Energy Vault Holdings, Inc.

Condensed Consolidated Balance Sheets

(In thousands except par value)

Condensed Consolidated Statements of Operations and Comprehensive Loss

(In thousands except per share data)

Condensed Consolidated Statements of Stockholders’ Equity

Condensed Consolidated Statements of Stockholders’ Equity (Continued)

Condensed Consolidated Statements of Cash Flows

NOTE 1. ORGANIZATION AND DESCRIPTION OF BUSINESS

Energy Vault Holdings, Inc., which together with its subsidiaries is referred to herein as “Energy Vault” or the “Company,” provides a diverse technology portfolio of turnkey energy storage platforms, including proprietary gravity, battery, and green hydrogen energy storage hardware technologies, supported by our technology-agnostic energy management system software and integration platform. In 2024, we began a multi-year transition from providing this technology portfolio solely to third parties through a build-and-transfer model or licensing model, to also taking an ownership interest in energy storage assets in select attractive markets.

We incorporate a customer-centric, solutions-based approach toward helping utilities, independent power producers, and large industrial energy users reduce their energy costs while maintaining power reliability. As the global demand for electricity increases and the world transitions to an economy powered by increasingly intermittent renewable energy such as solar and wind, the ability to provide clean, reliable, and affordable electricity to a growing global population will depend heavily on the ability to store and distribute energy at appropriate times. We are striving to create a world powered by renewable resources so that everyone will have access to clean, reliable, sustainable, and affordable energy. The Company’s mission is to provide energy storage solutions to accelerate the global transition to renewable energy.

NOTE 2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation

The accompanying unaudited interim condensed consolidated financial statements have been prepared on an accrual basis of accounting in accordance with United States Generally Accepted Accounting Principles (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and disclosures normally included in consolidated financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. Accordingly, these unaudited interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and accompanying notes for the year ended December 31, 2024. The condensed consolidated balance sheet as of December 31, 2024, included herein, was derived from the consolidated financial statements of the Company as of that date.

These unaudited interim condensed consolidated financial statements, in the opinion of management, reflect all adjustments necessary to present fairly the Company’s financial position as of September 30, 2025, results of operations, comprehensive loss, and stockholders’ equity activities for the three and nine months ended September 30, 2025, and cash flows for the nine months ended September 30, 2025. The results for the three and nine months ended September 30, 2025 are not necessarily indicative of the results to be expected for the year ending December 31, 2025 or for any interim period or for any other future year.

Principles of Consolidation

These unaudited interim condensed consolidated financial statements include Energy Vault Holdings, Inc., its wholly owned subsidiaries, and a majority owned subsidiary. All intercompany balances and transactions have been eliminated in consolidation.

Non-controlling interest

In May 2024, the Company’s consolidated subsidiary, Cetus Energy, Inc. (“Cetus”), issued a share-based payment award to an employee of Cetus, representing a non-controlling interest. A non-controlling interest in a subsidiary is considered an ownership interest in a majority-owned subsidiary that is not attributable to the parent. The Company includes non-controlling interest as a component of stockholders’ equity on the Company’s condensed consolidated balance sheets.

During the second quarter of 2025, the Cetus employee that received a share-based payment award was terminated, and the employee forfeited their unvested shares.

Emerging Growth Company

Section 102(b)(1) of the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”) exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Exchange Act) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that an emerging growth company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging growth companies but any such election to opt out is irrevocable. The

Company has elected not to opt out of such extended transition period, which means that when a standard is issued or revised, and it has different application dates for public or private companies, the Company, as an emerging growth company, can adopt the new or revised standard at the time private companies adopt the new or revised standard.

This may make comparison of the Company’s consolidated financial statements with another public company that is neither an emerging growth company nor an emerging growth company that has opted out of using the extended transition period difficult or impossible because of the potential differences in accounting standards used.

Use of Estimates

The preparation of the condensed consolidated financial statements, in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the unaudited interim condensed consolidated financial statements and accompanying notes. The Company evaluates its assumptions on an ongoing basis. The Company’s management believes that the estimates, judgment, and assumptions used are reasonable based upon information available at the time they are made. Estimates made by management include, among others, revenue recognition, debt measured at fair value, provision for credit losses, warranty accruals, and stock-based compensation. Due to the inherent uncertainty involved in making assumptions and estimates, changes in circumstances could result in actual results differing from those estimates, and such differences could be material to the Company’s consolidated financial condition and results of operations.

Liquidity

The accompanying financial statements have been prepared assuming the Company will continue as a going concern, which contemplates continuity of operations, realization of assets, and the satisfaction of liabilities and commitments in the normal course of business.

Since our inception in October 2017, we have incurred significant net losses and have used significant cash in our business. As of September 30, 2025 and December 31, 2024, we had accumulated deficits of $466.7 million and $383.8 million, respectively, and net losses of $82.9 million and $73.9 million, respectively, for the nine months ended September 30, 2025 and 2024. We anticipate that we will incur net losses for the foreseeable future and there is no guarantee that we will achieve or maintain profitability.

The assessment of liquidity requires management to make estimates of future activity and judgments about whether the Company can meet its obligations and have adequate liquidity to operate. Significant inputs to the Company’s liquidity analysis include:

•$19.4 million in net proceeds from the issuance of a second tranche of Convertible Debentures. Refer to Note 9, Debt, for further details on the Convertible Debentures.

•$40.6 million in estimated proceeds from the sale of investment tax credits pursuant to a Tax Credit Transfer Commitment. Refer to Note 19, Commitments and Contingencies, for further details on this transaction.

•$45.4 million in investor contributions pursuant to the Asset Vault contribution and purchase agreement. Refer to Note 20, Subsequent Events, for further details on this transaction.

Management believes that its cash, cash equivalents, and restricted cash on hand as of the filing date of this Quarterly Report, along with the actions which can be taken subsequent to September 30, 2025 as discussed above, will be sufficient to fund our operating activities for at least the next twelve months. The condensed consolidated financial statements do not reflect any adjustments that would be necessary if we become unable to continue as a going concern.

Restricted Cash

Restricted cash primarily consists of cash deposits held in segregated accounts as collateral for certain debt financing requirements and for guarantees and bonds issued in connection with our customer projects. Under the terms of our senior notes, cash proceeds are restricted until pre-agreed milestones are achieved.

Additionally, our contractual arrangements with customers often require us to issue letters of credit, bank guarantees, and performance and payment bonds to secure our performance under those contracts. To collateralize these instruments, we deposit cash in restricted accounts that cannot be used for general corporate purposes until the underlying obligations are settled or the guarantees expire.

The following table summarizes restricted cash balances (amounts in thousands):

Inventory

Inventory consists of raw materials and components, including battery modules, inverters, transformers, and spare parts, to be used in battery energy storage projects under customer contracts.

Concentration of Credit and Other Risks

Financial instruments that subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash, accounts receivable, and customer financings receivable.

Risks associated with cash and cash equivalents and restricted cash are mitigated by banking with creditworthy institutions. Such balances with any one institution may, at times, be in excess of federally insured amounts.

As of September 30, 2025, four customers accounted for 34%,30%,23% and 13% of accounts receivable, respectively. As of December 31, 2024, one customer accounted for 100% of accounts receivable.

As of September 30, 2025 and December 31, 2024, one customer accounted for 100% of the customer financing receivable.

Revenue from two customers accounted for 70% and 23% of total revenue, respectively, for the three months ended September 30, 2025 and revenue from two customers accounted for 64% and 15% of total revenue, respectively, for the nine months ended September 30, 2025. Revenue from two customers accounted for 51% and 35% of total revenue, respectively, for the three months ended September 30, 2024 and revenue from two customers accounted for 59% and 38% of total revenue, respectively, for the nine months ended September 30, 2024.

Summary of Significant Accounting Policies

The Company’s significant accounting policies are discussed in Note 2 of the notes to the consolidated financial statements included in the Company’s 2024 Annual Report on Form 10-K filed with the SEC on April 1, 2025. There have not been any significant changes to these policies other than as described below during thenine months ended September 30, 2025.

Revenue from Tolling and Power Purchase Agreements (“PPA”)

The Company generates revenue from the sale of energy, capacity and related services from Company-owned energy storage systems through tolling arrangements and long-term power purchase agreements. Each arrangement is evaluated to determine whether it is accounted for as (i) a lease under Accounting Standard Codification (“ASC”) 842 (when the counterparty obtains the right to control the use of an identified storage asset and substantially all of its economic benefits) or (ii) a customer contract under ASC 606 (when the Company retains control of the asset and provides energy, capacity and/or market participation services to the customer). As of September 30, 2025, two energy storage systems were operating commercially: one accounted for as an operating lease under ASC 842 andone accounted for as a customer contract under ASC 606.

Arrangements Accounted for under ASC 606

For the arrangement accounted for under ASC 606, the Company’s performance obligation includes a stand-ready obligation to provide capacity/dispatch availability and, in some cases, delivery of energy and ancillary services. Stand-ready capacity services represent a single series of distinct services satisfied over time. Fixed consideration is recognized on a straight-line basis over the contract term, as this pattern depicts the transfer of the stand-ready service. Variable consideration is recognized in the period the underlying energy is delivered.

Arrangements Accounted for under ASC 842

For the arrangement accounted for as a lease, fixed consideration is recognized as operating lease revenue on a straight-line basis over the lease term and variable lease payments are recognized in the period the underlying energy is delivered. The agreement is accounted for as a lease because the customer (the “lessee”) has the right to obtain substantially all of the economic benefits from the use of the energy storage system and has the right to direct its use throughout the agreement's term. The lease term is ten years from the commercial operation date, which was May 31, 2025. The Company has elected the practical expedient in ASC 842-10-15-42A not to separate nonlease components from the associated lease component. The significant nonlease component combined with the lease component consists of operation and maintenance services for the energy storage system.

Under the tolling agreement, the Company, as lessor, is entitled to receive monthly lease payments based on a contractual floor amount (the “Monthly Floor”), which is subject to reduction each month based on the availability and round-trip efficiency of the energy storage system (the “Effective Monthly Floor”). Lease income is recognized monthly based on a straight-line allocation of the Monthly Floor over the term of the contract, to the extent it represents fixed or in-substance fixed consideration. Any difference between the recognized lease income and the Effective Monthly Floor earned in a given period is recorded as an adjustment to lease income in that period.

At the end of each contract year, if cumulative lease payments received during the year are less than the sum of thetwelve Effective Monthly Floors, the lessee is required to make a true-up payment for the shortfall. The Company is also entitled to variable lease payments equal to a specified percentage of the net market revenue generated by the lessee that exceeds the cumulative Effective Monthly Floors for that contract year.

The lease does not contain an option for the lessee to extend the term or purchase the asset. The agreement may be terminated early by either party under certain conditions, including for prolonged force majeure events, or by the non-defaulting party upon an event of default.

The aggregate remaining Monthly Floor payments as of September 30, 2025 presented in the table below do not reflect potential reductions due to performance-based adjustments that may occur throughout the contract term (amounts in thousands)(1):

(1) The table reflects contractual Monthly Floor payments due under the lease agreement for each fiscal year. These amounts represent the stated floor amounts prior to any performance-based adjustments. Actual lease payments may be lower in any given period based on the lessee’s achievement of availability and round-trip efficiency thresholds. Additionally, the timing of cash receipts within a year may vary, as monthly payments are dependent on the lessee's net market revenue. Pursuant to the agreement, if cumulative lease payments for the contract year are less than the aggregate Effective Monthly Floors earned, the lessee is required to pay the shortfall to the Company in an annual true-up following the end of each contract year in May.

Investment Tax Credits (“ITCs”)

The Company accounts for nonrefundable, transferable ITCs in accordance with ASC 740 and has elected the deferral method to recognize the benefit of those credits. Under this method, an ITC is generated when the qualified asset is placed in service, which is the date in which the qualified asset is ready and available for its intended use.

Upon generation of the ITC, the Company reduces the carrying amount of the related asset and records a deferred tax asset for the full statutory credit amount. The deferred tax asset is evaluated for realizability and an offsetting valuation allowance is recorded as necessary to reduce the deferred tax asset to its expected realizable value.

The deferred benefit from the ITC is recognized as a reduction to depreciation expense over the related asset’s useful life. Subsequent changes in the estimated realizable value of the ITCs, or changes in deferred tax assets or liabilities related to those credits, are recorded in income tax expense in the period of change.

The Company expects to monetize its nonrefundable, transferable ITCs through one or more sales to third-party buyers. Upon a sale, any difference between the proceeds of such sale and the carrying amount of the deferred tax asset is recorded in income tax expense.

Debt - Fair Value Option

The Company accounted for a financing arrangement, as described in Note 9, Debt, under the fair value option election pursuant to ASC 825. ASC 825 provides for the fair value option election, to the extent not otherwise prohibited by ASC 825, to be afforded to financial instruments, wherein bifurcation of an embedded derivative is not necessary, and the financial instrument is initially measured at its issue-date estimated fair value and then subsequently remeasured at estimated fair value on a recurring basis at each reporting period date. Period-to-period changes in fair value are recognized in the condensed consolidated statements of operations and comprehensive loss. Direct issuance costs and fees related to debt measured at fair value are expensed as incurred in the condensed consolidated statements of operations and comprehensive loss and are not deferred.

Recent Accounting Standards Issued, But Not Yet Adopted

In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-09, Income Taxes (Topics 740): Improvements to Income Tax Disclosures to expand the disclosure requirements for income taxes. Upon adoption we will be required to disclose additional specified categories in the rate reconciliation in both percentage and dollar amounts. We will also be required to disclose the amount of income taxes paid disaggregated by jurisdiction, among other disclosure requirements. The standard is effective for the 2025 annual period and can be applied either prospectively or retrospectively. We are currently evaluating this ASU would have on our consolidated financial statements and related disclosures.

In November 2024, the FASB issued ASU 2024-03, Income Statement — Reporting Comprehensive Income — Expense Disaggregation Disclosures (Subtopic 220-40) — Disaggregation of Income Statement Expenses. The ASU requires the disclosure of additional information about specific costs and expense categories in the notes to the consolidated financial statements. The standard is effective for annual periods beginning after December 15, 2026, and interim periods beginning after December 15, 2027, with early adoption permitted. The standard should be applied on a prospective basis with the option to apply the standard retrospectively. We are currently evaluating this ASU would have on our consolidated financial statements and related disclosures.

In July 2025, the FASB issued ASU 2025-05, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets. This ASU addresses the complexity and cost associated with estimating expected credit losses for current accounts receivable and current contract assets that arise from revenue contracts under ASC 606. The main provision applicable to all entities is a new practical expedient which, if elected, permits an entity to assume that current conditions as of the balance sheet date do not change for the remaining life of the asset when developing reasonable and supportable forecasts. The amendments in this ASU are effective for annual reporting periods beginning after December 15, 2025, and interim periods within those years. Early adoption is permitted. The guidance is to be applied prospectively upon adoption. We are currently evaluating the impact that electing the practical expedient in this ASU would have on our consolidated financial statements and related disclosures.

NOTE 3. REVENUE RECOGNITION

The Company recognized revenue for the product and service categories as follows for the three and nine months ended September 30, 2025 and 2024 (amounts in thousands):

(1) Revenue from the arrangement accounted for as an operating lease was $0.7 million and $1.1 million for the three and nine months ended September 30, 2025.

Remaining Performance Obligations

Remaining performance obligations represent the amount of unearned transaction prices under contracts for which work is wholly or partially unperformed. As of September 30, 2025, the amount of the Company’s remaining performance obligations was $280.0 million. The Company expects to recognize approximately 70% of the remaining performance obligations as revenue over the next 12 months and the remainder more than 12 months from September 30, 2025.

Contract Balances

The following table provides information about contract assets and contract liabilities from contracts with customers (amounts in thousands):

Contract assets consist of a refundable contribution and unbilled receivables. The refundable contribution was initially payable to the Company upon the customer’s first gravity energy storage system achieving substantial completion, subject to potential downward adjustment for liquidated damages if specified performance metrics were not met. In 2024, the customer agreed to remove the substantial completion condition and committed to repay the refundable contribution in the second half of 2024. However, the customer did not remit payment, and during 2024 the Company increased its allowance for credit losses to fully reserve this receivable. The Company is continuing to engage with the customer and is actively pursuing collection efforts.

Unbilled receivables represent the estimated value of unbilled work for projects with performance obligations recognized over time.

Contract liabilities consist of deferred revenue. Under certain contracts, the Company may be entitled to invoice the customer and receive payments in advance of performing the related contract work. In those instances, the Company recognizes a liability for advance billings in excess of revenue recognized, which is referred to as deferred revenue. Deferred revenue is not considered to be a significant financing component because it is generally used to meet working capital demands that can be higher in the early stages of a contract. For the three and nine months ended September 30, 2025, the Company recognized revenue of $0.1 million and $8.3 million, respectively, and for the three and nine months ended September 30, 2024, the Company recognized revenue of $40 thousand and $1.1 million, respectively, related to amounts that were included in the deferred revenue balance as of the beginning of each period.

NOTE 4. INVESTMENTS

The following table provides a reconciliation of investments to the Company’s condensed consolidated balance sheets (amounts in thousands):

(1) The balance is shown net of allowance for credit losses. Refer to Note 5, Allowance for credit losses, for further information.

(2) Presented within prepaid and other current assets on the condensed consolidated balance sheet.

Investment in Equity Securities

In 2022 and 2023, the Company purchased equity securities in KORE Power, Inc. (“KORE”), a U.S. manufacturer of battery cells and modules. These equity securities do not have a readily determinable fair value and are recorded at cost, less any impairment, plus or minus adjustments for observable price changes in orderly transactions for the same or similar securities, with unrealized gains and losses recognized in earnings. The cost basis of the KORE equity securities is $15.0 million, and cumulative impairment recorded as of September 30, 2025 and December 31, 2024 was $11.7 million.

Convertible Note Receivable

In October 2021, the Company entered into a convertible promissory note purchase agreement with DG Fuels, LLC (“DG Fuels”) and purchased a promissory note with a principal balance of $1.0 million (“DG Fuels Tranche 1 Note”). In April 2022, the Company purchased an additional promissory note from DG Fuels with a principal balance of $2.0 million. (“DG Fuels Tranche 2 Note”) (collectively, the “Convertible Note Receivable”).

The maturity date of the Convertible Note Receivable was the earlier of (i)30 days after a demand for payment is made by the Company at any time after thetwo year anniversary of the date of issuance of the note; (ii) thefour year anniversary of the date of issuance of the note; (iii)five days following a Financial Close (“Financial Close” means a project finance style closing by DG Fuels or its subsidiary of debt and equity capital to finance the construction of that certain biofuel facility currently under development by DG Fuels), or (iv) upon an event of default determined at the discretion of the Company. The Convertible Note Receivable has an annual interest rate of 10.0%. Per the conversion terms, the Company can convert the principal balance and unpaid accrued interest into equity securities of DG Fuels at a 20% discount.

In June 2025, the maturity date for the Convertible Note Receivable was amended to the earlier of (i)30 days after demand for payment is made by the Company at any time after June 1, 2027, (ii)five days following a Financial Close, or (iii) upon an event of default determined at the discretion of the Company.

As of September 30, 2025, the Company has a $1.9 million allowance for credit losses on its Convertible Note Receivable, inclusive of related accrued interest. In the second quarter of 2025, upon notification that DG Fuels was experiencing financial difficulties, management concluded that the note and accrued interest were partially impaired.

Other Note Receivable

Between October 2024 and June 2025, the Company loaned AUD 3.9 million (or approximately $2.7 million) to Stoney Creek BESS Pty Ltd (“Stoney Creek”) to fund their development costs for a battery energy storage system (“BESS”) to be located in Narrabri, New South Wales, Australia (“Stoney Creek BESS”). On March 17, 2025, the Company entered into a share purchase agreement to acquire all of the outstanding shares of Stoney Creek from Enervest Utility Pty Ltd (“Enervest”). The acquisition closed on August 5, 2025, at which time the outstanding note receivable from Stoney Creek was settled and applied against the purchase price. See Note 7, Property and Equipment, net, for additional information.

NOTE 5. ALLOWANCE FOR CREDIT LOSSES

Activity in the allowance for credit losses was as follows for the nine months ended September 30, 2025 and 2024 (amounts in thousands):

The Company estimates expected uncollectible amounts related to its accounts receivable, customer financing receivable, contract asset balances, and other notes receivable as of the end of each reporting period, and presents those financial asset balances net of an allowance for expected credit losses in the consolidated balance sheets. Due to the Company’s limited operating history, the Company generally utilizes a probability-of-default (“PD”) and loss-given-default (“LGD”) methodology to calculate the allowance for credit losses for each customer by type of financial asset. The Company derives its PD and LGD rates using historical rates for corporate bonds as published by Moody’s. The Company uses PD and LGD rates that correspond to the customer’s credit rating and period of time in which the financial asset is expected to remain outstanding.

For significantly past due receivables, such as the customer financing receivable and refundable contribution, or when counterparties are experiencing financial difficulties, the Company determines specific allowances for each receivable.

The amortized cost basis for the Company’s customer financing receivable was $11.5 million as of September 30, 2025 and December 31, 2024. Effective December 31, 2024, the Company placed the customer financing receivable on non-accrual status and discontinued the accrual of interest income due to the customer’s firsttwo installment payments being past-due.

During the nine months ended September 30, 2025, the Company recorded a $1.9 million allowance for credit losses on its Convertible Note Receivable and related accrued interest from DG Fuels. In the second quarter of 2025, upon notification that DG Fuels was experiencing financial difficulties, management concluded that the note and accrued interest were partially impaired. This activity is reflected within the column, notes receivable, in the preceding table for the nine months ended September 30, 2025.

NOTE 6. RELATED PARTY TRANSACTIONS

During the three and nine months ended September 30, 2025, the Company paid $0.1 million and $0.6 million respectively, in marketing and sales costs to a company owned by an immediate family member of an officer of the Company. During the three and nine months ended September 30, 2024, the Company paid $0.2 million and $0.8 million, respectively. At September 30, 2025, the Company had $44 thousand in payables due to this related party. At December 31, 2024, the Company had $0.1 million in payables due to this related party.

NOTE 7. PROPERTY AND EQUIPMENT, NET

As of September 30, 2025 and December 31, 2024, property and equipment, net consisted of the following (amounts in thousands):

(1) Consists of two energy storage systems with estimated useful lives of 10 and 20 years, respectively. One energy storage system is subject to an operating lease where the Company is the lessor. The Company has not estimated its salvage value as the Company intends to use the energy storage system for its entire useful life.

(2) The gross cost has been reduced by the estimated aggregate value of the statutory ITCs generated of $32.1 million.

(3) The CDU has an estimated useful life offive years and the gross cost has been reduced by the estimated value of the statutory ITC generated of $15.7 million.

During the nine months ended September 30, 2025, the Company placed into service its BESS in Snyder, Texas (“Cross Trails BESS”), its hybrid energy storage system in Calistoga, California (“CRC HESS”), and the CDU in Snyder, Texas.

The Company reclassified their carrying values, net of estimated ITCs, from construction in progress to energy storage systems and CDU in the preceding table.

On August 5, 2025, the Company acquired all of the outstanding shares of Stoney Creek pursuant to a Share Purchase Deed, dated March 17, 2025, to expand the Company’s portfolio of BESS projects in Australia. The acquisition provides the Company with project rights to a 125 MW/1,000 MWh BESS to be located in Narrabri, New South Wales, Australia.

The transaction was accounted for as an asset acquisition because the BESS development assets acquired do not constitute a business. In an asset acquisition, total consideration includes transaction costs, and is allocated to the acquired assets based on relative fair values. Because the Company effectively acquired a single asset group (BESS development assets), the total consideration was recorded to construction in progress within property and equipment, net. Total consideration was AUD 4.3 million (or approximately $2.9 million), comprised of (i) the settlement of the Company’s loan receivable and accrued interest due from Stoney Creek and (ii) transaction costs incurred to effect the acquisition.

Property and equipment depreciation and amortization expense was $1.2 million and $1.6 million for the three and nine months ended September 30, 2025, respectively, compared to$0.2 million and $0.6 million for the same periods in 2024. The increases reflect depreciation recognized after the Company placed its owned energy storage systems and the CDU into service during 2025.

NOTE 8. INTANGIBLE ASSETS, NET

Intangible assets are stated at amortized cost and consist of the following (amounts in thousands):

Once a software application is available for general release and is placed in service, the Company amortizes the capitalized costs 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 for our external-use software development costs isfive years. Amortization expense for the three and nine months ended September 30, 2025 was $0.3 million and $0.7 million, respectively, and amortization expense for the three and nine months ended September 30, 2024 was $0.1 million and $0.3 million, respectively.

Future amortization expense for intangible assets is estimated as follows (amounts in thousands):

NOTE 9. DEBT

A summary of the Company’s debt is as follows (amounts in thousands):

The line item, interest expense, on the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2025 and 2024, consists of the following (amounts in thousands):

CRC Bridge Loan

On March 31, 2025, Calistoga Resiliency Center, LLC (“CRC”), a wholly-owned subsidiary of the Company, entered into a $27.8 million credit agreement (“CRC Bridge Loan”) with Jefferies Finance LLC, as administrative agent, collateral agent, and lender. The CRC Bridge Loan was intended to provide interim financing until long-term debt could be arranged. The CRC Bridge Loan carried a 9.5% annual interest rate and had a scheduled maturity date of April 23, 2025. After deducting closing fees, net proceeds totaled $26.8 million.

On April 4, 2025, the Company refinanced the full outstanding balance of the CRC Bridge Loan through the issuance of $27.8 million in CRC Senior Notes (as described below). The Company recognized a loss on early debt extinguishment of $1.4 million, which is included in the line item, other income (expense), net, in the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2025.

CRC Senior Notes

On April 4, 2025, CRC issued $27.8 million of senior notes (“CRC Senior Notes”), with Eagle Point Credit as lender and Jefferies serving as agent for the transaction. The CRC Senior Notes were priced at 99.25% of par, resulting in gross proceeds of $27.6 million. After deducting debt issuance costs, net proceeds totaled $23.2 million.

The CRC Senior Notes bear interest at 12.5% per annum until the earlier of (i) the Company’s receipt of any tax credit transfer proceeds and (ii) December 31, 2025, and thereafter at a rate of 9.50% per annum. The CRC Senior Notes are senior secured obligations of CRC, backed by a first-priority pledge of all CRC assets and equity interests. The CRC Senior Notes include customary affirmative and negative covenants, including minimum cash reserves and a minimum debt service coverage ratio.

Principal and interest are payable semi-annually, with installments due each February 28 and August 31. The first principal payment of $12.9 million was paid on August 31, 2025, with subsequent payments as set forth in the financing agreement. A final balloon payment of $7.0 million is due at maturity on April 4, 2032.

The Company may, at its option, redeem all or a portion of the CRC Senior Notes prior to maturity, subject to specified call protection provisions and any prepayment premiums set forth in the agreement. In the event of a change of control, the Company may be required to offer to repurchase the notes at a specified price.

Cross Trails Bridge Loan

On May 12, 2025, the Company entered into a secured bridge loan (“Cross Trails Bridge Loan”) with Crescent Cove Opportunity Lending, LLC (“Crescent Cove”) for $10.0 million, bearing interest at 24% per annum and with a maturity date of July 14, 2025. The loan was issued net of a 5% original issue discount and a structuring fee of $0.2 million, for net proceeds of $9.3 million. Total interest expense on the loan of $0.4 million was deducted from the loan proceeds. On July 14, 2025, the Company repaid $5.0 million of principal and simultaneously amended the loan to extend the maturity of the remaining $5.0 million to July 21, 2025. In connection with the extension, the Company paid a $0.2 million amendment fee. The remaining principal and additional interest for the extension were paid on July 18, 2025.

Cross Trails Senior Note

On July 23, 2025, Cross Trails Energy Storage Project, LLC (“Cross Trails”), a wholly-owned subsidiary of the Company (the “Cross Trails Borrower”), entered into a credit agreement (the “Cross Trails Senior Note”) with Wilmington Trust, National Association, as administrative agent and collateral agent, and Jefferies Capital Services, LLC, as initial lender.

The Cross Trails Senior Note provides for a senior secured term loan facility in an aggregate principal amount of approximately $17.8 million. After origination costs were deducted from the loan proceeds by the lender, net proceeds from the Cross Trails Senior Note were $17.6 million. The Cross Trails Senior Note is structured as a single-draw term loan, with the full amount funded on July 23, 2025. The borrowing bears interest, at the Company’s election, at (i) the alternate base rate (“ABR”) plus 5.00% or (ii) the term secured overnight financing rate (“SOFR”) plus 6.00%. Principal and interest are payable semi-annually, with installments due each February 28 and August 31, beginning on February 28, 2026. The Cross Trails Senior Note matures on July 23, 2032.

The Cross Trails Senior Note may be repaid at any time, subject to payment of accrued interest, breakage costs and a repayment premium. Mandatory prepayments are required upon the occurrence of certain customary events, including the receipt of insurance or condemnation proceeds (subject to customary reinvestment rights), asset sales above specified thresholds, the incurrence of additional non-permitted indebtedness, or the non-permitted issuance of new equity interests by the borrower, and are subject to the payment of accrued interest, breakage costs and a repayment premium.

The obligations under the Cross Trails Senior Note are secured by a first priority security interest in substantially all of the assets of the Cross Trails Borrower, including the project assets, accounts, and related collateral, as well as the membership interests in the Cross Trails Borrower. The Cross Trails Senior Note contains customary affirmative and negative covenants for a project financing of this type, including limitations on additional indebtedness, liens, asset sales, investments, affiliate transactions, and distributions. The Cross Trails Borrower is also required to maintain certain financial ratios, including a minimum debt service coverage ratio of 1.10:1.00, and to maintain of insurance, deliver certain financial and other reports, and comply with applicable laws and permits. The Cross Trails Senior Note also includes customary representations and warranties, indemnification provisions and requirements for the maintenance of insurance and compliance with applicable laws and permits.

Sale of Future Receipts

On August 29, 2025, the Company, together with Energy Vault, Inc., its wholly-owned subsidiary (collectively with the Company, the “Sellers”) entered into an agreement of sale of future receipts (the “Cedar Arrangement”) with Cedar Advance LLC (“Cedar”). Cedar paid a purchase price of $5.0 million, from which $0.5 million of origination fees were deducted, resulting in net proceeds of $4.5 million. Under the agreement, the Sellers remit to Cedar $0.2 million per week, or approximately 27.0% of future receivables collections, until Cedar has received an aggregate amount equal to (i) $5.1 million if fully repaid within 30 days of funding, (ii) $5.2 million if fully repaid after 30 days but within 60 days of funding, or (iii) $6.3 million if not fully repaid within 60 days of funding.

The Company did not fully repay the Cedar Arrangement within 60 days of funding, therefore the applicable aggregate amount to be remitted to Cedar will be $6.3 million. Through September 30, 2025, the Company had remitted $0.5 million to Cedar, with $5.8 million remaining.

On September 2, 2025, the Sellers entered into an agreement of sale of future receipts (the “UFS Arrangement”) with UFS West LLC (“UFS”). UFS paid a purchase price of $1.0 million, from which $0.1 million of origination fees were deducted, resulting in net proceeds of $0.9 million. Under the agreement, the Sellers remit to UFS $35 thousand per week, or approximately 4.9% of future receivables collections, until UFS has received an aggregate amount equal to (i) $1.0 million if fully repaid within 30 days of funding, (ii) $1.0 million if fully repaid after 30 days but within 60 days of funding, or (iii) $1.3 million if not fully repaid within 60 days of funding.

The Company fully repaid the UFS Arrangement on November 4, 2025, which was within 60 days of funding, therefore the applicable aggregate amount remitted was $1.0 million. Through September 30, 2025, the Company had remitted $0.1 million to UFS, with $0.9 million remaining.

On September 4, 2025, the Sellers entered into an agreement of sale of future receipts (the “Reliance Arrangement”) with Reliance Financial FL LLC (“Reliance”). Reliance paid a purchase price of $1.5 million, from which $0.2 million of origination fees were deducted, resulting in net proceeds of $1.3 million. Under the agreement, the Sellers remit to Reliance $0.1 million per week, or approximately 1.0% of future receivables collections, until Reliance has received an aggregate amount equal to (i) $1.5 million if fully repaid within 30 days of funding, (ii) $1.6 million if fully repaid after 30 days but within 60 days of funding, or (iii) $1.9 million if not fully repaid within 60 days of funding.

The Company fully repaid the Reliance Arrangement on November 4, 2025, which was within 60 days of funding, therefore the applicable aggregate amount remitted was $1.6 million. Through September 30, 2025, the Company had remitted $0.2 million to Reliance, with $1.4 million remaining.

Convertible Debentures

On September 22, 2025, the Company entered into a Securities Purchase Agreement (the “Purchase Agreement”) with YA II PN, Ltd. (the “Investor”), pursuant to which the Company agreed to issue senior unsecured convertible debentures (the “Convertible Debentures”) in multiple tranches with an aggregate principal amount of up to $50.0 million. The initial tranche of $30.0 million was funded at closing and net proceeds were $29.1 million after deductions for an original issue discount and origination fees.

The Convertible Debentures were issued at 97% of par, bear interest at 7.0% per annum (18.0% upon an uncured event of default), and mature on March 22, 2027. Beginning on the 65th day after the applicable closing and monthly thereafter (each, a “Payment Date”), scheduled installments of principal and accrued interest are due as follows (per $10.0 million of original principal): $0.4 million on the first Payment Date, $0.6 million on each of the next 13 Payment Dates, $0.8 million on the next Payment Date, and $1.0 million at maturity.

For the initial tranche, the fixed conversion price is $4.50 per share. For each tranche, the fixed conversion price (the “Fixed Price”) is equal to 150% of the Bloomberg volume-weighted average price (“VWAP”) of the Company’s common stock on the trading day prior to that tranche’s closing.

On any Payment Date when the Company’s daily VWAP has equaled or exceeded 115% of the Fixed Price for each of thefive prior trading days, no Company Redemption (cash installment) is due for that date (the principal remains outstanding). For each installment, the Company may (i) pay cash plus a payment premium equal to 7.0% of the principal portion paid (“Payment Premium”) (10.0% while an Amortization Event is in effect, as defined below), (ii) elect to allow the Investor to convert the unpaid installment at a price equal to the lower of (A) the Fixed Price or (B)97% of the lowest daily VWAP during thefour trading days immediately preceding the conversion date, but not below the Floor Price (equal to $0.60 per share for the initial tranche), or (iii) satisfy the installment through a combination of cash and conversion.

Investor conversions are subject to a beneficial ownership limit of 4.99% of the Company’s common stock and to a limit of 19.99% of the Company’s outstanding common stock as of closing unless stockholder approval to exceed such cap is obtained in accordance with the rules and regulations of the New York Stock Exchange (the “Exchange Cap”). An “Amortization Event” includes, among other things, (i) the Company’s common stock trading below the Floor Price for 5 of 7 consecutive trading days, (ii) issuance of more than 99% of the shares available under the Exchange Cap without stockholder approval, or (iii) beginning 60 days after issuance, the resale registration statement being unusable for 10 consecutive trading days. While an Amortization Event is in effect, the monthly installment must be paid in cash, the applicable payment premium is 10.0%, and the installment amount may increase to the greater of the scheduled amount and 20.0% of then-outstanding principal.

Outside the monthly payment schedule, the Company may optionally redeem the Convertible Debentures upon advance notice for cash when the VWAP is below the Fixed Price (with the applicable Payment Premium). Upon a change of control, the Company may redeem all outstanding Convertible Debentures at 110% of principal.

In connection with the Purchase Agreement, the Company entered into a registration rights agreement (the “Registration Rights Agreement”) with the Investor, pursuant to which the Company agreed to file a registration statement covering the resale of the Common Stock issuable upon conversion of the Convertible Debentures within 10 business days after closing and to use commercially reasonable efforts to obtain effectiveness within 60 days. The Purchase Agreement includes customary covenants and restrictions, including a prohibition on variable-rate transactions while amounts may be or are outstanding, limitations on additional indebtedness and liens subject to agreed exceptions (including specified project-level indebtedness for subsidiaries such as Calistoga and Cross Trails and certain refinancings), and limitations on the Company’s use of existing equity lines without Investor consent. The Company may utilize its at-the-market equity (“ATM”) program only if specified conditions are satisfied, applying 25.0% of gross ATM proceeds to reduce the Convertible Debentures principal on the back end of the schedule, and observing a cooling-off period of three trading days after an Investor market-price conversion; if the ATM is used in any calendar month, the next scheduled amortization payment will be convertible at the Investor’s election. Any subsidiary that directly receives Convertible Debenture proceeds must guarantee the Company’s obligations. The Investor agreed not to engage in short sales of the Company’s equity, but may sell shares corresponding to submitted conversions.

Subject to customary conditions (including no event of default), the Company may draw an additional $20.0 million withinten business days after the closing of a qualifying preferred equity investment and the effectiveness of a resale registration statement. Any such second tranche would be issued on substantially the same terms as the initial tranche, except that its Fixed Price would reset to 150% of the Bloomberg VWAP on the trading day prior to that tranche’s closing.

The Convertible Debentures and the shares of common stock issuable upon conversion thereof have not been registered under the Securities Act of 1933, as amended (the “Securities Act”), and were offered and sold in a private placement in reliance on Section 4(a)(2) of the Securities Act and/or Rule 506 of Regulation D thereunder. The Investor represented that it is an accredited investor.

The Company elected the fair value option afforded by ASC 825 with respect to the Convertible Debentures because it includes features that meet the definition of an embedded derivative. As such, the Company initially recognized the Convertible Debentures at its fair value of $29.1 million and will subsequently measure it at fair value with changes recorded in the condensed consolidated statements of operations and comprehensive loss.

Debt Maturity

The following table summarizes the cash maturities of the Company’s debt instruments as of September 30, 2025 (amounts in thousands):

Insurance Premium Financings

In April 2024, the Company entered intotwo financing agreements related to premiums under certain insurance policies. For the first financing, the Company was obligated to repay the lender an aggregate sum of $1.4 million throughten equal monthly payments commencing on April 10, 2024. For the second financing, the Company was obligated to repay the lender an aggregate sum of $0.4 million through nine equal monthly payments commencing on May 10, 2024. Both financings had an annual interest rate of 7.4% and were fully repaid during the first quarter of 2025.

In June 2024, the Company entered into a financing agreement related to premiums under certain insurance policies. The Company is obligated to repay the lender an aggregate sum of AUD 0.3 million (or $0.2 million) through twelve equal monthly payments of AUD 22 thousand (or $15 thousand), at an annual interest rate of 4.4%, commencing on June 25, 2024. This financing was fully repaid in May 2025.

In July 2024, the Company entered into a financing agreement related to premiums under certain insurance policies. The Company is obligated to repay the lender an aggregate sum of $1.1 million through nine equal monthly payments, at an annual interest rate of 7.5%, commencing on August 15, 2024. This financing was fully repaid in April 2025.

In March 2025, the Company entered into a financing agreement related to premiums under certain insurance policies. The Company is obligated to repay the lender an aggregate sum of $1.5 million through nine equal monthly payments, at an annual interest rate of 5.8%, commencing on April 10, 2025.

In June 2025, the Company entered into a financing agreement related to premiums under certain insurance policies. The Company is obligated to repay the lender an aggregate sum of AUD 0.3 million (or $0.2 million) throughten equal monthly payments of AUD 31 thousand (or $21 thousand), at an annual interest rate of 8.7%, commencing on June 15, 2025.

In July 2025, the Company entered into a financing agreement related to premiums under certain insurance policies. The Company is obligated to repay the lender an aggregate sum of $0.9 million throughten equal monthly payments, at an annual interest rate of 7.1%, commencing on July 15, 2025.

As of September 30, 2025 and December 31, 2024, the carrying value of the Company’s insurance premium financings was $1.3 million and $0.7 million, respectively, and is included in the line item, accrued expenses, in the condensed consolidated balance sheets.

NOTE 10. PENSION

The components of net periodic pension benefit cost for the Company’s defined benefit pension plan was as follows (amounts in thousands):

NOTE 11. SUPPLEMENTAL BALANCE SHEETS DETAIL

NOTE 12. FAIR VALUE MEASUREMENTS

Carrying amounts of certain financial instruments, including cash, cash equivalents, restricted cash, accounts payable, and accrued expenses approximate their fair value due to their relatively short maturities and market interest rates, if applicable.

The Company categorizes assets and liabilities recorded or disclosed at fair value on the consolidated balance sheet based upon the level of judgment associated with inputs used to measure their fair value. The categories are as follows:

•Level 1—Inputs which included quoted prices in active markets for identical assets and liabilities.

•Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

•Level 3—Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.

The Company’s financial assets and liabilities measured at fair value on a recurring basis are as follows (amounts in thousands):

(1) The Company has elected to measure the Convertible Debentures at fair value (see Note 9, Debt). The Company uses a Monte Carlo simulation to value the Convertible Debentures. The significant assumptions used in the model includes volatility of the Company’s common stock (65.0%), the Company’s debt discount rate based on a CCC rating (21.5%), and the expected life of the instrument. There was no change in the fair value of the Convertible Debentures between their issuance date of September 22, 2025 and September 30, 2025.

(2) The warrants are not publicly traded and the Company uses a Black-Scholes model to determine the fair value of the warrants.

The carrying amount and estimated fair value of the Company’s financial instruments not measured at fair value are as follows (amounts in thousands):

(1) Includes short-term portion of long-term debt and excludes debt measured at fair value. The Company estimates the fair value using a discounted cash flow model which utilizes the Company’s incremental borrowing rate, which is estimated based on the Company’s assumptions.

NOTE 13. STOCKHOLDERS’ EQUITY

Hudson Equity Purchase Agreement

On March 31, 2025, the Company entered into an equity purchase agreement (the “Hudson Equity Purchase Agreement”) with Hudson Global Ventures, LLC, a Nevada limited liability company (“Hudson”). Pursuant to the Hudson Equity Purchase Agreement, the Company has the right, but not the obligation, to sell to Hudson, and Hudson is obligated to purchase, up to approximately $25.0 million of newly issued shares (the “Maximum Commitment”) of the Company’s common stock, from time to time during the term of the Hudson Equity Purchase Agreement, subject to certain limitations and conditions (the “Hudson Offering”). As consideration for Hudson’s commitment to purchase shares of common stock under the Hudson Equity Purchase Agreement, we paid Hudson a commitment fee of $0.2 million during the first quarter of 2025 and issued them 452,000 shares of common stock during the second quarter of 2025, valued at $0.4 million at the time of issuance, following the execution of the Hudson Equity Purchase Agreement (the “Commitment Shares”). The commitment fees were recorded within other income (expense), net in the Company’s condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2025.

The Hudson Equity Purchase Agreement initially precludes the Company from issuing and selling more than 30,833,163 shares of our common stock, including the Commitment Shares, which number equaled 19.99% of our common stock issued and outstanding as of March 31, 2025, unless the Company obtains stockholder approval to issue additional shares, or unless certain exceptions apply. In addition, a beneficial ownership limitation in the agreement initially limits the Company from directing Hudson to purchase shares of common stock if such purchases would result in Hudson beneficially owning more than 4.99% of the then-outstanding shares of our common stock.

From and after the initial satisfaction of the conditions to commence sales to Hudson under the Hudson Equity Purchase Agreement (such event, the “Commencement,” and the date of initial satisfaction of all such conditions, the “Commencement Date”), the Company may direct Hudson to purchase shares of common stock at a purchase price per share equal to the lesser of (i)88% of the closing price of the Company’s common stock on the Principal Market on the Trading Day immediately preceding the respective Put Date (as defined in the Hudson Equity Purchase Agreement) (the “Initial Purchase Price”), or (ii)88% of the lowest closing price of the Company’s common stock on the Principal Market on any Trading Day during the period beginning on the Put Date and continuing through the date that is three Trading Days immediately following the Clearing Date associated with the applicable Put Notice (such three trading day period is the “Valuation Period”, and the price is the “Market Price”), on such date on which the Purchase Price is calculated in accordance with the terms of the Hudson Equity Purchase Agreement. The Company will control the timing and amount of any such sales of common stock to Hudson. Actual sales of shares of common stock to Hudson will depend on a variety of factors to be determined by the Company from time to time, including, among other things, market conditions, the trading price of our common stock, and determinations by us as to the appropriate sources of funding for the Company and our operations.

Unless earlier terminated, the Hudson Equity Purchase Agreement will automatically terminate upon the earliest of (i) the expiration of the Commitment Period (as defined in the Hudson Equity Purchase Agreement), (ii) Hudson’s purchase or receipt of the Maximum Commitment worth of common stock, or (iii) the occurrence of certain other events set forth in the Hudson Equity Purchase Agreement. We have the right to terminate the Hudson Equity Purchase Agreement at any time after Commencement, at no cost or penalty, upon prior written notice to Hudson.

The Company intends to use the net proceeds, if any, from the Hudson Offering for working capital and general corporate purposes, including sales and marketing activities, product development, and capital expenditures. The Company may also use a portion of the net proceeds to acquire or invest in complementary businesses, products, and technologies. The Hudson Equity Purchase Agreement contains customary representations, warranties, and agreements, as well as customary indemnification obligations of the Company.

In connection with the Hudson Equity Purchase Agreement, the Company entered into a Registration Rights Agreement, pursuant to which the Company agreed to register the Commitment Shares and the shares issuable pursuant to the Purchase Agreement. The securities to be offered pursuant to the Hudson Equity Purchase Agreement will be offered pursuant to our effective shelf registration statement on Form S-3/A shelf registration statement (File No. 333-273089), which was filed with the Securities and Exchange Commission (the “SEC”) on July 14, 2023 and declared effective on July 20, 2023.

During the three and nine months ended September 30, 2025, the Company sold 3.9 million and 6.2 million shares of common stock, respectively, to Hudson for net proceeds of $5.7 million and $6.8 million, respectively.

Helena Equity Purchase Agreement

On August 6, 2025, the Company entered into an equity purchase agreement (the “Helena Purchase Agreement”) with Helena Global Investment Opportunities I Ltd. (“Helena”). Pursuant to the Helena Purchase Agreement, the Company has the right, but not the obligation, to sell to Helena, and Helena is obligated to purchase, up to $25.0 million of newly issued shares of the Company’s common stock, from time to time over a 36-month term, subject to certain limitations and conditions. The obligations under the Helena Purchase Agreement are subject to a standstill period and will not commence until the later of (i) ninety days from the execution of the Helena Purchase Agreement, or (ii) the termination or expiration of the Company's existing Hudson Equity Purchase Agreement.

As consideration for Helena’s commitment, the Company is obligated to issue commitment shares to Helena with an aggregate value of $0.2 million. The number of commitment fee shares is determined by dividing this value by the lowest one-day VWAP during the five trading days preceding the date of the agreement.

The Helena Purchase Agreement initially precludes the Company from issuing and selling more than 19.99% of the Company’s common stock issued and outstanding as of the date of the Helena Purchase Agreement, including the commitment fee shares, unless the Company obtains stockholder approval to issue additional shares. In addition, a beneficial ownership limitation in the Helena Purchase agreement restricts the Company from directing Helena to purchase shares of common stock if such purchases would result in Helena beneficially owning more than 4.99% of the then-outstanding shares of our common stock.

After the initial conditions are met, the Company may direct Helena to purchase shares of common stock through an advance notice. The purchase price for shares in such an advance will be equal to 95% of the lowest closing price during thethree-day pricing period following the advance. The agreement also allows for a subsequent advance notice for a number of shares mutually agreed upon, with a purchase price equal to 100% of the lowest intraday sale price on the day the notice is received. The Company will control the timing and amount of any sales of common stock to Helena.

Unless earlier terminated, the Helena Purchase Agreement will automatically terminate upon the earliest of (i) the expiration of the 36-month term, or (ii) Helena’s purchase of $25.0 million worth of common stock. The Company has the right to terminate the Helena Purchase Agreement at any time, at no cost or penalty, upon five trading days’ prior written notice to Helena.

NYSE Notification

On April 16, 2025, the Company was notified by the NYSE that it was not in compliance with Section 802.01C of the NYSE Listed Company Manual because the average closing price of the Company’s common stock was less than $1.00 over a consecutive 30 trading-day period. On September 3, 2025, the Company received written notice from the NYSE stating that the Company regained compliance with the minimum continued listing criteria set forth in Section 802.01C of the NYSE Listed Company Manual, based upon an average share price for the trailing 30-consecutive trading days above $1.00.

Dorado Goose Warrants

On August 18, 2025, the Company completed the private issuance of an aggregate of 4.5 million warrants (the “Dorado Goose Warrants”) to purchase shares of the Company’s common stock to Dorado Goose, LLC in exchange for professional services. The Dorado Goose Warrants are exercisable until August 18, 2027 and permit cashless exercise. The exercise price for the warrants range from $1.50 per share to $3.00 per share, and the number of shares issuable upon exercise are subject to customary anti-dilution adjustments for stock splits, stock dividends, and similar events. Until exercised, the Dorado Goose Warrants do not entitle the holder to voting or other stockholder rights.

The issuance of the Dorado Goose Warrants and the shares issuable upon exercise of those warrants have not been registered under the Securities Act or under any state securities law. The Company believes that the transaction is exempt from registration under Section 4(a)(2) of the Securities Act, and customary legends were affixed to the Dorado Goose Warrants and will be affixed to any shares issued upon exercise of the Dorado Goose Warrants.

The Dorado Goose Warrants are accounted for under ASC 718 as an equity-classified award to a non-employee service provider. Because the award is equity-classified, it was measured at grant date fair value and is not remeasured subsequently. The full fair value of the Dorado Goose Warrants was recognized as expense in the condensed consolidated statement of operations within general and administrative expenses during the three and nine months ended September 30, 2025.

The grant date fair value of the award was $1.2 million and was estimated using a Black-Scholes option pricing model with the following assumptions:

NOTE 14. STOCK-BASED COMPENSATION

2022 Equity Incentive Plan

In 2022, the Company adopted its 2022 Equity Incentive Plan (the “2022 Incentive Plan”). The 2022 Incentive Plan provides for the granting of stock options, stock appreciation rights (“SARs”), restricted stock, and RSUs to employees, non-employee directors, and consultants of the Company. Shares of common stock underlying awards that expire or are forfeited or canceled will again be available for issuance under the 2022 Incentive Plan.

The initial number of shares of the Company’s common stock reserved for issuance under the 2022 Incentive Plan was approximately 15.5 million, plus up to approximately 8.3 million shares subject to awards granted under the 2017 and 2020 Stock Incentive Plans. Annually, beginning in March 2022 and ending in (and including) March 2031, the number of shares of the Company’s common stock that may be issued under the 2022 Incentive Plan increases by a number of shares equal to the lesser of (i)4.0% of the outstanding shares on the last day of the immediately preceding month or (ii) such lesser number of shares (including zero) that the Company’s Board determines for the purposes of the annual increase for that fiscal year.

2022 Inducement Plan

In 2022, the Company adopted its 2022 Inducement Plan, which provides for the granting of stock options, SARs, restricted stock, and RSUs to individuals who were not previously employees of Energy Vault, or following a bona fide period of non-employment, as inducement material to such individuals entering into employment with Energy Vault. Shares of common stock underlying awards that expire or are forfeited or canceled will again be available for issuance under the 2022 Inducement Plan.8.0 million shares of the Company’s common stock are reserved for issuance under the 2022 Inducement Plan.

2025 Inducement Plan

In February 2025, the Board approved the Company’s 2025 Inducement Plan, which provides for the granting of stock options, SARs, restricted stock, and RSUs to individuals who were not previously employees of Energy Vault, or following a bona fide period of non-employment, as inducement material to such individuals entering into employment with Energy Vault. Shares of common stock underlying awards that expire or are forfeited or canceled will again be available for issuance under the 2025 Inducement Plan.8.0 million shares of the Company’s common stock are reserved for issuance under the 2025 Inducement Plan.

Stock Option Activity

Stock option activity for the nine months ended September 30, 2025 was as follows (amounts in thousands, except per share data):

As of September 30, 2025, total unrecognized stock-based compensation expense related to unvested option awards that are expected to vest was $1.9 million. The weighted-average period over which such stock-based compensation expense will be recognized is approximately 1.3 years.

The aggregate intrinsic values of options outstanding, exercisable, vested and expected to vest were calculated as the difference between the exercise price of the options and the closing stock price of the Company’s common stock on the NYSE as of September 30, 2025.

Restricted Stock Units

During the nine months ended September 30, 2025, pursuant to the 2022 Inducement Plan, the Company granted RSUs to employees that vest based on market-based conditions. These RSUs will vest and convert to common stock if the Company’s stock price reaches certain price targets for 20 days in any 30 day trading window. The fair value of the RSUs are recognized as expense over the requisite service period regardless of whether or not the RSUs ultimately vest and convert to common stock. The fair value of these market-based RSUs were measured on their grant date, using a Monte Carlo simulation model based on the following range and weighted-average assumptions:

RSU activity for the nine months ended September 30, 2025 was as follows (amounts in thousands, except per share data):

As of September 30, 2025, unrecognized stock-based compensation expense related to these RSUs was $27.3 million which is expected to be recognized over the remaining weighted-average vesting period of approximately 1.5 years.

Stock-Based Compensation Expense

Total stock-based compensation expense for the three and nine months ended September 30, 2025 and 2024 was as follows (amounts in thousands):

NOTE 15. REORGANIZATION EXPENSES

Periodically, the Company implements cost savings measures and recognizes reorganization costs related to those measures. Reorganization expenses consist of personnel reduction costs.

During the three and nine months ended September 30, 2025, the Company recognized $— million and $1.2 million in reorganization costs. Currently, the Company does not expect to incur additional charges related to this cost reduction plan.

Total reorganization expenses for the three and nine months ended September 30, 2025 and 2024 are as follows (amounts in thousands):

A reconciliation of the beginning and ending liability balances for reorganization expenses included in the line item, accrued expenses, on the condensed consolidated balance sheets is as follows (amounts in thousands):

NOTE 16. SEGMENT REPORTING

As a single reportable segment entity, the Company’s chief operating decision maker (“CODM”) uses the profit measure of net loss to allocate resources and assess performance of our business by comparing actual results to historical results and previously forecasted financial information. The measure of segment assets is reported on the condensed consolidated balance sheets as total assets.

See Note 3 for the Company’s revenue disaggregated by product line.

The following table presents revenue, significant segment expenses provided to the CODM, and net loss for our consolidated segment (amounts in thousands):

(1) Represents sales and marketing, research and development, and general and administrative expenses, excluding personnel related costs and reorganization expenses.

(2) Represents the costs of employees’ salaries, benefits, and payroll taxes that are reported within sales and marketing, research and development, and general and administrative expenses in the condensed consolidated statements of operations and comprehensive loss. This amount excludes stock-based compensation expense and reorganization expenses.

(3)$1.2 million of depreciation and amortization expense recognized within cost of revenue for the three and nine months ended September 30, 2025.

(4) Represents certain other segment items that are not deemed significant segment expenses and primarily consists of provision for credit losses, reorganization expenses, and other income/expense items.

NOTE 17. INCOME TAXES

The Company recognized a tax provision of $5.5 million and $8.0 million for the three and nine months ended September 30, 2025, respectively, and didnot recognize any tax provision for the three and nine months ended September 30, 2024.

The provision for income taxes for the three months ended September 30, 2025 is primarily related to the recording of a partial valuation allowance against ITCs generated during the period. The provision for income taxes for the nine months ended September 30, 2025 is primarily related to the recording of a partial valuation allowance against ITCs generated during the period and tax withholdings on foreign revenue.

The Company has recorded a full valuation allowance against substantially all of the Company’s deferred tax assets, except for the deferred tax assets associated with the ITCs that the Company intends to sell. The Company provides for a valuation allowance when it is more likely than not that some portion of, or all of the Company’s deferred tax assets will not be realized. Due to the Company’s history of losses, the Company determined that it is not more likely than not to realize its deferred tax assets, with the exception of deferred tax assets associated with the ITCs that the Company intends to sell.

On July 4, 2025, Public Law No. 119-21, commonly referred to as the One Big Beautiful Bill Act (the “OBBBA”), was enacted. The OBBBA contains a broad range of changes to U.S. federal income tax laws. These changes include, among others, permanently restoring an EBITDA-based business interest deduction limitation, permanently restoring 100% bonus depreciation for certain property, permanently restoring immediate expensing for certain domestic research and experimental expenditures, and changes with respect to ITCs. The effects of changes in tax laws are recognized in the condensed consolidated financial statements during the period of enactment. The effects of the OBBBA are not expected to have a material impact on the Company’s condensed consolidated financial statements.

NOTE 18. NET LOSS PER SHARE OF COMMON STOCK

Basic and diluted net loss per share attributable to common stockholders are calculated as follows (amounts in thousands, except per share amounts):

There wereno common share equivalents that were dilutive for the three and nine months ended September 30, 2025 and 2024. Due to net losses during those periods, basic and diluted net loss per common share were the same, as the effect of potentially dilutive securities would have been anti-dilutive.

The following outstanding balances of common share equivalent securities have been excluded from the calculation of diluted weighted-average common shares outstanding because the effect is anti-dilutive for the three and nine months ended September 30, 2025 and 2024 (amounts in thousands):

(1) The increase in warrants represents the Dorado Goose Warrants issued on August 18, 2025. Refer to Note 13, Stockholders’ Equity, for further details.

In connection with the reverse recapitalization in 2022, eligible Energy Vault stockholders immediately prior to the closing of the transaction obtained a contingent right to receive 9.0 million shares of the Company’s common stock (“Earn-Out Shares”) upon the Company’s common stock quoted on the NYSE equaling or exceeding certain specified prices for any 20 trading days within a 30 consecutive day trading period (“Earn-Out Triggering Event”).9.0 million of common stock equivalents subject to the Earn-Out Shares are excluded from the anti-dilutive table above as of September 30, 2025 and 2024 as the Earn-Out Triggering Events for the underlying shares had not been satisfied. The contingent right for Earn-Out Shares expired on May 12, 2025.

NOTE 19. COMMITMENTS AND CONTINGENCIES

Our principal commitments as of September 30, 2025 consisted primarily of obligations under operating leases, finance leases, a deferred pension, warranty liabilities, and issued purchase orders. Our non-cancelable purchase obligations as of September 30, 2025 totaled approximately $4.0 million.

Loss Contingencies:

In the ordinary course of business, the Company is regularly subject to various legal proceedings. The Company has identified certain legal matters where the Company believes an unfavorable outcome is not probable and, therefore, no reserve has been established. Although the Company currently believes that resolving claims against the Company, including claims where an unfavorable outcome is reasonably possible, will not have a material impact on the Company’s business, financial position, results of operations, or cash flows, these matters are subject to inherent uncertainties and the Company’s view of these matters may change in the future.

Warranty Liabilities:

The Company provides a limited warranty to its BESS customers assuring that the BESSs are free from defects. The Company’s limited warranties are generally for a period oftwo orthree years after the substantial completion date of a project. These warranties are considered assurance-type warranties which provide a guarantee of quality of the products. For assurance-type warranties in engineering, procurement, and construction (“EPC”) contracts, the Company records an estimate of future warranty costs over the period of construction. For assurance-type warranties in engineered equipment (“EEQ”) contracts, the Company records an estimate of future warranty costs upon the transfer of the equipment to the customer. Warranty costs are recorded as a component of cost of revenue in the Company’s condensed consolidated statements of operations and comprehensive loss.

As of September 30, 2025 and 2024, the Company accrued the below estimated warranty liabilities, respectively (amounts in thousands):

The key inputs and assumptions used in calculating the estimated warranty liabilities are reviewed by management each reporting period. The Company may make additional adjustments to the estimated warranty liability based on a comparison of actual warranty results to expected results for significant differences or based on performance trends or other qualitative factors. If actual failure rates or replacement costs differ from our estimates in future periods, changes to these estimates may be required, resulting in increases or decreases in the estimated warranty liability, which may be material.

Letters of Credit and Bank Guarantees:

In the ordinary course of business and under certain contracts, the Company is required to post letters of credit or bank guarantees for its customers, for project performance, and for its vendors for payment guarantees. Such letters of credit or bank guarantees are generally issued by a bank or a similar financial institution. The letter of credit or bank guarantee commits the issuer to pay specified amounts to the holder of the letter of credit or bank guarantee under certain conditions. As of September 30, 2025, the Company had $14.7 million in outstanding letters of credit and $8.7 million in bank guarantees issued through the Company’s credit relationships. The Company is not aware of any material claims relating to its outstanding letters of credit or bank guarantees.

Performance and Payment Bonds:

In the ordinary course of business, Energy Vault is required by certain customers to provide performance and payment bonds for contractual commitments related to its projects. These bonds provide a guarantee that the Company will perform under the terms of a contract and that the Company will pay its subcontractors and vendors. If the Company fails to perform under a contract or to pay its subcontractors and vendors, the customer may demand that the surety make payments or provide services under the bond. The Company must reimburse the surety for expenses or outlays it incurs. As of September 30, 2025, the Company had $134.6 million in outstanding performance and payment bonds.

Other Bonds:

In the ordinary course of business, Energy Vault is required to obtain other bonds, such as for insurance and government payments. These bonds provide a guarantee that the Company will post the necessary reserves as required by banks and tax or licensing authorities. Additionally, bonds are issued to banks as support for letters of credit provided by those banks. As of September 30, 2025, the Company had $20.5 million in outstanding other bonds.

Tax Credit Transfer Commitment

On March 28, 2025, the Company entered into a Tax Credit Transfer Commitment, on behalf of its wholly-owned subsidiary companies, with a third-party purchaser pursuant to which the Company agreed to sell certain ITCs generated by the CRC HESS, the Cross Trails BESS, and the Snyder CDU. The Tax Credit Transfer commitment is subject to certain conditions set forth therein, and requires the Company to incur the remaining associated capital expenditures to complete the projects (via internal sources or external sources such as project financing). The third-party purchaser has agreed to purchase on or before December 15, 2025, all the eligible ITCs generated by these projects, in an amount to be finalized subject to final cost segregation reports, which management believes will be approximately $40.6 million, net of fees, across all three projects. On July 18, 2025, the Company’s wholly-owned subsidiaries related to the Calistoga Resiliency Center entered into a Tax Credit Purchase Agreement with Vitol, Inc. for the sale of certain ITCs generated at the Calistoga Resiliency Center.

Asset Retirement Obligation

In connection with the acquisition or development of energy storage systems, the Company may have the legal requirement to remove long-lived assets constructed on leased property and to restore the leased property to its condition prior to the construction of the long-lived asset. This legal requirement is referred to as an asset retirement obligation (“ARO”). If the Company determines that an ARO is necessary for a specific energy storage system, the Company records the present value of the estimated future liability when the energy storage system is placed in service as an ARO liability. The Company accretes the ARO liability to its future value over the energy storage system’s useful life in the condensed consolidated statements of operations and comprehensive loss. The initial ARO is recorded as part of the carrying value of the related long-lived asset and depreciated over the energy storage system’s useful life. The CRC HESS is the only energy storage system currently subject to an ARO. The initial ARO for the CRC HESS was $1.0 million.

The Company measured the ARO for the CRC HESS at fair value (level 3) using an expected present value technique. This approach estimates the cash flows a market participant would require to perform the retirement activities and discounts those cash flows using a credit-adjusted risk-free rate (10.8% at initial recognition).

As of September 30, 2025, the carrying value of the Company’s ARO was $1.0 million. For the three and nine months ended September 30, 2025, the Company recognized accretion expense of $17 thousand.

NOTE 20. SUBSEQUENT EVENTS

Asset Vault Funding

On October 9, 2025, Energy Vault, Inc, a wholly-owned subsidiary of the Company, entered into a contribution and purchase agreement (the “Contribution Agreement”) with OIC Structured Equity Fund I, L.P., OIC Structured Equity Fund I AUS, L.P., and OIC Structured Equity Fund I GPFA, L.P., (collectively, “OIC”) and Asset Vault, LLC (“Asset Vault”), which at the time was a wholly-owned subsidiary of the Company, to establish a joint venture among the Company and OIC dedicated to developing, building, owning and operating energy storage assets globally. Pursuant to the Contribution Agreement, Asset Vault issued to OIC 300 million preferred units in Asset Vault (the “Series A Preferred Units”) in exchange for an initial cash contribution of $35.0 million and a commitment to make further cash contributions upon the satisfaction of certain conditions in an amount up to an aggregate of $300.0 million. Additionally, pursuant to the Contribution Agreement, in exchange for 1.2 billion common units of Asset Vault, Energy Vault contributed to Asset Vault:

•100% of the equity interests of Calistoga Resiliency Center Holdco, LLC;

•100% of the equity interests of Cross Trails Energy Storage Project Holdco, LLC;

•100% of the equity interests of Energy Vault Stoney Creek HoldCo Pty Ltd;

•100% of the equity interests of Energy Vault Stoney Creek Holdings Unit Trust;

•and 100% of any right, title, and interest in a certain future battery energy storage system following its acquisition by Energy Vault.

Energy Vault, Asset Vault, and OIC have made customary representations and warranties, and have agreed to customary covenants in the Contribution Agreement. The Contribution Agreement also provides for indemnification rights with respect to, among other things, breaches of representations, warranties or covenants by the parties.

The Series A Preferred Units in Asset Vault are non-voting, and do not have any consent, approval, or voting rights, except as set forth in the amended and restated limited liability company agreement of Asset Vault. The Series A Preferred Units are subject to mandatory redemption upon the consummation of a sale of Asset Vault. The redemption price of each Series A Preferred Unit equals the greater of (i) the cumulative capital contributions in respect of such Series A Preferred Unit plus the amount of accrued preferred distributions on such Series A Preferred Unit (including any such accrued distributions previously compounded as a “payment-in-kind” accrual) and (ii) the greater of (x) a 1.65 x multiple on invested capital on the cumulative capital contributions in respect of such Series A Preferred Unit and (y) a 12% internal rate of return in respect of such Series A Preferred Unit.

Pursuant to the Contribution Agreement, in connection with OIC’s initial contribution of $35.0 million with respect to its Series A Preferred Units, the Company issued to OIC an aggregate of 5.6 million warrants to purchase common stock of the Company at an exercise price of $4.24 per share (“OIC Warrants”). The OIC Warrants are entitled to a cashless exercise, are subject to athree-year holding period, and are exercisable until October 9, 2030.

In connection with future capital contributions to Asset Vault by OIC, the Company shall issue additional warrants to OIC at an exercise price equal to the product of (a)1.25 and (b) the VWAP for thefive trading days preceding such capital contribution. For capital contributions in excess of $35.0 million and up to $125.0 million in the aggregate, the number of warrant shares issued would equal the following rounded down to the nearest whole share: (a)14.3 million shares of common stock multiplied by (b) the amount of such capital contribution divided by $90.0 million. For capital contributions in excess of $125.0 million in the aggregate (up to $300.0 million), the number of warrant shares issued would equal the following rounded down to the nearest whole share: (a)19.9 million multiplied by (b) the amount of such capital contribution amount divided by $175.0 million.

The exercise price and the number of shares of the Company’s common stock issuable upon exercise of the OIC Warrants are subject to customary anti-dilution adjustments. So long as the OIC Warrants are unexercised, the OIC Warrants do not entitle the holder to any voting rights or any other shareholder rights. The issuance of the OIC Warrants and the shares issuable upon exercise have not been registered under the Securities Act, or under any state securities law. The Company believes that the transaction is exempt from registration under Section 4(a)(2) of the Securities Act, and customary legends were affixed to the OIC Warrants and will be affixed to any shares issued upon exercise of the OIC Warrants.

SOSA Acquisition

On October 23, 2025, the Company acquired 100% of the membership interests of SOSA Energy Center, LLC (“SOSA”) from Savion, LLC (“Savion”). SOSA has the rights to build a 150 MW/300 MWh BESS project located in Madison County, Texas and represents the first project formally acquired under the Company’s Asset Vault platform.

Under the membership interest purchase agreement, consideration is defined as a capacity-based purchase price equal to the project’s MWs (“Project Capacity”) at the commercial operate date (“COD”), multiplied by a fixed per-MW rate, subject to a cap that uses the greater of 150.54 MW or the ERCOT-allowed MW discharge limit. The agreement requires (i) a closing payment at signing of $4.7 million and (ii) a true-up within 30 days after the project’s COD based on Project Capacity as of COD. If the Project Capacity increases after COD, an additional payment is due within 30 days, subject to an aggregate 150 MW limit for that post-COD true-up. If the COD calculation is negative, no payment is due and no refund is owed.

Assuming project capacity of 150 MW at COD, the capacity-based purchase price would be $5.7 million if COD occurs after June 1, 2026 and $6.3 million if COD occurs on or before June 1, 2026. After applying the $4.7 million payment made at closing, the additional amount payable within 30 days after COD would therefore be approximately $1.0 million or $1.6 million, respectively. The ultimate amount will depend on Project Capacity at COD and COD timing.

Concurrently with the SOSA acquisition, the Company entered into equipment purchase agreements with Savion to acquire specific project equipment for aggregate fixed consideration of $3.4 million.