including, but not limited to, alternative benchmark rates, customary spread adjustments with respect to borrowings in foreign currencies and benchmark replacement conforming changes. Fluence Energy, LLC is required to pay to the lenders a commitment fee on the average daily unused portion of the commitments through maturity, which shall accrue at the rate of 0.50% per annum. The 2024 Credit Agreement provides for a cash draw sublimit of $150.0 million as well as a letter of credit sublimit in the amount of $500.0 million if certain conditions are met.

The 2024 Credit Agreement contains customary covenants for this type of financing, including, but not limited to, covenants that restrict our and certain of our subsidiaries ability to: incur indebtedness; incur liens; sell, transfer, or dispose of property and assets; make investments or acquisitions; pay dividends, make distributions or other restricted payments; and engage in affiliate transactions. The 2024 Credit Agreement limits our ability to make certain payments, including dividends and distributions on Fluence Energy, LLC's equity, the Company's equity and other restricted payments. Under the terms of the 2024 Credit Agreement, Fluence Energy, LLC and its subsidiaries are currently limited in their ability to pay cash dividends to, lend to, or make other investments in the Company, subject to certain exceptions. In addition, we are required to maintain (i) from the Amendment Effective Date through December 31, 2025, Total Liquidity of no less than $150,000,000, (ii) from January 1, 2026 and thereafter, Total Liquidity of no less than $100,000,000 or a Consolidated Leverage Ratio as of the last day of any Measurement Period not to exceed 3.50:1.00, and (iii) certain other financial requirements at each Guarantor Coverage Test Date. Such covenants are tested on a quarterly basis and upon the occurrence of other certain restricted payments, the incurrence of indebtedness, certain dispositions, and other specified transactions. As of September 30, 2025, we were in compliance with all such covenants.

The 2024 Credit Agreement contains customary events of default for this type of financing. If an event of default occurs with respect to a borrower, the lenders will be able to, among other things, terminate the commitments immediately, cash collateralize any outstanding letters of credit, declare any loans outstanding to be due and payable in whole or in part, and exercise other rights and remedies. The maturity date and the date of termination of lending commitments under the 2024 Credit Agreement both remain unchanged at November 22, 2027. As of September 30, 2025, there are no cash borrowings under the 2024 Revolver, and there are $194.4 million letters of credit outstanding under the 2024 Revolver, with remaining availability of $305.6 million, net of letters of credit issued.

Borrowings Against Note Receivable - Pledged as Collateral

In December 2022, the Company transferred $24.3 million in customer receivables to Standard Chartered Bank (“SCB”) in the Philippines for proceeds of $21.1 million. The receivables all related to our largest customer in that country. The underlying receivables transferred were previously aggregated into a long-term note, with interest, and a maturity date of September 30, 2024. In April 2023, the Company aggregated into an additional long-term note and transferred an additional $30.9 million in receivables with the same customer to SCB for proceeds of $27.0 million, upon substantially similar terms as the December 2022 transfer and with a maturity date of December 27, 2024. These transactions were treated as secured borrowings as the Company did not transfer the entire note receivables due from the customer to SCB. The Company continued to receive quarterly interest income from the customer, while

SCB was responsible for collecting payments on the principal balances which represented the initial receivable balances from the customer. The Company had no other continuing involvement or exposure related to the underlying receivables. On September 16, 2024 and December 27, 2024, $24.3 million and $30.9 million of receivables, respectively, were paid in full, resulting in the release of the corresponding notes and borrowings. As of September 30, 2025, the Company recorded net interest income of $0.0 million, which represents the net of $0.5 million in interest income and $0.5 million in interest expense recorded in “Interest expense (income), net.” As of September 30, 2024, the Company recorded net interest income of $0.3 million, which represents the aggregate of $4.4 million in interest income and $4.1 million in “Interest expense (income), net”. As of September 30, 2023, the Company recorded net interest income of $1.0 million, which represents the aggregate of $3.4 million in interest income recorded in “Interest expense (income), net” and $2.4 million in interest expense.

Convertible Senior Notes, Net

2030 Convertible Senior Notes

In December 2024, the Company issued $400.0 million aggregate principal amount of 2.25% convertible senior notes due 2030. These 2030 Convertible Senior Notes were issued pursuant to, and are governed by, an indenture, dated as of December 12, 2024, between the Company and UMB Bank, National Association, as trustee (the “Indenture”). The net proceeds from the issuance of the 2030 Convertible Senior Notes were $389.4 million, net of $10.6 million of debt issuance costs.

The 2030 Convertible Senior Notes are senior unsecured obligations of the Company and accrue interest at a rate of 2.25% per year, payable semi-annually in arrears, on June 15 and December 15 of each year, beginning on June 15, 2025. The 2030 Convertible Senior Notes will mature on June 15, 2030, unless earlier converted, redeemed, or repurchased. The 2030 Convertible Senior Notes have an initial conversion rate of 46.8472 shares of the Company’s Class A common stock per $1,000 principal amount of 2030 Convertible Senior Notes, which represents an initial conversion price of approximately $21.35 per share of the Company’s Class A common stock. The conversion rate is subject to customary adjustments upon the occurrence of certain events but will not be adjusted for any accrued and unpaid interest. If a “make-whole fundamental change” (as defined in the Indenture) occurs, then the Company will in certain circumstances increase the conversion rate for a specified period of time.

Prior to the close of business on the business day immediately preceding March 15, 2030, holders of the 2030 Convertible Senior Notes will have the right to convert their 2030 Convertible Senior Notes only upon satisfaction of one or more of the following conditions:

(1) during any calendar quarter (and only during such calendar quarter) commencing after the calendar quarter ending on March 31, 2025, if the last reported sale price per share of the Company’s Class A common stock exceeds 130% of the conversion price for each of at least 20 trading days (whether or not consecutive) during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter;

(2) during the five consecutive business days immediately after any 10 consecutive trading day period (the “measurement period”) if the ‘trading price’ per $1,000 principal amount of the 2030 Convertible Senior Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price per share of the Company’s Class A common stock on such trading day and the conversion rate on such trading day;

(3) upon the occurrence of specified corporate events, as set forth in the Indenture; or

(4) if the Company calls any or all the 2030 Convertible Senior Notes for redemption, but only with respect to such 2030 Convertible Senior Notes called for redemption.

On or after March 15, 2030, holders may convert their 2030 Convertible Senior Notes at any time until the close of business on the second scheduled trading day immediately before June 15, 2030.

Upon conversion, the Company may satisfy its conversion obligation by paying or delivering, as the case may be, cash, shares of the Company’s Class A common stock, or a combination of both, at the Company’s election, in the manner and subject to the terms and conditions provided in the Indenture.

The 2030 Convertible Senior Notes will be redeemable, in whole or in part (subject to the partial redemption limitation described in the Indenture), at our option at any time, and from time to time, on or after December 20, 2027 and on or before the 50th scheduled trading day immediately before the maturity date, at a cash redemption price equal to the principal amount of the 2030 Convertible Senior Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date, but only if (i) the 2030 Convertible Senior Notes are “freely tradable” (as defined in the Indenture), and all accrued and unpaid additional interest, if any, has been paid in full, as of the date we send the related redemption notice; and (ii) the last reported sale price per share of our Class A common stock exceeds 130% of the conversion price on (1) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date the Company sends the redemption notice for such redemption; and (2) the trading day immediately before the date the Company sends such redemption notice. In addition, calling any 2030 Convertible Senior Note for redemption will constitute a make-whole fundamental change with respect to

that 2030 Convertible Senior Note, in which case the conversion rate applicable to the conversion of that 2030 Convertible Senior Note will be increased in certain circumstances if it is converted after it is called for redemption.

No sinking fund is required to be provided for the 2030 Convertible Senior Notes. If a “fundamental change” (as defined in the Indenture) occurs prior to the maturity date of the 2030 Convertible Senior Notes, holders may require the Company to repurchase all or a portion of their 2030 Convertible Senior Notes at a cash repurchase price equal to 100% of the principal amount of the 2030 Convertible Senior Notes to be repurchased, plus any accrued and unpaid interest to, but excluding, the “fundamental change repurchase date” (as defined in the Indenture).

The 2030 Convertible Senior Notes are accounted for as a liability in their entirety, measured at amortized cost. The debt issuance costs for the 2030 Convertible Senior Notes are amortized to interest expense using the effective interest method over the term of the 2030 Convertible Senior Notes, with an effective interest rate of 2.80%.

The following table presents the net carrying value and fair value of the 2030 Convertible Senior Notes as of September 30, 2025:


In thousands	Principal Amount		Unamortized Debt Issuance Costs		Net Carrying Amount		Fair Value
							Amount		Leveling
2030 Convertible Senior Notes	$	400,000	$	(9,196)	$	390,804	$	348,540	Level 2

The fair value was determined based on the quoted prices of the 2030 Convertible Senior Notes in an inactive market on the last traded day of the fiscal year ended September 30, 2025 and has been classified as Level 2 in the fair value hierarchy.

The following table presents the interest expense recognized related to the 2030 Convertible Senior Notes:


In thousands	Fiscal Year Ended September 30,
	2025		2024
Coupon interest	$	7,200	$	—
Amortization of debt issuance costs	1,426		—
Total	$	8,626	$	—

Capped Call Transactions

In connection with the 2030 Convertible Senior Notes, the Company entered into privately negotiated capped call transactions with certain financial institutions pursuant to capped call confirmations (collectively the “Capped Calls”). The premiums paid for the purchases of the Capped Calls were $29.0 million. The Capped Calls have an initial strike price of approximately $21.35 per share, subject to certain adjustments, which corresponds to the initial conversion price of the 2030 Convertible Senior Notes. The Capped Calls have an initial cap price of $28.74 per share, subject to certain adjustments substantially similar to those applicable to the corresponding 2030 Convertible Senior Notes. The Capped Calls cover, subject to anti-dilution adjustments, approximately 18.7 million shares of the Company’s Class A common stock.

The Capped Calls are generally expected to offset the potential dilution to the Company’s Class A common stock upon any conversion of the 2030 Convertible Senior Notes and/or offset any cash payments the Company is required to make in excess of the principal amount of any converted 2030 Convertible Senior Notes, with such reduction and/or offset subject to a cap.

The Capped Calls are separate transactions and are not part of the terms of the 2030 Convertible Senior Notes. As the Capped Calls qualify for a scope exception from derivative accounting for instruments that are both indexed to the Company’s own stock and classified in stockholders’ equity, the Capped Calls are not accounted for as derivatives and the premiums paid for the purchases of the Capped Calls were recorded as a reduction to the additional paid-in capital.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-8A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481544/470-10-50-6

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481544/470-10-50-6

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 470
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/470/tableOfContent

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482925/835-30-45-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1C

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1C

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1C

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1I

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1I

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1I

+ Details

Schedule I Condensed Financial Information of the Registrant - CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Condensed Income Statements, Captions [Line Items]
Total revenue	$ 2,262,830	$ 2,698,562	$ 2,217,978
Operating expenses:
General and administrative	163,068	172,996	136,308
Interest expense (income), net	4,110	(5,676)	(5,388)
Other income, net	(5,375)	(7,276)	(6,952)
(Loss) income before income taxes	(45,072)	39,573	(100,269)
Income tax expense	22,917	9,206	4,549
Net (loss) income	(67,989)	30,367	(104,818)
Net (loss) income attributable to non-controlling interest	(19,675)	7,651	(35,198)
Net (loss) income attributable to Fluence Energy, Inc.	(48,314)	22,716	(69,620)
Gain (loss) on foreign currency translation, net of tax	15,595	(598)	586
Gain (loss) on cash flow hedges, net of tax	3,108	(6,276)	0
Actuarial gain (loss) on pension liabilities, net of tax	73	(211)	15
Total other comprehensive income (loss)	18,776	(7,085)	601
Total comprehensive (loss) income	(49,213)	23,282	(104,217)
Consolidated Entities, Excluding Affiliated Entities, Parent
Condensed Income Statements, Captions [Line Items]
Total revenue	0	0	0
Affiliated Entity, Parent
Condensed Income Statements, Captions [Line Items]
Total revenue	0	0	0
Parent
Condensed Income Statements, Captions [Line Items]
Total revenue	0	0	0
Operating expenses:
General and administrative	1,401	1,837	1,478
Interest expense (income), net	1,417	0	0
Other income, net	(1,209)	1,507	8
Equity in net (loss) income of subsidiaries	(46,540)	28,008	(68,133)
(Loss) income before income taxes	(48,149)	24,664	(69,620)
Income tax expense	165	1,948	0
Net (loss) income	(48,314)	22,716	(69,620)
Net (loss) income attributable to non-controlling interest	0	0	0
Net (loss) income attributable to Fluence Energy, Inc.	(48,314)	22,716	(69,620)
Gain (loss) on foreign currency translation, net of tax	11,185	(411)	408
Gain (loss) on cash flow hedges, net of tax	2,216	(4,480)	0
Actuarial gain (loss) on pension liabilities, net of tax	52	(151)	10
Total other comprehensive income (loss)	13,453	(5,042)	418
Total comprehensive (loss) income	$ (34,861)	$ 17,674	$ (69,202)

Revenue from Contracts with Customers - Revenue by Contracts (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Total revenue	$ 2,262,830	$ 2,698,562	$ 2,217,978
Revenue from sale of energy storage products and solutions
Disaggregation of Revenue [Line Items]
Total revenue	2,172,360	2,648,013	2,197,633
Revenue from services
Disaggregation of Revenue [Line Items]
Total revenue	84,439	45,353	15,992
Revenue from digital applications
Disaggregation of Revenue [Line Items]
Total revenue	$ 6,031	$ 5,196	$ 4,353

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Employee Benefit Plan (Details) - USD ($) $ in Millions	12 Months Ended
Employee Benefit Plan (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Retirement Benefits [Abstract]
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent of employees' annual salary	5.00%
Company contribution	$ 6.1	$ 5.9

Stock-Based Compensation - Option Activity under Option Plan (Details) - The Option Plan - $ / shares	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Number of options
Outstanding, beginning balance (in shares)	3,100,158
Exercised (in shares)	(885,853)
Forfeited (in shares)	(2,445)
Outstanding, ending balance (in shares)	2,211,860	3,100,158
Exercisable (in shares)	2,211,860
Weighted average exercise price per option
Outstanding, beginning balance (in usd per share)	$ 2.45
Exercised (in usd per share)	2.45
Forfeited (in usd per share)	2.45
Outstanding, ending balance (in usd per share)	2.45	$ 2.45
Exercisable (in usd per share)	$ 2.45
Weighted average remaining contractual term, outstanding (in years)	5 years 4 months 13 days	6 years 6 months 3 days
Weighted average remaining contractual term, exercisable (in years)	5 years 4 months 13 days

Leases - Supplemental Information Related to Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Leases [Abstract]
Cash paid for amounts included in the measurements of lease liabilities	$ 2,462
Operating cash flows	92
Financing cash flows	2,370	$ 0	$ 0
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 5,861
Weighted average remaining lease term	9 months 18 days
Weighted average discount rate	5.60%

Convertible Senior Notes, Net - Narrative (Details) $ / shares in Units, shares in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2024 USD ($) day $ / shares	Sep. 30, 2025 USD ($) $ / shares $ / Unit shares
Debt Instrument [Line Items]
Premium paid \| $		$ 29,000,000
Strike price (in usd per share) \| $ / shares		$ 21.35
Cap price (in usd per share) \| $ / Unit		28.74
Number of shares covered by capped calls (in shares) \| shares		18.7
Convertible Senior Notes, 2030 \| Convertible Debt
Debt Instrument [Line Items]
Principal Amount \| $	$ 400,000,000	$ 400,000,000
Stated percentage	2.25%
Proceeds from issuance of debt \| $	$ 389,400,000
Debt issuance costs, net \| $	$ 10,600,000
Debt instrument, convertible, conversion ratio	0.0468472
Debt instrument, conversion price (in usd per share) \| $ / shares	$ 21.35
Effective percentage	2.80%
Convertible Senior Notes, 2030 \| Convertible Debt \| Debt Conversion Terms One
Debt Instrument [Line Items]
Debt instrument, threshold percentage of stock price trigger	130.00%
Debt instrument, threshold trading days	20
Debt instrument, threshold consecutive trading days	30
Convertible Senior Notes, 2030 \| Convertible Debt \| Debt Conversion Terms Two
Debt Instrument [Line Items]
Debt instrument, threshold percentage of stock price trigger	98.00%
Debt instrument, threshold trading days	5
Debt instrument, threshold consecutive trading days	10
Convertible Senior Notes, 2030 \| Convertible Debt \| Debt Conversion Terms Three
Debt Instrument [Line Items]
Debt instrument, threshold trading days	50

Stock-Based Compensation (Tables)

12 Months Ended

Sep. 30, 2025

Share-Based Payment Arrangement [Abstract]

Schedule of Share-Based Payment Arrangement, Options

The following table summarizes the unit option activity under the Option Plan:


	Number of options	Weighted average exercise price per option		Weighted average remaining contractual term (years)




Outstanding as of October 1, 2024	3,100,158	$	2.45	6.51
Exercised	(885,853)	2.45		—
Forfeited	(2,445)	2.45		—
Outstanding and exercisable as of September 30, 2025	2,211,860	$	2.45	5.37

The following table summarizes activity under the 2021 Incentive Plan for the fiscal year ended September 30, 2025:


	Number of RSUs	Weighted Average Grant Date Fair Values
Outstanding as of October 1, 2024	1,760,418	$	20.57
Granted	1,830,935	14.75
Vested	(920,873)	20.45
Forfeited	(438,160)	17.67
Outstanding as of September 30, 2025	2,232,320	$	16.41


	Number of Options	Weighted average exercise price per share		Weighted average remaining contractual term (years)
Outstanding as of October 1, 2024	187,379	$	21.70	9.29
Granted	310,422	16.07		9.22
Vested	—	—		—
Forfeited	(27,908)	19.28		—
Outstanding as of September 30, 2025	469,893	18.12		8.88


	Number of Units	Weighted Average Grant Date Fair Values
Outstanding as of October 1, 2024	391,032	$	21.61
Granted	690,147	15.69
Vested	—	—
Forfeited	(179,663)	18.17
Outstanding as of September 30, 2025	901,516	$	17.77

Schedule of Stock Based Compensation Expense

The stock-based compensation expense was recorded as follows (in thousands):


	Fiscal Year Ended September 30,
in thousands (a)	2025		2024		2023
Cost of goods and services	$	2,597	$	4,079	$	4,164
Research and development	972		2,309		5,062
Sales and marketing	1,792		1,486		2,024
General and administrative	14,289		16,001		15,670
Total stock-based compensation expense	$	19,650	$	23,875	$	26,920

(a) Includes incentive awards that will be settled in shares and incentive awards that will be settled in cash.

Stock-Based Compensation

12 Months Ended

Sep. 30, 2025

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

The Option Plan

In 2020, Fluence Energy, LLC established the 2020 Unit Option Plan (the “Option Plan”) whereby employees, directors, and consultants, were originally granted non-qualified options to purchase Class A-1 units of Fluence Energy, LLC. As of September 30, 2021, the Company determined that achievement of the performance conditions related to awards granted under the Option Plan was not probable and therefore, no expense was recognized for the non-qualified options during the fiscal year ended September 30, 2021.

The completion of the IPO on November 1, 2021 resulted in achievement of the performance condition for the majority of the underlying awards granted under the Option Plan. In connection with the IPO, the non-qualified options were converted into non-qualified stock options to purchase shares of Class A common stock of Fluence Energy, Inc. Non-qualified stock options under the Option Plan have a contractual term of ten years from the date of grant and an exercise price of $2.45. The Company estimated the fair value of the awards using the Black-Scholes option-pricing model. The outstanding unexercised options will continue to be governed by the terms of the existing Option Plan. The Option Plan is accounted for as an equity plan. The Company will not grant any further awards under the Option Plan.

The following table summarizes the unit option activity under the Option Plan:


	Number of options	Weighted average exercise price per option		Weighted average remaining contractual term (years)




Outstanding as of October 1, 2024	3,100,158	$	2.45	6.51
Exercised	(885,853)	2.45		—
Forfeited	(2,445)	2.45		—
Outstanding and exercisable as of September 30, 2025	2,211,860	$	2.45	5.37

The total intrinsic value of the stock options outstanding under the Option Plan during the fiscal year ended September 30, 2025 was $18.5 million. As of September 30, 2025, the Option Plan had no unrecognized stock compensation expense.

The total intrinsic value of the stock options issued under the Option Plan that were exercised during the years ended September 30, 2025, 2024 and 2023, was $7.4 million, $40.0 million and $56.3 million, respectively.

Phantom Units

Employees, directors, and consultants were granted compensation under Fluence Energy, LLC’s Phantom Equity Incentive Plan (the “Phantom Incentive Plan”). As of September 30, 2021, the Company determined that achievement of the performance conditions related to awards granted under the Phantom Incentive Plan was not probable and therefore, no expense was recognized for the phantom units during the fiscal year ended September 30, 2021. The completion of the IPO on November 1, 2021 resulted in achievement of the performance condition for the majority of the underlying awards granted under the Phantom Incentive Plan. At the completion of the IPO, a portion of the awards to the Company’s officers were modified, extending out the vesting period. The Company will not make any further awards under the Phantom Incentive Plan. As of September 30, 2025 and 2024, there were no phantom unit awards previously issued outstanding and there is no unrecognized stock compensation expense.

2021 Stock-Based Compensation Plan

During fiscal year 2021, the Company established the 2021 Incentive Award Plan (the “2021 Incentive Plan”) which reserves 9,500,000 shares of Class A common stock of Fluence Energy, Inc. for issuance to management, other employees, consultants, and board members of the Company. The 2021 Incentive Plan governs both equity-based and cash-based awards, including incentive stock options, non-qualified stock options, performance share units (“PSUs”), and restricted stock units (“RSUs”). Stock-based awards currently issued pursuant to the 2021 Incentive Plan that are expected to be settled by issuing shares of Class A common stock are recorded as equity awards. The Company accounts for forfeitures as they occur.

Restricted Stock Units

RSUs granted under the 2021 Incentive Plan vest ratably at one-third annually on the anniversary of the grant date over a three-year period. The Company generally expenses the grant date fair value of the awards on a straight-line basis over each of the three separately vesting tranches within a given grant. There is no contractual term on the RSUs granted under the 2021 Incentive Plan. The Company estimated the fair value of the awards using the market value of our Class A common stock. The market value of our Class A common stock is calculated using the closing price of our Class A common stock on the date of grant. The following table summarizes activity under the 2021 Incentive Plan for the fiscal year ended September 30, 2025:


	Number of RSUs	Weighted Average Grant Date Fair Values
Outstanding as of October 1, 2024	1,760,418	$	20.57
Granted	1,830,935	14.75
Vested	(920,873)	20.45
Forfeited	(438,160)	17.67
Outstanding as of September 30, 2025	2,232,320	$	16.41

The granted RSUs generally vest in three equal annual installments. Total compensation cost related to non-vested awards not yet recognized as of September 30, 2025, was $15.1 million and is expected to be recognized over a weighted average period of 1.0 years.

Non-Qualified Stock Options

During the fiscal year ended September 30, 2025, the Company granted 310,422 non-qualified stock options to purchase Class A common stock under the 2021 Incentive Plan with a weighted average exercise price of $16.07. Non-qualified stock options under the 2021 Incentive Plan have a contractual term of ten years from the date of grant. The Company estimated the fair value of the awards using the Black-Scholes option-pricing model. The non-qualified stock options granted under the 2021 Incentive Plan vest ratably at one-third annually on the anniversary of the grant date over a three-year period pursuant to the terms of their applicable award agreements. The Company generally expenses the grant date fair value of the awards on a straight-line basis over each of the three separately vesting tranches within a given grant.


	Number of Options	Weighted average exercise price per share		Weighted average remaining contractual term (years)
Outstanding as of October 1, 2024	187,379	$	21.70	9.29
Granted	310,422	16.07		9.22
Vested	—	—		—
Forfeited	(27,908)	19.28		—
Outstanding as of September 30, 2025	469,893	18.12		8.88

The total intrinsic value of the non-qualified stock options outstanding during the fiscal year ended September 30, 2025 was $0.0 million. Total compensation cost related to non-vested awards not yet recognized as of September 30, 2025 totaled $1.8 million, and is expected to be recognized over a weighted average period of 1.1 years.

There were no non-qualified stock options issued under the 2021 Incentive Plan that are exercisable as of September 30, 2025 and 2024. The number of options expected to vest is equal to the number of options granted, which reflects no expected forfeiture.

Performance Share Units

During the fiscal year ended September 30, 2025, the Company granted 690,147 PSUs redeemable for Class A common stock under the 2021 Incentive Plan. The Company has issued two rounds of PSU grants under the 2021 Incentive Plan, the first commencing at the start of fiscal year 2024 and the second commencing at the start of fiscal year 2025. The PSUs for the 2024-2026 performance cycle and the 2025-2027 performance cycle are both earned based on (i) the achievement of two financial performance metrics: cumulative Adjusted EBITDA (65% weight) and cumulative revenue (35% weight), over a two-year performance period beginning October 1st in the year of grant through September 30th in the second year after grant, and (ii) service-based vesting based on continued employment from the date of grant through September 30th in the third year after grant. The performance targets for cumulative revenue and cumulative Adjusted EBITDA are set by the Compensation and Human Resources Committee of the Company’s Board of Directors. PSUs are considered fully vested when both the performance and service based requirements are met in accordance with the vesting requirements and will be settled in Class A common stock no more than 60 days after the end of the third fiscal year. The awards can be paid out in a range of 50% to 200%, with 0% paid out for below-threshold performance, based on the achievement of the performance criteria and upon continued service through the performance period. The Company estimated the fair value of the awards using the market value of our Class A common stock. The market value is calculated using the closing price of our Class A common stock on the date of grant. The Company monitors the achievement of the performance criteria and expenses ratably the grant date fair value of the awards probable to vest over the requisite service period. If there are changes to the amount of probable awards to vest based on achievement of performance criteria, the related stock-based compensation expense may be significantly increased or reduced in the period that our estimate changes.


	Number of Units	Weighted Average Grant Date Fair Values
Outstanding as of October 1, 2024	391,032	$	21.61
Granted	690,147	15.69
Vested	—	—
Forfeited	(179,663)	18.17
Outstanding as of September 30, 2025	901,516	$	17.77

As of September 30, 2025, 901,516 PSUs previously issued remained outstanding with estimated unrecognized stock compensation expense of $0.0 million.

Other

In connection with the acquisition of Nispera AG in 2022, Fluence issued 531,202 shares of restricted stock to Nispera’s management team. The post combination expense to the Company as a result of the business combination was approximately $6.9 million which was recognized on a straight-line basis over the remaining service period that was stipulated in each holder’s original restricted stock agreement.

Stock-based compensation expense

The stock-based compensation expense was recorded as follows (in thousands):


	Fiscal Year Ended September 30,
in thousands (a)	2025		2024		2023
Cost of goods and services	$	2,597	$	4,079	$	4,164
Research and development	972		2,309		5,062
Sales and marketing	1,792		1,486		2,024
General and administrative	14,289		16,001		15,670
Total stock-based compensation expense	$	19,650	$	23,875	$	26,920

(a) Includes incentive awards that will be settled in shares and incentive awards that will be settled in cash.

Commitments and Contingencies - Guarantees (Details) $ in Millions	Sep. 30, 2025 USD ($) agreement
Other Commitments [Line Items]
Amount	$ 5,844
Number of Agreements \| agreement	196
Guarantees and commitments
Other Commitments [Line Items]
Amount	$ 4,930
Number of Agreements \| agreement	91
Guarantees and commitments \| Minimum
Other Commitments [Line Items]
Maximum exposure range for each agreement	$ 0
Guarantees and commitments \| Maximum
Other Commitments [Line Items]
Maximum exposure range for each agreement	417
Letters of credit under bilateral credit facilities
Other Commitments [Line Items]
Amount	$ 5
Number of Agreements \| agreement	3
Letters of credit under bilateral credit facilities \| Minimum
Other Commitments [Line Items]
Maximum exposure range for each agreement	$ 0
Letters of credit under bilateral credit facilities \| Maximum
Other Commitments [Line Items]
Maximum exposure range for each agreement	3
Letters of credit under 2024 Revolver
Other Commitments [Line Items]
Amount	$ 194
Number of Agreements \| agreement	35
Letters of credit under 2024 Revolver \| Minimum
Other Commitments [Line Items]
Maximum exposure range for each agreement	$ 0
Letters of credit under 2024 Revolver \| Maximum
Other Commitments [Line Items]
Maximum exposure range for each agreement	56
Surety bonds
Other Commitments [Line Items]
Amount	$ 715
Number of Agreements \| agreement	67
Surety bonds \| Minimum
Other Commitments [Line Items]
Maximum exposure range for each agreement	$ 0
Surety bonds \| Maximum
Other Commitments [Line Items]
Maximum exposure range for each agreement	$ 79

Supply Chain Financing - Narrative (Details) $ in Millions	12 Months Ended
Supply Chain Financing - Narrative (Details) $ in Millions	Sep. 30, 2025 USD ($) party supplier	Aug. 08, 2025 USD ($)
Supplier Finance Program [Line Items]
Extended payment terms period	120 days
Number of parties involved \| party	2
Number of suppliers \| supplier	2
Supplier Finance Program, Obligation, Statement of Financial Position [Extensible Enumeration]	Accounts payable
Revolving Credit Facility \| New SCF Facility \| Line of Credit
Supplier Finance Program [Line Items]
Maximum borrowing capacity		$ 150.0
Affiliated Entity
Supplier Finance Program [Line Items]
Guarantees issued	$ 100.0
AES Grid Stability \| Affiliated Entity
Supplier Finance Program [Line Items]
Guarantees issued	50.0
Siemens Industry \| Affiliated Entity
Supplier Finance Program [Line Items]
Guarantees issued	$ 50.0

Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Taxes recoverable	$ 15,186	$ 23,962
Prepaid expenses	21,667	10,370
Prepaid insurance	2,538	2,069
Current portion of recoverable warranty costs from suppliers	8,585	5,013
Other	6,695	5,105
Total	$ 54,671	$ 46,519

Summary of Significant Accounting Policies and Estimates - Non-controlling Interest (Details)	Sep. 30, 2025	Sep. 30, 2024
Fluence Energy, LLC
Noncontrolling Interest [Line Items]
Controlling Interest Ownership	71.81%	71.53%
AES Grid Stability
Noncontrolling Interest [Line Items]
Non-Controlling Interest Ownership (AES)	28.19%	28.47%

Commitments and Contingencies (Tables)

12 Months Ended

Sep. 30, 2025

Commitments and Contingencies Disclosure [Abstract]

Schedule Of Contractual Obligations

The following table summarizes contractual obligations as of September 30, 2025. Amounts presented in the following table represent the Company's current undiscounted exposure to guarantees, commitments, letters of credit, and surety bonds and the range of maximum undiscounted potential exposure. The maximum exposure is not reduced by the amounts, if any, that could be recovered under the recourse or collateralization provisions in the guarantees, commitments, letters of credit, and surety bonds.


Contractual Obligations	Amount (in $ millions)		Number of Agreements	Maximum Exposure Range for Each Agreement (in $ millions)
Guarantees and commitments	$	4,930	91	0 - 417
Letters of credit under bilateral credit facilities	5		3	0 - 3
Letters of credit under 2024 Revolver	194		35	0 - 56
Surety bonds	715		67	0 - 79
Total	$	5,844	196

Schedule of Purchase Commitments

The following table presents our future minimum purchase commitments by fiscal year, primarily for battery cells and modules, and liquidated damages, if the minimum purchase volumes or spend are not met, as of September 30, 2025.


in thousands	Purchase Commitments		Liquidated Damages
2026	$	205,821	$	7,358
2027	254,120		8,100
2028	254,120		8,100

2029	244,120		8,100
2030 and thereafter	237,000		8,100
Total	$	1,195,181	$	39,758

Schedule of Product Warranty Liability

As of September 30, 2025 and 2024, the Company accrued the below estimated warranty liabilities:


In thousands	September 30,
	2025		2024
Warranty balance, beginning	$	40,242	$	26,909
Warranties issued and assumed in period	22,409		19,554
Change in estimates	3,173		(1,692)
Net changes in liability for warranty expirations, costs incurred, and foreign exchange impact	(14,017)		(4,529)
Warranty balance, ending	$	51,807	$	40,242
Less: Recoverable warranty costs from suppliers	23,578		12,704
Warranty balance, net of recoverable warranty costs from suppliers, at end of period	$	28,229	$	27,538

Summary of Significant Accounting Policies and Estimates - Recent Accounting Standards Adopted (Details)	12 Months Ended
	Sep. 30, 2025 segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	1

Summary of Significant Accounting Policies and Estimates - Receivables (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Reserve for credit loss	$ (0.7)	$ (2.9)

Related-Party Transactions - Balance Sheet Information (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Related Party Transaction [Line Items]
Accounts receivable	$ 200,748	$ 362,523
Advances to suppliers	126,778	174,532
Accounts payable	321,004	436,744
Accruals and provisions	246,235	338,311
Other current liabilities	20,590	24,246
Other non-current liabilities	37,449	29,100
Related Party
Related Party Transaction [Line Items]
Accounts receivable	26,615	92,183
Unbilled receivables	174,133	270,340
Total receivables from related parties	200,748	362,523
Advances to suppliers	9,603	32,074
Accounts payable	4,985	3,410
Deferred revenue	79,916	38,162
Accruals and provisions	6,353	6,099
Other current liabilities	301	428
Other non-current liabilities	$ 0	$ 1,507

Leases - Narrative (Details)	Sep. 30, 2025
Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term	1 year
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	9 years

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes - Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 208,900	$ 135,800
Valuation allowance	367,323	377,218
Increase (decrease) in valuation allowance	9,900	(5,500)
AUSTRALIA
Operating Loss Carryforwards [Line Items]
Increase (decrease) in valuation allowance	(11,700)
Equity Related to IPO and Other Organizational Transactions
Operating Loss Carryforwards [Line Items]
Increase (decrease) in valuation allowance	(1,100)
Current Year Activity in Jurisidictions
Operating Loss Carryforwards [Line Items]
Increase (decrease) in valuation allowance	11,700
Currency Translation Adjustment
Operating Loss Carryforwards [Line Items]
Increase (decrease) in valuation allowance	(700)
Increase in Equity
Operating Loss Carryforwards [Line Items]
Increase (decrease) in valuation allowance	2,500
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	215,600	186,200
Operating loss carryforwards subject to expiration	20,200
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	115,900	51,100
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	93,100	$ 84,700
Operating loss carryforwards subject to expiration	$ 82,500

Property and Equipment, Net - Amortized Costs (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Property, Plant and Equipment [Line Items]
Net	$ 50,320	$ 15,350
Right-of-use assets – finance leases, cost	24,814	0
Right-of-use assets – finance leases, accumulated depreciation	2,757	0
Right-of-use assets – finance leases, net	22,057	0
Total cost	76,325	30,081
Total accumulated depreciation	26,005	14,731
Total net	50,320	15,350
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Cost	25,574	12,571
Accumulated Depreciation	10,612	5,087
Net	14,962	7,484
Construction in Progress
Property, Plant and Equipment [Line Items]
Cost	8,128	3,434
Accumulated Depreciation	0	0
Net	8,128	3,434
IT Equipment
Property, Plant and Equipment [Line Items]
Cost	10,109	7,683
Accumulated Depreciation	6,735	4,674
Net	3,374	3,009
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Cost	1,915	1,421
Accumulated Depreciation	1,336	1,003
Net	579	418
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Cost	3,261	1,653
Accumulated Depreciation	2,066	1,494
Net	1,195	159
Other
Property, Plant and Equipment [Line Items]
Cost	2,524	3,319
Accumulated Depreciation	2,499	2,473
Net	$ 25	$ 846

Inventory, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Inventory [Line Items]
Cost	$ 485,908	$ 207,743
Provision	(30,893)	(25,142)
Net	455,015	182,601
Integrated systems, enclosures, batteries and other equipment
Inventory [Line Items]
Cost	463,493	200,171
Provision	(30,891)	(25,012)
Net	432,602	175,159
Spare parts
Inventory [Line Items]
Cost	22,415	7,572
Provision	(2)	(130)
Net	$ 22,413	$ 7,442

Property and Equipment, Net

12 Months Ended

Sep. 30, 2025

Property, Plant and Equipment [Abstract]

Property and Equipment, Net

Property and equipment are stated at amortized cost and consisted of the following:


In thousands	September 30, 2025						September 30, 2024
	Cost		Accumulated Depreciation		Net		Cost		Accumulated Depreciation		Net
Machinery and Equipment	$	25,574	$	10,612	$	14,962	$	12,571	$	5,087	$	7,484
Construction in Progress	8,128		—		8,128		3,434		—		3,434
IT Equipment	10,109		6,735		3,374		7,683		4,674		3,009
Furniture and Fixtures	1,915		1,336		579		1,421		1,003		418
Leasehold Improvements	3,261		2,066		1,195		1,653		1,494		159
Right-of-use assets – finance leases	24,814		2,757		22,057		—		—		—
Other	2,524		2,499		25		3,319		2,473		846
Total	$	76,325	$	26,005	$	50,320	$	30,081	$	14,731	$	15,350

Total depreciation expense was $11.3 million, $5.6 million and $4.3 million for the fiscal years ended September 30, 2025, 2024 and 2023, respectively.

Property and equipment are depreciated over the estimated useful lives of the respective assets on a straight-line basis. The range of estimated lives for the respective assets is as follows:


Machinery and equipment			10 years
IT equipment			3 years
Furniture and fixtures			5 years
Leasehold Improvements			10 years, or lease term if shorter
Finance lease right-of-use assets			3 years
Other			5 years

Schedule I Condensed Financial Information of the Registrant

12 Months Ended

Sep. 30, 2025

Condensed Financial Information Disclosure [Abstract]

Schedule I Condensed Financial Information of the Registrant

SCHEDULE I. CONDENSED FINANCIAL INFORMATION OF THE REGISTRANT

FLUENCE ENERGY, INC.

CONDENSED BALANCE SHEETS

(PARENT COMPANY ONLY)

(U.S. Dollars in Thousands, except share and per share amounts)


	September 30,
	2025		2024
Assets
Current assets:
Cash and cash equivalents	$	371	$	267
Accounts receivable - related party	6,464		—
Other receivables	68		443
Tax receivable	49		—
Total current assets	6,952		710
Non-current assets:
Long-term notes receivable - related party	400,000		—
Investment in subsidiaries	727,297		802,606
Total non-current assets	1,127,297		802,606
Total assets	$	1,134,249	$	803,316
Liabilities, and stockholders’ equity
Current liabilities:
Accounts payable	119		74
Accounts payable - related party	6,657		2,803
Accruals and provisions	2,625		74
Taxes payable	—		1,955
Other current liabilities - related party	301		—
Total current liabilities	9,702		4,906
Non-current liabilities:
Convertible senior notes, net	390,804		$	—
Other non-current liabilities - related party	—		$	1,507
Total non-current liabilities	390,804		1,507
Total liabilities	400,506		6,413
Commitments and Contingencies (Note 3)
Stockholders’ Equity:
Preferred stock, $0.00001 per share, 10,000,000 shares authorized; no shares issued and outstanding as of September 30, 2025 and 2024	—		—
Class A common stock, $0.00001 par value per share,1,200,000,000 shares authorized; 132,014,571 shares issued and 131,164,365 shares outstanding as of September 30, 2025; 130,207,845 shares issued and 129,421,797 shares outstanding as of September 30, 2024	—		—
Class B-1 common stock, $0.00001 par value per share, 134,325,805 shares authorized; 51,499,195 shares issued and outstanding as of September 30, 2025; 51,499,195 shares issued and outstanding as of September 30, 2024	—		—
Class B-2 common stock, $0.00001 par value per share, 200,000,000 shares authorized; no shares issued and outstanding as of September 30, 2025 and 2024	—		—
Treasury stock, at cost	(10,213)		(9,460)
Additional paid-in capital	939,433		965,562
Distribution from Fluence Energy, LLC	10,213		9,460
Contribution to Fluence Energy, LLC	(17,811)		(15,641)
Accumulated deficit	(187,879)		(153,018)
Total stockholders’ equity	733,743		796,903
Total liabilities, stockholders’ equity	$	1,134,249	$	803,316

The accompanying notes are an integral part of these condensed financial statements.

SCHEDULE I. CONDENSED FINANCIAL INFORMATION OF THE REGISTRANT

FLUENCE ENERGY, INC.

CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS)

(PARENT COMPANY ONLY)

(U.S. Dollars in Thousands)


	Fiscal Year Ended September 30,
	2025		2024		2023
Revenue	$	—	$	—	$	—
Revenue from related parties	—		—		—
Total Revenue	—		—		—
Operating expenses:
General and administrative	1,401		1,837		1,478
Interest expense, net	1,417		—		—
Other (income) expense, net	(1,209)		1,507		8
Equity in net (loss) income of subsidiaries	(46,540)		28,008		(68,133)
(Loss) income before income taxes	(48,149)		24,664		(69,620)
Income tax expense	165		1,948		—
Net (loss) income	$	(48,314)	$	22,716	$	(69,620)
Net (loss) income attributable to non-controlling interest	—		—		—
Net (loss) income attributable to Fluence Energy, Inc.	$	(48,314)	$	22,716	$	(69,620)

Gain (loss) on foreign currency translation, net of tax	11,185		(411)		408
Gain (loss) on cash flow hedges, net of tax	2,216		(4,480)		—
Actuarial gain (loss) on pension liabilities, net of tax	52		(151)		10
Total other comprehensive income (loss)	13,453		(5,042)		418
Total comprehensive (loss) income	$	(34,861)	$	17,674	$	(69,202)

The accompanying notes are an integral part of these condensed financial statements.

SCHEDULE I. CONDENSED FINANCIAL INFORMATION OF THE REGISTRANT

FLUENCE ENERGY, INC.

CONDENSED STATEMENTS OF CASH FLOWS

(PARENT COMPANY ONLY)

(U.S. Dollars in Thousands)


	Fiscal Year Ended September 30,
	2025		2024		2023
Operating activities
Net (loss) income	$	(48,314)	$	22,716	$	(69,620)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:



Equity in net income (loss) of subsidiaries	46,540		(28,008)		68,133
Amortization of debt issuance costs	1,426		—		—
Stock-based compensation expense	701		821		443


Changes in operating assets and liabilities:
Other receivables	375		(75)		(348)
Accounts receivable - related party	(6,464)		—		—
Taxes receivables	(49)		—		—




Accounts payable	44		74		—
Accounts payable - related party	3,854		1,142		1,453
Accruals and provisions	2,551		74		—
Taxes payable	(1,955)		1,949		6
Other non-current liabilities - related party	(1,507)		1,507		—



Other current liabilities - related party	301		—		—


Net cash provided by operating activities	(2,496)		200		67
Investing activities
Purchase of long-term notes receivable - related party	(400,000)		—		—



Net cash used in investing activities	(400,000)		—		—
Financing activities






Distributions from Fluence Energy, LLC	42,974		1,663		2,784
Class A common stock withheld related to settlement of employee taxes for stock-based compensation awards	(752)		(1,663)		(2,784)
Proceeds from exercise of stock options	2,170		5,335		7,203
Contributions to Fluence Energy, LLC	(2,170)		(5,335)		(7,203)
Purchases of Capped Calls related to 2030 Convertible Senior Notes	(29,000)		—		—
Proceeds from issuance of 2030 Convertible Senior Notes, net	400,000		—		—
Payments of debt issuance costs	(10,622)		—		—
Net cash provided by financing activities	402,600		—		—
Effect of exchange rate changes on cash and cash equivalents	—		—		—
Net increase in cash and cash equivalents	104		200		67
Cash, cash equivalents, as of the beginning of the period	267		67		—
Cash, cash equivalents, as of the end of the period	$	371	$	267	$	67

The accompanying notes are an integral part of these condensed financial statements.

SCHEDULE I. CONDENSED FINANCIAL INFORMATION OF THE REGISTRANT

FLUENCE ENERGY, INC.

NOTES TO CONDENSED FINANCIAL STATEMENTS

(PARENT COMPANY ONLY)

(U.S. Dollars in Thousands)

1.Organization and Operations

Fluence Energy, Inc., a Delaware corporation (the “Parent Company”), was formed on June 21, 2021. We conduct our business operations through Fluence Energy, LLC and its direct and indirect subsidiaries. Upon the completion of our initial public offering (the “IPO”) on November 1, 2021, Fluence Energy, Inc. became a holding company whose sole material assets are the limited liability interests (“LLC Interests”) in Fluence Energy, LLC. All of our business is conducted through Fluence Energy, LLC, together with its direct and indirect subsidiaries. Fluence Energy, LLC is treated as a partnership for federal income tax purposes and, as a result, its members, including Fluence Energy, Inc. will pay income taxes with respect to their allocable shares of its net taxable income.

Our fiscal year begins on October 1 and ends on September 30. References to “fiscal year 2023,” “fiscal year 2024”, and “fiscal year 2025” refer to the fiscal years ended September 30, 2023, September 30, 2024 and September 30, 2025, respectively.

On November 1, 2021, the Parent Company completed an IPO and a series of organization transactions (collectively with the IPO, the “Transactions”), in which the Company issued and sold 35,650,000 shares of its Class A common stock, par value $0.00001 per share (the “Class A common stock”), at the public offering price of $28.00 per share, which includes the exercise by the underwriters of their option to purchase an additional 4,650,000 shares of the Class A common stock. The net proceeds to the Company from the IPO were $948.0 million, after deducting underwriting discounts. Other offering expenses incurred related to the IPO were paid for by Fluence Energy, LLC.

2. Basis of Presentation

These condensed parent company financial statements should be read in conjunction with the consolidated financial statements of Fluence Energy, Inc. and the accompanying notes thereto, included in this Annual Report on Form 10-K for the fiscal year ended September 30, 2025. For purposes of these condensed financial statements, the Parent Company's interest in Fluence Energy, LLC is recorded based upon its proportionate share of Fluence Energy, LLC’s net assets (similar to presenting them on the equity method).

Certain intercompany balances presented as related party balances in these condensed Parent Company financial statements are eliminated in the consolidated financial statements.

3. Commitments and Contingencies

On October 27, 2021, the Parent Company entered into the Tax Receivable Agreement (the “Tax Receivable Agreement”) with Fluence Energy, LLC, Siemens Industry, Inc. (“Siemens Industry”) and AES Grid Stability, LLC (“AES Grid Stability” and together with Siemens Industry, the “Founders”) which obligates the Parent Company to make payments to the Founders of 85% of the amount of certain tax benefits that Fluence Energy, Inc. actually realizes, or in some circumstances is deemed to realize, arising from the basis adjustments and certain other tax benefits arising from payments made under the Tax Receivable Agreement. Increases in tax basis and tax basis adjustments generated over time may increase (for tax purposes) the depreciation and amortization deductions available to Fluence Energy, Inc. and, therefore, may reduce the amount of U.S. federal, state, and local tax that Fluence Energy, Inc. would otherwise be required to pay in the future, although the Internal Revenue Service may challenge all or part of the validity of that tax basis, and a court could sustain such a challenge.

The amounts payable under the Tax Receivable Agreement are contingent upon (i) sufficient taxable income to fully utilize the tax benefits; (ii) Fluence Energy, LLC is able to fully depreciate or amortize its assets; and (iii) no material changes in applicable tax law. The payments under the Tax Receivable Agreement are not conditioned upon continued ownership of Fluence Energy, LLC by the Founders. With the exception of a $0.3 million payment under the Tax Receivable Agreement realized as of September 30, 2025, we determined it is not probable that additional payments under the Tax Receivable Agreement would be made, given there was no expectation of future sufficient taxable income over the term of the agreement to utilize deductions in the future.

Refer to “Note 15 - Commitments and Contingencies” to the consolidated financial statements for information regarding pending and threatening legal proceedings, regulatory proceedings, and governmental investigations.

4. Convertible Senior Notes, Net

2030 Convertible Senior Notes

In December 2024, the Parent Company issued $400.0 million aggregate principal amount of 2.25% convertible senior notes due 2030. These 2030 Convertible Senior Notes were issued pursuant to, and are governed by, an indenture, dated as of December 12, 2024, between the Parent Company and UMB Bank, National Association, as trustee (the “Indenture”). The net proceeds from the issuance of the 2030 Convertible Senior Notes were $389.4 million, net of $10.6 million of debt issuance costs.

The 2030 Convertible Senior Notes are senior unsecured obligations of the Parent Company and accrue interest at a rate of 2.25% per year, payable semi-annually in arrears, on June 15 and December 15 of each year, beginning on June 15, 2025. The 2030 Convertible Senior Notes will mature on June 15, 2030, unless earlier converted, redeemed, or repurchased. The 2030 Convertible Senior Notes have an initial conversion rate of 46.8472 shares of the Parent Company’s Class A common stock per $1,000 principal amount of 2030 Convertible Senior Notes, which represents an initial conversion price of approximately $21.35 per share of the Parent Company’s Class A common stock. The conversion rate is subject to customary adjustments upon the occurrence of certain events but will not be adjusted for any accrued and unpaid interest. If a “make-whole fundamental change” (as defined in the Indenture) occurs, then the Parent Company will in certain circumstances increase the conversion rate for a specified period of time.

Capped Call Transactions

In connection with the 2030 Convertible Senior Notes, the Parent Company entered into privately negotiated capped call transactions with certain financial institutions pursuant to capped call confirmations (collectively the “Capped Calls”). The premiums paid for the purchases of the Capped Calls were $29.0 million. The Capped Calls have an initial strike price of approximately $21.35 per share, subject to certain adjustments, which corresponds to the initial conversion price of the 2030 Convertible Senior Notes. The Capped Calls have an initial cap price of $28.74 per share, subject to certain adjustments substantially similar to those applicable to the corresponding 2030 Convertible Senior Notes. The Capped Calls cover, subject to anti-dilution adjustments, approximately 18.7 million shares of the Parent Company’s Class A common stock.

Intercompany Convertible Subordinated Note

In relation to the 2030 Convertible Senior Notes issued by the Parent Company, an intercompany convertible subordinated note (the “Intercompany Note”) was issued by Fluence Energy, LLC to the Parent Company on December 12, 2024 and is presented as “Long-term notes receivable - related party” on the condensed balance sheet. The Intercompany Note has the same principal amount of the 2030 Convertible Senior Notes and mirrors the terms and conditions of the 2030 Convertible Senior Notes. Pursuant to the Intercompany Note, the Parent Company has transferred the net proceeds received from the issuance of the 2030 Convertible Senior Notes to Fluence Energy, LLC, and Fluence Energy, LLC effectively assumes all the rights and obligations of the Parent Company under the 2030 Convertible Senior Notes.

An expense reimbursement agreement was also executed between the Parent Company and Fluence Energy, LLC on December 12, 2024. Pursuant to this agreement, Fluence Energy, LLC has reimbursed and indemnified the Parent Company for all expenses related to the offering and issuance of the 2030 Convertible Senior Notes, including the associated Capped Calls. As of September 30, 2025, the Parent Company recorded net interest expense of $1.4 million, comprised of $8.6 million interest expense on the 2030 Convertible Senior Notes and $7.2 million intercompany interest income on the Intercompany Note.

Refer to “Note 13 - Convertible Senior Notes, Net” to the consolidated financial statements for information regarding the 2030 Convertible Senior Notes and the associated Capped Calls.

Derivatives and Hedging - Changes in the Cumulative Impact (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
AOCI Attributable To Parent Before Reclassification And Tax [Roll Forward]
Beginning balance	$ 607,139	$ 556,330
Ending balance	548,848	607,139
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
AOCI Attributable To Parent Before Reclassification And Tax [Roll Forward]
Beginning balance	(6,276)	0
Gain (loss) recognized in accumulated other comprehensive income (loss)	4,018	(7,394)
(Gain) loss reclassified from accumulated other comprehensive income (loss) into earnings	(910)	1,118
Ending balance	$ (3,168)	$ (6,276)

- Definition

Amount after tax, before reclassification adjustments of other comprehensive income (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-14A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-5

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-17

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-20

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(19))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-4

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482739/220-10-55-15

+ Details

- Definition

Amount after tax of reclassification adjustments of other comprehensive income (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-14A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-5

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-17

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-20

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(19))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-4

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482739/220-10-55-15

+ Details

- Definition

Amount of equity (deficit) attributable to parent and noncontrolling interest. Excludes temporary equity.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(i))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-9

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-9

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 17
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480336/718-10-65-17

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 605
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477548/944-605-55-14

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 605
-Name Accounting Standards Codification
-Section 55
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477548/944-605-55-11

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-6

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476176/805-60-65-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476176/805-60-65-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)(3)(iii)(03)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483550/848-10-65-2

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479832/842-10-65-8

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483421/250-10-45-24

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 23
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483421/250-10-45-23

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483421/250-10-45-5

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479654/326-10-65-5

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (h)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (h)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (h)(1)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (h)(1)(iv)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (i)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-6

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-6

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (f)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (f)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482615/740-10-65-8

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (d)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482615/740-10-65-8

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479654/326-10-65-4

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-7

Reference 38: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-5

Reference 39: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-1

Reference 40: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-17

Reference 41: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-20

Reference 42: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 830
-Name Accounting Standards Codification
-Section 55
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479168/946-830-55-11

Reference 43: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 205
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478009/946-205-45-3

Reference 44: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478448/946-505-50-3

Reference 45: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(19))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1

Reference 46: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.6-05(4))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479170/946-210-S99-2

Reference 47: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(4)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3

Reference 48: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(6))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3

Reference 49: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(7))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3

Reference 50: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

Reference 51: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 52: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

Reference 53: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481231/810-10-45-15

Reference 54: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 16
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481231/810-10-45-16

Reference 55: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4I
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481175/810-10-55-4I

Reference 56: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476166/350-60-65-1

Reference 57: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (f)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481538/470-20-65-4

+ Details

Supply Chain Financing - Outstanding Obligations under Supplier Financing Program (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Supplier Finance Program, Obligation [Roll Forward]
Obligations outstanding at the beginning of the period	$ 81,289	$ 30,001
Invoices issued during the period	63,316	243,655
Invoices paid during the period	(144,605)	(192,367)
Obligations outstanding at the end of the period	$ 0	$ 81,289

Supply Chain Financing (Tables)

12 Months Ended

Sep. 30, 2025

Payables and Accruals [Abstract]

Schedule of Supplier Finance Program

The Company’s outstanding obligations confirmed as valid under its supplier financing program for periods ended September 30, 2025 and September 30, 2024, are as follows:


In thousands	September 30, 2025		September 30, 2024
Obligations outstanding at the beginning of the period	$	81,289	$	30,001
Invoices issued during the period	63,316		243,655
Invoices paid during the period	(144,605)		(192,367)
Obligations outstanding at the end of the period	$	—	$	81,289

Organization and Operations (Details)		12 Months Ended
Organization and Operations (Details)	Dec. 08, 2023 USD ($) shares	Sep. 30, 2025 segment
Class of Stock [Line Items]
Number of operating segments \| segment		1
Number of reportable segments \| segment		1
AES Grid Stability \| Fluence Energy, LLC
Class of Stock [Line Items]
Investment owned (in shares)	7,087,500
Class A Common Stock \| Secondary Offering
Class of Stock [Line Items]
Shares sold in offering (in shares)	0
Aggregate net proceeds from stock offering \| $	$ 0
Class A Common Stock \| Secondary Offering \| Selling Stockholders
Class of Stock [Line Items]
Shares sold in offering (in shares)	18,000,000
Class A Common Stock \| Redemption
Class of Stock [Line Items]
Shares sold in offering (in shares)	7,087,500

Convertible Senior Notes, Net - Interest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Debt Instrument [Line Items]
Amortization of debt issuance costs	$ 4,217	$ 3,091	$ 914
Total	500	4,100	$ 2,400
Convertible Debt \| Convertible Senior Notes, 2030
Debt Instrument [Line Items]
Coupon interest	7,200	0
Amortization of debt issuance costs	1,426	0
Total	$ 8,626	$ 0

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-8A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(f))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482949/835-30-55-8

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69E

Reference 12: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69F
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69F

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 15: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1I

Reference 30: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482925/835-30-45-2

Reference 31: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482900/835-30-50-1

+ Details

Inventory, Net

12 Months Ended

Sep. 30, 2025

Inventory Disclosure [Abstract]

Inventory, Net

Inventory consisted of the following:


In thousands	September 30, 2025						September 30, 2024
	Cost		Provision		Net		Cost		Provision		Net
Integrated systems, enclosures, batteries and other equipment	$	463,493	$	(30,891)	$	432,602	$	200,171	$	(25,012)	$	175,159
Spare parts	22,415		(2)		$	22,413	7,572		(130)		7,442
Total	$	485,908	$	(30,893)	$	455,015	$	207,743	$	(25,142)	$	182,601

Convertible Senior Notes, Net - Net Carrying Value and Fair Value of the Convertible Senior Notes (Details) - Convertible Senior Notes, 2030 - Convertible Debt - USD ($)	Sep. 30, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Principal Amount	$ 400,000,000	$ 400,000,000
Unamortized Debt Issuance Costs	(9,196,000)
Long-term debt, fair value	348,540,000
Fair Value, Inputs, Level 2
Debt Instrument [Line Items]
Net Carrying Amount	$ 390,804,000

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-8A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(f))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482949/835-30-55-8

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69E

Reference 12: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69F
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69F

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 15: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1I

Reference 30: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482925/835-30-45-2

Reference 31: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482900/835-30-50-1

+ Details

- Definition

Amount of unamortized debt discount (premium) and debt issuance costs.

+ References + Details

- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-SubTopic 10
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482949/835-30-55-8

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-4

+ Details

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-SubTopic 10
-Topic 825
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482881/825-10-55-10

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-10

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482881/825-10-55-12

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

+ Details

Derivatives and Hedging - Cash Flow Hedging Instruments (Details) - Foreign currency forward contracts - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Foreign Currency Fair Value Hedge Derivative [Line Items]
Notional Value	$ 80,269	$ 106,650
Other Current Assets	155	0
Other Current Liabilities	1,493	5,498
Foreign currency forward contracts, net of tax	4,018	(7,394)	$ 0
Foreign currency forward contracts
Foreign Currency Fair Value Hedge Derivative [Line Items]
Foreign currency forward contracts	$ 2,883	$ (8,544)	$ 0

- Definition

Amount after tax, before reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

+ References + Details

Income Taxes - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Current income tax expense:
Domestic	$ 165	$ 1,948	$ 0
Foreign	14,343	13,700	1,349
Deferred income tax expense (benefit):
Domestic	0	0	0
Foreign	6,293	(6,719)	2,541
Withholding income tax expense:
Domestic	0	0	0
Foreign	2,115	277	659
Income tax expense	$ 22,917	$ 9,206	$ 4,549

Property and Equipment, Net (Tables)

12 Months Ended

Sep. 30, 2025

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment

Property and equipment are stated at amortized cost and consisted of the following:


In thousands	September 30, 2025						September 30, 2024
	Cost		Accumulated Depreciation		Net		Cost		Accumulated Depreciation		Net
Machinery and Equipment	$	25,574	$	10,612	$	14,962	$	12,571	$	5,087	$	7,484
Construction in Progress	8,128		—		8,128		3,434		—		3,434
IT Equipment	10,109		6,735		3,374		7,683		4,674		3,009
Furniture and Fixtures	1,915		1,336		579		1,421		1,003		418
Leasehold Improvements	3,261		2,066		1,195		1,653		1,494		159
Right-of-use assets – finance leases	24,814		2,757		22,057		—		—		—
Other	2,524		2,499		25		3,319		2,473		846
Total	$	76,325	$	26,005	$	50,320	$	30,081	$	14,731	$	15,350

The range of estimated lives for the respective assets is as follows:


Machinery and equipment			10 years
IT equipment			3 years
Furniture and fixtures			5 years
Leasehold Improvements			10 years, or lease term if shorter
Finance lease right-of-use assets			3 years
Other			5 years

Summary of Significant Accounting Policies and Estimates - Software Development Costs (Details) $ in Millions	12 Months Ended
	Sep. 30, 2025 USD ($) Category	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)
Finite-Lived Intangible Assets [Line Items]
Number of categories \| Category	3
Capitalized internal-use software
Finite-Lived Intangible Assets [Line Items]
Useful life	4 years
Capitalized software costs	$ 8.8	$ 8.9	$ 6.4
Hosting Arrangements
Finite-Lived Intangible Assets [Line Items]
Capitalized software costs	$ 12.7	37.4	0.0
External-Use Software Development Cost
Finite-Lived Intangible Assets [Line Items]
Useful life	5 years
Capitalized software costs	$ 5.5	$ 2.3	$ 3.3
Minimum \| Capitalized internal-use software
Finite-Lived Intangible Assets [Line Items]
Useful life	3 years
Minimum \| Hosting Arrangements
Finite-Lived Intangible Assets [Line Items]
Useful life	5 years
Maximum \| Capitalized internal-use software
Finite-Lived Intangible Assets [Line Items]
Useful life	5 years
Maximum \| Hosting Arrangements
Finite-Lived Intangible Assets [Line Items]
Useful life	7 years

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 20
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-20

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 20
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-20

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-38

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-38

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-38

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-38

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-38

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-38

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 12: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 13: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 14: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 15: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 16: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 17: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 18: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 19: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 29
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-29

Reference 20: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 29
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-29

Reference 21: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 20
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-20

Reference 22: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 20
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-20

Reference 23: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-14

Reference 24: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-14

Reference 25: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-14

Reference 26: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-14

Reference 27: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-14

Reference 28: http://www.xbrl.org/2003/role/exampleRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 40
-SubTopic 30
-Topic 350
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482640/350-30-55-40

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482665/350-30-50-2

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482665/350-30-50-2

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482686/350-30-45-1

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482665/350-30-50-2

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482665/350-30-50-3

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 985
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481283/985-20-50-2

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Topic 926
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483154/926-20-50-5

+ Details

(Loss) income per Share - Basic and Diluted (Loss) Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Basic (loss) income per Share
Net (loss) income attributable to Fluence Energy, Inc.- basic	$ (48,314)	$ 22,716	$ (69,620)
Net (loss) income attributable to Fluence Energy, Inc., shares - basic (in shares)	130,307,162	126,180,011	116,448,602
Net (loss) income attributable to Fluence Energy, Inc., $ per share - basic (in usd per share)	$ (0.37)	$ 0.18	$ (0.60)
Effect of Dilutive Securities
Net (loss) income attributable to Fluence Energy, Inc. - diluted	$ (48,314)	$ 24,821	$ (69,620)
Net (loss) income attributable to Fluence Energy, Inc., shares - diluted (in shares)	130,307,162	184,034,832	116,448,602
Net (loss) income attributable to Fluence Energy, Inc., $ per share - diluted (in usd per share)	$ (0.37)	$ 0.13	$ (0.60)
Class B-1 Common Stock
Effect of Dilutive Securities
Net (loss) income attributable to Fluence Energy, Inc. - diluted	$ 0	$ 2,105	$ 0
Net (loss) income attributable to Fluence Energy, Inc., shares - diluted (in shares)	0	52,835,363	0
Net (loss) income attributable to Fluence Energy, Inc., $ per share - diluted (in usd per share)
Pre-IPO options
Effect of Dilutive Securities
Net (loss) income attributable to Fluence Energy, Inc. - diluted	$ 0	$ 0	$ 0
Net (loss) income attributable to Fluence Energy, Inc., shares - diluted (in shares)	0	3,799,239	0
Net (loss) income attributable to Fluence Energy, Inc., $ per share - diluted (in usd per share)
Phantom units
Effect of Dilutive Securities
Net (loss) income attributable to Fluence Energy, Inc. - diluted	$ 0	$ 0	$ 0
Net (loss) income attributable to Fluence Energy, Inc., shares - diluted (in shares)	0	105,468	0
Net (loss) income attributable to Fluence Energy, Inc., $ per share - diluted (in usd per share)
RSUs
Effect of Dilutive Securities
Net (loss) income attributable to Fluence Energy, Inc. - diluted	$ 0	$ 0	$ 0
Net (loss) income attributable to Fluence Energy, Inc., shares - diluted (in shares)	0	826,469	0
Net (loss) income attributable to Fluence Energy, Inc., $ per share - diluted (in usd per share)
RSUs \| Nispera
Effect of Dilutive Securities
Net (loss) income attributable to Fluence Energy, Inc. - diluted	$ 0	$ 0	$ 0
Net (loss) income attributable to Fluence Energy, Inc., shares - diluted (in shares)	0	216,429	0
Net (loss) income attributable to Fluence Energy, Inc., $ per share - diluted (in usd per share)
PSUs
Effect of Dilutive Securities
Net (loss) income attributable to Fluence Energy, Inc. - diluted	$ 0	$ 0	$ 0
Net (loss) income attributable to Fluence Energy, Inc., shares - diluted (in shares)	0	71,535	0
Net (loss) income attributable to Fluence Energy, Inc., $ per share - diluted (in usd per share)
NQSOs
Effect of Dilutive Securities
Net (loss) income attributable to Fluence Energy, Inc. - diluted	$ 0	$ 0	$ 0
Net (loss) income attributable to Fluence Energy, Inc., shares - diluted (in shares)	0	318	0
Net (loss) income attributable to Fluence Energy, Inc., $ per share - diluted (in usd per share)

Intangible Assets, Net - Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Finite-Lived Intangible Assets [Line Items]
Cost	$ 106,775	$ 90,706
Accumulated Amortization	(43,372)	(30,704)
Net	$ 63,403	60,002
Patents and licenses
Finite-Lived Intangible Assets [Line Items]
Weighted Average Estimated Useful Lives	15 years
Cost	$ 28,856	28,765
Accumulated Amortization	(14,911)	(12,950)
Net	$ 13,945	15,815
Developed technology
Finite-Lived Intangible Assets [Line Items]
Weighted Average Estimated Useful Lives	12 years
Cost	$ 31,932	30,842
Accumulated Amortization	(10,910)	(7,966)
Net	$ 21,022	22,876
Customer relationship
Finite-Lived Intangible Assets [Line Items]
Weighted Average Estimated Useful Lives	6 years
Cost	$ 4,825	4,624
Accumulated Amortization	(3,035)	(2,104)
Net	$ 1,790	2,520
Tradenames/Trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted Average Estimated Useful Lives	8 years
Cost	$ 5,379	5,329
Accumulated Amortization	(4,640)	(3,984)
Net	$ 739	1,345
Capitalized internal-use software
Finite-Lived Intangible Assets [Line Items]
Weighted Average Estimated Useful Lives	4 years
Cost	$ 24,674	15,562
Accumulated Amortization	(7,966)	(3,010)
Net	$ 16,708	12,552
Capitalized software to be sold
Finite-Lived Intangible Assets [Line Items]
Weighted Average Estimated Useful Lives	5 years
Cost	$ 11,109	5,584
Accumulated Amortization	(1,910)	(690)
Net	$ 9,199	$ 4,894

Revenue from Contracts with Customers - Narrative (Details) - USD ($) $ in Billions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Amount of remaining performance obligations	$ 5.3
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Expected time period of satisfaction	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01 \| Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percentage of remaining performance obligations	55.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01 \| Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percentage of remaining performance obligations	60.00%
Revenue from Contract with Customer Benchmark \| Customer Concentration Risk \| Two Customers
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total revenue percentage	41.00%	50.00%	49.00%

Organization and Operations	12 Months Ended
Organization and Operations	Sep. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Operations	Organization and Operations Fluence Energy, Inc., a Delaware corporation (the “Company”), was formed on June 21, 2021. We conduct our business operations through Fluence Energy, LLC and its direct and indirect subsidiaries. Fluence Energy, LLC was formed on June 30, 2017 as a joint venture between Siemens Industry, Inc. (“Siemens Industry”), an indirect subsidiary of Siemens AG (“Siemens”), and AES Grid Stability, LLC (“AES Grid Stability”), an indirect subsidiary of The AES Corporation (“AES”), and commenced operations on January 1, 2018. We refer to Siemens Industry and AES Grid Stability as the “Founders” in this Annual Report on Form 10-K for the fiscal year ended September 30, 2025 (this “Report”). Upon the completion of our IPO on November 1, 2021, Fluence Energy, Inc. became a holding company whose sole material assets are the limited liability company interests (the “LLC Interests”) in Fluence Energy, LLC. All of our business is conducted through Fluence Energy, LLC, together with its subsidiaries, and the financial results of Fluence Energy, LLC are consolidated in our financial statements. Fluence Energy LLC is taxed as a partnership for federal income tax purposes and, as a result, its members, including Fluence Energy, Inc., will pay income taxes with respect to their allocable shares of its net taxable income. As of September 30, 2025, Fluence Energy, LLC had subsidiaries including Fluence Energy GmbH in Germany, Fluence Energy Pty Ltd. in Australia, Fluence Energy Inc. in the Philippines, Fluence Energy Chile SpA in Chile, Fluence Energy B.V. in Netherlands, Fluence Energy Global Production Operation, LLC in the United States, Fluence BESS India Private Ltd in India, Fluence Energy AG in Switzerland, Fluence Energy UK Ltd. in the United Kingdom, Fluence Energy Canada Inc in Canada, Fluence Energy Singapore Pte Ltd in Singapore, Fluence Energy Taiwan Ltd. in Taiwan, Fluence Energy Japan GK in Japan, and Fluence Energy Ireland Limited in Ireland. Except where the content clearly indicates otherwise, reference to “Fluence,” “we,” “us,” “our” or “the Company” refers to Fluence Energy, Inc. and all of its direct and indirect subsidiaries, including Fluence Energy, LLC. When used in a historical context that is prior to the completion of the IPO, “we,” “us,” “our” or “the Company” refer to Fluence Energy, LLC and its subsidiaries. Our fiscal year begins on October 1 and ends on September 30. References to “fiscal year 2023,” “fiscal year 2024,” and “fiscal year 2025” refer to the fiscal years ended September 30, 2023, September 30, 2024, and September 30, 2025, respectively. The Company’s chief operating decision maker (“CODM”) is its Chief Executive Officer. The Company’s CODM reviews financial information on a consolidated basis for purposes of making operating decisions, allocating resources, and evaluating financial performance. As such, the Company has determined that it operates in one operating segment, which corresponds to one reportable segment. The CODM uses gross margin, earnings before interest, taxes, depreciation and amortization (“EBITDA”) and consolidated net income to assess performance for the Company, monitor budget versus actual results, and determine how to allocate resources. The Company has concluded that consolidated net income (loss) as reported in the consolidated statements of operations is the measure of segment profit or loss. There are no other expense categories regularly provided to the CODM that are not already included in the primary financial statements herein. Secondary Offering and AES Redemption On December 8, 2023, AES Grid Stability, Siemens Pension-Trust e.V. (“Siemens Pension Trust”), and Qatar Holding LLC (“QHL” and together with AES Grid Stability and Siemens Pension Trust in such context, the “Selling Stockholders”) closed an underwritten public offering (the “Offering”) of 18,000,000 shares of Class A common stock by the Selling Stockholders. In conjunction with the Offering, AES Grid Stability exercised its redemption right pursuant to the terms of the LLC Agreement with respect to 7,087,500 LLC Interests held by AES Grid Stability, together with the corresponding cancellation of an equivalent number of shares of Class B-1 common stock of the Company (the “AES Redemption”). The Company elected to settle the AES Redemption through the issuance of 7,087,500 shares of the Company’s Class A common stock. All of the 7,087,500 shares issued to AES Grid Stability in connection with the AES Redemption were sold in the Offering. The Company did not sell any of its shares of Class A common stock in the Offering and the Company did not receive any proceeds from the Offering. The impact of the change in ownership interest did not result in a change in control. The AES Redemption has been accounted for as an equity transaction and the carrying amount of the non-controlling interest has been adjusted. Refer to “Consolidated statements of changes in stockholders’ equity” included herein for more information on the impacts of this redemption to stockholders’ equity.

Schedule I Condensed Financial Information of the Registrant - CONDENSED STATEMENTS OF CASH FLOWS (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Operating activities
Net (loss) income	$ (48,314)	$ 22,716	$ (69,620)
Adjustments to reconcile net (loss) income to net cash (used in) provided by operating activities:
Amortization of debt issuance costs	4,217	3,091	914
Stock-based compensation	19,540	23,855	26,920
Changes in operating assets and liabilities:
Accounts receivable - related party	(56,715)	(114,577)	(13,397)
Accounts payable	(119,228)	370,124	(242,268)
Accruals and provisions	(93,586)	160,206	(12,360)
Taxes payable	(27,891)	22,799	15,753
Other non-current liabilities - related party	10,425	(23,274)	18,124
Other current liabilities - related party	(58,305)	18,185	39,467
Net cash (used in) provided by operating activities	(145,538)	79,685	(111,927)
Investing activities
Net cash (used in) provided by investing activities	(29,799)	(18,975)	94,437
Financing activities
Class A common stock withheld related to settlement of employee taxes for stock-based compensation awards	(753)	(1,663)	(2,784)
Proceeds from exercise of stock options	2,170	5,335	7,203
Purchases of Capped Calls related to 2030 Convertible Senior Notes	(29,000)	0	0
Proceeds from issuance of 2030 Convertible Senior Notes, net	400,000	0	0
Payments of debt issuance costs	(12,132)	(8,456)	0
Net cash provided by (used in) financing activities	356,880	(8,676)	52,595
Effect of exchange rate changes on cash and cash equivalents	14,381	3,941	(2,095)
Net increase in cash and cash equivalents	195,924	55,975	33,010
Cash, cash equivalents, and restricted cash as of the beginning of the period	518,706	462,731	429,721
Cash, cash equivalents, and restricted cash as of the end of the period	714,630	518,706	462,731
Parent
Operating activities
Net (loss) income	(48,314)	22,716	(69,620)
Adjustments to reconcile net (loss) income to net cash (used in) provided by operating activities:
Equity in net income (loss) of subsidiaries	46,540	(28,008)	68,133
Amortization of debt issuance costs	1,426	0	0
Stock-based compensation	701	821	443
Changes in operating assets and liabilities:
Other receivables	375	(75)	(348)
Accounts receivable - related party	(6,464)	0	0
Taxes receivables	(49)	0	0
Accruals and provisions	2,551	74	0
Taxes payable	(1,955)	1,949	6
Other non-current liabilities - related party	(1,507)	1,507	0
Other current liabilities - related party	301	0	0
Net cash (used in) provided by operating activities	(2,496)	200	67
Investing activities
Purchase of long-term notes receivable - related party	(400,000)	0	0
Net cash (used in) provided by investing activities	(400,000)	0	0
Financing activities
Distributions from Fluence Energy, LLC	42,974	1,663	2,784
Class A common stock withheld related to settlement of employee taxes for stock-based compensation awards	(752)	(1,663)	(2,784)
Proceeds from exercise of stock options	2,170	5,335	7,203
Contributions to Fluence Energy, LLC	(2,170)	(5,335)	(7,203)
Purchases of Capped Calls related to 2030 Convertible Senior Notes	(29,000)	0	0
Proceeds from issuance of 2030 Convertible Senior Notes, net	400,000	0	0
Payments of debt issuance costs	(10,622)	0	0
Net cash provided by (used in) financing activities	402,600	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0	0
Net increase in cash and cash equivalents	104	200	67
Cash, cash equivalents, and restricted cash as of the beginning of the period	267	67	0
Cash, cash equivalents, and restricted cash as of the end of the period	371	267	67
Parent \| Nonrelated Party
Changes in operating assets and liabilities:
Accounts payable	44	74	0
Parent \| Related Party
Changes in operating assets and liabilities:
Accounts payable	$ 3,854	$ 1,142	$ 1,453

Related-Party Transactions (Tables)

12 Months Ended

Sep. 30, 2025

Schedule of Related Party Transactions

The following table presents the components of receivables from related parties and payables to related parties on the Company’s consolidated balance sheets:


in thousands	September 30,
	2025		2024
Accounts receivable	$	26,615	$	92,183
Unbilled receivables	174,133		270,340
Total receivables from related parties	200,748		362,523
Advances to suppliers	9,603		32,074
Accounts payable	4,985		3,410
Deferred revenue	79,916		38,162
Accruals and provisions	6,353		6,099
Other current liabilities	301		428
Other non-current liabilities	—		1,507

The following table presents the related party transactions that are included the Company’s consolidated statements of operations for the periods indicated:


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Revenue(a)	$	557,621	$	1,096,999	$	653,809
Cost of goods and services(b)	80,482		50,653		15,925
Research and development	31		192		912
Sales and marketing	—		123		135
General and administrative	2,061		6,113		5,215
Other income, net(c)	(1,206)		(571)		—

(a) Revenue from AES and its affiliates was approximately $555.1 million, $1,082.3 million, and $642.7 million for the fiscal years ended September 30, 2025, 2024 and 2023, respectively.

(b) Represent purchases from related parties that are included in cost of goods and services and are not associated with the revenue listed in the table above.

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Current assets:
Cash and cash equivalents	$ 690,768	$ 448,685
Restricted cash	23,862	46,089
Trade receivables, net	272,820	216,458
Unbilled receivables	239,594	172,115
Receivables from related parties	200,748	362,523
Advances to suppliers	126,778	174,532
Inventory, net	455,015	182,601
Current portion of notes receivable - pledged as collateral	0	30,921
Other current assets	54,671	46,519
Total current assets	2,064,256	1,680,443
Non-current assets:
Property and equipment, net	50,320	15,350
Intangible assets, net	63,403	60,002
Goodwill	28,584	27,482
Deferred income tax asset, net	4,046	8,880
Other non-current assets	146,391	110,031
Total non-current assets	292,744	221,745
Total assets	2,357,000	1,902,188
Current liabilities:
Accounts payable	321,004	436,744
Current portion of borrowings against note receivable - pledged as collateral	0	30,360
Personnel related liabilities	31,850	58,584
Accruals and provisions	246,235	338,311
Taxes payable	30,317	57,929
Other current liabilities	20,590	24,246
Total current liabilities	1,370,369	1,258,835
Non-current liabilities:
Deferred income tax liability	9,530	7,114
Convertible senior notes, net	390,804	0
Other non-current liabilities	37,449	29,100
Total non-current liabilities	437,783	36,214
Total liabilities	1,808,152	1,295,049
Commitments and Contingencies (Note 15)
Stockholders’ equity:
Preferred stock, $0.00001 per share, 10,000,000 share authorized; no shares issued and outstanding as of September 30, 2025 and 2024	0	0
Treasury stock, at cost	(10,213)	(9,460)
Additional paid-in capital	627,956	634,851
Accumulated other comprehensive income (loss)	11,613	(1,840)
Accumulated deficit	(199,762)	(151,448)
Total stockholders’ equity attributable to Fluence Energy, Inc.	429,595	472,104
Non-controlling interest	119,253	135,035
Total stockholders’ equity	548,848	607,139
Total liabilities, stockholders’ equity	2,357,000	1,902,188
Nonrelated Party
Current liabilities:
Deferred revenue	640,457	274,499
Related Party
Current assets:
Receivables from related parties	26,615	92,183
Advances to suppliers	9,603	32,074
Current liabilities:
Accounts payable	4,985	3,410
Deferred revenue	79,916	38,162
Accruals and provisions	6,353	6,099
Other current liabilities	301	428
Non-current liabilities:
Other non-current liabilities	0	1,507
Class A common stock
Stockholders’ equity:
Common stock	$ 1	$ 1
Common stock, shares authorized (in shares)	1,200,000,000	1,200,000,000
Common stock, shares issued (in shares)	132,014,571	130,207,845
Common stock, shares outstanding (in shares)	131,164,365	129,421,797
Class B-1 common stock
Stockholders’ equity:
Common stock	$ 0	$ 0
Common stock, shares authorized (in shares)	134,325,805	134,325,805
Common stock, shares issued (in shares)	51,499,195	51,499,195
Common stock, shares outstanding (in shares)	51,499,195	51,499,195
Class B-2 common stock
Stockholders’ equity:
Common stock	$ 0	$ 0
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	0	0
Common stock, shares outstanding (in shares)	0	0

Accruals and Provisions

12 Months Ended

Sep. 30, 2025

Payables and Accruals [Abstract]

Accruals and Provisions

Accruals mainly represent milestones not yet invoiced for inventory such as, but not limited to, batteries, integrated systems, and inverters. Generally, according to master supply agreements between the Company and suppliers of our inventory, vendor invoices are issued according to contracted billing schedules with certain milestones invoiced after delivery, upon full installation and commissioning of the equipment at substantial completion and final completion project stages. Accruals and provisions consisted of the following:


In thousands	September 30,
	2025		2024
Accruals	$	203,410	$	287,566
Accruals with related parties	6,353		6,099
Accruals for software development costs	23		10,903
Provisions for expected project losses	15,684		14,652
Current portion of warranty accrual	20,765		19,091
Total	$	246,235	$	338,311

- Definition

The entire disclosure for long-term contracts or programs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-SubTopic 35
-Topic 605
-Publisher FASB
-URI https://asc.fasb.org/605-35/tableOfContent

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(c)(3))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(6)(d)(ii))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 912
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/912/tableOfContent

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 912
-SubTopic 275
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479072/912-275-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 912
-SubTopic 275
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479072/912-275-50-3

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 912
-SubTopic 275
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479072/912-275-50-4

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 912
-SubTopic 275
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479072/912-275-50-5

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 912
-SubTopic 275
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479072/912-275-50-6

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 912
-SubTopic 310
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478685/912-310-50-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 912
-SubTopic 310
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478685/912-310-50-4

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 912
-SubTopic 405
-Name Accounting Standards Codification
-Section 45
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478788/912-405-45-4

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 912
-SubTopic 405
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477623/912-405-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 912
-SubTopic 405
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477623/912-405-50-3

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 910
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482332/910-20-50-1

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(c)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

Accruals and Provisions (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Supplier Finance Program [Line Items]
Accruals for software development costs	$ 23	$ 10,903
Provisions for expected project losses	15,684	14,652
Current portion of warranty accrual	20,765	19,091
Accruals and provisions	246,235	338,311
Nonrelated Party
Supplier Finance Program [Line Items]
Accruals	203,410	287,566
Related Party
Supplier Finance Program [Line Items]
Accruals	6,353	6,099
Accruals and provisions	$ 6,353	$ 6,099

Sale of Receivables under Master Receivables Purchase Agreement	12 Months Ended
	Sep. 30, 2025
Transfers and Servicing [Abstract]
Sale of Receivables under Master Receivables Purchase Agreement	Sale of Receivables under Master Receivables Purchase Agreement On February 27, 2024, Fluence Energy, LLC entered into a Master Receivables Purchase Agreement (“MRPA”), by and among Fluence Energy, LLC and any other seller from time to time party thereto, as sellers and servicers, and Credit Agricole Corporate and Investment Bank ("CACIB"), as purchaser. Pursuant to the MRPA, Fluence Energy, LLC may sell certain receivables (the “Purchased Receivables”) to CACIB from time to time, and CACIB may agree to purchase the Purchased Receivables in each case, on an uncommitted basis. The MRPA provides that the outstanding amount of all purchased receivables under the MRPA will not exceed $75.0 million, with sublimits for each account debtor and for certain kinds of receivables. The MRPA may be terminated by either party at any time by 30 days’ prior written notice. Fluence Energy, LLC has granted CACIB a security interest in the purchased receivables, and proceeds thereof, as more fully described in the MRPA, in order to perfect CACIB’s ownership interest in the purchased receivables and secure the payment and performance of all obligations of Fluence Energy, LLC to CACIB under the MRPA. The MRPA contains other customary representations and warranties and covenants. When receivables are sold under the MRPA, they are sold without recourse, and our continuing involvement is limited to their servicing, for which the Company receives a fee commensurate with the service provided and therefore no servicing asset or liability related to these receivables was recognized for any period presented. The fair value of the sold receivables approximated their book value due to their short-term nature. For the fiscal year ended September 30, 2024, we sold receivables to CACIB under the MRPA for net proceeds of $71.5 million. At the date of the true sale, the receivables were de-recognized in their entirety from the consolidated balance sheets. We charged a fee to our customer, primarily for providing extended payment terms, in relation to the sale of receivables. We recorded factoring income of $2.1 million and related factoring discount of $2.1 million during the period. The factoring income is recorded in “Other (income) expense, net” and the factoring discount is recorded in “Sales and marketing expense” on the consolidated statements of operations. Proceeds from the sold receivables are reflected in operating cash flows on the consolidated statements of cash flows. There were no sales of receivables during the fiscal year ended September 30, 2025.

- Definition

The entire disclosure for a transferor's continuing involvement in financial assets that it has transferred in a securitization or asset-backed financing arrangement, the nature of any restrictions on assets reported by an entity in its statement of financial position that relate to a transferred financial asset (including the carrying amounts of such assets), how servicing assets and servicing liabilities are reported, and (for securitization or asset-backed financing arrangements accounted for as sales) when a transferor has continuing involvement with the transferred financial assets and transfers of financial assets accounted for as secured borrowings, how the transfer of financial assets affects an entity's financial position, financial performance, and cash flows.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480591/815-20-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481420/860-30-50-1A

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(11))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481420/860-30-50-1A

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)(7)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-4

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-3

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-3

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-4

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-3

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(4)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-3

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(5)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-3

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/860/tableOfContent

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-3

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (cc)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-3

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)(5)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-4

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-4

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4D
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-4D

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481420/860-30-50-7

Reference 20: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-2

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-2

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-4

+ Details

Summary of Significant Accounting Policies and Estimates (Tables)

12 Months Ended

Sep. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Ownership Interests

The table below summarizes the ownership structure at the end of each respective period:


	September 30,
	2025		2024
Controlling Interest Ownership	71.81	%	71.53	%
Non-Controlling Interest Ownership (AES)	28.19	%	28.47	%

Schedule of Restrictions on Cash and Cash Equivalents

The following table provides a reconciliation of cash, cash equivalents, and restricted cash at the end of each respective period as shown in the Company’s consolidated balance sheets.


	September 30,
in thousands	2025		2024
Cash and cash equivalents	$	690,768	$	448,685
Restricted cash	23,862		46,089
Restricted cash included in “Other non-current assets”	—		23,932
Total cash, cash equivalents and restricted cash shown in the statements of cash flows	$	714,630	$	518,706

Restricted cash consisted of the following:


	September 30,
in thousands	2025		2024
Collateral for credit card program	$	6,112	$	2,757
Collateral for outstanding bank guarantees	7,309		31,360
Collateral for surety program	10,370		9,551
Term deposits	71		2,421
Collateral for surety program included in “Other non-current assets”	—		23,932
Total restricted cash	$	23,862	$	70,021

Schedule of Accounting Standards Update and Change in Accounting Principle

The following table presents accounting standards adopted in 2025:


Standard	Description	Date of adoption	Effect on the financial statements and other significant matters
Accounting Standards Update (“ASU”) No. 2024-04: Debt—Debt with Conversion and Other Options (Subtopic 470-20): Induced Conversions of Convertible Debt Instruments	ASU 2024-04 clarifies the requirements for determining whether certain settlements of convertible debt instruments should be accounted for as an induced conversion.	As of the three months ended December 31, 2024.	The new standard was early adopted by the Company and applied for the Company’s 2030 Convertible Senior Notes. Refer to “Note 13 – Convertible Senior Notes, Net” for further details. The new standard did not have an impact on the condensed consolidated financial statements.
ASU No. 2023-07: Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures	ASU 2023-07 requires disclosure of incremental segment information on an annual and interim basis for all public entities to enable investors to develop more decision-useful financial analyses. The update requires other specified segment items and amounts, such as depreciation, amortization, and depletion expense, to be disclosed under certain circumstances. The amendments in this update do not change or remove those disclosure requirements. The amendments in this update also do not change how a public entity identifies its operating segments, aggregates those operating segments, or applies the quantitative thresholds to determine its reportable segments.	As of the three months ended September 30, 2025.	The Company only has one reportable segment. The Company adopted this standard in the fourth quarter of 2025, which did not have a material impact on the consolidated financial statements and related disclosures. Refer to “Note 1 – Organization and Operations” for further details.

The following table presents accounting standards not yet adopted:


Standard	Description	Required date of adoption	Effect on the financial statements and other significant matters
ASU No. 2023-09: Income Taxes (Topic 740): Improvements to Income Tax Disclosures	ASU 2023-09 adopts certain amendments to improve the effectiveness of income tax disclosures, including jurisdictional information, by requiring (1) consistent categories and greater disaggregation of information in the rate reconciliation, and (2) income taxes paid, disaggregated by jurisdiction.	ASU 2023-09 is effective for the Company’s annual report for fiscal year ending September 30, 2026.	The Company is evaluating the impact this guidance will have on income tax disclosures.
SEC Final Rule Release Nos. 33-11275; 34-99678: The Enhancement and Standardization of Climate-Related Disclosures for Investors	SEC Final Rule Release Nos. 33-11275; 34-99678 requires registrants to provide certain climate-related information in their registration statements and annual reports, including climate-related risks that have materially impacted, or are reasonably likely to have a material impact on, its business strategy, results of operations, or financial condition. In addition, certain disclosures related to severe weather events and other natural conditions will be required in registrants’ annual reports.	SEC Final Rule Release Nos. 33-11275; 34-99678 is effective for the Company’s annual report for fiscal year ending September 30, 2026.	The Company is evaluating the impact this guidance will have on climate-related disclosures.
ASU No. 2024-03: Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses	ASU 2024-03 requires disclosure of qualitative and quantitative information about certain costs and expenses in the notes to the financial statements on an interim and annual basis. ASU No. 2025-01: Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date, was subsequently issued and clarified the effective date of ASU 2024-03.	ASU 2024-03 is effective for the Company’s annual report for fiscal year ending September 30, 2028.	The Company is evaluating the impact this guidance will have on its disclosures.
ASU No. 2025-05: Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets	ASU 2025-05 amends ASC 326-20 to provide a practical expedient (for all entities) and an accounting policy election (for all entities, other than public business entities, that elect the practical expedient) related to the estimation of expected credit losses for current accounts receivable and current contract assets that arise from transactions accounted for under ASC 606.	ASU 2025-05 is effective for the Company’s annual report for fiscal year ending September 30, 2027.	The Company is evaluating the impact this guidance will have on its disclosures.
ASU No. 2025-06: Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software	ASU 2025-06 makes targeted improvements to ASC 350-40 and amends certain aspects of the accounting for and disclosure of software costs under ASC 350-40. The amendments supersede the guidance on Web site development costs in ASC 350-50 and relocate that guidance, along with the recognition requirements for development costs specific to Web sites, to ASC 350-40.	ASU 2025-06 is effective for the Company’s annual report for fiscal year ending September 30, 2029.	The Company is evaluating the impact this guidance will have on its disclosures.

Goodwill - Narrative (Details) - USD ($)	12 Months Ended
Goodwill - Narrative (Details) - USD ($)	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Impairment of goodwill	$ 0	$ 0	$ 0

- Definition

Amount of impairment loss from asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

+ References + Details

Property and Equipment, Net - Useful Lives (Details)	Sep. 30, 2025
Property, Plant and Equipment [Line Items]
Finance lease right-of-use assets	3 years
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Depreciable life	10 years
IT Equipment
Property, Plant and Equipment [Line Items]
Depreciable life	3 years
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Depreciable life	5 years
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Depreciable life	10 years
Other
Property, Plant and Equipment [Line Items]
Depreciable life	5 years

Leases (Tables)

12 Months Ended

Sep. 30, 2025

Leases [Abstract]

Schedule of Assets and Liabilities, Operating Lease

The amounts of assets and liabilities and other information for our operating and finance leases are as follows:


In thousands		September 30,
	Balance Sheet Caption	2025		2024
Right-of-use assets:
Operating leases	Other non-current assets	$	11,256	$	8,186
Finance leases	Property and equipment, net	22,057		—
Total right-of-use assets		33,313		8,186

Lease liabilities:
Operating leases	Other current liabilities	$	6,789	$	3,064
	Other non-current liabilities	5,044		5,492
Finance leases	Other current liabilities	3,492		—
	Other non-current liabilities	—		—
		$	15,325	$	8,556

Schedule of Lease Cost

Components of total lease cost for the fiscal years ended September 30, 2025, 2024, and 2023 were as follows:


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Lease cost
Finance lease cost:	$	2,849	$	—	$	—
Amortization of right-of-use assets	2,757		—		—
Interest on lease liabilities	92		—		—
Operating lease cost	6,608		3,326		1,939
Short-term and variable lease cost	6,169		3,789		17,123
Sublease income	—		—		(194)
Total lease cost	$	15,626	$	7,115	$	18,868

Supplemental information related to the Company’s operating leases for the fiscal years ended September 30, 2025, 2024 and 2023 was as follows:


in thousands	Fiscal Year Ended September 30,
	2025			2024			2023
Cash paid for amounts included in the measurements of lease liabilities	$	6,250		$	3,003		2,246
Right-of-use assets obtained in exchange for new operating lease liabilities	$	8,642		$	6,536		1,024
Weighted average remaining lease term	2.7 years			4.0 years			2.0 years
Weighted average discount rate	6.63		%	6.96		%	7.20	%

Supplemental information related to the Company’s finance lease executed during the fiscal year ended September 30, 2025 was as follows:


in thousands	Fiscal Year Ended September 30,
	2025
Cash paid for amounts included in the measurements of lease liabilities	$	2,462
Operating cash flows	$	92
Financing cash flows	$	2,370
Right-of-use assets obtained in exchange for new finance lease liabilities	$	5,861
Weighted average remaining lease term	0.8 years
Weighted average discount rate	5.60		%

Schedule of Maturity of Operating Lease Payments

Total remaining lease payments under the Company’s leases for each of the succeeding years are as follows (in thousands):


Year Ended September 30,	Operating Leases		Finance Leases		Total
2026	$	7,259	$	3,576	$	10,835
2027	2,977		—		2,977
2028	953		—		953
2029	590		—		590
2030	246		—		246
Thereafter	951		—		951
Total lease payments	12,976		3,576		16,552
Less: Interest	(1,143)		(84)		(1,227)
Present value of lease liabilities	$	11,833	$	3,492	$	15,325

Schedule of Maturity of Finance Lease Payments

Total remaining lease payments under the Company’s leases for each of the succeeding years are as follows (in thousands):


Year Ended September 30,	Operating Leases		Finance Leases		Total
2026	$	7,259	$	3,576	$	10,835
2027	2,977		—		2,977
2028	953		—		953
2029	590		—		590
2030	246		—		246
Thereafter	951		—		951
Total lease payments	12,976		3,576		16,552
Less: Interest	(1,143)		(84)		(1,227)
Present value of lease liabilities	$	11,833	$	3,492	$	15,325

Schedule I Condensed Financial Information of the Registrant - CONDENSED BALANCE SHEETS - Parenthetical (Details) - $ / shares	Sep. 30, 2025	Sep. 30, 2024	Nov. 01, 2021
Condensed Balance Sheet Statements, Captions [Line Items]
Preferred stock, par value (in usd per share)	$ 0.00001	$ 0.00001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Parent
Condensed Balance Sheet Statements, Captions [Line Items]
Preferred stock, par value (in usd per share)	$ 0.01000	$ 0.01000
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Class A common stock
Condensed Balance Sheet Statements, Captions [Line Items]
Common stock, par value (in usd per share)	$ 0.01000	$ 0.01000
Common stock, shares authorized (in shares)	1,200,000,000	1,200,000,000
Common stock, shares issued (in shares)	132,014,571	130,207,845
Common stock, shares outstanding (in shares)	131,164,365	129,421,797
Class A common stock \| Parent
Condensed Balance Sheet Statements, Captions [Line Items]
Common stock, par value (in usd per share)	$ 0.01000	$ 0.01000	$ 0.00001
Common stock, shares authorized (in shares)	1,200,000,000	1,200,000,000
Common stock, shares issued (in shares)	132,014,571	130,207,845
Common stock, shares outstanding (in shares)	131,164,365	129,421,797
Class B-1 Common Stock
Condensed Balance Sheet Statements, Captions [Line Items]
Common stock, par value (in usd per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized (in shares)	134,325,805	134,325,805
Common stock, shares issued (in shares)	51,499,195	51,499,195
Common stock, shares outstanding (in shares)	51,499,195	51,499,195
Class B-1 Common Stock \| Parent
Condensed Balance Sheet Statements, Captions [Line Items]
Common stock, par value (in usd per share)	$ 0.01000	$ 0.01000
Common stock, shares authorized (in shares)	134,325,805	134,325,805
Common stock, shares issued (in shares)	51,499,195	51,499,195
Common stock, shares outstanding (in shares)	51,499,195	51,499,195
Class B-2 common stock
Condensed Balance Sheet Statements, Captions [Line Items]
Common stock, par value (in usd per share)	$ 0.01000	$ 0.01000
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	0	0
Common stock, shares outstanding (in shares)	0	0
Class B-2 common stock \| Parent
Condensed Balance Sheet Statements, Captions [Line Items]
Common stock, par value (in usd per share)	$ 0.01000	$ 0.01000
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	0	0
Common stock, shares outstanding (in shares)	0	0

Intangible Assets, Net - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 12.7	$ 9.1	$ 6.6
Capitalized software amortization expense	$ 6.2	$ 2.9	$ 0.8

- Definition

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-18

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-11

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-24

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476148/220-40-50-12

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 40
-SubTopic 30
-Topic 350
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482640/350-30-55-40

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482665/350-30-50-2

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482686/350-30-45-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476148/220-40-50-6

+ Details

(Loss) income per Sharee - Dilutive Securities (Details) - shares	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Class B-1 Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	51,499,195	0	58,586,695
Shares underlying the conversion option in the 2030 Convertible Senior Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	18,738,880	0	0
Outstanding pre-IPO options issued pursuant to the 2020 Unit Option Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	2,211,860	511,756	5,351,585
Outstanding phantom units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	0	0	256,935
Outstanding restricted stock units (“RSUs”)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	2,232,320	1,103,968	1,843,570
Outstanding restricted stock units (“RSUs”) \| Nispera
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	0	49,171	354,134
Outstanding performance share units (“PSUs”)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	901,516	300,387	0
Outstanding non-qualified stock options (“NQSOs”)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	469,893	162,419	0

Commitments and Contingencies - Purchase Commitments (Details) $ in Thousands	Sep. 30, 2025 USD ($)
Purchase Commitments
2026	$ 205,821
2027	254,120
2028	254,120
2029	244,120
2030 and thereafter	237,000
Total	1,195,181
Liquidated Damages
Liquidated Damages
2026	7,358
2027	8,100
2028	8,100
2029	8,100
2030 and thereafter	8,100
Total	$ 39,758

CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) - $ / shares	Sep. 30, 2025	Sep. 30, 2024
Preferred stock, par value (in usd per share)	$ 0.00001	$ 0.00001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Class A common stock
Common stock, par value (in usd per share)	$ 0.01000	$ 0.01000
Common stock, shares authorized (in shares)	1,200,000,000	1,200,000,000
Common stock, shares issued (in shares)	132,014,571	130,207,845
Common stock, shares outstanding (in shares)	131,164,365	129,421,797
Class B-1 common stock
Common stock, par value (in usd per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized (in shares)	134,325,805	134,325,805
Common stock, shares issued (in shares)	51,499,195	51,499,195
Common stock, shares outstanding (in shares)	51,499,195	51,499,195
Class B-2 common stock
Common stock, par value (in usd per share)	$ 0.01000	$ 0.01000
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	0	0
Common stock, shares outstanding (in shares)	0	0

Intangible Assets, Net (Tables)

12 Months Ended

Sep. 30, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Finite-Lived Intangible Assets

Intangible assets are stated at amortized cost and consist of the following:


in thousands	Weighted Average Estimated Useful Lives	September 30, 2025								September 30, 2024
		Cost		Accumulated Amortization			Net			Cost		Accumulated Amortization		Net
Patents and licenses	15 years	$	28,856	$	(14,911)		$	13,945		$	28,765	$	(12,950)	$	15,815
Developed technology	12 years	31,932		(10,910)			21,022			30,842		(7,966)		22,876
Customer relationship	6 years	4,825		(3,035)			1,790			4,624		(2,104)		2,520
Tradenames/Trademarks	8 years	5,379		(4,640)			739			5,329		(3,984)		1,345
Capitalized internal-use software	4 years	24,674		(7,966)			16,708			15,562		(3,010)		12,552
Capitalized software to be sold	5 years	11,109		(1,910)			9,199			5,584		(690)		4,894
Total		$	106,775	$	(43,372)	—	$	63,403	—	$	90,706	$	(30,704)	$	60,002

Schedule of Future Amortization Expense

Total future amortization expense for finite-lived intangible assets was estimated as follows:


In thousands	Future Amortization Expenses
2026	$	12,167
2027	10,448
2028	8,257
2029	6,730
2030	5,538
Thereafter	12,222
Subtotal	$	55,362
Internally developed software projects in process	8,041
Total	$	63,403

Schedule I Condensed Financial Information of the Registrant - Narrative (Details)			1 Months Ended	12 Months Ended
	Nov. 01, 2021 USD ($) $ / shares shares	Oct. 27, 2021	Dec. 31, 2024 USD ($) $ / shares	Sep. 30, 2025 USD ($) $ / shares $ / Unit shares	Sep. 30, 2024 USD ($) $ / shares	Sep. 30, 2023 USD ($)
Consolidated Entities [Line Items]
Purchases of capped calls related to convertible senior notes				$ 29,000,000
Strike price (in usd per share) \| $ / shares				$ 21.35
Cap price (in usd per share) \| $ / Unit				28.74
Number of shares covered by capped calls (in shares) \| shares				18,700,000
Interest income (expense)				$ 4,110,000	$ (5,676,000)	$ (5,388,000)
Convertible Senior Notes, 2030 \| Convertible Debt
Consolidated Entities [Line Items]
Principal amount			$ 400,000,000	$ 400,000,000
Stated percentage			2.25%
Proceeds from issuance of debt			$ 389,400,000
Debt issuance costs, net			$ 10,600,000
Debt instrument, convertible, conversion ratio			0.0468472
Debt instrument, conversion price (in usd per share) \| $ / shares			$ 21.35
Class A common stock
Consolidated Entities [Line Items]
Par value, Class A common stock (in usd per share) \| $ / shares				$ 0.01000	$ 0.01000
Parent
Consolidated Entities [Line Items]
Proceeds from issuance of Class A common stock sold in an IPO, net of underwriting discounts and commissions	$ 948,000,000
Tax receivable agreement tax benefit payment percentage		85.00%
Other commitment				$ 300,000
Purchases of capped calls related to convertible senior notes				$ 29,000,000.0
Strike price (in usd per share) \| $ / shares				$ 21.35
Cap price (in usd per share) \| $ / Unit				28.74
Number of shares covered by capped calls (in shares) \| shares				18,700,000
Interest income (expense)				$ 1,417,000	$ 0	$ 0
Parent \| Convertible Senior Notes, 2030
Consolidated Entities [Line Items]
Interest income (expense)				8,600,000
Parent \| Convertible Senior Notes, 2030 \| Convertible Debt
Consolidated Entities [Line Items]
Principal amount			$ 400,000,000.0
Stated percentage			2.25%
Proceeds from issuance of debt			$ 389,400,000
Debt issuance costs, net			$ 10,600,000
Debt instrument, convertible, conversion ratio			0.0468472
Debt instrument, conversion price (in usd per share) \| $ / shares			$ 21.35
Parent \| Intercompany Note
Consolidated Entities [Line Items]
Interest income (expense)				$ 7,200,000
Parent \| Class A common stock
Consolidated Entities [Line Items]
Par value, Class A common stock (in usd per share) \| $ / shares	$ 0.00001			$ 0.01000	$ 0.01000
Parent \| Class A common stock \| IPO
Consolidated Entities [Line Items]
Shares sold in offering (in shares) \| shares	35,650,000
Public offering price per share (in usd per share) \| $ / shares	$ 28.00
Parent \| Class A common stock \| Over-Allotment Option
Consolidated Entities [Line Items]
Shares sold in offering (in shares) \| shares	4,650,000

Intangible Assets, Net

12 Months Ended

Sep. 30, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets, Net

Intangible assets are stated at amortized cost and consist of the following:


in thousands	Weighted Average Estimated Useful Lives	September 30, 2025								September 30, 2024
		Cost		Accumulated Amortization			Net			Cost		Accumulated Amortization		Net
Patents and licenses	15 years	$	28,856	$	(14,911)		$	13,945		$	28,765	$	(12,950)	$	15,815
Developed technology	12 years	31,932		(10,910)			21,022			30,842		(7,966)		22,876
Customer relationship	6 years	4,825		(3,035)			1,790			4,624		(2,104)		2,520
Tradenames/Trademarks	8 years	5,379		(4,640)			739			5,329		(3,984)		1,345
Capitalized internal-use software	4 years	24,674		(7,966)			16,708			15,562		(3,010)		12,552
Capitalized software to be sold	5 years	11,109		(1,910)			9,199			5,584		(690)		4,894
Total		$	106,775	$	(43,372)	—	$	63,403	—	$	90,706	$	(30,704)	$	60,002

Intangible assets are amortized over the estimated useful lives of the respective assets on a straight-line basis. Total amortization expense was $12.7 million, $9.1 million, and $6.6 million for the fiscal years ended September 30, 2025, 2024, and 2023, respectively. The amortization expense included $6.2 million, $2.9 million, and $0.8 million for capitalized software for the fiscal years ended September 30, 2025, 2024, and 2023, respectively.

Total future amortization expense for finite-lived intangible assets was estimated as follows:


In thousands	Future Amortization Expenses
2026	$	12,167
2027	10,448
2028	8,257
2029	6,730
2030	5,538
Thereafter	12,222
Subtotal	$	55,362
Internally developed software projects in process	8,041
Total	$	63,403

Leases - Maturity (Details) $ in Thousands	Sep. 30, 2025 USD ($)
Operating Leases
2026	$ 7,259
2027	2,977
2028	953
2029	590
2030	246
Thereafter	951
Total lease payments	12,976
Less: Interest	(1,143)
Present value of lease liabilities	11,833
Finance Leases
2026	3,576
2027	0
2028	0
2029	0
2030	0
Thereafter	0
Total lease payments	3,576
Less: Interest	(84)
Present value of lease liabilities	3,492
Total
2026	10,835
2027	2,977
2028	953
2029	590
2030	246
Thereafter	951
Total lease payments	16,552
Less: Interest	(1,227)
Present value of lease liabilities	$ 15,325

(Loss) income per Share

12 Months Ended

Sep. 30, 2025

Earnings Per Share [Abstract]

(Loss) income per Share

As of September 30, 2025, the Company has two classes of common stock outstanding, Class A and Class B-1. (Loss) income per share is calculated and reported under the “two-class” method. The “two-class” method is an earnings allocation method under which (loss) income per share is calculated for each class of common stock considering both distributions declared or accumulated and participation rights in undistributed earnings as if all such loss had been distributed during the period.

In periods in which we have a loss, diluted loss per share is equal to basic loss per share because the effect of potentially dilutive securities would be antidilutive.

The following table presents the potentially dilutive securities that were excluded from the computation of diluted (loss) income per share:


	Fiscal Year Ended September 30,
	2025	2024	2023
Class B-1 common stock	51,499,195	—	58,586,695
Shares underlying the conversion option in the 2030 Convertible Senior Notes	18,738,880	—	—
Outstanding pre-IPO options issued pursuant to the 2020 Unit Option Plan	2,211,860	511,756	5,351,585
Outstanding phantom units	—	—	256,935
Outstanding restricted stock units (“RSUs”)	2,232,320	1,103,968	1,843,570
Outstanding performance share units (“PSUs”)	901,516	300,387	—
Outstanding non-qualified stock options (“NQSOs”)	469,893	162,419	—
Outstanding restricted stock (“Nispera equity”)	—	49,171	354,134

Basic and diluted (loss) income per share of Class A common stock for the fiscal year ended September 30, 2025, 2024 and 2023 respectively, have been computed as follows:


	Fiscal Year Ended September 30,
	2025					2024					2023
In thousands, except share and per share amounts	Income		Shares	$ per Share		Income		Shares	$ per Share		Income		Shares	$ per Share
Basic (loss) income per Share
Net (loss) income attributable to Fluence Energy, Inc.	$	(48,314)	130,307,162	$	(0.37)	$	22,716	126,180,011	$	0.18	$	(69,620)	116,448,602	$	(0.60)
Effect of Dilutive Securities											—		—
Class B-1 common stock	—		—			2,105		52,835,363			—		—
Pre-IPO options	—		—			—		3,799,239			—		—
Phantom units	—		—			—		105,468			—		—
RSUs	—		—			—		826,469			—		—
PSUs	—		—			—		71,535			—		—
NQSOs	—		—			—		318			—		—
Nispera equity	—		—			—		216,429			—		—
Diluted (loss) Income per Share
Net (loss) income attributable to Fluence Energy, Inc.	$	(48,314)	130,307,162	$	(0.37)	$	24,821	184,034,832	$	0.13	$	(69,620)	116,448,602	$	(0.60)

Revenue from Contracts with Customers

12 Months Ended

Sep. 30, 2025

Revenue from Contract with Customer [Abstract]

Revenue from Contracts with Customers

Our revenue is primarily derived from sales of our energy storage products and solutions. The following table presents the Company’s revenue disaggregated by revenue type:


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Revenue from sale of energy storage products and solutions	$	2,172,360	$	2,648,013	$	2,197,633
Revenue from services	84,439		45,353		15,992
Revenue from digital applications	6,031		5,196		4,353

Total	$	2,262,830	$	2,698,562	$	2,217,978

The following table presents the Company’s revenue disaggregated by geographical region. Revenues are attributed to regions based on location of customers:


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Americas (North, Central and South America)(a)	$	1,305,941	$	1,593,003	$	1,645,107
APAC (Asia Pacific)	348,573		579,255		266,077
EMEA (Europe, Middle-East and Africa)	608,316		526,304		306,794
Total	$	2,262,830	$	2,698,562	$	2,217,978

(a) Revenue from United States of America was $877.3 million, $1,442.0 million and $1,495.0 million for fiscal years 2025, 2024 and 2023, respectively.

Customer Concentration

For the fiscal year ended September 30, 2025, 2024 and 2023, our top two customers, in the aggregate, accounted for approximately 41%, 50% and 49% of total revenue, respectively.

Deferred revenue

The following tables provides information about deferred revenue from contracts with customers:


in thousands	September 30,
	2025		2024		2023
Deferred revenue beginning of period	$	274,499	$	273,164	$	273,073
Additions	587,933		224,423		273,164
Revenue recognized related to amounts that were included in beginning balance of deferred revenue	(221,975)		(223,088)		(273,073)
Deferred revenue end of period	$	640,457	$	274,499	$	273,164


in thousands	September 30,
	2025		2024		2023
Deferred revenue from related parties beginning of period	$	38,162	$	110,274	$	300,697
Additions	71,710		37,382		98,891
Revenue recognized related to amounts that were included in beginning balance of deferred revenue	(29,956)		(109,494)		(289,314)
Deferred revenue from related parties end of period	$	79,916	$	38,162	$	110,274

Remaining performance obligations

The Company’s remaining performance obligations (“backlog”) represent the unrecognized revenue value of its contract commitments, which include deferred revenue and amounts that will be billed and recognized as revenue in future periods. The Company’s backlog may vary significantly each reporting period based on the timing of major new contract commitments and the backlog may fluctuate with currency movements. In addition, the Company’s customers have the right, under some circumstances, to terminate contracts or defer the timing of its services and their payments to the Company.

As of September 30, 2025, the Company had $5.3 billion of remaining performance obligations related to our contractual commitments, of which we expect to recognize in revenue approximately 55% to 60% in the next 12 months, with the remainder recognized in revenue in periods thereafter.

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-9

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-10

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-15

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-12

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-12

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-12

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-12

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-12

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-13

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Topic 606
-Publisher FASB
-URI https://asc.fasb.org/606/tableOfContent

+ Details

Property and Equipment, Net - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Depreciation	$ 11.3	$ 5.6	$ 4.3

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Class A Common Stock	Class B-1 Common Stock	Common Stock Class A Common Stock	Common Stock Class B-1 Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Non-Controlling interest
Beginning balance (in shares) at Sep. 30, 2022				114,873,121	58,586,695
Beginning balance, Treasury Stock (in shares) at Sep. 30, 2022									550,904
Beginning balance at Sep. 30, 2022	$ 629,208			$ 1	$ 0	$ 542,602	$ (104,544)	$ 2,784	$ (5,013)	$ 193,378
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(104,818)						(69,620)			(35,198)
Stock-based compensation (in shares)				1,171,496
Stock-based compensation	26,920					26,920
Class A common stock withheld related to settlement of employee taxes for stock-based compensation awards (in shares)				(139,070)					(139,070)
Class A common stock withheld related to settlement of employee taxes for stock-based compensation awards	(2,784)								$ (2,784)
Effect of remeasurement of non-controlling interest due to other share transactions	0					4,379				(4,379)
Proceeds from exercise of stock options (in shares)				2,997,888
Proceeds from exercise of stock options	7,203					7,203
Gain (loss) on foreign currency translation, net of tax	586							408		178
Actuarial gain (loss) on pension liabilities, net of tax	15							10		5
Gain (loss) on cash flow hedges, net of tax	0
Ending balance (in shares) at Sep. 30, 2023				118,903,435	58,586,695
Ending balance, Treasury Stock (in shares) at Sep. 30, 2023									689,974
Ending balance at Sep. 30, 2023	556,330			$ 1	$ 0	581,104	(174,164)	3,202	$ (7,797)	153,984
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	30,367						22,716			7,651
Stock-based compensation (in shares)				997,721
Stock-based compensation	23,855					23,855
Class A common stock withheld related to settlement of employee taxes for stock-based compensation awards (in shares)				(96,074)					(96,074)
Class A common stock withheld related to settlement of employee taxes for stock-based compensation awards	(1,663)								$ (1,663)
Effect of AES Grid Stability redemption of Class B-1 common stock for Class A common stock (in shares)				7,087,500	(7,087,500)
Effect of AES Grid Stability redemption of Class B-1 common stock for Class A common stock	0					21,428				(21,428)
Effect of remeasurement of non-controlling interest due to other share transactions (in shares)				354,134
Effect of remeasurement of non-controlling interest due to other share transactions	0					3,129				(3,129)
Proceeds from exercise of stock options (in shares)				2,175,081
Proceeds from exercise of stock options	5,335					5,335
Gain (loss) on foreign currency translation, net of tax	(598)							(411)		(187)
Actuarial gain (loss) on pension liabilities, net of tax	(211)							(151)		(60)
Gain (loss) on cash flow hedges, net of tax	(6,276)							(4,480)		(1,796)
Ending balance (in shares) at Sep. 30, 2024		129,421,797	51,499,195	129,421,797	51,499,195
Ending balance, Treasury Stock (in shares) at Sep. 30, 2024									786,048
Ending balance at Sep. 30, 2024	607,139			$ 1	$ 0	634,851	(151,448)	(1,840)	$ (9,460)	135,035
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(67,989)						(48,314)			(19,675)
Stock-based compensation (in shares)				920,873
Stock-based compensation	19,540					19,540
Class A common stock withheld related to settlement of employee taxes for stock-based compensation awards (in shares)				(64,158)					(64,158)
Class A common stock withheld related to settlement of employee taxes for stock-based compensation awards	(753)								$ (753)
Effect of remeasurement of non-controlling interest due to other share transactions	0					1,430				(1,430)
Proceeds from exercise of stock options (in shares)				885,853
Proceeds from exercise of stock options	2,170					2,170
Purchases of capped calls related to convertible senior notes	(29,000)					(29,000)
Cash Distribution to AES	(1,035)					(1,035)
Gain (loss) on foreign currency translation, net of tax	15,595							11,185		4,410
Actuarial gain (loss) on pension liabilities, net of tax	73							52		21
Gain (loss) on cash flow hedges, net of tax	3,108							2,216		892
Ending balance (in shares) at Sep. 30, 2025		131,164,365	51,499,195	131,164,365	51,499,195
Ending balance, Treasury Stock (in shares) at Sep. 30, 2025									850,206
Ending balance at Sep. 30, 2025	$ 548,848			$ 1	$ 0	$ 627,956	$ (199,762)	$ 11,613	$ (10,213)	$ 119,253

Convertible Senior Notes, Net (Tables)

12 Months Ended

Sep. 30, 2025

Debt Disclosure [Abstract]

Schedule of Net Carrying Value and Fair Value of the Convertible Senior Notes

The following table presents the net carrying value and fair value of the 2030 Convertible Senior Notes as of September 30, 2025:


In thousands	Principal Amount		Unamortized Debt Issuance Costs		Net Carrying Amount		Fair Value
							Amount		Leveling
2030 Convertible Senior Notes	$	400,000	$	(9,196)	$	390,804	$	348,540	Level 2

Schedule of Interest Expense

The following table presents the interest expense recognized related to the 2030 Convertible Senior Notes:


In thousands	Fiscal Year Ended September 30,
	2025		2024
Coupon interest	$	7,200	$	—
Amortization of debt issuance costs	1,426		—
Total	$	8,626	$	—

Audit Information	12 Months Ended
Audit Information	Sep. 30, 2025
Auditor Information [Abstract]
Auditor Firm ID	42
Auditor Name	Ernst & Young LLP
Auditor Location	Tysons, VA

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (67,989)	$ 30,367	$ (104,818)
Gain (loss) on foreign currency translation, net of tax	15,595	(598)	586
Gain (loss) on cash flow hedges, net of tax	3,108	(6,276)	0
Actuarial gain (loss) on pension liabilities, net of tax	73	(211)	15
Total other comprehensive income (loss)	18,776	(7,085)	601
Total comprehensive (loss) income	(49,213)	23,282	(104,217)
Comprehensive (loss) income attributable to non-controlling interest	(14,352)	5,608	(35,015)
Total comprehensive (loss) income attributable to Fluence Energy, Inc.	$ (34,861)	$ 17,674	$ (69,202)

- Definition

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

+ References + Details

- Definition

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income (loss) and other comprehensive income (loss), attributable to noncontrolling interests. Excludes changes in equity resulting from investments by owners and distributions to owners.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-SubTopic 10
-Topic 810
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481231/810-10-45-20

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(23))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(25))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(21))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481231/810-10-45-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1A

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1B

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(20))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4K
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481175/810-10-55-4K

+ Details

- Definition

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

+ References + Details

- Definition

Amount after tax and reclassification adjustments of other comprehensive income (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-6

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-17

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(19))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-4

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-5

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-20

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(21))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(23))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1B

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482739/220-10-55-15

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1A

+ Details

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478671/942-235-S50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-05(b)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477314/942-235-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(i))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-9

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 17
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480336/718-10-65-17

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-6

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-9

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476176/805-60-65-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-8

Reference 18: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 830
-Name Accounting Standards Codification
-Section 55
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479168/946-830-55-11

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 205
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478009/946-205-45-3

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479105/946-220-45-7

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(16))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(9))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(1)(d))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 19
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481231/810-10-45-19

Reference 25: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-6

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A

Reference 27: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(ii))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1B

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1B

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1B

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1B

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1B

Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483499/205-20-50-7

Reference 37: http://www.xbrl.org/2003/role/exampleRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 4J
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481175/810-10-55-4J

Reference 38: http://www.xbrl.org/2003/role/exampleRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 4K
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481175/810-10-55-4K

Reference 39: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1A

Reference 40: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1B

Reference 41: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-2

Reference 42: http://www.xbrl.org/2003/role/disclosureRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481203/810-10-50-1A

Reference 43: http://www.xbrl.org/2003/role/disclosureRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481203/810-10-50-1A

Reference 44: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (f)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481538/470-20-65-4

+ Details

Leases - Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
Leases - Lease Cost (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Leases [Abstract]
Finance lease cost:	$ 2,849	$ 0	$ 0
Amortization of right-of-use assets	2,757	0	0
Interest on lease liabilities	92	0	0
Operating lease cost	6,608	3,326	1,939
Short-term and variable lease cost	6,169	3,789	17,123
Sublease income	0	0	(194)
Total lease cost	$ 15,626	$ 7,115	$ 18,868

Other Current Assets (Tables)

12 Months Ended

Sep. 30, 2025

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Schedule of Other Current Assets

Other current assets consisted of the following amounts:


In thousands	September 30,
	2025		2024
Taxes recoverable	$	15,186	$	23,962
Prepaid expenses	21,667		10,370
Prepaid insurance	2,538		2,069
Current portion of recoverable warranty costs from suppliers	8,585		5,013
Other	6,695		5,105
Total	$	54,671	$	46,519

Leases - Assets and Liabilities Operating (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Right-of-use assets:
Operating leases	$ 11,256	$ 8,186
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other non-current assets	Other non-current assets
Finance leases	$ 22,057	$ 0
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property and equipment, net	Property and equipment, net
Total right-of-use assets	$ 33,313	$ 8,186
Lease liabilities:
Operating leases, current	$ 6,789	$ 3,064
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other current liabilities	Other current liabilities
Operating leases, noncurrent	$ 5,044	$ 5,492
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other non-current liabilities	Other non-current liabilities
Finance leases, current	$ 3,492	$ 0
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other current liabilities	Other current liabilities
Finance leases, noncurrent	$ 0	$ 0
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other non-current liabilities	Other non-current liabilities
Total lease liabilities	$ 15,325	$ 8,556

Related-Party Transactions - Narrative (Details) - USD ($)	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Related Party Transaction [Line Items]
Total revenue	$ 2,262,830,000	$ 2,698,562,000	$ 2,217,978,000
Provision for receivables from related parties	0	0
Related Party
Related Party Transaction [Line Items]
Total revenue	557,621,000	1,096,999,000	653,809,000
Consulting Services Revenue \| Related Party
Related Party Transaction [Line Items]
Total revenue	$ 7,700,000	$ 8,000,000.0	$ 12,300,000
AES Grid Stability \| Fluence Energy, Inc \| Class B-1 Common Stock
Related Party Transaction [Line Items]
Investment owned (in shares)	51,499,195
Siemens Industry \| Fluence Energy, Inc \| Class A Common Stock
Related Party Transaction [Line Items]
Investment owned (in shares)	51,499,195

Summary of Significant Accounting Policies and Estimates - Government Incentives and Grants (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Reduction to cost of goods and services	$ 6.1	$ 0.0

Leases - Supplemental Information Related to Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Leases [Abstract]
Cash paid for amounts included in the measurements of lease liabilities	$ 6,250	$ 3,003	$ 2,246
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 8,642	$ 6,536	$ 1,024
Weighted average remaining lease term	2 years 8 months 12 days	4 years	2 years
Weighted average discount rate	6.63%	6.96%	7.20%

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended
	Nov. 10, 2023	Oct. 31, 2023	Sep. 30, 2025	Sep. 30, 2024
Loss Contingencies [Line Items]
Advance payment			$ 126,778	$ 174,532
Other non-current assets			$ 146,391	$ 110,031
Fluence v.s. Diablo Energy Storage
Loss Contingencies [Line Items]
Damages sought, value	$ 25,000	$ 37,000
Estimated litigation liability	$ 230,000
Minimum
Loss Contingencies [Line Items]
Limited warranty, period			1 year
Maximum
Loss Contingencies [Line Items]
Limited warranty, period			5 years
Inventory Capacity Guarantee
Loss Contingencies [Line Items]
Advance payment			$ 53,300
Other non-current assets			$ 54,600

Derivatives and Hedging (Tables)

12 Months Ended

Sep. 30, 2025

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Cash Flow Hedging Instruments

The fair value of the Company’s cash flow hedges as well as their classification on the consolidated balance sheets as of September 30, 2025 and September 30, 2024 are as follows:


In thousands	September 30, 2025						September 30, 2024
In thousands	Notional Value		Other Current Assets		Other Current Liabilities		Notional Value		Other Current Assets		Other Current Liabilities
Foreign currency forward contracts	$	80,269	$	155	$	1,493	$	106,650	$	—	$	5,498

The gains or (losses) resulting from changes in fair value of the Company’s cash flow hedges recognized in accumulated other comprehensive (loss) income for the fiscal years ended September 30, 2025, 2024 and 2023 are as follows:


In thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Foreign currency forward contracts, net of tax	$	4,018	$	(7,394)	$	—

The amounts recognized within “Revenue” in the consolidated statements of operations with respect to the Company’s cash flow hedges for the fiscal years ended September 30, 2025, 2024 and 2023 are as follows:


In thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Foreign currency forward contracts	$	2,883	$	(8,544)	$	—

The following table details the changes in the cumulative impact of the gain (loss) on derivatives designated for hedge accounting for the fiscal year ended September 30, 2025 and 2024:


In thousands	September 30, 2025		September 30, 2024
Beginning balance	$	(6,276)	$	—
Gain (loss) recognized in accumulated other comprehensive income (loss)	4,018		(7,394)
(Gain) loss reclassified from accumulated other comprehensive income (loss) into earnings	(910)		1,118
Ending balance	$	(3,168)	$	(6,276)

Insider Trading Policies and Procedures	12 Months Ended
Insider Trading Policies and Procedures	Sep. 30, 2025
Insider Trading Policies and Procedures [Line Items]
Insider Trading Policies and Procedures Adopted	true

Debt - Revolving Credit Facility (Details)		12 Months Ended
Debt - Revolving Credit Facility (Details)	Aug. 06, 2024 USD ($)	Sep. 30, 2025 USD ($)	Apr. 08, 2024 USD ($)	Nov. 01, 2021 USD ($)
Line of Credit Facility [Line Items]
Letters of credit outstanding		$ 0
2024 Revolver \| Line of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 150,000,000
Outstanding borrowings		0
Letters of credit outstanding		194,400,000
Revolving Credit Facility \| The Revolver \| Line of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity				$ 200,000,000.0
Revolving Credit Facility \| Asset-Based Lending Facility
Line of Credit Facility [Line Items]
Outstanding borrowings		$ 0
Revolving Credit Facility \| Asset-Based Lending Facility \| Line of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity			$ 400,000,000
Revolving Credit Facility \| Asset-Based Lending Facility \| Line of Credit
Line of Credit Facility [Line Items]
Commitment fee percentage		0.45%
Commitment fee threshold percent		50.00%
Revolving Credit Facility \| Asset-Based Lending Facility \| Line of Credit \| Minimum
Line of Credit Facility [Line Items]
Commitment fee percentage		0.375%
Revolving Credit Facility \| Asset-Based Lending Facility \| Line of Credit \| Minimum \| Base Rate
Line of Credit Facility [Line Items]
Interest rate percentage		1.00%
Revolving Credit Facility \| Asset-Based Lending Facility \| Line of Credit \| Minimum \| Prime Rate
Line of Credit Facility [Line Items]
Interest rate percentage		1.00%
Revolving Credit Facility \| Asset-Based Lending Facility \| Line of Credit \| Minimum \| Adjust Term SOFR Rate, Adjusted EURIBOR Rate, Or Adjusted Term CORRA Rate
Line of Credit Facility [Line Items]
Interest rate percentage		2.00%
Revolving Credit Facility \| Asset-Based Lending Facility \| Line of Credit \| Maximum
Line of Credit Facility [Line Items]
Commitment fee percentage		0.45%
Revolving Credit Facility \| Asset-Based Lending Facility \| Line of Credit \| Maximum \| Base Rate
Line of Credit Facility [Line Items]
Interest rate percentage		1.50%
Revolving Credit Facility \| Asset-Based Lending Facility \| Line of Credit \| Maximum \| Prime Rate
Line of Credit Facility [Line Items]
Interest rate percentage		1.50%
Revolving Credit Facility \| Asset-Based Lending Facility \| Line of Credit \| Maximum \| Adjust Term SOFR Rate, Adjusted EURIBOR Rate, Or Adjusted Term CORRA Rate
Line of Credit Facility [Line Items]
Interest rate percentage		2.50%
Revolving Credit Facility \| 2024 Revolver \| Line of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 500,000,000
Leverage ratio	3.50
Revolving Credit Facility \| 2024 Revolver \| Line of Credit \| Base Rate
Line of Credit Facility [Line Items]
Interest rate percentage	2.00%
Revolving Credit Facility \| 2024 Revolver \| Line of Credit \| Adjust Term SOFR Rate, Adjusted EURIBOR Rate, Or Adjusted Term CORRA Rate
Line of Credit Facility [Line Items]
Interest rate percentage	3.00%
Revolving Credit Facility \| 2024 Revolver \| Line of Credit \| Daily Simple RFR
Line of Credit Facility [Line Items]
Interest rate percentage	3.00%
Revolving Credit Facility \| 2024 Revolver \| Line of Credit \| Minimum
Line of Credit Facility [Line Items]
Line cap additional threshold amount	$ 100,000,000
Revolving Credit Facility \| 2024 Revolver \| Line of Credit \| Maximum
Line of Credit Facility [Line Items]
Line cap additional threshold amount	150,000,000
Letter of Credit \| Asset-Based Lending Facility \| Line of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 200,000,000
Letter of Credit \| 2024 Revolver \| Line of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 500,000,000
Letter of credit participation fee percentage	0.50%
Letter of Credit Issued \| 2024 Revolver \| Line of Credit
Line of Credit Facility [Line Items]
Long term debt		$ 305,600,000

Revenue from Contracts with Customers (Tables)

12 Months Ended

Sep. 30, 2025

Revenue from Contract with Customer [Abstract]

Schedule of Disaggregation of Revenue

The following table presents the Company’s revenue disaggregated by revenue type:


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Revenue from sale of energy storage products and solutions	$	2,172,360	$	2,648,013	$	2,197,633
Revenue from services	84,439		45,353		15,992
Revenue from digital applications	6,031		5,196		4,353

Total	$	2,262,830	$	2,698,562	$	2,217,978

Schedule of Revenue by Geographical Regions

The following table presents the Company’s revenue disaggregated by geographical region. Revenues are attributed to regions based on location of customers:


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Americas (North, Central and South America)(a)	$	1,305,941	$	1,593,003	$	1,645,107
APAC (Asia Pacific)	348,573		579,255		266,077
EMEA (Europe, Middle-East and Africa)	608,316		526,304		306,794
Total	$	2,262,830	$	2,698,562	$	2,217,978

(a) Revenue from United States of America was $877.3 million, $1,442.0 million and $1,495.0 million for fiscal years 2025, 2024 and 2023, respectively.

Schedule of Deferred Revenue

The following tables provides information about deferred revenue from contracts with customers:


in thousands	September 30,
	2025		2024		2023
Deferred revenue beginning of period	$	274,499	$	273,164	$	273,073
Additions	587,933		224,423		273,164
Revenue recognized related to amounts that were included in beginning balance of deferred revenue	(221,975)		(223,088)		(273,073)
Deferred revenue end of period	$	640,457	$	274,499	$	273,164


in thousands	September 30,
	2025		2024		2023
Deferred revenue from related parties beginning of period	$	38,162	$	110,274	$	300,697
Additions	71,710		37,382		98,891
Revenue recognized related to amounts that were included in beginning balance of deferred revenue	(29,956)		(109,494)		(289,314)
Deferred revenue from related parties end of period	$	79,916	$	38,162	$	110,274

Derivatives and Hedging

12 Months Ended

Sep. 30, 2025

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivatives and Hedging

Certain of the Company’s foreign operations expose the Company to fluctuations of foreign exchange rates. These fluctuations may impact the value of the Company’s cash receipts and payments in terms of the functional currency of the transacting party. The Company’s primary exposure results from the foreign currency impact of intercompany sales of inventory to regional entities by the Company’s centralized procurement entity. These intercompany sales are denominated in the functional currency of the regional entities, primarily the Euro, the British Pound and the Australian dollar, while the functional currency of the centralized procurement entity is the U.S. dollar. This introduces foreign exchange risk on the revenues recorded for such intercompany sales. The Company enters into foreign currency forward contracts to manage its exposure to fluctuations in foreign exchange rates. These contracts are entered into with large, reputable financial institutions that are monitored for counterparty credit risks.

For the Company’s foreign currency forward contracts that are designated and qualify as cash flow hedges, the gains or losses on the effective portion of such hedges are recorded in accumulated other comprehensive income and subsequently reclassified in the period during which the hedged transaction affects earnings within revenue in the consolidated statements of operations (i.e., when control of the inventory is passed to third-party customers and revenue is recognized). The change in fair value of the components excluded from the assessment of effectiveness, including changes in the spot-forward differential and counterparty non-performance risk, will also be recognized within revenue in the consolidated statements of operations.

The Company currently also has foreign currency forward contracts that are not designated as hedges and the changes in fair value of such derivatives are recognized in current period earnings. As of September 30, 2025, the impact on our consolidated financial statements was not significant.

Cash Flow Hedges

The fair value of the Company’s cash flow hedges as well as their classification on the consolidated balance sheets as of September 30, 2025 and September 30, 2024 are as follows:


In thousands	September 30, 2025						September 30, 2024
In thousands	Notional Value		Other Current Assets		Other Current Liabilities		Notional Value		Other Current Assets		Other Current Liabilities
Foreign currency forward contracts	$	80,269	$	155	$	1,493	$	106,650	$	—	$	5,498


In thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Foreign currency forward contracts, net of tax	$	4,018	$	(7,394)	$	—


In thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Foreign currency forward contracts	$	2,883	$	(8,544)	$	—

The following table details the changes in the cumulative impact of the gain (loss) on derivatives designated for hedge accounting for the fiscal year ended September 30, 2025 and 2024:


In thousands	September 30, 2025		September 30, 2024
Beginning balance	$	(6,276)	$	—
Gain (loss) recognized in accumulated other comprehensive income (loss)	4,018		(7,394)
(Gain) loss reclassified from accumulated other comprehensive income (loss) into earnings	(910)		1,118
Ending balance	$	(3,168)	$	(6,276)

- Definition

The entire disclosure for derivative instruments and hedging activities including, but not limited to, risk management strategies, non-hedging derivative instruments, assets, liabilities, revenue and expenses, and methodologies and assumptions used in determining the amounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 182
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-182

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 185
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-185

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 184
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-184

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 181
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-181

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (a)(5)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4H
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4H

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4H
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4H

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 15
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480960/815-15-50-3

Reference 13: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 183
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-183

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (a)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4I
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4I

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4F
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4F

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-2

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-2

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-2

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-2

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-2

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/815/tableOfContent

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-5

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5C
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-5C

+ Details

Stock-Based Compensation - Restricted Stock Units and Performance Share Units (Details)	12 Months Ended
	Sep. 30, 2025 $ / shares shares
Outstanding restricted stock units (“RSUs”)
Number of Options
Outstanding, beginning balance (in shares) \| shares	1,760,418
Granted (in shares) \| shares	1,830,935
Vested (in shares) \| shares	(920,873)
Forfeited (in shares) \| shares	(438,160)
Outstanding, ending balance (in shares) \| shares	2,232,320
Weighted Average Grant Date Fair Values
Outstanding, beginning balance (in usd per share) \| $ / shares	$ 20.57
Granted (in usd per share) \| $ / shares	14.75
Vested (in usd per share) \| $ / shares	20.45
Forfeited (in usd per share) \| $ / shares	17.67
Outstanding, ending balance (in usd per share) \| $ / shares	$ 16.41
Outstanding performance share units (“PSUs”)
Number of Options
Outstanding, beginning balance (in shares) \| shares	391,032
Granted (in shares) \| shares	690,147
Vested (in shares) \| shares	0
Forfeited (in shares) \| shares	(179,663)
Outstanding, ending balance (in shares) \| shares	901,516
Weighted Average Grant Date Fair Values
Outstanding, beginning balance (in usd per share) \| $ / shares	$ 21.61
Granted (in usd per share) \| $ / shares	15.69
Vested (in usd per share) \| $ / shares	0
Forfeited (in usd per share) \| $ / shares	18.17
Outstanding, ending balance (in usd per share) \| $ / shares	$ 17.77

Income Taxes - Effective Income Tax Rate (Details)	12 Months Ended
Income Taxes - Effective Income Tax Rate (Details)	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Statutory rate	21.00%	21.00%	21.00%
State taxes	2.90%	(1.90%)	3.10%
Rate change	(34.20%)	52.60%	(15.50%)
Flow-through losses	(15.20%)	3.30%	(9.30%)
Foreign rate differential	(13.00%)	14.30%	2.20%
Withholding taxes	(4.70%)	0.70%	(0.70%)
Valuation allowance	1.40%	(118.60%)	(12.90%)
Permanent differences	(13.10%)	(12.20%)	7.80%
U.S. tax on foreign earnings	2.00%	50.60%	0.00%
Return to provision adjustments	3.70%	14.20%	(1.00%)
Other items, net	(1.60%)	(0.70%)	0.80%
Effective tax rate	(50.80%)	23.30%	(4.50%)

Summary of Significant Accounting Policies and Estimates

12 Months Ended

Sep. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Significant Accounting Policies and Estimates

Principles of Accounting and Consolidation

The accompanying consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles (U.S. GAAP) and under the rules of the U.S. Securities and Exchange Commission (the “SEC”). The accompanying consolidated financial statements include the accounts of Fluence Energy, Inc. and its subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

Non-Controlling Interest


	September 30,
	2025		2024
Controlling Interest Ownership	71.81	%	71.53	%
Non-Controlling Interest Ownership (AES)	28.19	%	28.47	%

Use of Estimates

Cash, Cash Equivalents, and Restricted Cash

Cash and cash equivalents include cash on-hand and highly liquid investments readily convertible to cash, with an original maturity of 90 days or less when purchased.

The following table provides a reconciliation of cash, cash equivalents, and restricted cash at the end of each respective period as shown in the Company’s consolidated balance sheets.


	September 30,
in thousands	2025		2024
Cash and cash equivalents	$	690,768	$	448,685
Restricted cash	23,862		46,089
Restricted cash included in “Other non-current assets”	—		23,932
Total cash, cash equivalents and restricted cash shown in the statements of cash flows	$	714,630	$	518,706

Restricted cash consisted of the following:


	September 30,
in thousands	2025		2024
Collateral for credit card program	$	6,112	$	2,757
Collateral for outstanding bank guarantees	7,309		31,360
Collateral for surety program	10,370		9,551
Term deposits	71		2,421
Collateral for surety program included in “Other non-current assets”	—		23,932
Total restricted cash	$	23,862	$	70,021

Receivables

Foreign Currency Transactions

Revenue and Cost Recognition

Revenue is recorded net of any taxes assessed on and collected from customers, which are remitted to the governmental authorities.

Customer payments are due upon meeting certain milestones as defined in the contract, which are generally consistent with contract-specific phases of a project.

Pre-contract costs with no future benefit are expensed in the period in which they are incurred. Generally, pre-contract costs are not material.

Inventory, Net

potential obsolescence and write down of its inventory, as appropriate, to net realizable value based on its assessment of usefulness and marketability conditions.

Software Development Costs

As of September 30, 2025, 2024 and 2023, the Company capitalized $8.8 million, $8.9 million, and $6.4 million respectively, of internal-use software.

As of September 30, 2025, 2024 and 2023, the Company capitalized $12.7 million, $37.4 million and $0.0 million respectively, of software development costs related to hosting arrangements.

As of September 30, 2025, 2024 and 2023, the Company capitalized $5.5 million, $2.3 million and $3.3 million, respectively, of external-use software to be sold.

Impairment of Long-Lived Assets

Intangible Assets

Operating Expenses

Advertising Costs

Advertising costs are expensed as incurred. Advertising expenses were $4.3 million, $3.3 million, and $1.4 million for the fiscal years ended September 30, 2025, 2024 and 2023, respectively.

Income Taxes

Government Incentives and Grants

Fair Value Measurements

Derivatives and Hedging

Convertible Senior Notes, Net

In December 2024, the Company issued $400.0 million aggregate principal amount of 2.25% convertible senior notes due 2030 (the “2030 Convertible Senior Notes”). The Company accounts for its 2030 Convertible Senior Notes as a liability in their entirety, measured at amortized cost. Debt issuance costs incurred in connection with the issuance of the Company’s 2030 Convertible Senior Notes are reflected in the condensed consolidated balance sheets as a direct deduction from the carrying amount of the outstanding 2030 Convertible Senior Notes. These costs are amortized using the effective interest rate method over the terms of the 2030 Convertible Senior Notes and are included within interest expense on the condensed consolidated statements of operations.

In connection with the issuance of the 2030 Convertible Senior Notes, the Company entered into privately negotiated capped call transactions with certain counterparties. The capped call transactions are generally expected to offset the potential dilution to the Company’s Class A common stock upon any conversion of the 2030 Convertible Senior Notes and/or offset any cash payments the Company is required to make in excess of the principal amount of converted notes, with such reduction and/or offset subject to a cap. Refer to “Note 13 – Convertible Senior Notes, Net” for further details.

Recent Accounting Standards Adopted

The following table presents accounting standards adopted in 2025:


Standard	Description	Date of adoption	Effect on the financial statements and other significant matters
Accounting Standards Update (“ASU”) No. 2024-04: Debt—Debt with Conversion and Other Options (Subtopic 470-20): Induced Conversions of Convertible Debt Instruments	ASU 2024-04 clarifies the requirements for determining whether certain settlements of convertible debt instruments should be accounted for as an induced conversion.	As of the three months ended December 31, 2024.	The new standard was early adopted by the Company and applied for the Company’s 2030 Convertible Senior Notes. Refer to “Note 13 – Convertible Senior Notes, Net” for further details. The new standard did not have an impact on the condensed consolidated financial statements.
ASU No. 2023-07: Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures	ASU 2023-07 requires disclosure of incremental segment information on an annual and interim basis for all public entities to enable investors to develop more decision-useful financial analyses. The update requires other specified segment items and amounts, such as depreciation, amortization, and depletion expense, to be disclosed under certain circumstances. The amendments in this update do not change or remove those disclosure requirements. The amendments in this update also do not change how a public entity identifies its operating segments, aggregates those operating segments, or applies the quantitative thresholds to determine its reportable segments.	As of the three months ended September 30, 2025.	The Company only has one reportable segment. The Company adopted this standard in the fourth quarter of 2025, which did not have a material impact on the consolidated financial statements and related disclosures. Refer to “Note 1 – Organization and Operations” for further details.

Recent Accounting Standards Not Yet Adopted

The following table presents accounting standards not yet adopted:


Standard	Description	Required date of adoption	Effect on the financial statements and other significant matters
ASU No. 2023-09: Income Taxes (Topic 740): Improvements to Income Tax Disclosures	ASU 2023-09 adopts certain amendments to improve the effectiveness of income tax disclosures, including jurisdictional information, by requiring (1) consistent categories and greater disaggregation of information in the rate reconciliation, and (2) income taxes paid, disaggregated by jurisdiction.	ASU 2023-09 is effective for the Company’s annual report for fiscal year ending September 30, 2026.	The Company is evaluating the impact this guidance will have on income tax disclosures.
SEC Final Rule Release Nos. 33-11275; 34-99678: The Enhancement and Standardization of Climate-Related Disclosures for Investors	SEC Final Rule Release Nos. 33-11275; 34-99678 requires registrants to provide certain climate-related information in their registration statements and annual reports, including climate-related risks that have materially impacted, or are reasonably likely to have a material impact on, its business strategy, results of operations, or financial condition. In addition, certain disclosures related to severe weather events and other natural conditions will be required in registrants’ annual reports.	SEC Final Rule Release Nos. 33-11275; 34-99678 is effective for the Company’s annual report for fiscal year ending September 30, 2026.	The Company is evaluating the impact this guidance will have on climate-related disclosures.
ASU No. 2024-03: Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses	ASU 2024-03 requires disclosure of qualitative and quantitative information about certain costs and expenses in the notes to the financial statements on an interim and annual basis. ASU No. 2025-01: Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date, was subsequently issued and clarified the effective date of ASU 2024-03.	ASU 2024-03 is effective for the Company’s annual report for fiscal year ending September 30, 2028.	The Company is evaluating the impact this guidance will have on its disclosures.
ASU No. 2025-05: Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets	ASU 2025-05 amends ASC 326-20 to provide a practical expedient (for all entities) and an accounting policy election (for all entities, other than public business entities, that elect the practical expedient) related to the estimation of expected credit losses for current accounts receivable and current contract assets that arise from transactions accounted for under ASC 606.	ASU 2025-05 is effective for the Company’s annual report for fiscal year ending September 30, 2027.	The Company is evaluating the impact this guidance will have on its disclosures.
ASU No. 2025-06: Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software	ASU 2025-06 makes targeted improvements to ASC 350-40 and amends certain aspects of the accounting for and disclosure of software costs under ASC 350-40. The amendments supersede the guidance on Web site development costs in ASC 350-50 and relocate that guidance, along with the recognition requirements for development costs specific to Web sites, to ASC 350-40.	ASU 2025-06 is effective for the Company’s annual report for fiscal year ending September 30, 2029.	The Company is evaluating the impact this guidance will have on its disclosures.

Goodwill - Goodwill Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Goodwill [Roll Forward]
Goodwill, Beginning of the period	$ 27,482	$ 26,020
Foreign currency adjustment	1,102	1,462
Goodwill, End of the period	$ 28,584	$ 27,482

- Definition

Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482548/350-20-55-24

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-8

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 41
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-41

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 740
-Name Accounting Standards Codification
-Section 55
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478064/805-740-55-13

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 39
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-39

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 49
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-49

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 100
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-100

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 852
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481372/852-10-55-10

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(15))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482598/350-20-45-1

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(10)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 14: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-4

+ Details

Intangible Assets, Net - Future Amortization Expense (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Finite-Lived Intangible Assets [Line Items]
2026	$ 12,167
2027	10,448
2028	8,257
2029	6,730
2030	5,538
Thereafter	12,222
Net	63,403	$ 60,002
Subtotal
Finite-Lived Intangible Assets [Line Items]
Net	55,362
Internally developed software projects in process
Finite-Lived Intangible Assets [Line Items]
Net	$ 8,041

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Sep. 30, 2025
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accounting Policies and Estimates - Cash Restrictions (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Cash and Cash Equivalents [Line Items]
Restricted cash	$ 23,862	$ 46,089
Collateral for surety program included in “Other non-current assets”	0	23,932
Total restricted cash	23,862	70,021
Collateral for credit card program
Cash and Cash Equivalents [Line Items]
Restricted cash	6,112	2,757
Collateral for outstanding bank guarantees
Cash and Cash Equivalents [Line Items]
Restricted cash	7,309	31,360
Collateral for surety program
Cash and Cash Equivalents [Line Items]
Restricted cash	10,370	9,551
Collateral for surety program included in “Other non-current assets”	0	23,932
Term deposits
Cash and Cash Equivalents [Line Items]
Restricted cash	$ 71	$ 2,421

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Total revenue	$ 2,262,830	$ 2,698,562	$ 2,217,978
Cost of goods and services	1,967,045	2,357,482	2,077,023
Gross profit	295,785	341,080	140,955
Operating expenses:
Research and development	86,217	66,195	66,307
Sales and marketing	79,489	63,842	41,114
General and administrative	163,068	172,996	136,308
Depreciation and amortization	13,348	11,426	9,835
Interest expense (income), net	4,110	(5,676)	(5,388)
Other income, net	(5,375)	(7,276)	(6,952)
(Loss) income before income taxes	(45,072)	39,573	(100,269)
Income tax expense	22,917	9,206	4,549
Net (loss) income	(67,989)	30,367	(104,818)
Net (loss) income attributable to non-controlling interest	(19,675)	7,651	(35,198)
Net (loss) income attributable to Fluence Energy, Inc.	$ (48,314)	$ 22,716	$ (69,620)
Weighted average number of Class A common shares outstanding
Basic (in shares)	130,307,162	126,180,011	116,448,602
Diluted (in shares)	130,307,162	184,034,832	116,448,602
(Loss) income per share of Class A common stock
Basic (in usd per share)	$ (0.37)	$ 0.18	$ (0.60)
Diluted (in usd per share)	$ (0.37)	$ 0.13	$ (0.60)
Nonrelated Party
Total revenue	$ 1,705,209	$ 1,601,563	$ 1,564,169
Related Party
Total revenue	557,621	1,096,999	653,809
Cost of goods and services	80,482	50,653	15,925
Operating expenses:
Research and development	31	192	912
Sales and marketing	0	123	135
General and administrative	$ 2,061	$ 6,113	$ 5,215

Commitments and Contingencies

12 Months Ended

Sep. 30, 2025

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Guarantees, Commitments, Letters of Credit, and Surety Bonds

As of September 30, 2025, the Company had outstanding bank guarantees, parent company guarantees, letters of credit, and surety bonds issued as performance security arrangements associated with a number of our customer projects. In addition, we have a limited number of parent company guarantees issued as payment security to certain vendors. These contractual commitments are all accounted for off-balance sheet. In the event that we fail to perform under a project backstopped by such credit support, the customer or vendor, respectively, may demand performance and/or payment, as applicable, pursuant to the terms of the project contract or vendor contract and applicable credit support instrument from the Company, surety, or bank, as the case may be. Our relationship with our sureties is such that we will indemnify the sureties for any damages and expenses they incur in connection with any of the bonds they issue on our behalf and we may be required to post collateral to support the bonds. With respect to letters of credit, in the event of non-performance under a contract, direct obligations to repay the banks may arise. The Company expects that its performance and payment obligations secured by these bank guarantees, parent company guarantees, letters of credit, and surety bonds will generally be completed in the ordinary course of business and in accordance with the applicable contractual terms.


Contractual Obligations	Amount (in $ millions)		Number of Agreements	Maximum Exposure Range for Each Agreement (in $ millions)
Guarantees and commitments	$	4,930	91	0 - 417
Letters of credit under bilateral credit facilities	5		3	0 - 3
Letters of credit under 2024 Revolver	194		35	0 - 56
Surety bonds	715		67	0 - 79
Total	$	5,844	196

Purchase Commitments

The Company has commitments for minimum volumes or spend under master supply agreements with our vendors. The majority of the commitments are for purchases of battery cells and modules. Liquidated damages apply if the minimum purchase volumes or spend are not met. The Company currently expects to meet the minimum committed volumes of purchases and spend. The following table presents our future minimum purchase commitments by fiscal year, primarily for battery cells and modules, and liquidated damages, if the minimum purchase volumes or spend are not met, as of September 30, 2025.


in thousands	Purchase Commitments		Liquidated Damages
2026	$	205,821	$	7,358
2027	254,120		8,100
2028	254,120		8,100

2029	244,120		8,100
2030 and thereafter	237,000		8,100
Total	$	1,195,181	$	39,758

The Company makes advance payments as capacity guarantees pursuant to purchase agreements with our suppliers. As of September 30, 2025, $53.3 million is recorded within “Advances to suppliers” and $54.6 million is recorded within “Other non-current assets” on the consolidated balance sheets.

Product Performance Guarantees

Typical energy storage products and solutions contracts and long-term service agreements contain provisions for performance liquidated damages payments if the energy storage solution fails to meet the guaranteed performance thresholds at completion of the project or throughout the service agreement period.

Warranties

The Company provides both assurance and service-type warranties to its customers. The Company recognizes revenue for service-type warranties, which are referred to as extended warranties, using a straight-line approach over the service period.

The Company provides assurance-type warranties, apart from the service-type warranties described above, related to the successful operation of battery-based energy storage solutions which typically extend from one to five years, beginning at the commercial operation date or substantial completion date, depending on the contract terms. The warranties are considered assurance-type warranties which provide a guarantee of quality of the products. The Company records an estimate of future warranty cost over the period of construction, consistent with transfer of control and revenue recognition. Additionally, we accrue estimated liability cost of specific reserves or recalls when they are probable and estimable if identified. Warranty expense is recorded as a component of “Cost of goods and services” in the Company’s consolidated statements of operations.

The Company’s assurance-type warranties are often backed by supplier covered warranties for major original equipment manufacturers (OEMs) such as batteries and inverters, which is included in our estimated warranty liability. For warranty obligations covered by supplier warranties, the Company records a corresponding asset for the contractually recoverable amounts due to the fact that the contracts are enforceable, the suppliers are financially viable, and we have a history of satisfying claims with our suppliers. The asset is recorded within “Other current assets” and “Other non-current assets” on the consolidated balance sheets.

As of September 30, 2025 and 2024, the Company accrued the below estimated warranty liabilities:


In thousands	September 30,
	2025		2024
Warranty balance, beginning	$	40,242	$	26,909
Warranties issued and assumed in period	22,409		19,554
Change in estimates	3,173		(1,692)
Net changes in liability for warranty expirations, costs incurred, and foreign exchange impact	(14,017)		(4,529)
Warranty balance, ending	$	51,807	$	40,242
Less: Recoverable warranty costs from suppliers	23,578		12,704
Warranty balance, net of recoverable warranty costs from suppliers, at end of period	$	28,229	$	27,538

The key inputs and assumptions used to estimate our warranty liability are: (1) the expected failure rate, representing the number of units projected to fail or require repair; and (2) the per unit cost to repair or replace, including shipping, labor, and equipment costs.

The assurance warranty liability and related warranty asset are reviewed quarterly and may be adjusted based on actual results, performance trends, or other qualitative factors. These estimates are subject to uncertainty, and differences between the actual failure rates or replacement costs and our assumptions may result in material changes.

Legal Contingencies

From time to time, the Company may be involved in litigation, government investigations, and other regulatory or legal proceedings relating to claims that arise out of our operations and businesses and that cover a wide range of matters, including, but not limited to, securities litigation, intellectual property matters, commercial and contract disputes, insurance and property damage claims, labor and employment claims, torts and personal injury claims, product liability claims, environmental claims, fire safety claims, and warranty claims. The Company accrues for litigation and claims when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. It is reasonably possible that some matters could have an unfavorable result to the Company and could require the Company to pay damages or make expenditures in amounts that could be material.

2021 Overheating Event at Customer Facility

On September 4, 2021, a 300 MW energy storage facility owned by one of our customers experienced an overheating event. Fluence served as the energy storage technology provider and designed and installed portions of the facility, which was completed in the fiscal year ended September 30, 2021. No injuries were reported from the incident. The facility was taken offline as teams from Fluence, our customer, and the battery designer/manufacturer investigated the incident. Our customer released initial findings in the second fiscal quarter of 2022 on what it contends is the root cause of the incident. The customer’s stated findings, if ultimately confirmed and proven, could relate to certain scopes of work for which Fluence or its subcontractors could be responsible. The customer’s stated findings, however, could also relate to certain scopes of work for which other parties were responsible and/or relate to other causes, including the design and installation of portions of the facility over which Fluence did not have responsibility or control. The customer has alleged that Fluence is liable for the incident. At this time, Fluence cannot accept the customer’s stated findings and has denied liability. No formal legal proceedings have been commenced, but it is reasonably possible that litigation may result from this matter if a resolution cannot be achieved. Any such dispute would also likely include claims by Fluence and counterclaims by the customer relating to disputed costs arising from the original design and construction of the facility. The customer announced in July of 2022 that a large portion of the facility was back online. We are currently not able to estimate the impact that this incident may have on our financial results. To date, we do not believe that this incident has impacted the market’s adoption of our products and solutions.

2023 Project-Related Litigation

In October 2023, Fluence filed a complaint in the Superior Court of California, Contra Costa County, against Diablo Energy Storage, LLC, Empire Business Park, LLC, the Bank of New York Mellon and others, seeking approximately $37.0 million in damages arising from the supply and construction of an energy storage facility for the defendants, including for the defendants’ nonpayment of contractual amounts owed. On or about November 10, 2023, Defendant Diablo Energy Storage, LLC filed a cross-complaint against Fluence, seeking a minimum of $25.0 million of alleged damages and disgorgement of all compensation received by Fluence for the project, in the amount of approximately $230.0 million. The disgorgement claim was based upon an alleged deficiency in Fluence’s contractor license. Fluence denies the allegations in the cross-complaint and intends to vigorously defend against them and to enforce our claims against the defendants. We are currently not able to estimate the impact, if any, that this litigation may have on our reputation or financial results, or on market adoption of our products and solutions.

SEC Investigation

On February 22, 2024, as previously disclosed, a short-seller report was published about the Company (the “Short Seller Report”). In response to the Short Seller Report, the Audit Committee of the Company’s Board of Directors completed an internal investigation, with the assistance of outside counsel and forensic accountants, into the allegations in the Short Seller Report. The Company has been informed that the SEC is conducting a formal investigation and asking for certain information regarding our financial reporting. The Company is fully cooperating with the SEC’s investigation. While we are unable to predict the likely outcome of this matter or the potential cost, exposure or duration of the process, based on the information we currently possess, we do not expect the total potential cost to be material to our financial condition.

Securities Class Actions

On March 11, 2025, a putative federal securities class action complaint captioned Abramov v. Fluence Energy, Inc. et al. (Case No. 1:25-cv-00444) was filed in the United States District Court, Eastern District of Virginia, against the Company and certain of the Company’s executive officers. On April 15, 2025, a putative federal securities class action complaint captioned Kramer v. Fluence Energy, Inc. et al. (Case No. 1:25-cv-00634) was filed in the United States District Court, Eastern District of Virginia, against the Company, certain of the Company’s current and former executive officers, AES Grid Stability, and AES. Both actions purported to be brought on behalf of a purported class of stockholders, and asserted violations of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and Rule 10b-5 promulgated thereunder. The complaints sought unspecified damages and other relief. On May 30, 2025, the United States District Court, Eastern District of Virginia ordered the consolidation of the Abramov and Kramer cases, captioned the consolidated matter In re Fluence Energy, Inc. Securities Litigation (Case No. 1:25-cv-00444-PTG-IDD) and appointed a lead plaintiff and lead counsel. The court-appointed lead plaintiff subsequently filed a consolidated complaint that asserts claims under Sections 10(b) and 20(a) of the Exchange Act, and Rule 10b-5 promulgated thereunder against the Company, AES Grid Stability, AES, and certain of the Company’s former and current executive officers. The consolidated complaint seeks unspecified damages and other relief. The defendants moved to dismiss the consolidated complaint on July 11, 2025. The Company does not believe the consolidated complaint states any meritorious claim and intends to defend this case vigorously.

Shareholder Derivative Actions

On March 25, 2025, a purported stockholder, Raffi Elmajian, filed a shareholder derivative complaint captioned Elmajian v. Nebreda et al. in the United States District Court, Eastern District of Virginia (Case No. 1:25-cv-521) against current and former officers and directors of the Company, naming the Company as a nominal defendant. On April 3, 2025, a purported stockholder, Diaa Al Amad, filed a second shareholder derivative complaint captioned Al Amad v. Nebreda et al. in the United States District Court, Eastern District of Virginia (Case No. 1:25-cv-577) against current and former officers and directors of the Company, naming the Company as a nominal defendant. Both derivative complaints allege claims under Section 14(a) of the Exchange Act and Rule 14-9 promulgated thereunder, and breaches of fiduciary duties, among other claims. The actions purport to be brought derivatively on behalf of the Company and seek damages and other various relief. On April 22, 2025, the United States District Court, Eastern District of Virginia ordered the consolidation of the Elmajian and Al Amad cases, captioned In re Fluence Energy, Inc. Shareholder Derivative Litigation (Case No.: 1:25-cv-00521). On July 21, 2025, the United States District Court, Eastern District of Virginia ordered a stay on all proceedings and deadlines in the consolidated derivative matter until resolution of the consolidated securities class action detailed above. The Company believes the claims in the complaints are without merit and intends to defend the matter vigorously.

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Operating activities
Net (loss) income	$ (67,989)	$ 30,367	$ (104,818)
Adjustments to reconcile net (loss) income to net cash (used in) provided by operating activities:
Depreciation and amortization	29,343	14,482	10,665
Amortization of debt issuance costs	4,217	3,091	914
Inventory provision (recovery)	6,959	23,972	(1,029)
Stock-based compensation	19,540	23,855	26,920
Deferred income taxes	6,351	(6,719)	2,542
Changes in operating assets and liabilities:
Trade receivables	(56,715)	(114,577)	(13,397)
Unbilled receivables	(68,045)	24,747	(50,503)
Receivables from related parties	161,780	(303,963)	53,611
Advances to suppliers	49,113	(64,258)	(36,490)
Inventory	(278,729)	21,731	432,767
Other current assets	20,413	(10,986)	(36,828)
Other non-current assets	(86,819)	(28,100)	(16,632)
Accounts payable	(119,228)	370,124	(242,268)
Current accruals and provisions	(93,586)	160,206	(12,360)
Taxes payable	(27,891)	22,799	15,753
Other current liabilities	(58,305)	18,185	39,467
Other non-current liabilities	10,425	(23,274)	18,124
Net cash (used in) provided by operating activities	(145,538)	79,685	(111,927)
Investing activities
Proceeds from maturities of short-term investments	0	0	111,674
Payments for purchase of investment in joint venture	0	0	(5,013)
Capital expenditures on software	(14,915)	(10,860)	(9,235)
Purchase of property and equipment	(14,884)	(8,115)	(2,989)
Net cash (used in) provided by investing activities	(29,799)	(18,975)	94,437
Financing activities
Proceeds from borrowing against note receivable - pledged as collateral	0	0	48,176
Class A common stock withheld related to settlement of employee taxes for stock-based compensation awards	(753)	(1,663)	(2,784)
Proceeds from issuance of 2030 Convertible Senior Notes	400,000	0	0
Purchases of Capped Calls related to 2030 Convertible Senior Notes	(29,000)	0	0
Proceeds from exercise of stock options	2,170	5,335	7,203
Distribution to AES Grid Stability	(1,035)	0	0
Principal payments on finance leases	(2,370)	0	0
Payments of debt issuance costs	(12,132)	(8,456)	0
Payments for acquisitions	0	(3,892)	0
Net cash provided by (used in) financing activities	356,880	(8,676)	52,595
Effect of exchange rate changes on cash and cash equivalents	14,381	3,941	(2,095)
Net increase in cash and cash equivalents	195,924	55,975	33,010
Cash, cash equivalents, and restricted cash as of the beginning of the period	518,706	462,731	429,721
Cash, cash equivalents, and restricted cash as of the end of the period	714,630	518,706	462,731
Supplemental disclosure of cash flow information
Interest paid	9,296	3,022	2,336
Cash paid for income taxes	19,043	2,661	1,240
Related Party
Changes in operating assets and liabilities:
Deferred revenue	41,725	(72,201)	(191,431)
Nonrelated Party
Changes in operating assets and liabilities:
Deferred revenue	$ 361,903	$ (9,796)	$ (6,934)

Commitments and Contingencies - Warranty Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Warranty balance, beginning	$ 40,242	$ 26,909
Warranties issued and assumed in period	22,409	19,554
Change in estimates	3,173	(1,692)
Net changes in liability for warranty expirations, costs incurred, and foreign exchange impact	(14,017)	(4,529)
Warranty balance, ending	51,807	40,242
Less: Recoverable warranty costs from suppliers	23,578	12,704
Warranty balance, net of recoverable warranty costs from suppliers, at end of period	$ 28,229	$ 27,538

Convertible Senior Notes, Net

12 Months Ended

Sep. 30, 2025

Debt Disclosure [Abstract]

Convertible Senior Notes, Net

Debt

Revolving Credit Facility

Asset-Based Lending Facility

2024 Revolver

Borrowings Against Note Receivable - Pledged as Collateral

Convertible Senior Notes, Net

2030 Convertible Senior Notes

(3) upon the occurrence of specified corporate events, as set forth in the Indenture; or

(4) if the Company calls any or all the 2030 Convertible Senior Notes for redemption, but only with respect to such 2030 Convertible Senior Notes called for redemption.

On or after March 15, 2030, holders may convert their 2030 Convertible Senior Notes at any time until the close of business on the second scheduled trading day immediately before June 15, 2030.

The following table presents the net carrying value and fair value of the 2030 Convertible Senior Notes as of September 30, 2025:


In thousands	Principal Amount		Unamortized Debt Issuance Costs		Net Carrying Amount		Fair Value
							Amount		Leveling
2030 Convertible Senior Notes	$	400,000	$	(9,196)	$	390,804	$	348,540	Level 2

The following table presents the interest expense recognized related to the 2030 Convertible Senior Notes:


In thousands	Fiscal Year Ended September 30,
	2025		2024
Coupon interest	$	7,200	$	—
Amortization of debt issuance costs	1,426		—
Total	$	8,626	$	—

Capped Call Transactions

- Definition

+ References

+ Details

Stock-Based Compensation - Narrative (Details)	1 Months Ended	12 Months Ended
Stock-Based Compensation - Narrative (Details)	Apr. 30, 2022 shares	Sep. 30, 2025 USD ($) metric $ / shares shares	Sep. 30, 2024 USD ($) $ / shares shares	Sep. 30, 2023 USD ($)	Sep. 30, 2021 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense		$ 19,650,000	$ 23,875,000	$ 26,920,000
Financial performance metric \| metric		2
Cumulative adjusted EBITDA during performance period, percentage		65.00%
Cumulative revenue during performance period, percentage		35.00%
Performance period		2 years
Award settlement period		60 days
Threshold performance, percentage		0.00%
Nispera \| Outstanding restricted stock units (“RSUs”)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense		$ 6,900,000
Class B units issued (in shares) \| shares	531,202
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage		50.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage		200.00%
The Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding, weighted average exercise price per share (in usd per share) \| $ / shares		$ 2.45	$ 2.45
Aggregate intrinsic value, exercisable		$ 7,400,000	$ 40,000,000	$ 56,300,000
2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class A common stock reserved (in shares) \| shares					9,500,000
Outstanding pre-IPO options issued pursuant to the 2020 Unit Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense					$ 0
Aggregate intrinsic value, outstanding		18,500,000
Unrecognized stock compensation expense, options		$ 0
Outstanding pre-IPO options issued pursuant to the 2020 Unit Option Plan \| The Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options expiration period		10 years
Options outstanding, weighted average exercise price per share (in usd per share) \| $ / shares		$ 2.45
Outstanding pre-IPO options issued pursuant to the 2020 Unit Option Plan \| 2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service requirement period		3 years
Outstanding phantom units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares) \| shares		0	0
Unrecognized stock compensation expense, excluding options		$ 0	$ 0
Outstanding restricted stock units (“RSUs”)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares) \| shares		2,232,320	1,760,418
Unrecognized stock compensation expense, excluding options		$ 15,100,000
Vesting period		1 year
Granted (in shares) \| shares		1,830,935
Outstanding restricted stock units (“RSUs”) \| 2021 Plan \| 6 month anniversary of IPO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage		33.33%
Outstanding restricted stock units (“RSUs”) \| 2021 Plan \| 18 month anniversary of IPO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage		33.33%
Outstanding restricted stock units (“RSUs”) \| 2021 Plan \| 30 month anniversary of IPO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage		33.33%
Non Qualified Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options expiration period		10 years
Options outstanding, weighted average exercise price per share (in usd per share) \| $ / shares		$ 18.12	$ 21.70
Aggregate intrinsic value, outstanding		$ 0.0
Service requirement period		3 years
Vesting period		1 year 1 month 6 days
Granted (in shares) \| shares		310,422
Options granted, weighted average exercise price per share (in usd per share) \| $ / shares		$ 16.07
Unrecognized stock compensation expense		$ 1,800,000
Non Qualified Stock Option \| 2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares) \| shares		0	0
Non Qualified Stock Option \| 2021 Plan \| 6 month anniversary of IPO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage		33.33%
Non Qualified Stock Option \| 2021 Plan \| 18 month anniversary of IPO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage		33.33%
Non Qualified Stock Option \| 2021 Plan \| 30 month anniversary of IPO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage		33.33%
Outstanding performance share units (“PSUs”)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares) \| shares		901,516	391,032
Unrecognized stock compensation expense, excluding options		$ 0.0
Granted (in shares) \| shares		690,147

Summary of Significant Accounting Policies and Estimates - Advertising Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Advertising costs	$ 4.3	$ 3.3	$ 1.4

Income Taxes - Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Deferred Tax Assets
Inventory	$ 147,457	$ 129,341
Investment in Fluence Energy, LLC	311,957	333,489
Deferred revenue	35,804	27,374
Tax loss carryforwards	66,641	47,765
Unrealized foreign exchange losses	5,301	5,270
Share-based compensation	3,450	3,843
Other deferred tax assets	4,957	2,047
Total deferred tax assets	575,569	549,129
Valuation allowance	(367,323)	(377,218)
Net deferred tax assets	208,246	171,911
Deferred Tax Liabilities
Trade receivables	(8,698)	(20,043)
Intangible assets	(3,676)	(3,697)
Accrued and other liabilities	(192,983)	(140,401)
Unrealized foreign exchange gains	(7,950)	(5,612)
Other deferred tax liabilities	(423)	(392)
Total deferred tax liabilities	(213,730)	(170,145)
Total net deferred tax assets (liabilities)	$ (5,484)
Total net deferred tax assets (liabilities)		$ 1,766

Sale of Receivables under Master Receivables Purchase Agreement (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Feb. 27, 2024
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Written notice period			30 days
Net proceeds sale of receivable		$ 71.5
Factoring income		2.1
Factoring discount	$ 2.1	$ 2.1
Maximum
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Purchasing receivables outstanding amount			$ 75.0

Schedule II Valuation And Qualifying Accounts (Details) - SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 377,218	$ 371,668	$ 354,404
Charged to costs and expenses	(11,699)	(44,126)	6,825
Charged to other accounts	1,804	49,676	10,439
Balance at end of period	$ 367,323	$ 377,218	$ 371,668

Related-Party Transactions - Statement of Operations and Comprehensive Loss Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Related Party Transaction [Line Items]
Revenue	$ 2,262,830	$ 2,698,562	$ 2,217,978
Cost of goods and services	1,967,045	2,357,482	2,077,023
Research and development	86,217	66,195	66,307
Sales and marketing	79,489	63,842	41,114
General and administrative	163,068	172,996	136,308
Factoring discount	2,100	2,100
Tax receivable agreement payments	1,500
Related Party
Related Party Transaction [Line Items]
Revenue	557,621	1,096,999	653,809
Cost of goods and services	80,482	50,653	15,925
Research and development	31	192	912
Sales and marketing	0	123	135
General and administrative	2,061	6,113	5,215
Other income, net	(1,206)	(571)	0
Related Party \| AES and Affiliates
Related Party Transaction [Line Items]
Revenue	$ 555,100	$ 1,082,300	$ 642,700

Other Current Assets

12 Months Ended

Sep. 30, 2025

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Other Current Assets

Other current assets consisted of the following amounts:


In thousands	September 30,
	2025		2024
Taxes recoverable	$	15,186	$	23,962
Prepaid expenses	21,667		10,370
Prepaid insurance	2,538		2,069
Current portion of recoverable warranty costs from suppliers	8,585		5,013
Other	6,695		5,105
Total	$	54,671	$	46,519

Leases

12 Months Ended

Sep. 30, 2025

Leases [Abstract]

Leases

The amounts of assets and liabilities and other information for our operating and finance leases are as follows:


In thousands		September 30,
	Balance Sheet Caption	2025		2024
Right-of-use assets:
Operating leases	Other non-current assets	$	11,256	$	8,186
Finance leases	Property and equipment, net	22,057		—
Total right-of-use assets		33,313		8,186

Lease liabilities:
Operating leases	Other current liabilities	$	6,789	$	3,064
	Other non-current liabilities	5,044		5,492
Finance leases	Other current liabilities	3,492		—
	Other non-current liabilities	—		—
		$	15,325	$	8,556

Components of total lease cost for the fiscal years ended September 30, 2025, 2024, and 2023 were as follows:


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Lease cost
Finance lease cost:	$	2,849	$	—	$	—
Amortization of right-of-use assets	2,757		—		—
Interest on lease liabilities	92		—		—
Operating lease cost	6,608		3,326		1,939
Short-term and variable lease cost	6,169		3,789		17,123
Sublease income	—		—		(194)
Total lease cost	$	15,626	$	7,115	$	18,868

Supplemental information related to the Company’s operating leases for the fiscal years ended September 30, 2025, 2024 and 2023 was as follows:


in thousands	Fiscal Year Ended September 30,
	2025			2024			2023
Cash paid for amounts included in the measurements of lease liabilities	$	6,250		$	3,003		2,246
Right-of-use assets obtained in exchange for new operating lease liabilities	$	8,642		$	6,536		1,024
Weighted average remaining lease term	2.7 years			4.0 years			2.0 years
Weighted average discount rate	6.63		%	6.96		%	7.20	%

Supplemental information related to the Company’s finance lease executed during the fiscal year ended September 30, 2025 was as follows:


in thousands	Fiscal Year Ended September 30,
	2025
Cash paid for amounts included in the measurements of lease liabilities	$	2,462
Operating cash flows	$	92
Financing cash flows	$	2,370
Right-of-use assets obtained in exchange for new finance lease liabilities	$	5,861
Weighted average remaining lease term	0.8 years
Weighted average discount rate	5.60		%

Total remaining lease payments under the Company’s leases for each of the succeeding years are as follows (in thousands):


Year Ended September 30,	Operating Leases		Finance Leases		Total
2026	$	7,259	$	3,576	$	10,835
2027	2,977		—		2,977
2028	953		—		953
2029	590		—		590
2030	246		—		246
Thereafter	951		—		951
Total lease payments	12,976		3,576		16,552
Less: Interest	(1,143)		(84)		(1,227)
Present value of lease liabilities	$	11,833	$	3,492	$	15,325

Leases

The amounts of assets and liabilities and other information for our operating and finance leases are as follows:


In thousands		September 30,
	Balance Sheet Caption	2025		2024
Right-of-use assets:
Operating leases	Other non-current assets	$	11,256	$	8,186
Finance leases	Property and equipment, net	22,057		—
Total right-of-use assets		33,313		8,186

Lease liabilities:
Operating leases	Other current liabilities	$	6,789	$	3,064
	Other non-current liabilities	5,044		5,492
Finance leases	Other current liabilities	3,492		—
	Other non-current liabilities	—		—
		$	15,325	$	8,556

Components of total lease cost for the fiscal years ended September 30, 2025, 2024, and 2023 were as follows:


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Lease cost
Finance lease cost:	$	2,849	$	—	$	—
Amortization of right-of-use assets	2,757		—		—
Interest on lease liabilities	92		—		—
Operating lease cost	6,608		3,326		1,939
Short-term and variable lease cost	6,169		3,789		17,123
Sublease income	—		—		(194)
Total lease cost	$	15,626	$	7,115	$	18,868

Supplemental information related to the Company’s operating leases for the fiscal years ended September 30, 2025, 2024 and 2023 was as follows:


in thousands	Fiscal Year Ended September 30,
	2025			2024			2023
Cash paid for amounts included in the measurements of lease liabilities	$	6,250		$	3,003		2,246
Right-of-use assets obtained in exchange for new operating lease liabilities	$	8,642		$	6,536		1,024
Weighted average remaining lease term	2.7 years			4.0 years			2.0 years
Weighted average discount rate	6.63		%	6.96		%	7.20	%

Supplemental information related to the Company’s finance lease executed during the fiscal year ended September 30, 2025 was as follows:


in thousands	Fiscal Year Ended September 30,
	2025
Cash paid for amounts included in the measurements of lease liabilities	$	2,462
Operating cash flows	$	92
Financing cash flows	$	2,370
Right-of-use assets obtained in exchange for new finance lease liabilities	$	5,861
Weighted average remaining lease term	0.8 years
Weighted average discount rate	5.60		%

Total remaining lease payments under the Company’s leases for each of the succeeding years are as follows (in thousands):


Year Ended September 30,	Operating Leases		Finance Leases		Total
2026	$	7,259	$	3,576	$	10,835
2027	2,977		—		2,977
2028	953		—		953
2029	590		—		590
2030	246		—		246
Thereafter	951		—		951
Total lease payments	12,976		3,576		16,552
Less: Interest	(1,143)		(84)		(1,227)
Present value of lease liabilities	$	11,833	$	3,492	$	15,325

Income Taxes

12 Months Ended

Sep. 30, 2025

Income Tax Disclosure [Abstract]

Income Taxes

The following table presents the components of income (loss) before income tax (in thousands):


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Domestic	$	(121,163)	$	(33,983)	$	(100,356)
Foreign	76,091		73,556		87
Income (loss) before income taxes	$	(45,072)	$	39,573	$	(100,269)

The major components of income tax expense/(benefit) were as follows:


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Current income tax expense:
Domestic	$	165	$	1,948	$	—
Foreign	14,343		13,700		1,349
Deferred income tax expense (benefit):
Domestic	—		—		—
Foreign	6,293		(6,719)		2,541
Withholding income tax expense:
Domestic	—		—		—
Foreign	2,115		277		659
Total income tax expense	$	22,917	$	9,206	$	4,549

The following table summarizes a reconciliation of the U.S. statutory federal income tax rate to the Company’s effective tax rate.


in thousands	Fiscal Year Ended September 30,
	2025		2024		2023
Statutory rate	21.0	%	21.0	%	21.0	%
State taxes	2.9	%	(1.9)	%	3.1	%
Rate change	(34.2)	%	52.6	%	(15.5)	%
Flow-through losses	(15.2)	%	3.3	%	(9.3)	%
Foreign rate differential	(13.0)	%	14.3	%	2.2	%
Withholding taxes	(4.7)	%	0.7	%	(0.7)	%
Valuation allowance	1.4	%	(118.6)	%	(12.9)	%
Permanent differences	(13.1)	%	(12.2)	%	7.8	%
U.S. tax on foreign earnings	2.0	%	50.6	%	—	%
Return to provision adjustments	3.7	%	14.2	%	(1.0)	%
Other items, net	(1.6)	%	(0.7)	%	0.8	%
Effective tax rate	(50.8)	%	23.3	%	(4.5)	%

In fiscal year 2025, the effective tax rate differs from the U.S. statutory tax rate of 21% primarily due to profitability in foreign jurisdictions with statutory tax rates higher than the U.S. and continued U.S. pre-tax losses that are fully offset with a valuation allowance.

Deferred income tax is generated by Fluence Energy, Inc. and its foreign subsidiaries and is comprised of the following:


in thousands	September 30,
	2025		2024
Deferred Tax Assets
Inventory	$	147,457	$	129,341
Investment in Fluence Energy, LLC	311,957		333,489
Deferred revenue	35,804		27,374
Tax loss carryforwards	66,641		47,765
Unrealized foreign exchange losses	5,301		5,270
Share-based compensation	3,450		3,843
Other deferred tax assets	4,957		2,047
Total deferred tax assets	575,569		549,129
Valuation allowance	(367,323)		(377,218)
Net deferred tax assets	208,246		171,911
Deferred Tax Liabilities
Trade receivables	(8,698)		(20,043)
Intangible assets	(3,676)		(3,697)
Accrued and other liabilities	(192,983)		(140,401)
Unrealized foreign exchange gains	(7,950)		(5,612)
Other deferred tax liabilities	(423)		(392)
Total deferred tax liabilities	(213,730)		(170,145)
Total net deferred tax assets (liabilities)	$	(5,484)	$	1,766

As of September 30, 2025 and 2024, the Company did not have material undistributed foreign earnings. The Company has not recorded a deferred tax liability on the undistributed earnings from its foreign subsidiaries, as such earnings are considered to be indefinitely reinvested.

The foreign net operating loss carryforwards as of September 30, 2025 and 2024 are approximately $215.6 million and $186.2 million, respectively. Approximately $20.2 million of the foreign net operating losses will expire between fiscal year 2026 and fiscal year 2035. The federal and state net operating loss carryforwards as of September 30, 2025 and 2024 are approximately $208.9 million ($115.9 million federal and $93.1 million state) and $135.8 million ($51.1 million federal and $84.7 million state), respectively. The federal and state net operating loss carryforwards are attributable to Fluence Energy, Inc., a corporate entity which, upon IPO on November 1, 2021, became the holding company of Fluence Energy, LLC. The federal net operating losses have an unlimited carryforward period. Approximately $82.5 million of state net operating losses will expire between fiscal year 2032 and fiscal year 2045.

As of September 30, 2025 and 2024, the Company had recorded a valuation allowance of $367.3 million and $377.2 million, respectively. In fiscal year 2024, the valuation allowances were recorded against deferred tax assets of the Company’s German, Philippines, Taiwan, and Netherlands subsidiaries, as well as Fluence Energy, Inc. As a holding company, Fluence Energy, Inc. recorded deferred tax assets primarily related to its investment in Fluence Energy, LLC. In fiscal year 2025, the Company maintains that based on the weight of available evidence, including cumulative losses, it is more likely-than-not that the net deferred tax assets of Fluence Energy, Inc. and subsidiaries in Germany, Philippines, Taiwan, and Netherlands will not be realized and recorded a valuation allowance against such deferred tax assets.

The net decrease in the valuation allowance of $9.9 million in fiscal year 2025 is due to a $1.1 million increase recorded through equity, a $11.7 million decrease in valuation allowance related to current year activity in jurisdictions with full valuation allowances of $11.7 million, and a $0.7 million increase related to currency translation adjustments. Further, a future reversal of $2.5 million of the valuation allowance on deferred tax assets as of September 30, 2025, would be accounted for as an increase in equity. For fiscal year 2024, the net increase in the valuation allowance was $5.5 million.

As of September 30, 2025 and 2024, the Company has not recorded any unrecognized tax benefits. All tax jurisdictions remain subject to examination by foreign, federal, and state taxing authorities with the exception of Germany for the tax periods 2018 to 2020 for which the entity was issued a Cancellation Reservation of Review, which permanently closed these periods for audit. The Company’s policy is to recognize interest and penalties related to unrecognized tax benefits as a component of income tax expense.

- Definition

The entire disclosure for income tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 740
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477617/942-740-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 740
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478822/944-740-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 231
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-231

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12C

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12B

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477891/740-270-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479360/740-10-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-13

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/740/tableOfContent

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-14

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-21

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-17

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479360/740-10-S99-2

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482603/740-30-50-2

+ Details

Schedule I Condensed Financial Information of the Registrant (Tables)

12 Months Ended

Sep. 30, 2025

Condensed Financial Information Disclosure [Abstract]

Schedule of Condensed Balance Sheets

CONDENSED BALANCE SHEETS

(PARENT COMPANY ONLY)

(U.S. Dollars in Thousands, except share and per share amounts)


	September 30,
	2025		2024
Assets
Current assets:
Cash and cash equivalents	$	371	$	267
Accounts receivable - related party	6,464		—
Other receivables	68		443
Tax receivable	49		—
Total current assets	6,952		710
Non-current assets:
Long-term notes receivable - related party	400,000		—
Investment in subsidiaries	727,297		802,606
Total non-current assets	1,127,297		802,606
Total assets	$	1,134,249	$	803,316
Liabilities, and stockholders’ equity
Current liabilities:
Accounts payable	119		74
Accounts payable - related party	6,657		2,803
Accruals and provisions	2,625		74
Taxes payable	—		1,955
Other current liabilities - related party	301		—
Total current liabilities	9,702		4,906
Non-current liabilities:
Convertible senior notes, net	390,804		$	—
Other non-current liabilities - related party	—		$	1,507
Total non-current liabilities	390,804		1,507
Total liabilities	400,506		6,413
Commitments and Contingencies (Note 3)
Stockholders’ Equity:
Preferred stock, $0.00001 per share, 10,000,000 shares authorized; no shares issued and outstanding as of September 30, 2025 and 2024	—		—
Class A common stock, $0.00001 par value per share,1,200,000,000 shares authorized; 132,014,571 shares issued and 131,164,365 shares outstanding as of September 30, 2025; 130,207,845 shares issued and 129,421,797 shares outstanding as of September 30, 2024	—		—
Class B-1 common stock, $0.00001 par value per share, 134,325,805 shares authorized; 51,499,195 shares issued and outstanding as of September 30, 2025; 51,499,195 shares issued and outstanding as of September 30, 2024	—		—
Class B-2 common stock, $0.00001 par value per share, 200,000,000 shares authorized; no shares issued and outstanding as of September 30, 2025 and 2024	—		—
Treasury stock, at cost	(10,213)		(9,460)
Additional paid-in capital	939,433		965,562
Distribution from Fluence Energy, LLC	10,213		9,460
Contribution to Fluence Energy, LLC	(17,811)		(15,641)
Accumulated deficit	(187,879)		(153,018)
Total stockholders’ equity	733,743		796,903
Total liabilities, stockholders’ equity	$	1,134,249	$	803,316

Schedule of Condensed Statement of Operations and Comprehensive Loss

CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS)

(PARENT COMPANY ONLY)

(U.S. Dollars in Thousands)


	Fiscal Year Ended September 30,
	2025		2024		2023
Revenue	$	—	$	—	$	—
Revenue from related parties	—		—		—
Total Revenue	—		—		—
Operating expenses:
General and administrative	1,401		1,837		1,478
Interest expense, net	1,417		—		—
Other (income) expense, net	(1,209)		1,507		8
Equity in net (loss) income of subsidiaries	(46,540)		28,008		(68,133)
(Loss) income before income taxes	(48,149)		24,664		(69,620)
Income tax expense	165		1,948		—
Net (loss) income	$	(48,314)	$	22,716	$	(69,620)
Net (loss) income attributable to non-controlling interest	—		—		—
Net (loss) income attributable to Fluence Energy, Inc.	$	(48,314)	$	22,716	$	(69,620)

Gain (loss) on foreign currency translation, net of tax	11,185		(411)		408
Gain (loss) on cash flow hedges, net of tax	2,216		(4,480)		—
Actuarial gain (loss) on pension liabilities, net of tax	52		(151)		10
Total other comprehensive income (loss)	13,453		(5,042)		418
Total comprehensive (loss) income	$	(34,861)	$	17,674	$	(69,202)

Schedule of Condensed Statements of Cash Flows

CONDENSED STATEMENTS OF CASH FLOWS

(PARENT COMPANY ONLY)

(U.S. Dollars in Thousands)


	Fiscal Year Ended September 30,
	2025		2024		2023
Operating activities
Net (loss) income	$	(48,314)	$	22,716	$	(69,620)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:



Equity in net income (loss) of subsidiaries	46,540		(28,008)		68,133
Amortization of debt issuance costs	1,426		—		—
Stock-based compensation expense	701		821		443


Changes in operating assets and liabilities:
Other receivables	375		(75)		(348)
Accounts receivable - related party	(6,464)		—		—
Taxes receivables	(49)		—		—




Accounts payable	44		74		—
Accounts payable - related party	3,854		1,142		1,453
Accruals and provisions	2,551		74		—
Taxes payable	(1,955)		1,949		6
Other non-current liabilities - related party	(1,507)		1,507		—



Other current liabilities - related party	301		—		—


Net cash provided by operating activities	(2,496)		200		67
Investing activities
Purchase of long-term notes receivable - related party	(400,000)		—		—



Net cash used in investing activities	(400,000)		—		—
Financing activities






Distributions from Fluence Energy, LLC	42,974		1,663		2,784
Class A common stock withheld related to settlement of employee taxes for stock-based compensation awards	(752)		(1,663)		(2,784)
Proceeds from exercise of stock options	2,170		5,335		7,203
Contributions to Fluence Energy, LLC	(2,170)		(5,335)		(7,203)
Purchases of Capped Calls related to 2030 Convertible Senior Notes	(29,000)		—		—
Proceeds from issuance of 2030 Convertible Senior Notes, net	400,000		—		—
Payments of debt issuance costs	(10,622)		—		—
Net cash provided by financing activities	402,600		—		—
Effect of exchange rate changes on cash and cash equivalents	—		—		—
Net increase in cash and cash equivalents	104		200		67
Cash, cash equivalents, as of the beginning of the period	267		67		—
Cash, cash equivalents, as of the end of the period	$	371	$	267	$	67

Schedule II Valuation And Qualifying Accounts

12 Months Ended

Sep. 30, 2025

SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]

Schedule II Valuation And Qualifying Accounts

SCHEDULE II. VALUATION AND QUALIFYING ACCOUNTS


			Additions
in thousands	Balance at beginning of period		Charged to costs and expenses		Charged to other accounts			Balance at end of period
Deferred tax asset valuation allowance:
Fiscal year ended September 30, 2023	$	354,404	$	6,825	$	10,439	(1)	$	371,668
Fiscal year ended September 30, 2024	$	371,668	$	(44,126)	$	49,676	(1)	$	377,218
Fiscal year ended September 30, 2025	$	377,218	$	(11,699)	$	1,804	(1)	$	367,323

(1) Amount relates primarily to a valuation allowance established on deferred tax assets related to our investment in Fluence Energy, LLC.

Goodwill (Tables)

12 Months Ended

Sep. 30, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The following table presents the goodwill activity:


In thousands	September 30,
	2025		2024
Goodwill, Beginning of the period	$	27,482	$	26,020
Foreign currency adjustment	1,102		1,462
Goodwill, End of the period	$	28,584	$	27,482

- Definition

Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482548/350-20-55-24

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1A

Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-2

+ Details