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

(In thousands)

Condensed Consolidated Statements of Cash Flows

(In thousands)

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,” is an integrated power infrastructure platform that builds, owns and operates flexible, reliable energy systems designed to accelerate time-to-power for utilities, independent power producers, industrial customers and the artificial intelligence and data center market. At the core of our platform is a technology-agnostic, software-enabled architecture that is designed to accelerate project delivery, optimize performance and drive faster time-to-revenue. Energy Vault’s integrated solutions combine energy storage, generation, and advanced energy management to deliver scalable infrastructure tailored to customer needs. Our portfolio spans short-, long-, and multi-day duration storage, engineered to enable reliability, flexibility and cost efficiency across applications.

Through this integrated model, we offer utilities, independent power producers, and large energy users solutions that may include standalone energy storage, integrated generation and storage configurations, and related power infrastructure. We manage projects across the lifecycle, from sourcing and development through permitting and interconnection, engineering and construction management, commissioning, and operations, and we provide software enabled monitoring, controls, and services intended to support asset availability, operational efficiency, and lifecycle performance.

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, 2025. The condensed consolidated balance sheet as of December 31, 2025, 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 March 31, 2026 and results of operations and comprehensive loss, stockholders’ equity activities, and cash flows for the three months ended March 31, 2026. The results for the three months ended March 31, 2026 are not necessarily indicative of the results to be expected for the year ending December 31, 2026 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 majority owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

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 March 31, 2026 and December 31, 2025, we had accumulated deficits of $519.9 million and $487.4 million, respectively, and net losses of $32.5 million and $21.1 million, respectively, for the three months ended March 31, 2026 and 2025. We anticipate that we will incur net losses for the foreseeable future and there is no guarantee that we will achieve or maintain profitability.

Management believes that its cash, cash equivalents, and restricted cash on hand as of the filing date of this Quarterly Report will be sufficient to fund the Company’s operating activities and meet its obligations as they become due for at least the next twelve months. This assessment reflects the Company’s expected operating cash requirements and the subsequent payments and commitments described in Notes 19 and 20. The condensed consolidated financial statements do not reflect any adjustments that would be necessary if the Company becomes 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):

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 March 31, 2026, one customer accounted for 82% of accounts receivable. As of December 31, 2025, one customer accounted for 93% of accounts receivable.

Revenue from one customer accounted for 81% of total revenue for the three months ended March 31, 2026 and revenue from two customers accounted for 55% and 38% of total revenue, respectively, for the three months ended March 31, 2025.

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 2025 Annual Report on Form 10-K filed with the SEC on March 18, 2026. There have not been any significant changes to these policies other than as described below during thethree months ended March 31, 2026.

Capitalized Software Development Costs

Effective January 1, 2026, the Company changed its accounting policy for capitalized software development costs from Accounting Standards Codification (“ASC”) 985-20, Costs of Software to Be Sold, Leased, or Marketed(“ASC 985-20”), to ASC 350-40, Internal-Use Software(“ASC 350-40”) due to a change in facts and circumstances. The Company originally applied ASC 985-20 because it initially intended to allow customers to take possession of the software. The Company no longer offers the software in a manner that permits customers to take possession and instead uses the software solely in hosted software-as-a-service arrangements and in its own operations, including Company-owned energy storage systems. As a result, the Company concluded that ASC 350-40 is the appropriate accounting model beginning January 1, 2026 and applied the change prospectively. Immediately prior to the change, the Company performed an impairment assessment of its capitalized software costs as of December 31, 2025 under ASC 985-20 and determined that no impairment was required. The remaining carrying value was reclassified to internal-use software on January 1, 2026. The change in accounting policy had no impact on the Company’s condensed consolidated financial statements.

Recently Adopted Accounting Standards

In July 2025, the Financial Accounting Standards Board (“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 Company elected the practical expedient on January 1, 2026 and the adoption of this standard did not have a material impact on the Company’s consolidated balance sheets, results of operations and comprehensive loss, or cash flows.

Recent Accounting Standards Issued, But Not Yet Adopted

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 the impact this ASU would have on our consolidated financial statements and related disclosures.

In September 2025, the FASB issued ASU 2025-06, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software. ASU 2025-06 updates the accounting for internal use software by removing the existing project stage framework and requiring capitalization of qualifying software costs when management has authorized and committed to funding the software project and it is probable that the project will be completed and the software will be used to perform its intended function. The amendments also apply to website development costs currently accounted for under Subtopic 350-50. The standard is effective for annual reporting periods beginning after December 15, 2027, and interim reporting periods within those annual reporting periods. Early adoption is permitted. The amendments may be adopted on a prospective, modified transition, or retrospective basis. The Company is currently evaluating the effect that adoption of ASU 2025-06 will have on its consolidated financial statements and related disclosures.

In December 2025, the FASB issued ASU 2025-11, Interim Reporting (Topic 270): Narrow-Scope Improvements, which is intended to improve navigability of the guidance in Topic 270, Interim Reporting, and clarify when it applies. The ASU also addresses the form and content of such financial statements and interim disclosure requirements, and establishes a principle under which an entity must disclose events since the end of the last annual reporting period that have a material impact on the entity. This ASU is effective for annual reporting periods beginning after December 15, 2027, and interim reporting periods within those annual reporting periods, with early adoption permitted. The Company is currently evaluating the impact that ASU 2025-11 will have on its 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 months ended March 31, 2026 and 2025 (amounts in thousands):

(1) Revenue from the arrangement accounted for as an operating lease was $0.6 million for the three months ended March 31, 2026.

Remaining Performance Obligations

Remaining performance obligations represent the amount of unearned transaction price for contracts accounted for under ASC 606, Revenue from Contracts with Customers (“ASC 606”). As of March 31, 2026, the amount of the Company’s remaining performance obligations was $142.4 million, of which approximately 32% related to domestic projects and approximately 68% related to international projects. The Company expects to recognize approximately 68% of the remaining performance obligations as revenue over the next 12 months and the remainder more than 12 months from March 31, 2026.

Contract Balances

The following table provides information about contract assets and contract liabilities from contracts with customers accounted for under ASC 606 (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.

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 months ended March 31, 2026 and 2025, the Company recognized revenue of $0.6 million and $5.2 million, respectively, related to amounts that were included in the deferred revenue balance as of the beginning of each period.

Lease Revenue

The Company has one tolling agreement that is accounted for as a lease under ASC 842, Leases (“ASC 842”). 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 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 March 31, 2026 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.

NOTE 4. INVESTMENTS

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

(1) Presented within prepaid expenses and other current assets on the condensed consolidated balance sheets.

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 March 31, 2026 and December 31, 2025 was $11.7 million.

NOTE 5. ALLOWANCE FOR CREDIT LOSSES

Activity in the allowance for credit losses was as follows for the three months ended March 31, 2026 and 2025 (amounts in thousands):

The Company estimates expected uncollectible amounts related to its accounts receivable, contract assets, customer financing receivable, 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. 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, contract assets, or the customer financing receivable, the Company determines specific allowances for these assets.

NOTE 6. RELATED PARTY TRANSACTIONS

During the three months ended March 31, 2026 and 2025, the Company paid $0.2 million and $0.3 million, respectively, in marketing and sales costs to a company owned by an immediate family member of an officer of the Company. At March 31, 2026 and December 31, 2025, the Company had $0.1 million in payables due to this related party.

NOTE 7. PROPERTY AND EQUIPMENT, NET

As of March 31, 2026 and December 31, 2025, property and equipment, net consisted of the following (amounts in thousands):

Depreciation and amortization expense related to property and equipment was $3.2 million for the three months ended March 31, 2026, of which $1.0 million was included in cost of revenue and the remaining $2.2 million was included in depreciation, amortization, and accretion in the condensed consolidated statement of operations and comprehensive loss.

Depreciation and amortization expense related to property and equipment was$0.1 millionfor the three months ended March 31, 2025, which was included in depreciation, amortization, and accretion in the condensed consolidated statement of operations and comprehensive loss.

The increase in depreciation and amortization expense related to property and equipment primarily reflects depreciation recognized after the Company placed its owned energy storage systems and the Snyder CDU into service in the second half of 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 placed in service, the Company amortizes its internal-use software by software application on a straight-line basis over its estimated economic life. The useful life for the Company’s internal-use software isfive years.

During the three months ended March 31, 2026, the Company reclassified $1.4 million from favorable acquired contracts, included in intangible assets, net, to construction in progress, included in property and equipment, net, upon receipt of the related equipment because the favorable contract terms were realized through delivery of that equipment.

Amortization expense for the three months ended March 31, 2026 was $0.3 million, which was included in cost of revenue in the condensed consolidated statement of operations and comprehensive loss.

Amortization expense for the three months ended March 31, 2025 was $0.2 million, all of which was included in depreciation, amortization, and accretion in the condensed consolidated statement of operations and comprehensive loss.

Future amortization expense for internal-use software 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 months ended March 31, 2026 and 2025, consists of the following (amounts in thousands):

CRC Senior Notes

On April 4, 2025, Calistoga Resiliency Center, LLC (“CRC”), a subsidiary of the Company, 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 bear interest at 9.5% per annum and 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. A final balloon payment of $7.0 million is due at maturity on April 4, 2032.

Cross Trails Senior Note

On July 23, 2025, Cross Trails Energy Storage Project, LLC (“Cross Trails”), a 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. 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%. As of March 31, 2026, the Company was utilizing a SOFR of 3.6%, resulting in an interest rate of 9.6%.

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.

Reflecting performance within the ERCOT market since operations commenced at the Cross Trails BESS Project on May 31, 2025, the Company has not satisfied the current minimum Cross Trails Senior Note debt service coverage ratio under the covenant calculation for the quarter ended March 31, 2026. Under the terms of the Cross Trails Senior Note, the applicable reporting period has not yet occurred; the delivery date for the financial statements for the quarter ended March 31, 2026 is June 29, 2026. Also, the lender has informed the Company that an event of default has not occurred as of the date of this Quarterly Report. The Company intends to work with the lender between now and the delivery date to remedy this issue through a series of options, including but not limited to the receipt of waivers, project equity investments, and/or partial or full repayment in the appropriate time frame. As of March 31, 2026, the Company has classified the outstanding balance under the Cross Trails Senior Note as current as a result of the noncompliance.

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 March 31, 2026, the Company had remitted $5.1 million to Cedar, with $1.2 million remaining to be paid to Cedar.

Senior Convertible Notes

On February 17, 2026, the Company completed a private offering of $140.0 million aggregate principal amount of Senior Convertible Notes due 2031 (the “Senior Convertible Notes”). On February 27, 2026, the Company issued an additional $10.0 million aggregate principal amount of Senior Convertible Notes pursuant to the initial purchasers’ option. The Senior Convertible Notes bear interest at 5.250% per annum, payable in cash semi-annually in arrears on March 1 and September 1 of each year, beginning on September 1, 2026, and mature on March 1, 2031, unless earlier converted, redeemed or repurchased. After deducting the 3.25% initial purchasers’ discount, which was accounted for as debt issuance costs, the Company received net proceeds of $145.1 million from the issuance of the Senior Convertible Notes.

The Senior Convertible Notes are convertible prior to the close of business on the business day immediately preceding September 1, 2030 only upon the occurrence of specified events and during certain periods set forth in the indenture. On or after September 1, 2030, the Senior Convertible Notes are convertible at any time until the close of business on the second trading day immediately preceding the maturity date. The Senior Convertible Notes initially are convertible at a rate of 193.1807 shares of the Company’s common stock per $1,000 principal amount of Senior Convertible Notes, which is equivalent to an initial conversion price of approximately $5.18 per share, subject to customary anti-dilution and other adjustments. Upon conversion, the Company may settle the conversion obligation in cash, shares of common stock, or a combination of cash and shares, at its election. In addition, holders who convert their Senior Convertible Notes in connection with certain make-whole fundamental changes or notices of redemption may be entitled to an increase in the conversion rate, subject to a maximum conversion rate of 246.3054 shares per $1,000 principal amount.

The Company may redeem the Senior Convertible Notes for cash, in whole or in part, at its option on or after March 5, 2029, but only if a liquidity condition is satisfied and the last reported sale price of the Company’s common stock has been at least 130% of the conversion price then in effect for at least 20 trading days during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which the Company provides notice of redemption. The redemption price is equal to 100% of the principal amount of the Senior Convertible Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. Upon the occurrence of a fundamental change, holders may require the Company to repurchase all or any portion of their Senior Convertible Notes for cash at a price equal to 100% of the principal amount of the notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date.

The Company evaluated the accounting for the Senior Convertible Notes under ASC 470-20, Debt—Debt with Conversion and Other Options, and ASC 815, Derivatives and Hedging. The Company concluded that the embedded conversion feature qualifies for the scope exception in ASC 815-40 and therefore does not require separate accounting as a derivative. Accordingly, the Company accounts for the Senior Convertible Notes as a single debt instrument at amortized cost. The Company also identified certain additional-interest provisions that are required to be bifurcated from the host contract as those features are not clearly and closely related to the host convertible debt contract. The fair value of these additional-interest features was determined to be de minimis; therefore, the Company did not recognize a separate derivative asset or liability in connection with this transaction.

In connection with the issuance of the Senior Convertible Notes, the Company also entered into capped call transactions with certain option counterparties. The capped call transactions have an initial strike price of approximately $5.18 per share, consistent with the initial conversion price of the Senior Convertible Notes, and an initial cap price of $8.12 per share, which represents a premium of 100% above the $4.06 closing price of the Company's common stock on February 11, 2026. The capped call transactions are intended to reduce potential dilution to the Company's common stock upon any conversion of the Senior Convertible Notes, and/or offset any cash payments the Company is required to make in excess of the principal amount upon conversion, with such reduction and/or offset subject to a cap based on the cap price.

The capped call transactions are separate freestanding instruments and are accounted for independently from the Senior Convertible Notes. The $20.5 million in premiums paid for the capped call transactions were recorded as a reduction to additional paid-in capital and were not included in the carrying amount of the Senior Convertible Notes.

As of March 31, 2026, the Senior Convertible Notes had unamortized debt issuance costs of $9.6 million, and the net carrying amount was $140.4 million. Total interest expense related to the Senior Convertible Notes was $1.1 million for the three months ended March 31, 2026, consisting of $0.9 million of contractual interest and $0.2 million of amortization of debt issuance costs. The effective interest rate for the Senior Convertible Notes was 6.9%.

Convertible Debentures

On September 22, 2025, the Company entered into a Securities Purchase Agreement with YA II PN, Ltd. (the “Investor”), pursuant to which the Company agreed to issue senior unsecured convertible debentures in multiple tranches. On December 30, 2025, the agreement was amended to increase the aggregate principal amount available under the facility from $50.0 million to $65.0 million (collectively, the “Convertible Debentures”). The initial tranche of $30.0 million (“Tranche 1”) was funded on September 22, 2025, the second tranche of $20.0 million (“Tranche 2”) was funded on December 16, 2025, and the third tranche of $15.0 million (“Tranche 3”) was funded on December 30, 2025.

All three tranches bear or bore interest at 7.0% per annum. Installment payments of principal and interest are due monthly (each, a “Payment Date,” beginning on the applicable payment commencement date). For each installment, the Company may (i) pay cash plus a payment premium equal to 7.0% for Tranches 1 and 2 or 4.0% for Tranche 3 of the principal portion paid (“Payment Premium”), (ii) elect to allow the Investor to convert the unpaid installment at a price equal to the lower of (A) the Applicable Fixed Price (defined below) 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), or (iii) satisfy the installment through a combination of cash and conversion. The fixed conversion price is $4.50 per share for Tranche 1, $7.53 per share for Tranche 2, and $7.41 per share for Tranche 3.

Tranche 1 matures on March 22, 2027, Tranche 2 was to mature on March 22, 2027, and Tranche 3 was to mature on August 30, 2027. During the three months ended March 31, 2026, Tranche 1 was partially repaid and Tranches 2 and 3 were fully repaid. As of March 31, 2026, $5.9 million of principal remained outstanding under Tranche 1. Of this amount,

$1.6 million was subject to a conversion notice issued to the Investor that had not yet been converted into shares of the Company’s common stock as of March 31, 2026.

The Company elected the fair value option afforded by ASC 825 with respect to the Convertible Debentures because they include features that meet the definition of embedded derivatives. The Company initially recognized the Convertible Debentures at fair value and subsequently remeasures them at fair value, with changes in fair value recognized in the consolidated statements of operations and comprehensive loss. The Convertible Debentures are measured at fair value on a recurring basis and are classified within Level 3 of the fair value hierarchy due to the use of significant unobservable inputs.

The following table presents a rollforward of the fair value of the Convertible Debentures for the periods presented, including issuances, cash settlements, and the components of earnings that impacted the fair value during the period.

(1) Recognized within the line item, change in fair value of financial instruments carried at fair value, in the condensed consolidated statement of operations and comprehensive loss.

(2) Recognized within the line item, interest expense, in the condensed consolidated statement of operations and comprehensive loss.

(3) Recognized within the line item, other expense, net, in the condensed consolidated statement of operations and comprehensive loss.

Debt Maturity

The following table summarizes the cash maturities of the Company’s debt instruments as of March 31, 2026 (amounts in thousands):

(1) Reflects contractual principal maturity and does not reflect the balance sheet classification as current as of March 31, 2026, as described above.

Insurance Premium Financings

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. This financing was fully repaid in March 2026.

As of March 31, 2026 and December 31, 2025, the carrying value of the Company’s insurance premium financings was $0.1 million and $0.4 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 were as follows (amounts in thousands):

NOTE 11. SUPPLEMENTAL BALANCE SHEETS DETAIL

NOTE 12. REDEEMABLE NON-CONTROLLING INTEREST

On October 9, 2025, Energy Vault, Inc. (“EV Inc.”) and OIC Structured Equity Fund I, L.P. and affiliated funds (collectively, “OIC”) completed the Asset Vault transaction previously described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025.

Asset Vault is a variable interest entity (“VIE”) for which the Company is the primary beneficiary because the Company has (i) the power to direct the activities that most significantly affect Asset Vault’s economic performance, including project development, financing, and operational decisions, and (ii) the obligation to absorb losses and the right to receive benefits that could potentially be significant to Asset Vault through its ownership of common units and related support arrangements. Accordingly, Asset Vault is consolidated and OIC’s interest is presented as redeemable non-controlling interest in the mezzanine section of the condensed consolidated balance sheets. As of March 31, 2026, management continued to consider redemption of the Series A Preferred Units to be probable and recognized accretion to redemption value for the period using the effective interest method based on the then-estimated redemption value and earliest probable redemption date.

The following table presents, on an aggregated basis, the carrying amounts and classification of the consolidated assets and liabilities of Asset Vault included in the Company’s condensed consolidated balance sheets. The table excludes intercompany balances between Asset Vault and other consolidated subsidiaries of the Company, which are eliminated in consolidation (amounts in thousands):

Asset Vault is financed in part by redeemable preferred equity units classified in mezzanine equity of $23.3 million and $21.2 million as of March 31, 2026 and December 31, 2025, respectively. This balance is not included in the assets and liabilities table above because it is not a liability under GAAP. Creditors of Asset Vault do not have recourse to the general credit of Energy Vault Holdings, Inc. or its other wholly-owned subsidiaries. The assets of Asset Vault are not available to settle the obligations of the Company’s other subsidiaries. Certain of Asset Vault’s debt obligations are secured by substantially all of the assets of Asset Vault and its project subsidiaries, including project-level cash flows, and are subject to customary covenants and restrictions on distributions.

The following table presents a roll-forward of the redeemable non-controlling interest for the three months ended March 31, 2026 (amounts in thousands):

(1) Net income (loss) attributable to redeemable non-controlling interest is determined using the hypothetical liquidation at book value (“HLBV”) methodology based on each party’s contractual rights. Under the HLBV method, income is allocated based on the change in each party's claim on the net assets of Asset Vault under a hypothetical liquidation scenario at the beginning and end of each reporting period. This allocation may differ significantly from the non-controlling interest's nominal percentage of total units outstanding.

(2) Accretion represents the increase in the carrying amount of the redeemable non-controlling interest toward its estimated redemption value, calculated using the effective interest method over the period to the earliest probable redemption date. Accretion is recorded as an adjustment to additional paid-in-capital. Although accretion does not affect total net loss, it is treated as a deemed dividend and therefore as an adjustment to net loss attributable to common stockholders for purposes of computing net loss per share.

NOTE 13. WARRANTS

Roll-Forward of Warrants

The following table presents a roll-forward of the Company’s warrants for the three months ended March 31, 2026 and 2025 (amounts in thousands):

(1) Dorado Goose Warrants with an exercise price of $1.50 per warrant were exercised on a cashless basis in exchange for 0.3 million shares of common stock.

Roll-Forward of Warrant Liabilities

The following table presents a roll-forward of the Company’s warrant liabilities for the three months ended March 31, 2026 and 2025 (amounts in thousands):

(1) Recognized within the line item, change in fair value of financial instruments carried at fair value, in the condensed consolidated statements of operations and comprehensive loss.

Fair Value Measurement - Liability Classified Warrants

The Company measures the fair value of the OIC and Novus Warrant liabilities using a Black-Scholes option pricing model, both of which require the use of significant judgments and the use of unobservable inputs. As such, the Company’s warrant liabilities are classified within Level 3 of the fair value hierarchy. The key unobservable inputs used to value the

OIC Warrants include the expected volatility and the Company’s estimated future EBITDA. The key unobservable input used to value the Novus Warrants is expected volatility. A significant increase in the expected volatility in isolation would result in a significantly higher fair value measurement.

The following table provides the assumptions used to estimate the fair value of the Company’s liability classified warrants as of March 31, 2026 and December 31, 2025:

NOTE 14. 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 that models potential settlement outcomes under the contractual terms. The significant assumptions used in the model include the volatility of the Company’s common stock (100.0%) and a discount rate of 28.6%, which was derived from market yields for comparable CCC- rated debt. The model also incorporates the instrument’s contractual term, redemption features, and conversion mechanics.

(2) The warrants are not publicly traded and the Company uses a Black-Scholes model to determine the fair value of the warrants. See Note 13, Warrants, for additional information.

(3) The derivative liability relates to certain redemption and settlement features in the Contribution and Purchase Agreement with OIC. The Company utilized an income approach using a probability weighted expected present value method to value the derivative liability. Significant assumptions include a discount rate of 22.8% and estimated probabilities and timing associated with the occurrence of various mandatory redemption events.

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. The estimated fair value of the Company’s Senior Convertible Notes was $151.3 million as of March 31, 2026.

NOTE 15. 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 shares, RSUs, and other awards 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 that may become available for issuance under the 2022 Incentive Plan to the extent such awards are forfeited, expired, unexercised, or otherwise unsettled. Annually, beginning in March 2022 and ending in (and including) March 1, 2031, the number of shares of the Company’s common stock that may be issued under the 2022 Incentive Plan increases automatically 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 Employment Inducement Award Plan (the “2022 Inducement Plan”), which provides for the granting of stock options, SARs, restricted shares, RSUs, and other awards to individuals who were not previously employees of the Company, or following a bona fide period of non-employment, as inducement material to such individuals entering into employment with the Company. 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 Employment Inducement Award Plan (the “2025 Inducement Plan”), which provides for the granting of stock options, SARs, restricted shares, RSUs, and other awards to individuals who were not previously employees of the Company, or following a bona fide period of non-employment, as inducement material to such individuals entering into employment with the Company. 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

The following table summarizes stock option activity for the three months ended March 31, 2026 (amounts in thousands, except per share data):

As of March 31, 2026, total unrecognized stock-based compensation expense related to unvested option awards that are expected to vest was $0.6 million. The weighted-average period over which such stock-based compensation expense will be recognized is approximately 1.4 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 New York Stock Exchange (“NYSE”) as of March 31, 2026.

Restricted Stock Units

During the three months ended March 31, 2026, pursuant to the 2022 Inducement Plan, the Company granted RSUs to employees that vest based on market-based conditions. These market-based 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, subject to the applicable employee’s continued service. The fair value of market-based RSUs is 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 was measured on their grant date, using a Monte Carlo simulation model based on the following assumptions:

The following table summarizes activity for all RSUs, including time-based and market-based awards, for the three months ended March 31, 2026 (amounts in thousands, except per share data):

As of March 31, 2026, unrecognized stock-based compensation expense related to these RSUs was $27.1 million which is expected to be recognized over the remaining weighted-average vesting period of approximately 2.5 years.

Stock-Based Compensation Expense

Total stock-based compensation expense for the three months ended March 31, 2026 and 2025 was as follows (amounts in thousands):

NOTE 16. SEGMENT REPORTING

As a single reportable segment entity, the Company’s Chief Executive Officer, who is the 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)Includes $1.3 million of depreciation and amortization expense for the three months ended March 31, 2026.

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

(3) 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.

(4) Represents certain other segment items that are not deemed significant segment expenses and primarily consists of provision for credit losses, loss on financial instruments carried at fair value, and other income/expense items.

NOTE 17. INCOME TAXES

The Company recognized a tax provision of $1 thousand for the three months ended March 31, 2026 and a tax provision of $0.4 million for the three months ended March 31, 2025.

During 2025, the Company generated $47.7 million of investment tax credits (“ITC”). On March 28, 2025, the Company entered into a Tax Credit Transfer Commitment, on behalf of its majority and wholly-owned subsidiary companies, with a third-party purchaser pursuant to which the Company agreed to sell these ITCs at a price equal to 85% of the value of the credits. The Company has recorded a valuation allowance for the 15% discount to reflect the expected net sale proceeds.

On February 26, 2026, the Company collected $11.8 million in proceeds from the transfer of the Cross Trails ITC to the third-party purchaser. As of the date of the Quarterly Report, the sales of the eligible ITCs generated by CRC and the Snyder CDU are expected to close following the satisfaction of certain customary closing conditions.

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.

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 months ended March 31, 2026 and 2025. 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 months ended March 31, 2026 and 2025 (amounts in thousands):

NOTE 19. COMMITMENTS AND CONTINGENCIES

Our principal commitments as of March 31, 2026 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 March 31, 2026 totaled approximately $5.0 million, which is all expected to be paid in the next twelve months.

Loss Contingencies:

In the ordinary course of business, the Company is regularly subject to various legal proceedings. The Company records a loss contingency accrual when a loss is both probable and reasonably estimable. As of March 31, 2026, the Company had not recorded any material loss contingency accruals related to legal proceedings. 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 battery energy storage system (“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 the applicable 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 March 31, 2026 and 2025, 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 March 31, 2026, the Company had $29.3 million in outstanding letters of credit and $17.5 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 March 31, 2026, the Company had $88.6 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 March 31, 2026, the Company had $12.5 million in outstanding other bonds.

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 energy storage system is the only energy storage system currently subject to an ARO. The initial ARO for the CRC energy storage system was $1.0 million.

The Company measured the ARO for the CRC energy storage system 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 March 31, 2026, the carrying value of the Company’s ARO was $1.1 million. For the three months ended March 31, 2026, the Company recognized accretion expense of $26 thousand.

McMurtre Project

On March 24, 2026, the Company acquired rights to the McMurtre BESS, a 175 MW / 350 MWh BESS project to be located near Dallas, Texas. The Company paid $0.3 million for the rights to the project and will owe the seller an additional $5.6 million if the project reaches the notice to proceed milestone and $1.4 million if the project reaches commercial operation.

Mesa Del Sol Project

In March 2026, the Company entered into a reimbursement agreement with Public Service Company of New Mexico (“PNM”) to advance preliminary work related to electrical interconnection and related infrastructure planning activities in connection with the Company’s potential development of a battery energy storage, power generation, and data center project in Albuquerque, New Mexico. Under the reimbursement agreement, the Company authorized PNM to undertake certain preliminary work, including engineering and design work, permitting, surveys, studies, environmental review, initial equipment orders, land rights, easements, public outreach and other related work. The estimated cost of the preliminary work is $7.5 million, which the Company is required to fund in advance as prepaid development costs upon invoice by PNM. Amounts funded by the Company will be applied against reimbursable development costs as such costs are incurred or otherwise fully committed to third parties. Any amounts paid to PNM that are not actually incurred or otherwise fully committed to third parties in the performance of the preliminary work are required to be returned to the Company. In connection with the reimbursement agreement, the Company was required to provide a letter of credit in the amount of $7.5 million. Subsequent to March 31, 2026, PNM released the letter of credit and consented to its cancellation in connection with the Company’s funding of the $7.5 million in April 2026.

In addition, in March 2026, the Company entered into a deposit agreement with PNM pursuant to which PNM agreed to perform the next phase of engineering studies required to assess the requirements for PNM to provide electric service to the project. Subsequent to March 31, 2026, the Company paid the non-refundable deposit of $0.5 million. If the Company enters into a reimbursement agreement or electric facilities agreement with PNM, any portion of the deposit not used to fund the services under the deposit agreement, other than certain administrative and overhead costs, will be applied toward costs properly incurred under such agreement.

Subsequent to March 31, 2026, the Company, through its subsidiary Mesa Del Sol Energy Campus, LLC, completed the assignment of certain real estate purchase rights relating to approximately 486 acres of land in Albuquerque, New Mexico for the potential development of a battery energy storage, power generation, and data center project. In connection with the assignment, the Company agreed to pay a nonrefundable assignment fee of $0.8 million, which included $0.5 million paid on February 18, 2026 for the exclusive right to negotiate with the assignor that was credited toward the assignment fee upon completion of the assignment subsequent to March 31, 2026. The underlying purchase agreement provides for an aggregate purchase price of approximately $120.1 million for all land tracts, with an initial closing requirement for certain tracts representing approximately $57.4 million of the aggregate purchase price by December 18, 2026, and an outside closing date for the remaining tracts of December 18, 2027. If the Company does not satisfy the initial acquisition requirement, the Company may terminate the arrangement without incurring liability in excess of the nonrefundable assignment fee. The Company is also required to pay a contingent service fee equal to 7% of the gross purchase price of each acquired tract, payable only upon the closing of each applicable tract. Also subsequent to March 31, 2026, the Company entered into a term sheet with Clean AI, LLC related to the development of the project. The term sheet is non-binding, except for certain binding provisions, including a $0.5 million start fee, exclusivity and confidentiality provisions, and a land purchase participation right in favor of Clean AI, LLC for up to a 35% undivided interest in any land tract purchased by the Company.

Also subsequent to March 31, 2026, the Company, through Mesa Del Sol Energy Campus, LLC, entered into a production slots reservation agreement with 2G Energy Inc. to reserve manufacturing capacity for certain power generation equipment for the Mesa Del Sol project. Under the agreement, the Company paid a reservation fee of $10.0 million. The reservation fee is generally non-refundable, except in limited circumstances, and will be credited toward future milestone payments if the parties execute a separate sales contract by the applicable deadline. The reservation agreement does not obligate either party to execute the sales contract, and the production and delivery of the equipment would be governed by the separate sales contract, if executed.

NOTE 20. SUBSEQUENT EVENTS

BayWa r.e. Japan Development Portfolio

Subsequent to March 31, 2026, the Company entered into an agreement with BayWa r.e. Japan K.K. to acquire certain development-stage assets and project rights related to a portfolio of battery energy storage system projects in Japan. The assets to be acquired include certain land rights, transferred agreements, grid connection applications and related project development rights. The closing of the transaction is subject to certain conditions, including the incorporation of a Japanese subsidiary, satisfaction of applicable regulatory notification and waiting period requirements in Japan and receipt of required corporate approvals. Under the agreement, the Company is required to pay initial consideration of approximately $0.3 million and a working capital payment of $0.5 million, excluding applicable consumption tax. The agreement also provides for additional milestone payments based on the achievement of specified project development milestones, including ready-to-build status, final investment decision, financial close or a project sale, subject to an aggregate milestone payment cap of approximately $4.9 million, excluding applicable consumption tax.

Sale of Equipment

Subsequent to March 31, 2026, the Company entered into an agreement with a third-party for the sale, supply and delivery of certain equipment. The transaction is expected to be accounted for as a sale of property and equipment rather than as a revenue contract. The total contract price is approximately $10.3 million. Under the agreement, the Company is required to provide a performance bond equal to 6% of the contract price.

Issuance of Senior Secured Convertible Debentures

Subsequent to March 31, 2026, on May 18, 2026, 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 secured convertible debentures (the “Senior Secured Convertible Debentures”) in multiple tranches with an aggregate principal amount of up to $75.0 million.

The initial tranche of $42.0 million will be funded at closing and net proceeds are expected to be $39.6 million after deductions for an original issue discount and origination fees. The Senior Secured Convertible Debentures are secured by assets of the Company, Energy Vault, Inc. and the Company’s Swiss and Australian subsidiaries.

The Senior Secured Convertible Debentures were issued at 95% of par, bear interest at 7.5% per annum (18.0% upon an uncured event of default), and mature on May 17, 2027. Beginning on September 18, 2026 and monthly thereafter (each, a “Payment Date”), approximate scheduled installments of principal and accrued interest are due as follows (per $10.0 million of original principal): $1.2 million on the first Payment Date, $1.2 million on each of the next three Payment Dates, $1.1 million on each of the next four Payment Dates, and $1.1 million at maturity. For the initial tranche, the floor price is $1.19 per share.

For each installment, the Company may (i) pay cash, (ii), if certain conditions are satisfied, elect to allow the Investor to convert the unpaid installment at a price equal to 97% of the lowest daily VWAP during the four consecutive trading days immediately preceding the conversion date, 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 NYSE (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) from any time after the six-month anniversary of the issuance of the Senior Secured Convertible Debentures, the Investor is unable to sell its shares pursuant to Rule 144. While an Amortization Event is in effect, the monthly installment must be paid in cash and the installment amount may increase to the greater of the scheduled amount and 20.0% of then-outstanding principal.