Energy Vault (NRGV) 10-K 12 Apr 23 2022 FY Annual report Financial data

Cover

Cover - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Apr. 07, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-39982
Entity Registrant Name	ENERGY VAULT HOLDINGS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	85-3230987
Entity Address, Address Line One	4360 Park Terrace Drive
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	Westlake Village
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	91361
City Area Code	805
Local Phone Number	852-0000
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	NRGV
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 661.6
Entity Common Stock, Shares Outstanding		141,392,243
Documents Incorporated by Reference	Part III of this Annual Report on Form 10-K incorporates certain information by reference from the definitive proxy statement for the registrant’s 2023 annual meeting of stockholders to be filed within 120 days of the registrant’s fiscal year ended December 31, 2022, or the Proxy Statement. Except with respect to information specifically incorporated by reference in this Annual Report on Form 10-K, the Proxy Statement is not deemed to be filed as part of this Annual Report on Form 10-K.
Entity Central Index Key	0001828536
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2022
Auditor Information [Abstract]
Auditor Name	BDO USA, LLP
Auditor Location	New York, NY
Auditor Firm ID	243

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current Assets
Cash and cash equivalents	$ 203,037	$ 105,125
Restricted cash	83,145	0
Accounts receivable	37,460	0
Contract assets	28,978	0
Customer financing receivable, current portion	1,500	0
Inventory	4,378	0
Prepaid expenses and other current assets	31,569	5,538
Total current assets	390,067	110,663
Property and equipment, net	3,044	11,868
Operating lease right-of-use assets	1,442	1,238
Customer financing receivable, long-term portion	8,260	0
Other assets	13,900	1,525
Total Assets	416,713	125,294
Current Liabilities
Accounts payable	60,315	1,979
Accrued expenses	14,749	4,704
Contract liabilities, current portion	49,434	0
Finance leases, current portion	38	48
Operating leases, current portion	787	612
Total current liabilities	125,323	7,343
Deferred pension obligation	890	734
Asset retirement obligation	560	978
Contract liabilities, long-term portion	1,500	1,500
Long-term finance leases	16	34
Long-term operating leases	709	662
Warrant liability	2	0
Total liabilities	129,000	11,251
Commitments and contingencies (Note 18)
Convertible preferred stock, $0.0001 par value; no shares authorized, none issued and outstanding at December 31, 2022; 85,741 shares authorized, 85,741 issued and outstanding at December 31, 2021; liquidation preference of $171,348	0	182,709
Stockholders’ Equity (Deficit)
Preferred stock, $0.0001 par value; 5,000 shares authorized, none issued and outstanding	0	0
Common stock, $0.0001 par value; 500,000 shares authorized, 138,530 issued and outstanding at December 31, 2022; 120,568 shares authorized, 20,432 issued and outstanding at December 31, 2021	14	0
Additional paid-in capital	435,852	713
Accumulated deficit	(147,265)	(68,966)
Accumulated other comprehensive loss	(888)	(413)
Total stockholders’ equity (deficit)	287,713	(68,666)
Total Liabilities, Convertible Preferred Stock, and Stockholders’ Equity (Deficit)	$ 416,713	$ 125,294

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock authorized (in shares)	500,000,000	120,568,000
Common stock issued (in shares)	138,530,000	20,432,000
Convertible preferred stock
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	0	85,741
Preferred stock, shares issued (in shares)	0	85,741,000
Preferred stock, shares outstanding (in shares)	0	85,741,000
Preferred stock, liquidation preference		$ 171,348,000

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Total revenue	$ 145,877	$ 0
Operating expenses:
Cost of revenue	86,580	0
Sales and marketing	12,582	845
Research and development	50,058	7,912
General and administrative	56,912	18,056
Asset impairment	2,828	2,724
Loss from operations	(63,083)	(29,537)
Other income (expense)
Interest expense	(2)	(7)
Change in fair value of warrant liability	2,330	0
Transaction costs	(20,586)	0
Other income (expense), net	3,469	(1,793)
Loss before income taxes	(77,872)	(31,337)
Provision for income taxes	427	1
Net loss	$ (78,299)	$ (31,338)
Net loss per share — basic (in dollars per share)	$ (0.64)	$ (2.45)
Net loss per share — diluted (in dollars per share)	$ (0.64)	$ (2.45)
Weighted average shares of outstanding — basic (in shares)	123,241	12,780
Weighted average shares of outstanding — diluted (in shares)	123,241	12,780
Other comprehensive income (loss) — net of tax
Actuarial gain (loss) on pension	$ (188)	$ 166
Foreign currency translation gain (loss)	(287)	1,519
Total other comprehensive income (loss)	(475)	1,685
Total comprehensive loss	$ (78,774)	$ (29,653)

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders’ Equity (Deficit) - USD ($) $ in Thousands		Total	Convertible preferred stock	Convertible Preferred Stock Convertible preferred stock		Convertible Preferred Stock Series B-1 preferred stock	Convertible Preferred Stock Series C preferred stock	Common Stock		Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2020	[1]			63,805,000
Beginning balance at Dec. 31, 2020				$ 62,042
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of preferred stock for cash (in shares)	[1]					7,153,000	14,783,000
Issuance of preferred stock for cash						$ 15,320	$ 107,000
Preferred stock issuance costs						$ (25)	$ (1,628)
Ending balance (in shares) at Dec. 31, 2021		0	85,741,000	85,741,000	[1]
Ending balance at Dec. 31, 2021		$ 182,709		$ 182,709
Beginning balance (in shares) at Dec. 31, 2020	[1]							14,404,000
Beginning balance at Dec. 31, 2020		$ (39,627)						$ 0		$ 99	$ (37,628)	$ (2,098)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock option (in shares)		373,000						373,000	[1]
Exercise of stock options		$ 10								10
Stock based compensation (in shares)	[1]							5,655,000
Stock based compensation		604								604
Net loss		(31,338)									(31,338)
Actuarial gain (loss) on pension		166										166
Foreign currency translation gain (loss)		$ 1,519										1,519
Ending balance (in shares) at Dec. 31, 2021		20,432,000						20,432,000	[1]
Ending balance at Dec. 31, 2021		$ (68,666)						$ 0		713	(68,966)	(413)
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of convertible preferred stock into common stock in connection with reverse the recapitalization (in shares)	[1]			(85,741,000)
Conversion of convertible preferred stock into common stock in connection with reverse recapitalization				$ (182,709)
Ending balance (in shares) at Dec. 31, 2022		0	0	0	[1]
Ending balance at Dec. 31, 2022		$ 0		$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of convertible preferred stock into common stock in connection with reverse the recapitalization (in shares)	[1]							85,741,000
Conversion of convertible preferred stock into common stock in connection with reverse recapitalization		182,709						$ 9		182,700
Issuance of common stock upon the reverse recapitalization, net of transaction costs (in shares)	[1]							27,553,000
Issuance of common stock upon the reverse recapitalization, net of transaction costs		$ 191,859						$ 3		191,856
Exercise of stock option (in shares)		212,000						196,000	[1]
Exercise of stock options		$ 171						$ 1		170
Exercise of warrants (in shares)	[1]							2,873,000
Exercise of warrants		25,360								25,360
Stock based compensation		41,058								41,058
Vesting of RSUs, net of shares withheld for payroll taxes (in shares)	[1]							1,735,000
Vesting of RSUs, net of shares withheld for payroll taxes		(6,004)						$ 1		(6,005)
Net loss		(78,299)									(78,299)
Actuarial gain (loss) on pension		(188)										(188)
Foreign currency translation gain (loss)		$ (287)										(287)
Ending balance (in shares) at Dec. 31, 2022		138,530,000						138,530,000	[1]
Ending balance at Dec. 31, 2022		$ 287,713						$ 14		$ 435,852	$ (147,265)	$ (888)
[1]The number of shares of convertible preferred stock and common stock prior to the Merger (defined in Note 1) have been retroactively restated to reflect the exchange ratio of 6.7735 established in the Merger as described in Note 1 and Note 3.

Consolidated Statements of Co_2

Consolidated Statements of Convertible Preferred Stock and Stockholders’ Equity (Deficit) - (Parenthetical)	Feb. 11, 2022
Energy Vault Holdings Inc
Exchange ratio	6.7735

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash Flows From Operating Activities
Net loss	$ (78,299)	$ (31,338)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	7,743	2,320
Non-cash operating lease expense	744	117
Non-cash interest income	(365)	0
Stock based compensation	41,058	500
Asset impairment	2,828	3,225
Gain on change in fair value of warrant liability	(2,330)	0
Change in pension obligation	(12)	92
Change in asset retirement obligation	(392)	(52)
Foreign exchange gains and losses	316	64
Accounts receivable	(37,460)	0
Contract assets	(28,978)	0
Prepaid expenses and other current assets	(29,613)	217
Inventory	(4,378)	(213)
Customer financing receivable	9,725	0
Other assets	(1,052)	0
Accounts payable and accrued expenses	67,861	3,002
Contract liabilities	49,434	0
Operating lease liabilities	(726)	0
Net cash used in operating activities	(23,346)	(22,066)
Cash Flows From Investing Activities
Purchase of property and equipment	(2,319)	(170)
Purchase of convertible notes	(2,000)	(1,000)
Purchase of equity securities	(9,000)	0
Net cash used in investing activities	(13,319)	(1,170)
Cash Flows From Financing Activities
Proceeds from exercise of stock options	171	5
Proceeds from reverse recapitalization and PIPE financing, net	235,940	0
Proceeds from exercise of warrants	7,855	0
Payment of transaction costs related to reverse recapitalization	(20,651)	(3,592)
Payment of taxes related to net settlement of equity awards	(5,482)	0
Repayment of debt	0	(765)
Payment of finance lease obligations	(62)	(53)
Proceeds from issue of shares, net of issuance costs	0	116
Net cash provided by financing activities	217,771	116,379
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(49)	1,931
Net increase in cash, cash equivalents, and restricted cash	181,057	95,074
Cash, cash equivalents, and restricted cash  –  beginning of the period	105,125	10,051
Cash, cash equivalents, and restricted cash –  end of the period	286,182	105,125
Less: Restricted cash at end of period	83,145	0
Cash and cash equivalents - end of period	203,037	105,125
Supplemental Disclosures of Cash Flow Information:
Income taxes paid	3	1
Cash paid for interest	2	70
Supplemental Disclosures of Non-Cash Investing and Financing Information:
Conversion of redeemable preferred stock into common stock in connection with the reverse recapitalization	182,709	0
Warrants assumed as part of reverse recapitalization	19,838	0
Actuarial gain (loss) on pension	(188)	166
Property, plant and equipment financed through accounts payable	0	39
Assets acquired on finance lease	37	44
Reclassification of inventory costs to property and equipment, net	0	11,156
Merger related costs in accounts payable	0	529
Series B-1 preferred stock | Convertible Preferred Stock
Cash Flows From Financing Activities
Proceeds from Series B-1 preferred stock, net of issuance costs	0	15,295
Series C preferred stock | Convertible Preferred Stock
Cash Flows From Financing Activities
Proceeds from Series B-1 preferred stock, net of issuance costs	$ 0	$ 105,373

ORGANIZATION AND DESCRIPTION OF

ORGANIZATION AND DESCRIPTION OF BUSINESS	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION AND DESCRIPTION OF BUSINESS	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 a grid-scale energy storage company that is driving a faster transition to renewable power by solving the intermittence issues that are inherent to the most prevalent sources of renewable energy, solar and wind. The Company’s mission is to provide energy storage solutions to accelerate the global transition to renewable energy. The Company’s project delivery generally relies on third-party EPC firms to construct our storage systems, under our supervision with dedicated teams tasked with project management. Our current business model options include: • Building, operating, and transferring energy storage projects to potential customers, • Building, operating, and holding energy storage systems as equity (co-) sponsor that may provide recurring revenue in the future, • Recurring software revenue through licensing software for asset management and use case applications, • Recurring service revenue through long term service agreements, and • Intellectual property licenses and royalties associated with our energy storage technologies that may provide recurring revenues in the future. The Company’s subsidiary, Energy Vault SA, was formed in December 2017 in Lugano Switzerland to the CDU, and serves as the Company’s research and development hub, and operates as the Company’s international headquarters. Energy Vault was originally incorporated under the name Novus Capital Corporation II as a special purpose acquisition company in the state of Delaware in September 2020 with the purpose of effecting a merger with one or more operating businesses. On September 8, 2021, Novus announced that it had entered into the Merger Agreement with Legacy Energy Vault that would result in the Merger. Upon the closing of the Merger on February 11, 2022 (the “Closing”), Novus was immediately renamed to “Energy Vault Holdings, Inc.” The Merger between Novus and Legacy Energy Vault was accounted for as a reverse recapitalization. See Note 3 - Reverse Capitalization for more information. Energy Vault Holdings, Inc. is headquartered in Los Angeles, California. Throughout the notes to the consolidated financial statements, unless otherwise noted, the “Company,” “we,” “us,” or “our” and similar terms refer to Legacy Energy Vault and its subsidiaries prior to the consummation of the Merger, and Energy Vault and its subsidiaries after the consummation of the Merger.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The accompanying consolidated financial statements have been prepared on an accrual basis of accounting in accordance with GAAP and applicable rules and regulations of the SEC regarding financial reporting. Principles of Consolidation These consolidated financial statements include Energy Vault Holdings, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. If the Company has a variable interest in an entity, an assessment is performed to determine if that entity is a variable interest entity (“VIE”), and if so, if the Company is the primary beneficiary of the VIE. The assessment of whether an entity is a VIE requires an evaluation of qualitative factors and, where applicable, quantitative factors. These factors include: (i) determining whether the entity has sufficient equity at risk, (ii) evaluating whether the equity holders, as a group, lack the ability to make decisions that significantly affect the economic performance of the entity, and (iii) determining whether the entity is structured with disproportionate voting rights in relation to their equity interests. The Company has determined that it is not the primary beneficiary of any VIEs in which it has a variable interest. 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 statement 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 consolidated financial statements, in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the 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. Significant estimates made by management include, among others, revenue recognition, stock-based compensation, and valuation of warrant liability. 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. Segment Reporting The Company reports its operating results and financial information in one operating and reportable segment. Our chief operating decision maker, which is our chief executive officer, reviews our operating results on a consolidated basis and uses that consolidated financial information to make operating decisions, assess financial performance, and allocate resources. Concentration of Credit Risk 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 December 31, 2022, two customers had trade receivable balances exceeding 10% of total accounts receivable. These customers accounted for 78% and 16% of total accounts receivable, respectively. As of December 31, 2022, one customer accounted for 100% of the customer financing receivable. For the year ended December 31, 2022, revenue from two different customers accounted for 57% and 35% of total revenue, respectively. Foreign Currency Assets and liabilities denominated in a foreign currency are translated into U.S dollars using the exchange rates in effect at the balance sheet date. Revenue and expense accounts are translated at the average exchange rates during the periods. The impact of exchange rate fluctuations from translation of assets and liabilities is included in accumulated other comprehensive loss, a component of stockholders’ equity (deficit). As of December 31, 2022, accumulated other comprehensive loss included a $0.2 million loss related to currency translation adjustments. As of December 31, 2021, accumulated other comprehensive loss included a $44 thousand gain related to currency translation adjustments. Gains and losses resulting from foreign currency transactions are included in other income (expense), net in the accompanying consolidated statements of operations. Fair Value Measurements ASC 820, Fair Value Measurement (“ASC 820”), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value as follows: Level I — Inputs which include quoted prices in active markets for identical assets and liabilities. Level II — Inputs other than Level I 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 III — Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. Revenue Recognition The Company recognizes revenue from contracts with customers in accordance with ASC 606, Revenue from Contracts with Customers (“ASC 606”). Under ASC 606, revenue is recognized when, or as, control of promised goods and services is transferred to customers, and the amount of revenue recognized reflects the consideration to which the Company expects to be entitled in exchange for the goods and services transferred. The Company determines revenue recognition through the following steps: (1) Identification of the contract, or contracts, with a customer. (2) Identification of the performance obligations in the contract. (3) Determination of the transaction price. (4) Allocation of the transaction price to the performance obligations in the contract. (5) Recognition of revenue when, or as, a performance obligation is satisfied. Once a contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations. Arrangements that include rights to additional goods or services that are exercisable at a customer’s discretion are generally considered options. The Company assesses if these options provide a material right to the customer and if so, they are considered performance obligations. The identification of material rights requires judgments related to the determination of the value of the underlying good or service relative to the option exercise price. The Company assesses whether each promised good or service is distinct for the purposes of identifying performance obligations in the contract. This assessment involves subjective determination and requires management to make judgments about the individual promised goods or services and whether such are separable from the other aspects of the contractual relationship. Promised goods and services are considered to be distinct provided that: (i) the customer can benefit from the good or service either on its own or together with the other resources that are readily available to the customer (that is, the good or service is capable of being distinct) and (ii) the entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (that is, the promise to transfer the good or service is distinct within the context of the contract). The Company also considers the intended benefit of the contract in assessing whether a promised good or service is separately identifiable from other promises in the contract. If a promised good or service is not distinct, an entity is required to combine that good or service with other promised goods or services until it identifies a bundle of goods or services that is distinct. The transaction price is determined and allocated to the identified performance obligations in proportion to their stand-alone selling prices (“SSP”) on a relative SSP basis. SSP is determined at contract inception and is not updated to reflect changes between contract inception and when the performance obligations are satisfied. Determining the SSP for performance obligations requires significant judgment. In developing the SSP for a performance obligation, the Company considers applicable market conditions and relevant entity-specific factors, including factors that were contemplated in negotiating the agreement with the customer and estimated costs. In determining the transaction price, the Company adjusts consideration for the effects of the time value of money if the timing of payments provides the Company with a significant benefit of financing. When a contract provides the customer with a significant benefit of financing, the Company recognizes a customer financing receivable and recognizes interest income separate from the revenue recognized on the contracts with customers. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment and the transfer of the promised goods or services will be one year or less. The Company recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) each performance obligation is satisfied, either at a point in time or over time. Over time revenue recognition is based on the use of an output or input method. Build and Transfer Energy Storage Projects: The Company enters into contracts with utility companies and independent power producers to build and transfer energy storage projects. The Company has entered into contracts to build and transfer battery-based energy storage projects and intends to enter into contracts to build and transfer gravity-based energy storage projects in the future. Each storage project is customized depending on the customer’s energy needs. Customer payments are due upon meeting certain milestones that are consistent with contract-specific phases of a project. The Company determines the transaction price based on the consideration expected to be received, which includes estimates of liquidated damages or other variable consideration. Generally, each contract to design and construct an energy storage project contains one performance obligation. Multiple contracts entered into with the same customer and near the same time to construct energy storage projects are combined in accordance with ASC 606. In these situations, the contract prices are aggregated and then allocated to each energy storage project based upon their relative stand-alone selling price. The Company recognizes revenue over time as a result of the continuous transfer of control of its products to the customer. The continuous transfer of control to the customer is supported by clauses in the contracts that provide enforceable rights to payment of the transaction price associated with work performed to date for products that do not have an alternative use to the Company and/or the project is built on the customer’s land that is under the customer’s control. Revenue for these performance obligations is recognized using the percentage of completion method based on cost incurred as a percentage of total estimated contract costs. Contract costs include all direct materials and labor costs related to contract performance. Pre-contract costs with no future benefit are expensed in the period in which they are incurred. Since the revenue recognition of these contracts depends on estimates, which are assessed continually during the term of the contract, recognized revenues and profit are subject to revisions as the contract progresses to completion. The cumulative effects of revisions of estimated total contract costs and revenues, together with any contract reserves which may be deemed appropriate, are recorded in the period in which the facts and changes in circumstances become known. Due to uncertainties inherent in the estimation process, it is reasonably possible that these estimates will be revised in a different period. When a loss is forecasted for a contract, the full amount of the anticipated loss is recognized in the period in which it is determined that a loss will incur. The Company’s contracts generally provide customers the right to liquidated damages (“LDs”) against Energy Vault in the event specified milestones are not met on time, or certain performance metrics are not met upon or after the substantial completion date. LDs are accounted for as variable consideration, and the contract price is reduced by the expected penalty or LD amount when recognizing revenue. Variable consideration is included in the transaction price only to the extent that it is improbable that a significant reversal in the amount of cumulative revenue recognized will occur when the uncertainty is resolved. Estimating variable consideration requires certain estimates and assumptions, including whether and by how much a project will be delayed. The existence and measurement of liquidated damages may also be impacted by the Company’s judgment about the probability of favorable outcomes of customer disputes involving whether certain events qualify as force majeure or the reason for the events that caused project delays. Variable consideration for LDs is estimated using the expected value of the consideration to be received. If Energy Vault has a claim against the customer for an amount not specified in the contract, such claim is recognized as an increase to the contract price when it is legally enforceable, which is usually upon signing a respective change order or equivalent document confirming the claim acceptance by the customer. The Company offers limited warranties on the Company’s energy storage systems which provide the customer assurance that the energy storage systems will function as the parties intended because it complies with agreed-upon specifications and are free from defects. These assurance-type warranties are not treated as a separate revenue performance obligation and are accounted for as guarantees under GAAP. Operate Energy Storage Projects: To date, the Company has not recognized any revenue related to providing operation services for its energy storage projects. The method of revenue recognition will be determined once the Company finalizes agreements with its future customers. Energy Management Software as a Service and Long Term Service Arrangements: To date, the Company has not recognized any revenue related to providing energy management software as a service or related to long term service arrangements. The method of revenue recognition will be determined once the Company finalizes agreements with its future customers. Intellectual Property Licensing: The Company enters into licensing agreements of its intellectual property that are within the scope of ASC 606. The terms of such licensing agreements include the license of functional intellectual property, given the functionality of the intellectual property is not expected to change substantially as a result of the licensor’s ongoing activities. The transaction price allocated to the licensing of intellectual property is recognized as revenue at a point in time when the licensed intellectual property is made available for the customer’s use and be nefit. Certain licensing agreements contain a significant financing component due to the customer having extended payment terms. The amounts due from customers under extended payment terms are included in the line item, customer financing receivable, on the consolidated balance sheets. One of the Comp any’s intellectual property licensing customers is Atlas, which was an investor in the Company’s PIPE. As part of the Company’s licensing agreement with Atlas, the Company agreed to provide Atlas with a final update to its functional intellectual property upon the completion of the Company’s research and development activities related to the intellectual property that was previously provided to Atlas. The Company identified the obligation to provide this update to Atlas as a performance obligation and deferred $5.9 million of the transaction price related to this performance obligation during the first quarter of 2022. This deferred amount was recognized as revenue during the fourth quarter of 2022 upon the Company transferring the technology update to Atlas. The contract with Atlas includes variable consideration of $25.0 million due to the Company’s commitment to provide a $25.0 million refundable contribution to Atlas during the construction period of Atlas’ first project. The Company has considered this to be variable consideration as the Company will be repaid when Atlas’ first project reaches substantial completion, subject to adjustment for potential liquidated damages if certain performance metrics are not met. The Company has determined that it is probable that Atlas will reach substantial completion and meet the performance metrics to repay Energy Vault, therefore the entire amount of variable consideration has been included in the transaction price. As of December 31, 2022, t he Company has contributed all $25.0 million to Atlas. The $25.0 million refundable contribution is included in the line item, contract assets, on the consolidated balance sheets. Royalty Revenue: In connection with entering into intellectual property licensing agreements, the Company also enters into royalty agreements whereby the customer agrees to pay the Company a percentage of the customer’s future sales revenue that is generated by using the Company’s intellectual property. The Company has not recognized any royalty revenue to date, but will recognize royalty revenue at the point in time when the customer’s sales occur. Other Revenue: In connection with entering into the intellectual property licensing agreement with Atlas, the Company agreed to provide construction support services to Atlas during the periods in which they construct energy storage projects. Energy Vault is reimbursed by Atlas at the Company’s cost to provide these services. Because the construction support services were considered to be an option that provided a material right for the customer to obtain services from the Company, this obligation was considered to be a performance obligation and required an allocation of the transaction price. The transaction price allocated to construction support services and deferred at the inception of the contract was $1.2 million. This amount is recognized as revenue over time using the cost-to-cost measure of progress as that method offers the best depiction of the continuous transfer of services to the customer. Cash, Cash Equivalents, and Restricted Cash The Company considers all highly liquid investments purchased with an original or remaining maturity of three months or less to be cash equivalents. At December 31, 2022 and 2021, the Company maintained money market accounts totaling $5.4 million and $5.3 million respectively; and a cash sweep account invested primarily in US Treasury and other short term securities totaling $66.5 million and $84.2 million, respectively. Restricted cash as of December 31, 2022 primarily consisted of cash held by banks as collateral for the Company’s letters of credit. Accounts Receivable Accounts receivable represents amounts that have an unconditional right to consideration, have been billed to customers, and do not bear interest. Receivables are carried at amortized cost. The Company periodically assesses collectability of its receivables from each customer and records an allowance for doubtful accounts for the estimated uncollectible amount when deemed appropriate. If circumstances related to specific customers change, the Company’s estimates of the recoverability of receivables could be adjusted. Accounts are written off after all means of collection, including legal action, have been exhausted. As of both December 31, 2022 and December 31, 2021, no allowance for doubtful accounts has been recorded. Customer Financing Receivable Customer financing receivable includes amounts due from a customer related to a licensing agreement under extended payment terms which contains a significant financing component. An interest rate is not stated in this agreement and is imputed using the effective interest method when recognizing interest income. The imputed interest rate on the note is 8.9% . Interest income on the customer financing receivable was $35 thousand for the year ended December 31, 2022 and was recognized within the line item, other income (expense), net in the consolidated statements of operations. As of December 31, 2022, no allowance for doubtful accounts has been recorded for customer financing receivable. Inventory Inventory consists of inverters and spare parts, which are used in ongoing battery storage projects for sale. Inventory is stated at the lower of cost or net realizable value with cost being determined by the specific identification method. Costs include the cost of purchase and other costs incurred in bringing the inventories to their present location and condition. The Company periodically reviews its inventory for potential obsolescence and write down of its inventory, as appropriate, to net realizable value based on its assessment of market conditions. Property and Equipment, Net Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the respective assets. Maintenance and repairs are charged to expense as incurred. When assets are retired or sold, the cost and related accumulated depreciation are removed from the consolidated balance sheet and any resulting gain or loss is reflected in operating expenses in the period realized. Impairment of Long-Lived Assets The Company reviews long-lived assets, primarily comprised of property and equipment and operating right-of-use assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amount to the future undiscounted net cash flows which the assets are expected to generate. If the carrying value of the assets exceeds the sum of the estimated future cash flows, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceed their fair value. Investment in Equity Securities During 2022, the Company made a strategic investment and purchased equity securities of a private company active in the energy transition industry. These equity securities do not have a readily determinable fair value and are recorded at cost, less any impairment, plus or minus adjustments related to observable transactions for the same or similar securities, with unrealized gains and losses included in earnings. As of December 31, 2022, both the cost basis and carrying value of these equity securities was $9.0 million. The Company did not recognize any impairments or value changes resulting from observable price changes during the year ended December 31, 2022. The carrying value of the Company’s investment in equity securities is included in the line item, other assets, in the consolidated balance sheets. Leases The Company determines if a contract contains a lease at its inception based on whether or not the Company has the right to control the asset during the contract period and other facts and circumstances. Right-of-use (“ROU”) assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. ROU assets are classified as either operating or finance leases. Upon commencement of the lease, a ROU asset and corresponding lease liability are recognized for all operating and finance leases. The Company has elected the short-term lease exemption, which does not require a ROU asset or lease liability to be recognized when the lease term is 12 months or less and does not include an option to purchase the underlying asset that the lessee is reasonably certain to exercise. The Company has decided not to elect the policy to not separate lease and non-lease component in arrangements whereby the Company is the lessee. Upon commencement of the lease, ROU assets are recognized based on the initial measurement of the lease liability and adjusted for any lease payments made before commencement date of the lease, less any lease incentives and including any initial direct costs incurred. Lease liabilities are initially measured at the present value of future minimum lease payments over the lease term. The discount rate used to determine the present value is the rate implicit in the lease unless that rate cannot be determined, in which case Company’s incremental borrowing rate is used, which is based on the estimated interest rate for collateralized borrowing over a similar term of the lease at commencement date. Rights to extend or terminate a lease are included in the lease term when there is reasonable certainty the right will be exercised. Factors used to assess reasonable certainty of rights to extend or terminate a lease include current and forecasted lease improvement plans, anticipated changes in development strategies, historical practice in extending similar contracts and current market conditions. Operating lease ROU assets and liabilities are subsequently measured at the present value of the lease payments not yet paid and discounted at the initial discount rate at commencement of the lease, less any impairments to the ROU asset. Operating lease expense is recognized on a straight-line basis over the lease term. Finance lease ROU assets are amortized on a straight-line basis over the estimated useful life of the asset if the lessee is reasonably certain to exercise a purchase option or ownership of the leased asset transfers at the end of the lease term, otherwise the leased assets are amortized over the lease term. Amortization of finance lease ROU assets is included in depreciation and amortization. Operating lease ROU assets are recognized on the consolidated balance sheets in the line item, operating lease right-of-use assets, and finance lease ROU assets are recognized on the consolidated balance sheets within the line item, property and equipment, net. Asset Retirement Obligation Asset retirement obligations (AROs) are legal obligations associated with the retirement of tangible long-lived assets resulting from acquisition, construction, development, and/or normal use of the underlying assets. The ARO is recognized at its estimated fair value in the period in which it is incurred. These obligations generally include the estimated net future costs of dismantling the assets and restoring the land the assets are located on to its original condition in accordance with legal regulations and land lease agreement requirements. Upon initial recognition of a liability, the associated asset retirement costs are capitalized as part of the related long-lived asset and depreciated over the estimated useful life of the related asset. The liability is accreted over time through charges to earnings. If an ARO is settled for an amount other than the carrying amount of the liability, the Company recognizes a gain or loss on the settlement. The Company reviews its AROs on an ongoing basis. Defined Benefit Pension Obligation The Company’s wholly owned subsidiary in Switzerland has a defined benefit pension obligation covering retirement and other long-term benefits of the local employees. Accrued pension costs are developed using actuarial principles and assumptions which consider a number of factors, including estimates for the discount rate, expected long-term rate of return on assets and mortality. Changes in these estimates would impact the amounts that the Company records in the consolidated financial statements. Warrants The Company assumed Public Warrants and Private Warrants upon the Closing. The Company accounts for warrants for shares of the Company’s common stock that are not indexed to its own stock as liabilities at fair value on the consolidated balance sheets. The warrants are subject to remeasurement at each balance sheet date and any change in fair value is recognized in the Company’s consolidated statements of operations. For issued or modified warrants that meet all of the criteria for equity classification, the warrants are required to be recorded as a component of additional paid-in-capital at the time of issuance. For issued or modified warrants that do not meet all the criteria for equity classification, the warrants are required to be recorded as a liability at their initial fair value on the date of issuance, and each balance sheet date thereafter. Changes in the estimated fair value of the warrants are recognized as a non-cash gain or loss in the consolidated statements of operations. Earn-Out Shares In connection with the reverse recapitalization and pursuant to the Merger Agreement, eligible Legacy Energy Vault stockholders immediately prior to the Closing, have the contingent right to receive an aggregate of 9.0 million shares of the Company’s common stock (“Earn-Out Shares”) upon the Company achieving each Earn-Out Triggering Event (defined below) during the period beginning on the 90th day following the Closing and ending on the third anniversary of such date. An “Earn-Out Triggering Event” means the date on which the closing price of the Company’s common stock quoted on the NYSE is greater than or equal to certain specified prices for any 20 trading days within a 30 consecutive day trading period. The Earn-Out Shares were recognized at fair value upon the Closing of the Merger and classified in shareholders’ equity. Because the Merger was accounted for as a reverse recapitalization, the issuance of the Earn-Out Shares was treated as a deemed dividend and since the Company does not have retained earnings, the issuance was recorded within additional-paid-in capital (“APIC”) and has a net nil impact on APIC. Research and Development Expenses Research and development costs are expensed as incurred. Research and development costs consist of salaries and ot

REVERSE RECAPITALIZATION

REVERSE RECAPITALIZATION	12 Months Ended
	Dec. 31, 2022
Reverse Recapitalization [Abstract]
REVERSE RECAPITALIZATION	REVERSE RECAPITALIZATION On February 11, 2022, in connection with the Merger, the Company raised gross proceeds of $235.9 million , including the contribution of $40.9 million of cash, net of redemptions, held in Novus’ trust account from its initial public offering and an aggregate purchase price of $195.0 million from the sale and issuance of common shares in a PIPE at $10.00 per share. The Company and Novus incurred in aggregate approximately $44.8 million in transaction costs, consisting of underwriting, legal, and other professional fees, of which $24.2 million was recorded to additional paid-in-capital as a reduction of proceeds and the remaining $20.6 million was expensed immediately upon the Closing. The aggregate consideration paid to Legacy Energy Vault stockholders in connection with the Merger (excluding any potential Earn-Out Shares), was 106.2 million shares of the Company’s common stock, par value $0.0001 after giving effect to the exchange ratio of 6.7735 (the “Exchange Ratio”). The total net cash proceeds to the Company were $191.1 million. The following transactions were completed as part of the Merger: • All of the issued and outstanding shares of Legacy Energy Vault convertible preferred stock were canceled and c onverted into a total of 85.7 million shares of Energy Vault common stock; • Each issued and outstanding share of Legacy Energy Vault common stock was canceled and converted into a total of 20.4 million shares of Energy Vault common stock; • Each outstanding vested and unvested Legacy Energy Vault common stock option was converted into options exercisable for shares of Energy Vault common stock with the same terms except for the number of shares exercisable and the exercise price, each of which was adjusted by the Exchange Ratio; • Each outstanding and unvested Legacy Energy Vault restricted stock unit (“RSU”) was converted into RSUs for shares of Energy Vault common stock with the same terms except for the number of shares, each of which was adjusted by the Exchange Ratio; and • Each outstanding vested and unvested Legacy Energy Vault restricted stock award (“RSA”) was converted into RSAs for shares of Energy Vault common stock with the same terms except for the number of shares, each of which was adjusted by the Exchange Ratio. The Merger was accounted for as a reverse recapitalization in accordance with GAAP. Under this method of accounting, Novus was treated as the acquired company for financial reporting purposes. The reverse recapitalization accounting treatment was primarily determined based on the shareholders of Legacy Energy Vault having a relative majority of the voting power of Energy Vault and having the ability to nominate the majority of the members of the Energy Vault Board, senior management of Legacy Energy Vault comprise the senior management of Energy Vault, and the operations of Legacy Energy Vault prior to the Merger comprise the ongoing operations of Energy Vault. Accordingly, for accounting purposes, the financial statements of the combined entity upon consummation of the Merger represent a continuation of the financial statements of Legacy Energy Vault with the Merger being treated as the equivalent of Legacy Energy Vault issuing shares for the net assets of Novus, accompanied by a recapitalization. The net assets of Novus were recognized at historical cost, with no goodwill or other intangible assets recorded. Operations prior to the Merger are presented as those of Legacy Energy Vault and the accumulated deficit of Legacy Energy Vault has been carried forward after Closing. All periods prior to the Merger have been retroactively adjusted using the Exchange Ratio for the equivalent number of shares outstanding immediately after the Closing to effect the reverse recapitalization. The number of common stock issued following the consummation of the Merger was as follows (amounts in thousands): Shares Legacy Energy Vault stock converted as part of Merger (1) 106,172 Novus public shares (2) 4,079 Novus sponsor shares (3) 3,975 PIPE shares 19,500 Total shares of Energy Vault common stock issued as part of the Merger 133,726 __________________ (1) Excludes 9.0 million common shares issuable in earn-out arrangements as they are not issuable until 90 days after the Closing and are contingently issuable based upon the Company’s share price meeting certain thresholds. (2) Excludes 14.7 million warrants issued and outstanding as of the Closing of the Merger which includes 9.6 million public warrants and 5.2 million private warrants held by the Novus Sponsor.

REVENUE RECOGNITION

REVENUE RECOGNITION	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
REVENUE RECOGNITION	REVENUE RECOGNITION The Company recognized revenue for the product and service categories as follows for the years ended December 31, 2022 and 2021 (amounts in thousands): Year Ended December 31, 2022 2021 Build and transfer energy storage products (1) $ 85,636 $ — Licensing of intellectual property (2) 58,483 — Other (1) 1,758 — Total revenue $ 145,877 $ — __________________ (1) Represents revenue recognized over time (2) Represents revenue recognized at a point-in-time. Other revenue includes revenue of $0.7 million related to the amortization of deferred revenue related to providing construction support services to Atlas during the year ended December 31, 2022. Additionally, other revenue includes revenue of $1.1 million related to cos t reimbursements from Atlas for providing construction support services du ring the year ended December 31, 2022. The following table summarizes the Company’s revenue disaggregated by geographic region, which is determined based on the customer’s location, for the years ended December 31, 2022 and 2021 (amounts in thousands): Year Ended December 31, 2022 2021 United States $ 85,635 $ — China 50,518 — Other 9,724 — Total revenue $ 145,877 $ — 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 December 31, 2022, the amount of the Company’s remaining performance obligations was $331.0 million. The Company generally expects to recognize the majority of the remaining performance obligations as revenue within the next twelve months. Contract Balances The following table provides information about contract assets and contract liabilities from contracts with customers (amounts in thousands): December 31, 2022 2021 Refundable contribution $ 25,000 $ — Unbilled receivables 531 — Retainage 3,447 — Contract assets $ 28,978 $ — Contract liabilities, current portion $ 49,434 $ — Contract liabilities, long-term portion 1,500 1,500 Total contract liabilities $ 50,934 $ 1,500 Contract assets consist of a refundable contribution, unbilled receivables, and retainage. Refundable contribution represents the contribution the Company made to Atlas to be used during the construction of its first GESS, which will be refunded to the Company upon Atlas’ first GESS obtaining substantial completion, subject to adjustments for potential liquidated damages if certain performance metrics are not met. Unbilled receivables represent the estimated value of unbilled work for projects with performance obligations recognized over time. Retainage represents a portion of the contract amount that has been billed, but for which the contract allows the customer to retain a portion of the billed amount until final contract settlement. Retainage is not considered to be a significant financing component because the intent is to protect the customer. 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.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Carrying amounts of certain financial instruments, including cash, accounts payable, and accrued liabilities 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 that were measured at fair value on a recurring basis as of December 31, 2022 and December 31, 2021 were as follows (amounts in thousands): December 31, 2022 Level 1 Level 2 Level 3 Total Assets (Liabilities): Derivative asset —  conversion option (1) — — 1,025 1,025 Warrant liability (2) — — 2 2 December 31, 2021 Level 1 Level 2 Level 3 Total Assets (Liabilities): Derivative asset —  conversion option (1) — — 350 350 __________________ (1) Refer to Note 7 - Convertible Note Receivable for further information. (2) Refer to Note 12 - Warrants for further information.

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2022
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS In May 2019, the Company received a $1.5 million deposit for an “EV1” tower from a customer that is owned by one of its primary shareholders; the order remains outstanding as of December 31, 2022. The deposit and order were received before the owner of the customer became one of the Company’s primary shareholders and before it was represented on the Company’s Board. This deposit is recognized in the line item, contract liabilities, long-term portion, in the consolidated balance sheets. For the years ended December 31, 2022 and 2021, the Company paid contracted engineering, design, and civil tolerance code calculation support of $0.4 million and $0.3 million, resp ectively, to an immediate family member of an executive officer. The Company retains all intellectual property as part of these services. For the years ended December 31, 2022 and 2021, the Company paid construction labor costs of $0.5 million and $0.5 million, re spectively, for EV1 tower dismantlement and EVx test bed construction to a local company owned by an immediate family member of an employee. During the year ended December 31, 2022, the Company paid

CONVERTIBLE NOTE RECEIVABLE

CONVERTIBLE NOTE RECEIVABLE	12 Months Ended
	Dec. 31, 2022
Receivables [Abstract]
CONVERTIBLE NOTE RECEIVABLE	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 “DG Fuels Note”). The convertible promissory note is recorded in other assets in the consolidated balance sheets. The maturity date of the DG Fuels Note is the earlier of (i) 30 days after a demand for payment is made by the Company at any time after the two year anniversary of the date of issuance of the note; (ii) the four 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 DG Fuels Note has an annual interest rate of 10.0%. The Company intends to hold and convert the DG Fuels Note into the equity securities issued by DG Fuels in its next equity financing round that is greater than $20.0 million at a 20% discount to the issuance price. The principal balance and unpaid accrued interest on the DG Fuels Note will, at the option of the Company, convert into equity securities upon the closing of such next equity financing round. The discounted conversion rate in the DG Fuels Note is considered a redemption feature that is an embedded derivative, which requires bifurcation and separate accounting at its estimated fair value under ASC 815 – Derivative and Hedging . The embedded derivative upon the purchase of the DG Fuels Tranche 1 Note was an asset of $0.4 million and the embedded derivative upon the purchase of the DG Fuels Tranche 2 Note was an asset of $0.7 million. The estimated fair value of the derivative instruments were recognized as a derivative asset on the consolidated balance sheets, with an offsetting discount to the DG Fuels Note. The Company amortizes the discount on the Note into interest income using the effective interest method. The Company recognized interest income of $0.3 million and $21 thousand fo r the years ended December 31, 2022 and 2021, respectively, from the DG Fuels Note. Interest income included income from the amortization of the debt discount of $0.1 million and $4 thousand for the years ended December 31, 2022 and 2021, respectively. At each reporting period, the Company remeasures this derivative financial instrument to its estimated fair value. The change in the estimated fair value is recorded in other income (expense), net in the consolidated statements of operations and comprehensive loss. For the years ended December 31, 2022 and 2021, ther e was no change in fair value of th e embedded derivative. A reconciliation of the beginning and ending asset balance for the embedded derivative in the DG Fuels Note is as follows (amounts in thousands): Year Ended December 31, 2022 2021 Balance at beginning of period $ 350 $ — Additions 675 350 Change in fair value — — Balance at end of period $ 1,025 $ 350 The Company has determined that DG Fuels is a variable interest entity and that the Company has a variable interest in it through the DG Fuels Note. The Company is not the primary beneficiary of DG Fuels, and thus is not required to consolidate DG Fuels. The Company’s maximum exposure to loss related to DG Fuels is limited to the Company’s investment of $3.0 million.

PROPERTY AND EQUIPMENT, NET

PROPERTY AND EQUIPMENT, NET	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT, NET	PROPERTY AND EQUIPMENT, NET As of December 31, 2022 and 2021, property and equipment, net consisted of the following (amounts in thousands): December 31, Life (years) 2022 2021 Brick machines 6 $ 657 $ 2,515 Finance lease right-of-use assets – vehicles 4 178 175 Furniture and IT equipment 3 - 7 815 176 Leasehold improvements 4 - 7 529 179 Demonstration & test equipment — 11,218 Construction in progress 1,268 — Total property and equipment 3,447 14,263 Less: accumulated depreciation (403) (2,395) Property and equipment, net $ 3,044 $ 11,868 For the years ended December 31, 2022 and 2021 depreciation and amortization related to property and equipment was $7.7 million and $2.3 million, respectively . The Company recognized impairment charges related to property and equipment of $2.8 million for the year ended December 31, 2022 on its demonstration and test equipment and brick machines. Due to a change in the facts and circumstances during the year ended December 31, 2022, the Company completed the dismantling of the EV1 CDU during the 2022 fiscal year. Accordingly, the Company wrote off the carrying value of the demonstration and test equipment and certain components of the brick machines that could only be used for the EV1 CDU. This change in the facts and circumstances resulted in the recognition of accelerated depreciation of $3.8 million and impairment charges of $2.8 million during the year ended December 31, 2022. The Company did not recognize any impairment charges on property and equipment, net during the

ASSET RETIREMENT OBLIGATION

ASSET RETIREMENT OBLIGATION	12 Months Ended
	Dec. 31, 2022
Asset Retirement Obligation Disclosure [Abstract]
ASSET RETIREMENT OBLIGATION	ASSET RETIREMENT OBLIGATION The Company’s ARO relates to its obligation to dismantle the EV1 CDU and restore the land the EV1 CDU was located on to its original condition. The EV1 CDU was dismantled during 2022, but land restoration has not yet been completed as of December 31, 2022. The following table summarizes the asset retirement obligation activity for the years ended December 31, 2022 and 2021 (amounts in thousands): Year Ended December 31, 2022 2021 Balance at beginning of period $ 978 $ 123 Changes in estimates — 751 Accretion expense 95 107 Liabilities settled (487) — Foreign currency translation gain (26) (3) Balance at end of period $ 560 $ 978

DEFINED BENEFIT PENSION OBLIGAT

DEFINED BENEFIT PENSION OBLIGATION	12 Months Ended
	Dec. 31, 2022
Retirement Benefits [Abstract]
DEFINED BENEFIT PENSION OBLIGATION	DEFINED BENEFIT PENSION OBLIGATION The Company has a defined benefit pension plan for its employees in its wholly owned Switzerland subsidiary. The plan is a statutory requirement in accordance with local regulations. The Swiss pension plans are governed by the Swiss Federal Law on Occupational Retirements, Survivors’ and Disability Pension plans. The Company used third party providers to administer these plans. Benefits provided by the pension plan are based on years of service and employees’ remuneration over their employment period. The Company uses December 31 as the year end measurement date for this plan. The Company’s policy is to fund its pension obligations in conformity with the funding requirements under applicable laws and governmental regulations. The pension plans maintain investment policies that, among other things, establish a portfolio asset allocation methodology with percentage allocation bands for individual asset classes. The investment policies provide that investments are reallocated between asset classes as balances exceed or fall below the appropriate allocation bands. The assumption used for the expected long-term rate of return on plan asset is based on the long-term expected returns for the investment mix of assets currently in the portfolio. Historical return trends for the various asset classes in the class portfolio are combined with current and anticipated future market conditions to estimate the rate of return for each class. These rates are then adjusted for anticipated future inflation to determine estimated nominal rates of return for each class. The accumulated benefit obligation (ABO) represents the obligations of a pension plan for past service as of the measurement date, which is the present value of benefits earned to date based on current compensation levels. Obligations and Funded Status The following table presents the defined benefit plans’ funded status and amount recognized in the consolidated balance sheets as of December 31, 2022 and 2021 (amounts in thousands): Year Ended December 31, 2022 2021 Change in Benefit Obligation Benefit obligation at beginning of year $ 2,662 $ 2,425 Service cost 162 130 Interest cost 9 5 Actuarial (gain) loss (149) 99 Benefits paid 866 40 Plan participant’s contributions 137 86 Plan amendments 350 (50) Foreign currency translation adjustments 8 (73) Benefit obligation at end of year $ 4,045 $ 2,662 Change in Plan Assets Fair value of plans assets at beginning of year $ 1,928 $ 1,592 Actual return on plans’ assets 74 214 Employer contributions 137 43 Benefits paid 866 40 Plan participant’s contributions 137 85 Foreign currency translation adjustments 13 (46) Fair value of plans assets at end of year $ 3,155 $ 1,928 Funded Status at End of Year Fair value of plan assets $ 3,155 $ 1,928 Benefit obligation (4,045) (2,662) Liability recognized at end of year $ (890) $ (734) Components of Net Periodic Benefit Cost The components of net periodic pension benefit cost for the Company’s defined benefit pension plans for the years ended December 31, 2022 and 2021 were as follows (amounts in thousands): Year Ended December 31, 2022 2021 Employer service costs $ 162 $ 130 Interest cost 9 5 Expected return on plan assets (72) (53) Amortization of net prior service credit (13) (7) Amortization of net loss 39 59 Net periodic benefit cost $ 125 $ 134 Impact on Accumulated Other Comprehensive Income (Loss) Amounts recognized in accumulated other comprehensive income (loss) at December 31, 2022 and 2021 were as follows (amounts in thousands): December 31, 2022 2021 Net prior service credit (cost) $ (262) 94 Net loss (383) (551) Accumulated other comprehensive loss $ (645) $ (457) Changes in accumulated other comprehensive income (loss) for the Company’s pension plan were as follows (amounts in thousands): Year Ended December 31, 2022 2021 Accumulated other comprehensive loss at beginning of year $ (457) (623) Change in net prior service credit (cost) (360) 40 Change in net gain 189 112 Foreign currency translation adjustments (17) 14 Accumulated other comprehensive loss at end of year $ (645) $ (457) Assumptions The assumptions used to measure the benefit obligation and net periodic benefit cost for the Company’s defined benefit pension plan were as follows: 2022 2021 Discount rate 1.8 % 0.4 % Expected long-term return on plan assets 4.7 % 3.8 % Rate of compensation increase 1.5 % 1.0 % Pension increase rate (in payment) 0.0 % 0.0 % Investment Strategy As is customary with Swiss pension plans, the plan assets are invested in a Swiss collective fund with multiple employers. The Company does not have rights to the individual assets of the plans nor does the Company have investment authority over the assets of the plans. The collective fund maintains a variety of investment positions primarily in equity securities and highly rated debt securities. The valuation of the collective fund assets as a whole is a Level 3 measurement; however the individual investments of the fund are generally Level 1 (equity securities and cash), Level 2 (fixed income) and Level 3 (real estate and alternative) investments. The Company determines the fair value of the plan assets based on information provided by the collective fund, through review of the collective fund’s annual financial statements, and the Company further considers whether there are other indicators that the investment balances reported by the fund could be impaired. The Company concluded that no such impairment indicators were present at December 31, 2022. The Swiss pension plans’ actual asset allocation as compared to the plan administrators’ target asset allocations for fiscal years 2022 and 2021 were as follows: 2022 2021 Target Equity instruments (Level 1) 47.3 % 50.2 % 30% – 55% Debt instruments (Level 2) 9.7 % 10.6 % 5% – 30% Real estate (Level 3) 30.0 % 26.4 % 15% – 40% Alternative investments (Level 3) 7.7 % 5.3 % 0% – 15% Cash and equivalents (Level 1) 5.3 % 7.5 % 0% – 15% Total 100.0 % 100.0 % Cash Flows Estimated future benefit payments expected to be paid by the defined benefit pension plan at December 31, 2022 are as follows (amounts in thousands): Year Ending December 31, Future Benefits 2023 $ 42 2024 43 2025 43 2026 44 2027 45 Thereafter 227 Total $ 444 The estimated employer contribution to the defined benefit pension plan in fiscal year 2023 is approximately $0.2 million. Defined Contribution Plan The Company sponsors a defined contribution retirement plan for its United States employees. The Company did not make any matching contributions during 2022 and 2021. In January 2023, the Company began matching participants’ contributions up to a maximum of 3.5% of compensation.

LEASES

LEASES	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
LEASES	LEASES The Company has operating leases for its corporate offices, field offices, and vehicles. The Company recognizes a ROU asset and lease liability for operating leases based on the net present value of future minimum lease payments. Lease expense is recognized on a straight-line basis over the non-cancelable lease term and renewal periods that are considered reasonably certain. The Company has finance leases for vehicles. The Company recognizes a ROU asset and lease liability for finance leases based on the net present value of future minimum lease payments. Lease expense for the Company’s finance leases is comprised of the amortization of the right of use asset and interest expense recognized based on the effective interest method. The components of lease expense for the years ended December 31, 2022 and 2021 are as follows (amounts in thousands): Year Ended December 31, 2022 2021 Operating lease expense $ 853 $ 647 Finance lease expense Amortization of finance ROU assets 47 45 Interest on finance lease liabilities 2 3 Short-term lease expense 339 80 Variable lease expense 12 3 Sublease income (9) — Total $ 1,244 $ 778 Supplemental balance sheet information related to leases as of December 31, 2022 and 2021 is as follows: December 31, 2022 2021 Weighted Average Remaining Lease Term (Years) Operating leases 2.4 2.2 Finance leases 2.1 1.8 Weighted Average Discount Rate Operating leases 8.6 % 7.4 % Finance leases 4.4 % 2.8 % Supplemental cash flow information related to leases for the fiscal years ended December 31, 2022 and 2021 is as follows (amounts in thousands): Year Ended December 31, 2022 2021 Cash Paid for Amounts Included in the Measurement of Lease Liabilities Operating cash flows used for operating leases $ 836 $ 532 Operating cash flows used for finance leases 2 3 Financing cash flows used for finance leases 62 53 $ 900 $ 588 ROU Assets obtained in Exchange for Lease Liabilities Operating leases $ 962 $ 476 Finance leases 37 44 $ 999 $ 520 Future maturities of operating and finance lease liabilities as of December 31, 2022 are as follows (amounts in thousands): Operating Leases Finance Leases 2023 $ 876 $ 40 2024 482 6 2025 110 6 2026 105 5 2027 61 — Thereafter — — Total undiscounted cash flows 1,634 57 Less imputed interest (138) (3) Present value of lease liabilities $ 1,496 $ 54
LEASES	LEASES The Company has operating leases for its corporate offices, field offices, and vehicles. The Company recognizes a ROU asset and lease liability for operating leases based on the net present value of future minimum lease payments. Lease expense is recognized on a straight-line basis over the non-cancelable lease term and renewal periods that are considered reasonably certain. The Company has finance leases for vehicles. The Company recognizes a ROU asset and lease liability for finance leases based on the net present value of future minimum lease payments. Lease expense for the Company’s finance leases is comprised of the amortization of the right of use asset and interest expense recognized based on the effective interest method. The components of lease expense for the years ended December 31, 2022 and 2021 are as follows (amounts in thousands): Year Ended December 31, 2022 2021 Operating lease expense $ 853 $ 647 Finance lease expense Amortization of finance ROU assets 47 45 Interest on finance lease liabilities 2 3 Short-term lease expense 339 80 Variable lease expense 12 3 Sublease income (9) — Total $ 1,244 $ 778 Supplemental balance sheet information related to leases as of December 31, 2022 and 2021 is as follows: December 31, 2022 2021 Weighted Average Remaining Lease Term (Years) Operating leases 2.4 2.2 Finance leases 2.1 1.8 Weighted Average Discount Rate Operating leases 8.6 % 7.4 % Finance leases 4.4 % 2.8 % Supplemental cash flow information related to leases for the fiscal years ended December 31, 2022 and 2021 is as follows (amounts in thousands): Year Ended December 31, 2022 2021 Cash Paid for Amounts Included in the Measurement of Lease Liabilities Operating cash flows used for operating leases $ 836 $ 532 Operating cash flows used for finance leases 2 3 Financing cash flows used for finance leases 62 53 $ 900 $ 588 ROU Assets obtained in Exchange for Lease Liabilities Operating leases $ 962 $ 476 Finance leases 37 44 $ 999 $ 520 Future maturities of operating and finance lease liabilities as of December 31, 2022 are as follows (amounts in thousands): Operating Leases Finance Leases 2023 $ 876 $ 40 2024 482 6 2025 110 6 2026 105 5 2027 61 — Thereafter — — Total undiscounted cash flows 1,634 57 Less imputed interest (138) (3) Present value of lease liabilities $ 1,496 $ 54

WARRANTS

WARRANTS	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
WARRANTS	WARRANTS Upon the Closing of the Merger, the Company assumed 9.6 million Public Warrants and 5.2 million Private Warrants. Each whole warrant entitles the holder to purchase one share of the Company’s common stock at an exercise price of $11.50 per share, subject to adjustments. The warrants became exercisa ble on March 13, 2022, and at that time were scheduled to expire on February 11, 2027, which represents five years after the Closing. The Company filed a Registration Statement on Form S-1 on March 8, 2022 related to the issuance of an aggregate of up to approximately 14.8 million shares of common stock issuable upon the exercise of the Public and Private Warrants, which was declared effective by the SEC on May 6, 2022. Public Warrants On July 1, 2022 the Company announced (“Redemption Notice”) it would redeem all of its Public Warrants that remained outstanding at 5:00 p.m. New York City time on August 1, 2022 (the “Redemption Date”) for $0.10 per warrant (the “Redemption Price”). The Public Warrant Holders were permitted to exercise their warrants and receive common stock (i) in exchange for a payment in cash of the $11.50 per warrant exercise price, or (ii) on a cashless basis in which the exercising holder received 0.2526 of common stock for each warrant surrendered for exercise. Any Public Warrants that remained unexercised at 5:00 p.m. New York City time on the Redemption Date would be void and no longer exercisable, and the holders of those Public Warrants would be entitled to receive only the Redemption Price. Prior to the Redemption Notice, 0.7 million shares of common stock were issued related to the exercise of an equivalent number of Public Warrants. Subsequent to the Redemption Notice, 2.2 million shares of common stock were issued upon the cashless exercise of 8.7 million Public Warrants. 0.2 million in unexercised and outstanding Public Warrants as of 5:00 p.m., August 1, 2022 were redeemed at a price of $0.10 per Public Warrant. No Public Warrants remained outstanding as of December 31, 2022. Private Warrants The Private Warrants are exercisable on a cash or cashless basis, at the warrant holders’ option, and are not redeemable by the Company, in each case so long as the warrants are still held by Novus or their permitted transferees. If the Private Warrants are no longer held by Novus or their permitted transferees, the redemption right included in the Public Warrants will attach to the Private Warrants. The Private Warrants are exercisable until February 11, 2027. The following table summarizes the Public and Private Warrants activities for the year ended December 31, 2022 (amounts in thousands): Year Ended December 31, 2022 Public Warrants Private Warrants Total Warrants Warrants assumed upon the Closing of the Merger 9,583 5,167 14,750 Warrants exercised (9,348) — (9,348) Warrants redeemed (235) — (235) End of period — 5,167 5,167 The Public Warrants were classified as Level 1 measurements as the Public Warrants had an adequate trading volume to provide reliable indication of value from the Closing of the Merger to the Redemption Date. The Private Warrants were classified as Level 2 from the Closing of the Merger until the Redemption Date because the Private Warrants had similar terms to the Public Warrants. Upon the ceasing of trading of the Public Warrants on the Redemption Date, the fair value measurement of the Private Warrants transferred from Level 2 to Level 3 and the Company used a Black Scholes model to determine the fair value of the Private Warrants. The primary significant unobservable input used to evaluate the fair value measurement of the Company’s Private Warrants is the expected volatility. A significant increase in the expected volatility in isolation would result in a significantly higher fair value measurement. The Private Warrants were val ued at less than $0.01 per warrant a s of December 31, 2022. The following table provides the assumptions used to estimate the fair value of the Private Warrants as of December 31, 2022: December 31, 2022 Common stock price $ 3.12 Exercise price $ 11.50 Expected term (in years) 4.12 Expected volatility 17.4 % Risk-free interest rate 4.1 % Expected dividend yield — % The Public and Private Warrants are measured at fair value on a recurring basis. The following table presents the changes in the fair value of the Company’s Public and Private Warrants liabilities for the year ended December 31, 2022 (amounts in thousands): Year Ended December 31, 2022 Public Warrants Private Warrants Total Warrants Warrant liability assumed upon the Closing of the Merger $ 12,938 $ 6,900 $ 19,838 Warrants exercised (17,483) — (17,483) Warrants redeemed (23) — (23) Change in fair value 4,568 (6,898) (2,330) Warrant liability at end of period $ — $ 2 $ 2

SUPPLEMENTAL BALANCE SHEETS DET

SUPPLEMENTAL BALANCE SHEETS DETAIL	12 Months Ended
	Dec. 31, 2022
Offsetting [Abstract]
SUPPLEMENTAL BALANCE SHEETS DETAIL	SUPPLEMENTAL BALANCE SHEETS DETAIL December 31, (amounts in thousands) 2022 2021 Prepaid expenses and other current assets: Deposits for project equipment and materials $ 24,327 $ — Prepaid expenses 6,609 1,140 Tax refund receivable 454 121 Deferred merger costs — 4,121 Other 179 156 Total $ 31,569 $ 5,538 December 31, (amounts in thousands) 2022 2021 Other assets: Investment in equity securities $ 9,000 $ — Convertible note receivable 2,080 654 Derivative asset —  conversion option 1,025 350 Other 1,795 521 Total $ 13,900 $ 1,525 December 31, (amounts in thousands) 2022 2021 Accrued Expenses: Employee costs $ 8,711 $ 3,756 Taxes payable 4,168 — Professional fees 1,671 81 Prototype costs — 716 Other 199 151 Total $ 14,749 $ 4,704

STOCKHOLDERS_ EQUITY

STOCKHOLDERS’ EQUITY	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
STOCKHOLDERS’ EQUITY	STOCKHOLDERS’ EQUITY Redeemable Convertible Preferred Stock As part of the Merger, 85.7 million shares of issued and outstanding redeemable convertible preferred stock were cancelled and converted into 85.7 million shares of Energy Vault common stock based upon an exchange ratio of 6.7735. A total of $182.7 million redeemable convertible preferred stock was reclassified into common stock and additional paid-in-capital on the consolidated balance sheet. As of December 31, 2021, the Company’s convertible preferred stock consisted of the following (amounts in thousands and adjusted for Merger exchange ratio): Shares Designated Shares Issued and Outstanding Liquidation Preference Series C preferred stock 14,787 14,787 $ 107,000 Series B-1 preferred stock 14,475 14,475 31,003 Series B preferred stock 14,651 14,651 25,003 Series A-2 preferred stock 5,087 5,087 3,555 Series A-1 preferred stock 6,950 6,950 3,076 Series Seed 2 preferred stock 4,240 4,240 934 Series Seed 1 preferred stock 11,190 11,190 753 Series FR preferred stock 14,361 14,361 25 85,741 85,741 $ 171,349 The significant rights and preferences of the outstanding convertible preferred stock through the closing of the Merger were as follows: Dividends Through the closing date, the holders of each class of convertible preferred stock had been entitled to receive non-cumulative dividends at 8% per annum, if and when declared by the Board. Through the closing date of the Merger, no dividends had been declared. Conversion Until the closing of the Merger, each class of preferred stock was convertible to common stock at the option of the holder at the conversion price (as defined in the articles of incorporation) which was initially equal to the original issuance price of each of the preferred stock issuances. The preferred stock would be automatically converted to common stock upon the earlier of; (a) a firm commitment underwritten initial public offering to an effective registration statement and sale of common stock to the public of not less than $49.0258 per share (minimum price per share does not apply to Series FR, Seed 1 and Seed 2 preferred stock) with gross proceeds not less than $50.0 million, or (b) by written consent of the holders of a majority of the then outstanding shares of preferred stock voting as single class on an as-converted to common stock basis, with the holders of the Series A, Seed 2, Seed 1, and Series FR preferred stock voting as a separate class on an as-converted basis, the holders of the Series B voting as a separate class on an as-converted basis, the holders of the Series B-1 voting as a separate class on an as-converted basis, and the holders of the Series C voting as a separate class on an as-converted basis. The conversion price was subject to adjustment for stock splits and stock dividends, reorganization, reclassifications, or similar events and was to be adjusted proportionately. The conversion price would have also been adjusted for certain dilutive issuances of common stock or securities exercisable or convertible into common stock at a price below the conversion price in effect at the time (price protection or ratchet feature). The adjustment to the conversion price would have been determined by multiplying the conversion price by a fraction calculated as the diluted shares pre-issuance at the conversion price divided by the common stock pre-issuance plus the additional stock issued (partial ratchet). Liquidation Until the closing of the Merger, in the event of any liquidation, dissolution, or winding up of the Company, the holders of Series B, Series B-1 and Series C preferred stock would have been entitled to, in preference to the holders of each of the other classes of preferred stock, and to the common stockholder, an amount equal to the original issuance price plus declared but unpaid dividends. After payment in full to the holders of Series B, Series B-1 and Series C preferred stock, and prior to any distribution to the common stockholders, each of the other classes of preferred stock would have been entitled to receive an amount equal to the original issue price plus declared and unpaid dividends on such shares, payable on a pari-passu basis among the Series. A liquidation, dissolution, or winding up of the Company would have been deemed to have occurred upon completion of any transaction or event that resulted in a change of control as defined in the articles of incorporation (a “Deemed Liquidation Event”). Upon a Deemed Liquidation Event, the preferred stock would have become redeemable at the option of the holder and the Company would have been required to provide written notice to the holders of the preferred stock within 90 days of such an event informing them of their right to redeem the preferred stock. For purposes of determining the amount each holder of preferred stock would have been entitled to receive upon a Deemed Liquidation Event, each class of preferred stock would have been deemed to have automatically converted their shares into common stock at the as converted value (even if not elected by the holder) immediately prior to such a Deemed Liquidation Event, if the value was greater than the amount that would have been distributed to the holder of the preferred stock if it were not converted. Voting Until the closing of the Merger, each share of preferred stock was entitled to the number of votes equal to the number of shares of common stock into which the shares of preferred stock so held could be converted at the record date. Common Stock On February 11, 2022, in connection with the reverse recapitalization treatment of the Merger, the Company effectively issued 27.6 million new shares of common stock. Additionally as part of the Merger, the Company converted all 3.0 million issued and outstanding common stock and all 12.7 million issued and outstanding convertible preferred stock of Legacy Energy Vault into 106.2 million new shares of common stock using an exchange ratio of 6.7735.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION 2017 Stock Incentive Plan In 2017, the Company adopted its 2017 Stock Incentive Plan (the “2017 Plan”) which provides for the granting of stock options, restricted stock, and RSUs to employees, directors, and consultants of the Company. Options granted under the 2017 Plan were either ISOs or Nonqualified Stock Options (“NSOs”). Awards under the 2017 Plan may be granted for periods of up to ten years. Under the terms of the 2017 Plan, awards may be granted at an exercise price not less than the estimated fair value of the shares on the date of grant, as determined by the Company’s Board. For employees holding more than 10% of the voting rights of all classes of stock, the exercise price of ISOs and NSOs may not be less than 110% of the estimated fair value of the shares on the date of grant, as determined by the Board. Awards generally vest over one 2020 Stock Incentive Plan In 2020, the Company adopted its 2020 Stock Incentive Plan (the “2020 Plan”) which superseded the previous 2017 Plan. The 2020 Plan provides for the granting of stock options, restricted stock, and RSUs to employees, directors, and consultants of the Company. Options granted under the 2020 Plan may be either ISOs or NSOs. Awards under the 2020 Plan may be granted for periods of up to ten years. Under the terms of the 2020 Plan, awards may be granted at an exercise price not less than the estimated fair value of the shares on the date of grant, as determined by the Company’s Board. For employees holding more than 10% of the voting rights of all classes of stock, the exercise price of ISOs and NSOs may not be less than 110% of the estimated fair value of the shares on the date of grant, as determined by the Board. Awards generally vest over one 2022 Equity Incentive Plan In 2022, the Company adopted its 2022 Equity Incentive Plan (the “2022 Incentive Plan”), which superseded the previous 2020 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 number of shares of the Company’s common stock reserved for issuance under the 2022 Incentive Plan is approximately 15.5 million, plus up to approximately 8.3 million shares subject to awards granted under the 2017 and 2020 Plans. Additionally, beginning on March 1, 2022 and ending on (and including) March 31, 2031, the number of shares of the Company’s common stock that may be issued under the 2022 Incentive Plan will increase 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 fiscal year 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. Stock Option Activity Stock option activity for the years ended December 31, 2022 and 2021 are as follows (amounts in thousands, except per share data): Options Outstanding Number of Options (1) Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Balance as of December 31, 2020 576 $ 0.09 7.48 $ 423 Stock options granted 1,142 0.89 Stock options exercised (373) 0.01 Balance as of December 31, 2021 1,345 0.79 9.11 7,024 Stock options exercised (212) 0.80 Stock options forfeited, canceled, or expired (40) 0.80 Balance as of December 31, 2022 1,093 0.79 8.10 2,551 Options exercisable as of December 31, 2022 796 0.69 7.89 1,936 Options vested and expected to vest as of December 31, 2022 1,093 $ 0.79 8.10 2,551 __________________ (1) The number of options prior to the Merger have been retroactively restated to reflect the exchange ratio of 6.7735 established in the Merger. As of December 31, 2022 , total unamortized stock-based compensation expense related to unvested 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 2.74 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 December 31, 2022. The Company estimates the fair value of the options on the grant date utilizing the Black-Scholes option pricing model. No options were granted during 2022. Options granted during 2021 were valued based on the following range and weighted-average assumptions: 2021 Common stock price (1) $0.93 - $4.98 Expected term (in years) 6.25 Expected volatility 90.0 % Risk-free interest rate 0.1 % Expected dividend yield — __________________ (1) The stock price prior to the Merger has been retroactively restated to reflect the exchange ratio of 6.7735 established in the Merger. Restricted Stock Units Stock-based compensation expense for awards with only service conditions are recognized on a straight-line basis over the requisite service period of the award. Generally, awards granted under the 2022 plans vest based solely on a service condition. RSUs granted under the 2020 Plan contain both a service-based vesting condition and liquidity event-based vesting condition. The liquidity event-based vesting condition was satisfied upon the closing of the Merger. The service-based vesting period for these awards is generally three During 2022, the Company granted RSUs to its CEO that vest based on a market-based condition. These RSUs will vest and convert to common stock subject to the Company’s stock price reaching certain price targets for 20 days in any 30 day trading window. The fair value of the RSUs will be 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 respective grant dates, using a Monte Carlo simulation model based on the following range and weighted-average assumptions: 2022 Common stock price $2.93 - $3.10 Expected term (in years) 4.00 - 6.27 Expected volatility 90.0 % Risk-free interest rate 3.6% - 3.8% Expected dividend yield — As of December 31, 2022, none of the stock price targets have been achieved for the market-based RSUs. RSU activity for the years ended December 31, 2022 and 2021 are as follows (amounts in thousands, except per share data): RSUs (1) Weighted Average Grant Date Fair Value per Share Nonvested balance as of December 31, 2020 — $ — RSUs granted 6,170 2.11 Nonvested balance as of December 31, 2021 6,170 2.11 RSUs granted 23,412 6.31 RSUs forfeited (561) 5.64 RSUs vested (5,222) 1.55 Nonvested balance as of December 31, 2022 23,799 5.87 _________________ (1) The number of RSUs prior to the Merger have been retroactively restated to reflect the exchange ratio of 6.7735 established in the Merger. As of December 31, 2022, unrecognized stock-based compensation expense related to these RSUs wa s $113.2 million which is expected to be recognized over the remaining weighted-average vesting period of approximately 3.01 years . Unvested Common Stock/Restricted Stock Awards The Company has certain common stocks that are subject to repurchase at the election of the Company. These repurchase rights expire over time and therefore are accounted for as unvested common stock. The Company has RSAs that vest upon the satisfaction of both a service-based condition and a liquidity event-based condition. The liquidity event-based vesting condition was satisfied upon the closing of the Merger. The following table summarizes information about outstanding unvested stock activities for the years ended December 31, 2022 and 2021 (amounts in thousands): Unvested Common Stock (1) Balances outstanding at December 31, 2020 3,051 New grants or issues 5,655 Common stock vested (3,040) Repurchased stock (146) Balances outstanding at December 31, 2021 5,520 Common stock vested (5,520) Balances outstanding at December 31, 2022 — _________________ (1) The number of RSAs prior to the Merger have been retroactively restated to reflect the exchange ratio of 6.7735 established in the Merger. Stock-Based Compensation Expense Total stock-based compensation expense for the years ended December 31, 2022 and 2021 is as follows (amounts in thousands): Year Ended December 31, 2022 2021 Sales and marketing $ 5,111 $ 67 Research and development 14,775 370 General and administrative 21,172 63 Total stock-based compensation expense $ 41,058 $ 500 Total stock-based compensation expense for the year ended December 31, 2022 includes $7.1 million in expense that was recognized upon the Closing of the Merger, which includes $3.9 million related to RSUs and $3.2 million related to RSAs.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The components of pre-tax loss are as follows for the years ended December 31, 2022 and 2021 (amounts in thousands): Year Ended December 31, 2022 2021 United States $ (52,509) $ (12,308) Switzerland (25,363) (19,029) Total loss before tax $ (77,872) $ (31,337) The following table presents the principal reasons for the difference between the effective tax rate and the federal statutory income tax rate: Year Ended December 31, 2022 2021 US federal statutory income tax rate 21.0 % 21.0 % State and local income taxes, net of Federal benefit 2.7 % 0.3 % Non-deductible expenses (6.5) % (0.5) % Credits 0.7 % 0.4 % Foreign rate differential (0.9) % (0.6) % Valuation allowance (17.6) % (20.6) % Effective income tax rate (0.6) % — % The components of the provision for income taxes are as follows (amounts in thousands): Year Ended December 31, 2022 2021 Current Federal $ 388 $ — State 39 1 Foreign — — Total current tax provision 427 1 Deferred Federal — — State — — Foreign — — Total deferred tax provision — — Total provision for income taxes $ 427 $ 1 The components of the deferred tax asset are as follows (amounts in thousands): December 31, 2022 2021 Deferred tax assets: Net operating loss carryforwards $ 12,701 $ 10,905 Stock-based compensation 4,143 — Revenue recognition 1,937 — Accrued expense 1,324 425 Capitalized research and development 3,492 — Credits 374 167 Operating lease liabilities 191 228 Other 289 139 Gross deferred tax assets 24,451 11,864 Less: valuation allowance (24,043) (11,405) Net deferred tax assets 408 459 Deferred tax liabilities: Depreciation and amortization (229) (89) Right of use assets (179) (213) Other — (157) Net deferred tax assets (liabilities) $ — $ — In assessing the realizability of deferred tax assets, the Company considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Based upon the analysis of federal and state deferred tax balances, future tax projections and availability of taxable income in the carryback period, the Company recorded a valuation allowance against the federal, state, and international deferred tax assets of $24.0 million . As of December 31, 2022, the Company had federal net operating losses of $3.4 million , state net operating losses of $21.9 million , and foreign net operating losses of $37.3 million available to offset future taxable income. The federal and state net operating loss carryforwards will begin to expire, if unutilized, beginning in 2038 . The foreign net operating loss carryforwards will begin to expire, if unutilized, beginning in 2025 . At December 31, 2022, the Company had federal and state research tax credit carryforwards of $0.3 million and $0.3 million , respectively. The federal research tax credit carryforwards will begin to expire, if unutilized, in 2041. The state research tax credits do not expire. At December 31, 2022 and 2021, the Company recorded $1.1 million , and $0.9 million , respectively, of unrecognized tax benefits. The Company’s policy is to recognize interest and penalties related to uncertain tax positions, if any, in the income tax provision. During the years ended December 31, 2022 and 2021, the Company recognized no interest and penalties related to uncertain tax positions. The following table summarizes the activity related to the Company’s unrecognized tax benefits (amounts in thousands): Year Ended December 31, 2022 2021 Balance at beginning of year $ 908 $ 882 Increase related to prior year tax positions 31 13 Decrease related to prior year tax positions — (18) Increase related to current year tax positions 127 31 Decrease related to lapsing status of limitation — — Balance at end of year $ 1,066 $ 908 The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate as of December 31, 2022 and 2021 was zero , due to the valuation allowance that would otherwise be recorded on the deferred tax asset associated with the recognized position. The tax years en ded December 31, 2019 thro ugh December 31, 2022 remain open to examination by the Internal Revenue Service and California Franchise Tax Board. In addition, the utilization of net operating loss carryforwards are subject to Federal and State review for the periods in which those net losses were incurred. The Company is not under audit by any taxing jurisdictions at this time. Utilization of the net operating losses and tax credit carryforwards may be subject to an annual limitation based on changes in ownership, as defined by Section 382 and 383 of the Internal Revenue Code (“IRC”) of 1986, as amended. The Company has done a preliminary Section 382 study and has determined that none of the net operating losses are currently permanently impaired due to 382 limitations. The IRA was passed in August 2022, providing significant incentives for businesses to become more energy efficient by extending, increasing, or expanding credits applicable to the production of clean energy and fuels as well as other provisions. These changes do not have a material impact on the Company’s tax provision.

NET LOSS PER SHARE OF COMMON ST

NET LOSS PER SHARE OF COMMON STOCK	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
NET LOSS PER SHARE OF COMMON STOCK	NET LOSS PER SHARE OF COMMON STOCK The weighted-average number of shares of common stock outstanding prior to the Merger have been retroactively adjusted by the Exchange Ratio to give effect to the reverse recapitalization treatment of the Merger. Shares of common stock issued as a result of the conversion of Legacy Energy Vault convertible preferred stock in connection with the closing of the Merger have been included in the basic net loss per share calculation on a prospective basis. Basic and diluted net loss per share attributable to common stockholders are calculated as follows (amounts in thousands, except per share amounts): Year Ended December 31, 2022 2021 Net loss $ (78,299) $ (31,338) Weighted-average shares outstanding – basic and diluted (1) 123,241 12,780 Net loss per share – basic and diluted $ (0.64) $ (2.45) _________________ (1) The weighted-average number of shares prior to the Merger have been retroactively restated to reflect the exchange ratio of 6.7735 established in the Merger. There are no common stock and convertible preferred stock that were dilutive for the years ended December 31, 2022 and 2021. 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 periods presented (amounts in thousands): Year Ended December 31, 2022 2021 Private Warrants 5,167 — Stock options 1,093 1,345 Convertible preferred stock — 85,741 RSUs 23,799 — Total 30,059 87,086 The 9.0 million shares of common stock equivalents subject to the Earn-Out Shares are excluded from the anti-dilutive table above as of December 31, 2022, as the underlying shares remain contingently issuable as the Earn-Out Triggering Events have not been satisfied.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Our principal commitments as of December 31, 2022 consisted primarily of obligations under operating leases, finance leases, deferred pensions, a nd issued purchase orders. Our non-cancellable purchase obligations as of December 31, 2022 totaled approximately $50.2 million . In connection with the Company’s licensing agreement with Atlas, the Company agreed to make a refundable contribution to Atlas in the amount up to $25.0 million during the period in which Atlas constructs its first GESS. As of December 31, 2022, t he Company has contributed all $25.0 million. The refundable contribution will be returned to the Company upon Atlas’ first GESS reaching substantial completion, subject to adjustment for potential liquidated damages if certain performance metrics are not met. Other Commitments and Contingencies Letters of Credit: In the ordinary course of business and under certain contracts, the Company is required to post letters of credit for its customers, insurance carriers, and surety bond providers for project performance, and for its vendors for payment guarantees. Such letters of credit are generally issued by a bank or a similar financial institution. The letter of credit commits the issuer to pay specified amounts to the holder of the letter of credit under certain conditions. As of December 31, 2022, there was $82.9 million of letters of credit issued and secured by the Company’s cash. The Company is not aware of any material claims relating to its outstanding letters of credit. 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 December 31, 2022, there we re no outstanding performance and payment bonds.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2022
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	NOTE 19. SUBSEQUENT EVENTS On February 28, 2023, the Company purchased $6.0 million in equity securities of a private company active in the energy transition industry. After this investment, the carrying value of the Company’s investment in this private company totaled $15.0 million.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements have been prepared on an accrual basis of accounting in accordance with GAAP and applicable rules and regulations of the SEC regarding financial reporting.
Principles of Consolidation	Principles of Consolidation These consolidated financial statements include Energy Vault Holdings, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements, in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the 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. Significant estimates made by management include, among others, revenue recognition, stock-based compensation, and valuation of warrant liability. 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.
Segment Reporting	Segment Reporting The Company reports its operating results and financial information in one operating and reportable segment. Our chief operating decision maker, which is our chief executive officer, reviews our operating results on a consolidated basis and uses that consolidated financial information to make operating decisions, assess financial performance, and allocate resources.
Concentration of Credit Risk	Concentration of Credit Risk 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 December 31, 2022, two customers had trade receivable balances exceeding 10% of total accounts receivable. These customers accounted for 78% and 16% of total accounts receivable, respectively. As of December 31, 2022, one customer accounted for 100% of the customer financing receivable. For the year ended December 31, 2022, revenue from two different customers accounted for 57% and 35% of total revenue, respectively.
Foreign Currency	Foreign Currency Assets and liabilities denominated in a foreign currency are translated into U.S dollars using the exchange rates in effect at the balance sheet date. Revenue and expense accounts are translated at the average exchange rates during the periods. The impact of exchange rate fluctuations from translation of assets and liabilities is included in accumulated other comprehensive loss, a component of stockholders’ equity (deficit). As of December 31, 2022, accumulated other comprehensive loss included a $0.2 million loss related to currency translation adjustments. As of December 31, 2021, accumulated other comprehensive loss included a $44 thousand gain related to currency translation adjustments. Gains and losses resulting from foreign currency transactions are included in other income (expense), net in the accompanying consolidated statements of operations.
Fair Value Measurements	Fair Value Measurements ASC 820, Fair Value Measurement (“ASC 820”), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value as follows: Level I — Inputs which include quoted prices in active markets for identical assets and liabilities. Level II — Inputs other than Level I 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.
Revenue Recognition	Revenue Recognition The Company recognizes revenue from contracts with customers in accordance with ASC 606, Revenue from Contracts with Customers (“ASC 606”). Under ASC 606, revenue is recognized when, or as, control of promised goods and services is transferred to customers, and the amount of revenue recognized reflects the consideration to which the Company expects to be entitled in exchange for the goods and services transferred. The Company determines revenue recognition through the following steps: (1) Identification of the contract, or contracts, with a customer. (2) Identification of the performance obligations in the contract. (3) Determination of the transaction price. (4) Allocation of the transaction price to the performance obligations in the contract. (5) Recognition of revenue when, or as, a performance obligation is satisfied. Once a contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations. Arrangements that include rights to additional goods or services that are exercisable at a customer’s discretion are generally considered options. The Company assesses if these options provide a material right to the customer and if so, they are considered performance obligations. The identification of material rights requires judgments related to the determination of the value of the underlying good or service relative to the option exercise price. The Company assesses whether each promised good or service is distinct for the purposes of identifying performance obligations in the contract. This assessment involves subjective determination and requires management to make judgments about the individual promised goods or services and whether such are separable from the other aspects of the contractual relationship. Promised goods and services are considered to be distinct provided that: (i) the customer can benefit from the good or service either on its own or together with the other resources that are readily available to the customer (that is, the good or service is capable of being distinct) and (ii) the entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (that is, the promise to transfer the good or service is distinct within the context of the contract). The Company also considers the intended benefit of the contract in assessing whether a promised good or service is separately identifiable from other promises in the contract. If a promised good or service is not distinct, an entity is required to combine that good or service with other promised goods or services until it identifies a bundle of goods or services that is distinct. The transaction price is determined and allocated to the identified performance obligations in proportion to their stand-alone selling prices (“SSP”) on a relative SSP basis. SSP is determined at contract inception and is not updated to reflect changes between contract inception and when the performance obligations are satisfied. Determining the SSP for performance obligations requires significant judgment. In developing the SSP for a performance obligation, the Company considers applicable market conditions and relevant entity-specific factors, including factors that were contemplated in negotiating the agreement with the customer and estimated costs. In determining the transaction price, the Company adjusts consideration for the effects of the time value of money if the timing of payments provides the Company with a significant benefit of financing. When a contract provides the customer with a significant benefit of financing, the Company recognizes a customer financing receivable and recognizes interest income separate from the revenue recognized on the contracts with customers. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment and the transfer of the promised goods or services will be one year or less. The Company recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) each performance obligation is satisfied, either at a point in time or over time. Over time revenue recognition is based on the use of an output or input method. Build and Transfer Energy Storage Projects: The Company enters into contracts with utility companies and independent power producers to build and transfer energy storage projects. The Company has entered into contracts to build and transfer battery-based energy storage projects and intends to enter into contracts to build and transfer gravity-based energy storage projects in the future. Each storage project is customized depending on the customer’s energy needs. Customer payments are due upon meeting certain milestones that are consistent with contract-specific phases of a project. The Company determines the transaction price based on the consideration expected to be received, which includes estimates of liquidated damages or other variable consideration. Generally, each contract to design and construct an energy storage project contains one performance obligation. Multiple contracts entered into with the same customer and near the same time to construct energy storage projects are combined in accordance with ASC 606. In these situations, the contract prices are aggregated and then allocated to each energy storage project based upon their relative stand-alone selling price. The Company recognizes revenue over time as a result of the continuous transfer of control of its products to the customer. The continuous transfer of control to the customer is supported by clauses in the contracts that provide enforceable rights to payment of the transaction price associated with work performed to date for products that do not have an alternative use to the Company and/or the project is built on the customer’s land that is under the customer’s control. Revenue for these performance obligations is recognized using the percentage of completion method based on cost incurred as a percentage of total estimated contract costs. Contract costs include all direct materials and labor costs related to contract performance. Pre-contract costs with no future benefit are expensed in the period in which they are incurred. Since the revenue recognition of these contracts depends on estimates, which are assessed continually during the term of the contract, recognized revenues and profit are subject to revisions as the contract progresses to completion. The cumulative effects of revisions of estimated total contract costs and revenues, together with any contract reserves which may be deemed appropriate, are recorded in the period in which the facts and changes in circumstances become known. Due to uncertainties inherent in the estimation process, it is reasonably possible that these estimates will be revised in a different period. When a loss is forecasted for a contract, the full amount of the anticipated loss is recognized in the period in which it is determined that a loss will incur. The Company’s contracts generally provide customers the right to liquidated damages (“LDs”) against Energy Vault in the event specified milestones are not met on time, or certain performance metrics are not met upon or after the substantial completion date. LDs are accounted for as variable consideration, and the contract price is reduced by the expected penalty or LD amount when recognizing revenue. Variable consideration is included in the transaction price only to the extent that it is improbable that a significant reversal in the amount of cumulative revenue recognized will occur when the uncertainty is resolved. Estimating variable consideration requires certain estimates and assumptions, including whether and by how much a project will be delayed. The existence and measurement of liquidated damages may also be impacted by the Company’s judgment about the probability of favorable outcomes of customer disputes involving whether certain events qualify as force majeure or the reason for the events that caused project delays. Variable consideration for LDs is estimated using the expected value of the consideration to be received. If Energy Vault has a claim against the customer for an amount not specified in the contract, such claim is recognized as an increase to the contract price when it is legally enforceable, which is usually upon signing a respective change order or equivalent document confirming the claim acceptance by the customer. The Company offers limited warranties on the Company’s energy storage systems which provide the customer assurance that the energy storage systems will function as the parties intended because it complies with agreed-upon specifications and are free from defects. These assurance-type warranties are not treated as a separate revenue performance obligation and are accounted for as guarantees under GAAP. Operate Energy Storage Projects: To date, the Company has not recognized any revenue related to providing operation services for its energy storage projects. The method of revenue recognition will be determined once the Company finalizes agreements with its future customers. Energy Management Software as a Service and Long Term Service Arrangements: To date, the Company has not recognized any revenue related to providing energy management software as a service or related to long term service arrangements. The method of revenue recognition will be determined once the Company finalizes agreements with its future customers. Intellectual Property Licensing: The Company enters into licensing agreements of its intellectual property that are within the scope of ASC 606. The terms of such licensing agreements include the license of functional intellectual property, given the functionality of the intellectual property is not expected to change substantially as a result of the licensor’s ongoing activities. The transaction price allocated to the licensing of intellectual property is recognized as revenue at a point in time when the licensed intellectual property is made available for the customer’s use and be nefit. Certain licensing agreements contain a significant financing component due to the customer having extended payment terms. The amounts due from customers under extended payment terms are included in the line item, customer financing receivable, on the consolidated balance sheets. One of the Comp any’s intellectual property licensing customers is Atlas, which was an investor in the Company’s PIPE. As part of the Company’s licensing agreement with Atlas, the Company agreed to provide Atlas with a final update to its functional intellectual property upon the completion of the Company’s research and development activities related to the intellectual property that was previously provided to Atlas. The Company identified the obligation to provide this update to Atlas as a performance obligation and deferred $5.9 million of the transaction price related to this performance obligation during the first quarter of 2022. This deferred amount was recognized as revenue during the fourth quarter of 2022 upon the Company transferring the technology update to Atlas. The contract with Atlas includes variable consideration of $25.0 million due to the Company’s commitment to provide a $25.0 million refundable contribution to Atlas during the construction period of Atlas’ first project. The Company has considered this to be variable consideration as the Company will be repaid when Atlas’ first project reaches substantial completion, subject to adjustment for potential liquidated damages if certain performance metrics are not met. The Company has determined that it is probable that Atlas will reach substantial completion and meet the performance metrics to repay Energy Vault, therefore the entire amount of variable consideration has been included in the transaction price. As of December 31, 2022, t he Company has contributed all $25.0 million to Atlas. The $25.0 million refundable contribution is included in the line item, contract assets, on the consolidated balance sheets. Royalty Revenue: In connection with entering into intellectual property licensing agreements, the Company also enters into royalty agreements whereby the customer agrees to pay the Company a percentage of the customer’s future sales revenue that is generated by using the Company’s intellectual property. The Company has not recognized any royalty revenue to date, but will recognize royalty revenue at the point in time when the customer’s sales occur. Other Revenue:
Cash, Cash Equivalents, and Restricted Cash	Cash, Cash Equivalents, and Restricted Cash The Company considers all highly liquid investments purchased with an original or remaining maturity of three months or less to be cash equivalents. At December 31, 2022 and 2021, the Company maintained money market accounts totaling $5.4 million and $5.3 million respectively; and a cash sweep account invested primarily in US Treasury and other short term securities totaling $66.5 million and $84.2 million, respectively. Restricted cash as of December 31, 2022 primarily consisted of cash held by banks as collateral for the Company’s letters of credit.
Accounts Receivable	Accounts ReceivableAccounts receivable represents amounts that have an unconditional right to consideration, have been billed to customers, and do not bear interest. Receivables are carried at amortized cost. The Company periodically assesses collectability of its receivables from each customer and records an allowance for doubtful accounts for the estimated uncollectible amount when deemed appropriate. If circumstances related to specific customers change, the Company’s estimates of the recoverability of receivables could be adjusted. Accounts are written off after all means of collection, including legal action, have been exhausted. As of both December 31, 2022 and December 31, 2021, no allowance for doubtful accounts has been recorded.
Customer Financing Receivable	Customer Financing ReceivableCustomer financing receivable includes amounts due from a customer related to a licensing agreement under extended payment terms which contains a significant financing component.
Inventory	Inventory Inventory consists of inverters and spare parts, which are used in ongoing battery storage projects for sale. Inventory is stated at the lower of cost or net realizable value with cost being determined by the specific identification method. Costs include the cost of purchase and other costs incurred in bringing the inventories to their present location and condition. The Company periodically reviews its inventory for potential obsolescence and write down of its inventory, as appropriate, to net realizable value based on its assessment of market conditions.
Property and Equipment, Net	Property and Equipment, Net Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the respective assets. Maintenance and repairs are charged to expense as incurred. When assets are retired or sold, the cost and related accumulated depreciation are removed from the consolidated balance sheet and any resulting gain or loss is reflected in operating expenses in the period realized.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company reviews long-lived assets, primarily comprised of property and equipment and operating right-of-use assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amount to the future undiscounted net cash flows which the assets are expected to generate. If the carrying value of the assets exceeds the sum of the estimated future cash flows, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceed their fair value.
Investment in Equity Securities	Investment in Equity Securities During 2022, the Company made a strategic investment and purchased equity securities of a private company active in the energy transition industry. These equity securities do not have a readily determinable fair value and are recorded at cost, less any impairment, plus or minus adjustments related to observable transactions for the same or similar securities, with unrealized gains and losses included in earnings. As of December 31, 2022, both the cost basis and carrying value of these equity securities was $9.0 million. The Company did not recognize any impairments or value changes resulting from observable price changes during the year ended December 31, 2022. The carrying value of the Company’s investment in equity securities is included in the line item, other assets, in the consolidated balance sheets.
Leases	Leases The Company determines if a contract contains a lease at its inception based on whether or not the Company has the right to control the asset during the contract period and other facts and circumstances. Right-of-use (“ROU”) assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. ROU assets are classified as either operating or finance leases. Upon commencement of the lease, a ROU asset and corresponding lease liability are recognized for all operating and finance leases. The Company has elected the short-term lease exemption, which does not require a ROU asset or lease liability to be recognized when the lease term is 12 months or less and does not include an option to purchase the underlying asset that the lessee is reasonably certain to exercise. The Company has decided not to elect the policy to not separate lease and non-lease component in arrangements whereby the Company is the lessee. Upon commencement of the lease, ROU assets are recognized based on the initial measurement of the lease liability and adjusted for any lease payments made before commencement date of the lease, less any lease incentives and including any initial direct costs incurred. Lease liabilities are initially measured at the present value of future minimum lease payments over the lease term. The discount rate used to determine the present value is the rate implicit in the lease unless that rate cannot be determined, in which case Company’s incremental borrowing rate is used, which is based on the estimated interest rate for collateralized borrowing over a similar term of the lease at commencement date. Rights to extend or terminate a lease are included in the lease term when there is reasonable certainty the right will be exercised. Factors used to assess reasonable certainty of rights to extend or terminate a lease include current and forecasted lease improvement plans, anticipated changes in development strategies, historical practice in extending similar contracts and current market conditions. Operating lease ROU assets and liabilities are subsequently measured at the present value of the lease payments not yet paid and discounted at the initial discount rate at commencement of the lease, less any impairments to the ROU asset. Operating lease expense is recognized on a straight-line basis over the lease term. Finance lease ROU assets are amortized on a straight-line basis over the estimated useful life of the asset if the lessee is reasonably certain to exercise a purchase option or ownership of the leased asset transfers at the end of the lease term, otherwise the leased assets are amortized over the lease term. Amortization of finance lease ROU assets is included in depreciation and amortization. Operating lease ROU assets are recognized on the consolidated balance sheets in the line item, operating lease right-of-use assets, and finance lease ROU assets are recognized on the consolidated balance sheets within the line item, property and equipment, net.
Asset Retirement Obligation	Asset Retirement Obligation Asset retirement obligations (AROs) are legal obligations associated with the retirement of tangible long-lived assets resulting from acquisition, construction, development, and/or normal use of the underlying assets. The ARO is recognized at its estimated fair value in the period in which it is incurred. These obligations generally include the estimated net future costs of dismantling the assets and restoring the land the assets are located on to its original condition in accordance with legal regulations and land lease agreement requirements. Upon initial recognition of a liability, the associated asset retirement costs are capitalized as part of the related long-lived asset and depreciated over the estimated useful life of the related asset. The liability is accreted over time through charges to earnings. If an ARO is settled for an amount other than
Defined Benefit Pension Obligation	Defined Benefit Pension Obligation The Company’s wholly owned subsidiary in Switzerland has a defined benefit pension obligation covering retirement and other long-term benefits of the local employees. Accrued pension costs are developed using actuarial principles and assumptions which consider a number of factors, including estimates for the discount rate, expected long-term rate of return on assets and mortality. Changes in these estimates would impact the amounts that the Company records in the consolidated financial statements.
Warrants	WarrantsThe Company assumed Public Warrants and Private Warrants upon the Closing. The Company accounts for warrants for shares of the Company’s common stock that are not indexed to its own stock as liabilities at fair value on the consolidated balance sheets. The warrants are subject to remeasurement at each balance sheet date and any change in fair value is recognized in the Company’s consolidated statements of operations. For issued or modified warrants that meet all of the criteria for equity classification, the warrants are required to be recorded as a component of additional paid-in-capital at the time of issuance. For issued or modified warrants that do not meet all the criteria for equity classification, the warrants are required to be recorded as a liability at their initial fair value on the date of issuance, and each balance sheet date thereafter. Changes in the estimated fair value of the warrants are recognized as a non-cash gain or loss in the consolidated statements of operations.
Earn-Out Shares	Earn-Out Shares In connection with the reverse recapitalization and pursuant to the Merger Agreement, eligible Legacy Energy Vault stockholders immediately prior to the Closing, have the contingent right to receive an aggregate of 9.0 million shares of the Company’s common stock (“Earn-Out Shares”) upon the Company achieving each Earn-Out Triggering Event (defined below) during the period beginning on the 90th day following the Closing and ending on the third anniversary of such date. An “Earn-Out Triggering Event” means the date on which the closing price of the Company’s common stock quoted on the NYSE is greater than or equal to certain specified prices for any 20 trading days within a 30 consecutive day trading period.
Research and Development Expenses	Research and Development Expenses Research and development costs are expensed as incurred. Research and development costs consist of salaries and other personnel related expenses, engineering expenses, product development costs and facility costs.
Advertising Costs	Advertising Costs Advertising costs are expensed as incurred and are reflected in the line item, sales and marketing, in the consolidated statements of operations. Advertising expenses were $0.3 million for the year ended December 31, 2022. The Company did not incur any advertising expenses during the year ended December 31, 2021.
Stock-Based Compensation	Stock-Based Compensation The Company issues stock-based compensation awards to employees, directors, and non-employees in the form of stock options and restricted stock units (“RSUs”). The Company measures and recognizes compensation expense for stock-based awards based on the award’s fair value on the date of the grant. The Company accounts for forfeitures of stock-based awards when they occur. The fair value of RSUs that vest based on service conditions is measured using the fair value of the Company’s common stock on the date of the grant. The fair value of RSUs that vest based on market conditions is measured using a Monte Carlo simulation model on the date of the grant. The fair value of stock options that vest based on service conditions is measured using the Black-Scholes option pricing model on the date of the grant. The Monte Carlo simulation model and the Black-Scholes option pricing model require the input of highly subjective assumptions, including
Transaction Costs	Transaction Costs Transaction costs consist of direct legal, accounting, and other fees related to the consummation of the Merger. These costs were initially capitalized as incurred in prepaid assets and other current assets in the consolidated balance sheet. Upon the Closing, transaction costs related to the issuance of shares were recognized in stockholders’ deficit while costs associated with the public and private warrants liabilities were expensed in the consolidated statements of operations and comprehensive loss. As of December 31, 2021, $4.1 million of deferred Merger transaction costs were included within prepaid and other current assets in the consolidated balance sheet. The Company and Novus incurred in aggregate $44.8 million in transaction costs, consisting of underwriting, legal, and other professional fees, of which $24.2 million was recorded to additional paid-in-capital as a reduction of proceeds and the remaining $20.6 million was expensed immediately upon the Closing.
Income Taxes	Income Taxes The Company accounts for income taxes in accordance with ASC 740, Income Taxes (“ASC 740”). ASC 740 prescribes the use of the liability method, whereby deferred tax asset and liability account balances are determined based on differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates that will be in effect when the differences are expected to reverse. Deferred income tax balances reflect the effects of temporary differences between the carrying amounts of assets and liabilities and their tax bases and are stated at enacted tax rates expected to be in effect when taxes are actually paid or recovered. Deferred tax assets are evaluated for future realization and reduced by a valuation allowance to the extent the Company believes they will not be realized.
Net Loss Per Share	Net Loss Per Share Basic net loss per share of common stock is calculated by dividing net loss by the weighted average number of common shares outstanding for the applicable period. Diluted net loss is computed based on the weighted average number of common shares outstanding increased by the number of additional shares that would have been outstanding had the potentially dilutive common shares been issued, including any dilutive effect from convertible preferred stock, outstanding stock options, or unvested RSUs, and reduced by the number of shares the Company could have repurchased with the proceeds from the issuance of the potentially dilutive shares. Potentially dilutive instruments are excluded from the per share calculation because the Company is in a net loss position and they would therefore be anti-dilutive.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . ASU 2016-13 amends the impairment model to utilize an expected loss methodology in place of the currently used incurred loss methodology, which will result in the more timely recognition of losses. The new accounting standard will be effective for the fiscal year beginning on January 1, 2023 and will be adopted using the modified retrospective method, which requires a cumulative effect adjustment to retained ear nings. The Company is currently evaluating the impact this ASU will have on its consolidated financial statements and expects the adoption of the ASU will reduce opening retained earnings by approximately $2.4 million (pre-tax), driven by the Company’s accounts receivables, contract assets, and long-term financing receivable. In August 2020, FASB issued ASU No. 2020-06, Debt — Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging — in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity (“ASU 2020-06”) . ASU 2020-06 simplifies the accounting for convertible instruments. In addition to eliminating certain accounting models, this ASU includes improvements to the disclosures for convertible instruments and earnings-per-share (EPS) guidance and amends the guidance for the derivatives scope exception for contracts in an entity’s own equity. ASU 2020-06 is effective for fiscal years beginning after December 15, 2021. The Company adopted ASU 2020-06 on January 1, 2022 and it did not have an impact on the Company’s consolidated financial statements. In December 2020, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”) , which simplifies the accounting for income taxes. ASU 2019-12 is effective for nonpublic entities for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022. The Company adopted ASU 2019-12 on January 1, 2022 and it did not have an impact on the Company’s consolidated financial statements.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Schedule of Customer Financing Receivable Maturities	The following table provides information about contract assets and contract liabilities from contracts with customers (amounts in thousands): December 31, 2022 2021 Refundable contribution $ 25,000 $ — Unbilled receivables 531 — Retainage 3,447 — Contract assets $ 28,978 $ — Contract liabilities, current portion $ 49,434 $ — Contract liabilities, long-term portion 1,500 1,500 Total contract liabilities $ 50,934 $ 1,500

REVERSE RECAPITALIZATION (Table

REVERSE RECAPITALIZATION (Tables)	12 Months Ended
	Dec. 31, 2022
Reverse Recapitalization [Abstract]
Summary of Reverse Recapitalization	The number of common stock issued following the consummation of the Merger was as follows (amounts in thousands): Shares Legacy Energy Vault stock converted as part of Merger (1) 106,172 Novus public shares (2) 4,079 Novus sponsor shares (3) 3,975 PIPE shares 19,500 Total shares of Energy Vault common stock issued as part of the Merger 133,726 __________________ (1) Excludes 9.0 million common shares issuable in earn-out arrangements as they are not issuable until 90 days after the Closing and are contingently issuable based upon the Company’s share price meeting certain thresholds. (2) Excludes 14.7 million warrants issued and outstanding as of the Closing of the Merger which includes 9.6 million public warrants and 5.2 million private warrants held by the Novus Sponsor.

REVENUE RECOGNITION (Tables)

REVENUE RECOGNITION (Tables)	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	The Company recognized revenue for the product and service categories as follows for the years ended December 31, 2022 and 2021 (amounts in thousands): Year Ended December 31, 2022 2021 Build and transfer energy storage products (1) $ 85,636 $ — Licensing of intellectual property (2) 58,483 — Other (1) 1,758 — Total revenue $ 145,877 $ — __________________ (1) Represents revenue recognized over time (2) Represents revenue recognized at a point-in-time. The following table summarizes the Company’s revenue disaggregated by geographic region, which is determined based on the customer’s location, for the years ended December 31, 2022 and 2021 (amounts in thousands): Year Ended December 31, 2022 2021 United States $ 85,635 $ — China 50,518 — Other 9,724 — Total revenue $ 145,877 $ —
Schedule of Customer Financing Receivable Maturities	The following table provides information about contract assets and contract liabilities from contracts with customers (amounts in thousands): December 31, 2022 2021 Refundable contribution $ 25,000 $ — Unbilled receivables 531 — Retainage 3,447 — Contract assets $ 28,978 $ — Contract liabilities, current portion $ 49,434 $ — Contract liabilities, long-term portion 1,500 1,500 Total contract liabilities $ 50,934 $ 1,500

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Summary of Financial Assets and Liabilities at Fair Value on a Recurring Basis	The Company’s financial assets and liabilities that were measured at fair value on a recurring basis as of December 31, 2022 and December 31, 2021 were as follows (amounts in thousands): December 31, 2022 Level 1 Level 2 Level 3 Total Assets (Liabilities): Derivative asset —  conversion option (1) — — 1,025 1,025 Warrant liability (2) — — 2 2 December 31, 2021 Level 1 Level 2 Level 3 Total Assets (Liabilities): Derivative asset —  conversion option (1) — — 350 350 __________________ (1) Refer to Note 7 - Convertible Note Receivable for further information. (2) Refer to Note 12 - Warrants for further information.

CONVERTIBLE NOTE RECEIVABLE (Ta

CONVERTIBLE NOTE RECEIVABLE (Tables)	12 Months Ended
	Dec. 31, 2022
Receivables [Abstract]
Summary of Reconciliation of Asset Balance for the Embedded Derivative	A reconciliation of the beginning and ending asset balance for the embedded derivative in the DG Fuels Note is as follows (amounts in thousands): Year Ended December 31, 2022 2021 Balance at beginning of period $ 350 $ — Additions 675 350 Change in fair value — — Balance at end of period $ 1,025 $ 350

PROPERTY AND EQUIPMENT, NET (Ta

PROPERTY AND EQUIPMENT, NET (Tables)	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment, Net	As of December 31, 2022 and 2021, property and equipment, net consisted of the following (amounts in thousands): December 31, Life (years) 2022 2021 Brick machines 6 $ 657 $ 2,515 Finance lease right-of-use assets – vehicles 4 178 175 Furniture and IT equipment 3 - 7 815 176 Leasehold improvements 4 - 7 529 179 Demonstration & test equipment — 11,218 Construction in progress 1,268 — Total property and equipment 3,447 14,263 Less: accumulated depreciation (403) (2,395) Property and equipment, net $ 3,044 $ 11,868

ASSET RETIREMENT OBLIGATION (Ta

ASSET RETIREMENT OBLIGATION (Tables)	12 Months Ended
	Dec. 31, 2022
Asset Retirement Obligation Disclosure [Abstract]
Summary of Asset Retirement Obligation Activity	The following table summarizes the asset retirement obligation activity for the years ended December 31, 2022 and 2021 (amounts in thousands): Year Ended December 31, 2022 2021 Balance at beginning of period $ 978 $ 123 Changes in estimates — 751 Accretion expense 95 107 Liabilities settled (487) — Foreign currency translation gain (26) (3) Balance at end of period $ 560 $ 978

DEFINED BENEFIT PENSION OBLIG_2

DEFINED BENEFIT PENSION OBLIGATION (Tables)	12 Months Ended
	Dec. 31, 2022
Retirement Benefits [Abstract]
Schedule of Changes in Projected Benefit Obligations and Funded Status of Plan	The following table presents the defined benefit plans’ funded status and amount recognized in the consolidated balance sheets as of December 31, 2022 and 2021 (amounts in thousands): Year Ended December 31, 2022 2021 Change in Benefit Obligation Benefit obligation at beginning of year $ 2,662 $ 2,425 Service cost 162 130 Interest cost 9 5 Actuarial (gain) loss (149) 99 Benefits paid 866 40 Plan participant’s contributions 137 86 Plan amendments 350 (50) Foreign currency translation adjustments 8 (73) Benefit obligation at end of year $ 4,045 $ 2,662 Change in Plan Assets Fair value of plans assets at beginning of year $ 1,928 $ 1,592 Actual return on plans’ assets 74 214 Employer contributions 137 43 Benefits paid 866 40 Plan participant’s contributions 137 85 Foreign currency translation adjustments 13 (46) Fair value of plans assets at end of year $ 3,155 $ 1,928 Funded Status at End of Year Fair value of plan assets $ 3,155 $ 1,928 Benefit obligation (4,045) (2,662) Liability recognized at end of year $ (890) $ (734)
Schedule of Net Benefit Costs	The components of net periodic pension benefit cost for the Company’s defined benefit pension plans for the years ended December 31, 2022 and 2021 were as follows (amounts in thousands): Year Ended December 31, 2022 2021 Employer service costs $ 162 $ 130 Interest cost 9 5 Expected return on plan assets (72) (53) Amortization of net prior service credit (13) (7) Amortization of net loss 39 59 Net periodic benefit cost $ 125 $ 134
Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss)	Amounts recognized in accumulated other comprehensive income (loss) at December 31, 2022 and 2021 were as follows (amounts in thousands): December 31, 2022 2021 Net prior service credit (cost) $ (262) 94 Net loss (383) (551) Accumulated other comprehensive loss $ (645) $ (457) Changes in accumulated other comprehensive income (loss) for the Company’s pension plan were as follows (amounts in thousands): Year Ended December 31, 2022 2021 Accumulated other comprehensive loss at beginning of year $ (457) (623) Change in net prior service credit (cost) (360) 40 Change in net gain 189 112 Foreign currency translation adjustments (17) 14 Accumulated other comprehensive loss at end of year $ (645) $ (457)
Schedule of Defined Benefit Plan Assumptions	The assumptions used to measure the benefit obligation and net periodic benefit cost for the Company’s defined benefit pension plan were as follows: 2022 2021 Discount rate 1.8 % 0.4 % Expected long-term return on plan assets 4.7 % 3.8 % Rate of compensation increase 1.5 % 1.0 % Pension increase rate (in payment) 0.0 % 0.0 %
Schedule of Allocation of Plan Assets	The Swiss pension plans’ actual asset allocation as compared to the plan administrators’ target asset allocations for fiscal years 2022 and 2021 were as follows: 2022 2021 Target Equity instruments (Level 1) 47.3 % 50.2 % 30% – 55% Debt instruments (Level 2) 9.7 % 10.6 % 5% – 30% Real estate (Level 3) 30.0 % 26.4 % 15% – 40% Alternative investments (Level 3) 7.7 % 5.3 % 0% – 15% Cash and equivalents (Level 1) 5.3 % 7.5 % 0% – 15% Total 100.0 % 100.0 %
Schedule of Expected Benefit Payments	Estimated future benefit payments expected to be paid by the defined benefit pension plan at December 31, 2022 are as follows (amounts in thousands): Year Ending December 31, Future Benefits 2023 $ 42 2024 43 2025 43 2026 44 2027 45 Thereafter 227 Total $ 444

LEASES (Tables)

LEASES (Tables)	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Summary of Lease Expense	The components of lease expense for the years ended December 31, 2022 and 2021 are as follows (amounts in thousands): Year Ended December 31, 2022 2021 Operating lease expense $ 853 $ 647 Finance lease expense Amortization of finance ROU assets 47 45 Interest on finance lease liabilities 2 3 Short-term lease expense 339 80 Variable lease expense 12 3 Sublease income (9) — Total $ 1,244 $ 778 Supplemental balance sheet information related to leases as of December 31, 2022 and 2021 is as follows: December 31, 2022 2021 Weighted Average Remaining Lease Term (Years) Operating leases 2.4 2.2 Finance leases 2.1 1.8 Weighted Average Discount Rate Operating leases 8.6 % 7.4 % Finance leases 4.4 % 2.8 % Supplemental cash flow information related to leases for the fiscal years ended December 31, 2022 and 2021 is as follows (amounts in thousands): Year Ended December 31, 2022 2021 Cash Paid for Amounts Included in the Measurement of Lease Liabilities Operating cash flows used for operating leases $ 836 $ 532 Operating cash flows used for finance leases 2 3 Financing cash flows used for finance leases 62 53 $ 900 $ 588 ROU Assets obtained in Exchange for Lease Liabilities Operating leases $ 962 $ 476 Finance leases 37 44 $ 999 $ 520
Summary of Future Maturities of Operating Leases	Future maturities of operating and finance lease liabilities as of December 31, 2022 are as follows (amounts in thousands): Operating Leases Finance Leases 2023 $ 876 $ 40 2024 482 6 2025 110 6 2026 105 5 2027 61 — Thereafter — — Total undiscounted cash flows 1,634 57 Less imputed interest (138) (3) Present value of lease liabilities $ 1,496 $ 54
Summary of Future Maturities of Finance Leases	Future maturities of operating and finance lease liabilities as of December 31, 2022 are as follows (amounts in thousands): Operating Leases Finance Leases 2023 $ 876 $ 40 2024 482 6 2025 110 6 2026 105 5 2027 61 — Thereafter — — Total undiscounted cash flows 1,634 57 Less imputed interest (138) (3) Present value of lease liabilities $ 1,496 $ 54

WARRANTS (Tables)

WARRANTS (Tables)	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Summary of Public and Private Warrants Activities	The following table summarizes the Public and Private Warrants activities for the year ended December 31, 2022 (amounts in thousands): Year Ended December 31, 2022 Public Warrants Private Warrants Total Warrants Warrants assumed upon the Closing of the Merger 9,583 5,167 14,750 Warrants exercised (9,348) — (9,348) Warrants redeemed (235) — (235) End of period — 5,167 5,167
Summary of Valuations Assumptions to Estimate Fair Value of Private Warrants	The following table provides the assumptions used to estimate the fair value of the Private Warrants as of December 31, 2022: December 31, 2022 Common stock price $ 3.12 Exercise price $ 11.50 Expected term (in years) 4.12 Expected volatility 17.4 % Risk-free interest rate 4.1 % Expected dividend yield — %
Summary of Public and Private Warrants Liabilities Fair Value	The following table presents the changes in the fair value of the Company’s Public and Private Warrants liabilities for the year ended December 31, 2022 (amounts in thousands): Year Ended December 31, 2022 Public Warrants Private Warrants Total Warrants Warrant liability assumed upon the Closing of the Merger $ 12,938 $ 6,900 $ 19,838 Warrants exercised (17,483) — (17,483) Warrants redeemed (23) — (23) Change in fair value 4,568 (6,898) (2,330) Warrant liability at end of period $ — $ 2 $ 2

SUPPLEMENTAL BALANCE SHEETS D_2

SUPPLEMENTAL BALANCE SHEETS DETAIL (Tables)	12 Months Ended
	Dec. 31, 2022
Offsetting [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	December 31, (amounts in thousands) 2022 2021 Prepaid expenses and other current assets: Deposits for project equipment and materials $ 24,327 $ — Prepaid expenses 6,609 1,140 Tax refund receivable 454 121 Deferred merger costs — 4,121 Other 179 156 Total $ 31,569 $ 5,538
Schedule of Other Assets	December 31, (amounts in thousands) 2022 2021 Other assets: Investment in equity securities $ 9,000 $ — Convertible note receivable 2,080 654 Derivative asset —  conversion option 1,025 350 Other 1,795 521 Total $ 13,900 $ 1,525
Schedule of Accrued Expenses	December 31, (amounts in thousands) 2022 2021 Accrued Expenses: Employee costs $ 8,711 $ 3,756 Taxes payable 4,168 — Professional fees 1,671 81 Prototype costs — 716 Other 199 151 Total $ 14,749 $ 4,704

STOCKHOLDERS_ EQUITY (Tables)

STOCKHOLDERS’ EQUITY (Tables)	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Summary of Convertible Preferred Stock and Common Stock	As of December 31, 2021, the Company’s convertible preferred stock consisted of the following (amounts in thousands and adjusted for Merger exchange ratio): Shares Designated Shares Issued and Outstanding Liquidation Preference Series C preferred stock 14,787 14,787 $ 107,000 Series B-1 preferred stock 14,475 14,475 31,003 Series B preferred stock 14,651 14,651 25,003 Series A-2 preferred stock 5,087 5,087 3,555 Series A-1 preferred stock 6,950 6,950 3,076 Series Seed 2 preferred stock 4,240 4,240 934 Series Seed 1 preferred stock 11,190 11,190 753 Series FR preferred stock 14,361 14,361 25 85,741 85,741 $ 171,349

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Summary of Stock Option Activity	Stock option activity for the years ended December 31, 2022 and 2021 are as follows (amounts in thousands, except per share data): Options Outstanding Number of Options (1) Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Balance as of December 31, 2020 576 $ 0.09 7.48 $ 423 Stock options granted 1,142 0.89 Stock options exercised (373) 0.01 Balance as of December 31, 2021 1,345 0.79 9.11 7,024 Stock options exercised (212) 0.80 Stock options forfeited, canceled, or expired (40) 0.80 Balance as of December 31, 2022 1,093 0.79 8.10 2,551 Options exercisable as of December 31, 2022 796 0.69 7.89 1,936 Options vested and expected to vest as of December 31, 2022 1,093 $ 0.79 8.10 2,551 __________________ (1) The number of options prior to the Merger have been retroactively restated to reflect the exchange ratio of 6.7735 established in the Merger.
Summary of Weighted-average Assumptions	Options granted during 2021 were valued based on the following range and weighted-average assumptions: 2021 Common stock price (1) $0.93 - $4.98 Expected term (in years) 6.25 Expected volatility 90.0 % Risk-free interest rate 0.1 % Expected dividend yield — __________________ (1) The stock price prior to the Merger has been retroactively restated to reflect the exchange ratio of 6.7735 established in the Merger. 2022 Common stock price $2.93 - $3.10 Expected term (in years) 4.00 - 6.27 Expected volatility 90.0 % Risk-free interest rate 3.6% - 3.8% Expected dividend yield —
Summary of Restricted Stock Units Activity	RSU activity for the years ended December 31, 2022 and 2021 are as follows (amounts in thousands, except per share data): RSUs (1) Weighted Average Grant Date Fair Value per Share Nonvested balance as of December 31, 2020 — $ — RSUs granted 6,170 2.11 Nonvested balance as of December 31, 2021 6,170 2.11 RSUs granted 23,412 6.31 RSUs forfeited (561) 5.64 RSUs vested (5,222) 1.55 Nonvested balance as of December 31, 2022 23,799 5.87 _________________ (1) The number of RSUs prior to the Merger have been retroactively restated to reflect the exchange ratio of 6.7735 established in the Merger.
Summary of Outstanding Unvested Stock Activities	The following table summarizes information about outstanding unvested stock activities for the years ended December 31, 2022 and 2021 (amounts in thousands): Unvested Common Stock (1) Balances outstanding at December 31, 2020 3,051 New grants or issues 5,655 Common stock vested (3,040) Repurchased stock (146) Balances outstanding at December 31, 2021 5,520 Common stock vested (5,520) Balances outstanding at December 31, 2022 — _________________ (1) The number of RSAs prior to the Merger have been retroactively restated to reflect the exchange ratio of 6.7735 established in the Merger.
Summary of Stock-based Compensation Expense	Total stock-based compensation expense for the years ended December 31, 2022 and 2021 is as follows (amounts in thousands): Year Ended December 31, 2022 2021 Sales and marketing $ 5,111 $ 67 Research and development 14,775 370 General and administrative 21,172 63 Total stock-based compensation expense $ 41,058 $ 500

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Schedule of Components of Pre-tax Loss	The components of pre-tax loss are as follows for the years ended December 31, 2022 and 2021 (amounts in thousands): Year Ended December 31, 2022 2021 United States $ (52,509) $ (12,308) Switzerland (25,363) (19,029) Total loss before tax $ (77,872) $ (31,337)
Schedule of Effective Income Tax Rate Reconciliation	The following table presents the principal reasons for the difference between the effective tax rate and the federal statutory income tax rate: Year Ended December 31, 2022 2021 US federal statutory income tax rate 21.0 % 21.0 % State and local income taxes, net of Federal benefit 2.7 % 0.3 % Non-deductible expenses (6.5) % (0.5) % Credits 0.7 % 0.4 % Foreign rate differential (0.9) % (0.6) % Valuation allowance (17.6) % (20.6) % Effective income tax rate (0.6) % — %
Schedule of Components of Income Tax Expense (Benefit)	The components of the provision for income taxes are as follows (amounts in thousands): Year Ended December 31, 2022 2021 Current Federal $ 388 $ — State 39 1 Foreign — — Total current tax provision 427 1 Deferred Federal — — State — — Foreign — — Total deferred tax provision — — Total provision for income taxes $ 427 $ 1
Schedule of Deferred Tax Assets and Liabilities	The components of the deferred tax asset are as follows (amounts in thousands): December 31, 2022 2021 Deferred tax assets: Net operating loss carryforwards $ 12,701 $ 10,905 Stock-based compensation 4,143 — Revenue recognition 1,937 — Accrued expense 1,324 425 Capitalized research and development 3,492 — Credits 374 167 Operating lease liabilities 191 228 Other 289 139 Gross deferred tax assets 24,451 11,864 Less: valuation allowance (24,043) (11,405) Net deferred tax assets 408 459 Deferred tax liabilities: Depreciation and amortization (229) (89) Right of use assets (179) (213) Other — (157) Net deferred tax assets (liabilities) $ — $ —
Schedule of Unrecognized Tax Benefits	The following table summarizes the activity related to the Company’s unrecognized tax benefits (amounts in thousands): Year Ended December 31, 2022 2021 Balance at beginning of year $ 908 $ 882 Increase related to prior year tax positions 31 13 Decrease related to prior year tax positions — (18) Increase related to current year tax positions 127 31 Decrease related to lapsing status of limitation — — Balance at end of year $ 1,066 $ 908

NET LOSS PER SHARE OF COMMON _2

NET LOSS PER SHARE OF COMMON STOCK (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Summary of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders	Basic and diluted net loss per share attributable to common stockholders are calculated as follows (amounts in thousands, except per share amounts): Year Ended December 31, 2022 2021 Net loss $ (78,299) $ (31,338) Weighted-average shares outstanding – basic and diluted (1) 123,241 12,780 Net loss per share – basic and diluted $ (0.64) $ (2.45) _________________ (1) The weighted-average number of shares prior to the Merger have been retroactively restated to reflect the exchange ratio of 6.7735 established in the Merger.
Summary of Equivalent Securities Excluded from Computation of Diluted Weighted-Average Common Shares Outstanding	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 periods presented (amounts in thousands): Year Ended December 31, 2022 2021 Private Warrants 5,167 — Stock options 1,093 1,345 Convertible preferred stock — 85,741 RSUs 23,799 — Total 30,059 87,086

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($) shares in Millions		12 Months Ended
	Feb. 11, 2022	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2023
Business Acquisition [Line Items]
Accumulated foreign currency adjustments in accumulated other comprehensive loss		$ 200,000	$ 44,000
Performance obligation and deferred transaction price		331,000,000
Total refundable contributions to be made		25,000,000
Refundable contribution made		25,000,000	0
Deferred revenue		50,934,000	1,500,000
Money market accounts		5,400,000	5,300,000
Other short-term investments		$ 66,500,000	84,200,000
Interest rate		8.90%
Interest income		$ 35,000
Allowance for doubtful accounts		0
Equity securities without readily determinable fair value		9,000,000
Equity securities without readily determinable fair value impairment loss		0
Advertising expenses		300,000	0
Transaction costs	$ 44,800,000	20,586,000	0
Reduction to retained earnings expected (approximate)		$ 147,265,000	68,966,000
ASU 2016-13 | Forecast
Business Acquisition [Line Items]
Reduction to retained earnings expected (approximate)				$ 2,400,000
Customer One | Accounts Receivable | Customer Concentration Risk
Business Acquisition [Line Items]
Concentration risk percentage		78%
Customer One | Customer Financings | Customer Concentration Risk
Business Acquisition [Line Items]
Concentration risk percentage		100%
Customer One | Revenue Benchmark | Customer Concentration Risk
Business Acquisition [Line Items]
Concentration risk percentage		57%
Customer Two | Accounts Receivable | Customer Concentration Risk
Business Acquisition [Line Items]
Concentration risk percentage		16%
Customer Two | Revenue Benchmark | Customer Concentration Risk
Business Acquisition [Line Items]
Concentration risk percentage		35%
Atlas
Business Acquisition [Line Items]
Performance obligation and deferred transaction price		$ 5,900,000
Deferred revenue		$ 1,200,000
Business Combination, Acquisition Related Costs
Business Acquisition [Line Items]
Transaction costs	20,600,000
Additional Paid-In Capital
Business Acquisition [Line Items]
Transaction costs	$ 24,200,000
Common Stock
Business Acquisition [Line Items]
Number of earn-out shares (in shares)	9	9
Prepaid Expenses and Other Current Assets
Business Acquisition [Line Items]
Deferred merger related transaction costs			$ 4,100,000

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Performance Obligation (Details) $ in Millions	Dec. 31, 2022 USD ($)
Disaggregation of Revenue [Line Items]
Performance obligation and deferred transaction price	$ 331
Atlas
Disaggregation of Revenue [Line Items]
Performance obligation and deferred transaction price	$ 5.9

REVERSE RECAPITALIZATION - Narr

REVERSE RECAPITALIZATION - Narrative (Details) $ / shares in Units, $ in Thousands			12 Months Ended
		Feb. 11, 2022 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 shares
Business Acquisition [Line Items]
Proceeds from reverse recapitalization | $		$ 235,900
Cash, net of redemptions, held in Novus’ trust account | $		40,900
Sale of stock, consideration received on transaction | $		$ 195,000
Shares price (in dollars per share) | $ / shares		$ 10
Transaction costs | $		$ 44,800	$ 20,586	$ 0
Common stock, par value (in dollars per share) | $ / shares			$ 0.0001	$ 0.0001
Common stock issued (in shares) | shares			138,530,000	20,432,000
Common stock outstanding (in shares) | shares		133,726,000
Business Combination, Acquisition Related Costs
Business Acquisition [Line Items]
Transaction costs | $		$ 20,600
Energy Vault Holdings Inc
Business Acquisition [Line Items]
Proceeds from reverse recapitalization | $		$ 191,100
Consideration paid (in shares) | shares		106,200,000
Common stock, par value (in dollars per share) | $ / shares		$ 0.0001
Exchange ratio		6.7735
Additional Paid-In Capital
Business Acquisition [Line Items]
Transaction costs | $		$ 24,200
Common Stock
Business Acquisition [Line Items]
Common stock issued (in shares) | shares	[1]		138,530,000	20,432,000	14,404,000
Common Stock | Redeemable convertible preferred stock
Business Acquisition [Line Items]
Convertible preferred stock converted (in shares) | shares		85,700,000
Common Stock | Energy Vault Holdings Inc
Business Acquisition [Line Items]
Common stock issued (in shares) | shares		20,400,000
Common stock outstanding (in shares) | shares		20,400,000
[1]The number of shares of convertible preferred stock and common stock prior to the Merger (defined in Note 1) have been retroactively restated to reflect the exchange ratio of 6.7735 established in the Merger as described in Note 1 and Note 3.

REVERSE RECAPITALIZATION - Sche

REVERSE RECAPITALIZATION - Schedule of Reverse Recapitalization (Details) - shares			12 Months Ended
		Feb. 11, 2022	Dec. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Common stock outstanding (in shares)		133,726,000
Shares issued (in shares)		19,500,000
Warrants outstanding (in shares)		14,700,000	5,167,000	14,750,000
Warrants issued (in shares)		14,700,000
Common Stock
Business Acquisition [Line Items]
Shares issued (in shares)	[1]		27,553,000
Number of earn-out shares (in shares)		9,000,000	9,000,000
Public warrants
Business Acquisition [Line Items]
Warrants outstanding (in shares)		9,600,000	0	9,583,000
Warrants issued (in shares)		9,600,000
Private warrants
Business Acquisition [Line Items]
Warrants outstanding (in shares)		5,200,000	5,167,000	5,167,000
Warrants issued (in shares)		5,200,000
Novus | Public warrants
Business Acquisition [Line Items]
Warrants outstanding (in shares)		9,600,000
Novus | Private warrants
Business Acquisition [Line Items]
Warrants outstanding (in shares)		5,200,000
Novus | Public Shares
Business Acquisition [Line Items]
Shares issued (in shares)		4,079,000
Novus | Sponsor Shares
Business Acquisition [Line Items]
Shares issued (in shares)		3,975,000
Common shares that have transfer restrictions based on certain thresholds (in shares)		1,600,000
Legacy Energy Vault
Business Acquisition [Line Items]
Common stock outstanding (in shares)		106,172,000
[1]The number of shares of convertible preferred stock and common stock prior to the Merger (defined in Note 1) have been retroactively restated to reflect the exchange ratio of 6.7735 established in the Merger as described in Note 1 and Note 3.

REVENUE RECOGNITION - Recognize

REVENUE RECOGNITION - Recognized Revenue for Product and Service Categories (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Total revenue	$ 145,877	$ 0
Build and transfer energy storage products
Disaggregation of Revenue [Line Items]
Total revenue	85,636	0
Licensing of intellectual property
Disaggregation of Revenue [Line Items]
Total revenue	58,483	0
Other
Disaggregation of Revenue [Line Items]
Total revenue	$ 1,758	$ 0

REVENUE RECOGNITION - Narrative

REVENUE RECOGNITION - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($)
Revenue from Contract with Customer [Abstract]
Amortization of deferred revenue	$ 0.7
Cost reimbursements	1.1
Remaining performance obligations	$ 331

REVENUE RECOGNITION - Revenue D

REVENUE RECOGNITION - Revenue Disaggregated by Geographic Region (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Total revenue	$ 145,877	$ 0
United States
Disaggregation of Revenue [Line Items]
Total revenue	85,635	0
China
Disaggregation of Revenue [Line Items]
Total revenue	50,518	0
Other
Disaggregation of Revenue [Line Items]
Total revenue	$ 9,724	$ 0

REVENUE RECOGNITION - Contract

REVENUE RECOGNITION - Contract Assets and Contract Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Refundable contribution made	$ 25,000	$ 0
Unbilled receivables	531	0
Retainage	3,447	0
Contract assets	28,978	0
Contract with Customer, Liability [Abstract]
Contract liabilities, current portion	49,434	0
Contract liabilities, long-term portion	1,500	1,500
Total contract liabilities	$ 50,934	$ 1,500

FAIR VALUE MEASUREMENTS - Sched

FAIR VALUE MEASUREMENTS - Schedule of Fair Value of Financial Assets and Liabilities Measured on a Recurring Basis (Details) - Recurring basis - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Derivative asset —  conversion option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	$ 1,025	$ 350
Warrant liability
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	2
Level 1 | Derivative asset —  conversion option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	0	0
Level 1 | Warrant liability
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	0
Level 2 | Derivative asset —  conversion option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	0	0
Level 2 | Warrant liability
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	0
Level 3 | Derivative asset —  conversion option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets	1,025	$ 350
Level 3 | Warrant liability
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities	$ 2

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	May 31, 2019	Dec. 31, 2022	Dec. 31, 2021
Note Payable Agreement | Shareholder Lender
Related Party Transaction [Line Items]
Transaction amount	$ 1.5
Related Party Engineering, Design, And Civil Tolerance Code Calculation Support | Executive Officer Immediate Family Member
Related Party Transaction [Line Items]
Transaction amount		$ 0.4	$ 0.3
Related Party Engineering, Design, And Civil Tolerance Code Calculation Support | Executive Officer
Related Party Transaction [Line Items]
Transaction amount		0.3
Prototype Construction Labor Costs | Employee Immediate Family Member
Related Party Transaction [Line Items]
Transaction amount		0.5	$ 0.5
Related Party Marketing Costs | Executive Officer
Related Party Transaction [Line Items]
Transaction amount		$ 1.2

CONVERTIBLE NOTE RECEIVABLE - N

CONVERTIBLE NOTE RECEIVABLE - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Oct. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Apr. 30, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maximum loss exposure		$ 3,000
Convertible Notes Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal balance of promissory note	$ 1,000			$ 2,000
Maturity date description	The maturity date of the DG Fuels Note is the earlier of (i) 30 days after a demand for payment is made by the Company at any time after the two year anniversary of the date of issuance of the note; (ii) the four 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.
Annual interest rate	10%
Note converted into equity securities		$ 20,000
Note converted into equity securities at discount price		20%
Interest income		$ 300	$ 21
Amortization of debt discount		$ 100	$ 4
DG Fuels Tranche 1 Note | Convertible Notes Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair value of embedded derivative asset	$ 400
DG Fuels Tranche 2 Note | Convertible Notes Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair value of embedded derivative asset	$ 700

CONVERTIBLE NOTE RECEIVABLE - R

CONVERTIBLE NOTE RECEIVABLE - Reconciliation of Embedded Derivative Beginning and Ending Asset Balance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at the beginning	$ 350	$ 0
Additions	675	350
Change in fair value	0	0
Balance at the end	$ 1,025	$ 350

PROPERTY AND EQUIPMENT, NET- Sc

PROPERTY AND EQUIPMENT, NET- Schedule of Property and Equipment, net (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Finance lease right-of-use assets – vehicles	$ 178,000	$ 175,000
Property and equipment and finance lease right-of-use asset, before accumulated depreciation	3,447,000	14,263,000
Less: accumulated depreciation	(403,000)	(2,395,000)
Property and equipment and finance lease right-of-use asset, after accumulated depreciation and amortization	3,044,000	11,868,000
Depreciation	7,700,000	2,300,000
Property and equipment impairment charges	2,800,000	0
Accelerated depreciation expense	3,800,000
Brick machines
Property, Plant and Equipment [Line Items]
Property and equipment	$ 657,000	2,515,000
Useful life (in years)	6 years
Finance lease right-of-use assets – vehicles
Property, Plant and Equipment [Line Items]
Useful life (in years)	4 years
Furniture and IT equipment
Property, Plant and Equipment [Line Items]
Property and equipment	$ 815,000	176,000
Furniture and IT equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years
Furniture and IT equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	7 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	$ 529,000	179,000
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	4 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	7 years
Demonstration & test equipment
Property, Plant and Equipment [Line Items]
Property and equipment	$ 0	11,218,000
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment	$ 1,268,000	$ 0

ASSET RETIREMENT OBLIGATION (De

ASSET RETIREMENT OBLIGATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO, Beginning Balance	$ 978	$ 123
Changes in estimates	0	751
Change in asset retirement obligation	95	107
Liabilities settled	(487)	0
Foreign currency translation gain	(26)	(3)
ARO, Ending Balance	$ 560	$ 978

DEFINED BENEFIT PENSION OBLIG_3

DEFINED BENEFIT PENSION OBLIGATION - Funded Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Change in Benefit Obligation
Benefit obligation at beginning of year	$ 2,662	$ 2,425
Service cost	162	130
Interest cost	9	5
Actuarial (gain) loss	(149)	99
Benefits paid	866	40
Plan participant’s contributions	137	86
Plan amendments	350	(50)
Foreign currency translation adjustments	8	(73)
Benefit obligation at end of year	4,045	2,662
Change in Plan Assets
Fair value of plans assets at beginning of year	1,928	1,592
Actual return on plans’ assets	74	214
Employer contributions	137	43
Benefits paid	866	40
Plan participant’s contributions	137	85
Foreign currency translation adjustments	13	(46)
Fair value of plans assets at end of year	3,155	1,928
Fair value of plan assets	3,155	1,928
Benefit obligation	(4,045)	(2,662)
Net periodic benefit cost	$ (890)	$ (734)
Defined Benefit Plan Net Periodic Benefit Cost Credit Immediate Recognition Of Actuarial Gain Loss Statement Of Income Or Comprehensive Income Extensible List Not Disclosed Flag	Actuarial (gain) loss	Actuarial (gain) loss

DEFINED BENEFIT PENSION OBLIG_4

DEFINED BENEFIT PENSION OBLIGATION - Net Periodic Pension Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Employer service costs	$ 162	$ 130
Interest cost	9	5
Expected return on plan assets	(72)	(53)
Amortization of net prior service credit	(13)	(7)
Amortization of net loss	39	59
Net periodic benefit cost	$ 125	$ 134
Defined Benefit Plan Net Periodic Benefit Cost Credit Expected Return Loss Statement Of Income Or Comprehensive Income Extensible List Not Disclosed Flag	Expected return on plan assets	Expected return on plan assets
Defined Benefit Plan Net Periodic Benefit Cost Credit Amortization Of Gain Loss Statement Of Income Or Comprehensive Income Extensible List Not Disclosed Flag	Amortization of net loss	Amortization of net loss

DEFINED BENEFIT PENSION OBLIG_5

DEFINED BENEFIT PENSION OBLIGATION - Amounts Recognized in AOCI (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Retirement Benefits [Abstract]
Net prior service credit (cost)	$ (262)	$ 94
Net loss	(383)	(551)
Accumulated other comprehensive loss	$ (645)	$ (457)	$ (623)

DEFINED BENEFIT PENSION OBLIG_6

DEFINED BENEFIT PENSION OBLIGATION - Changes in AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Change in AOCI
Accumulated other comprehensive loss at beginning of year	$ (457)	$ (623)
Change in net prior service credit (cost)	(360)	40
Change in net gain	189	112
Foreign currency translation adjustments	(17)	14
Accumulated other comprehensive loss at end of year	$ (645)	$ (457)

DEFINED BENEFIT PENSION OBLIG_7

DEFINED BENEFIT PENSION OBLIGATION - Assumptions Used to Measure the Benefit Obligation (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Discount rate	1.80%	0.40%
Expected long-term return on plan assets	4.70%	3.80%
Rate of compensation increase	1.50%	1%
Pension increase rate (in payment)	0%	0%

DEFINED BENEFIT PENSION OBLIG_8

DEFINED BENEFIT PENSION OBLIGATION - Actual Asset Allocation (Details)	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan, Plan Assets, Category [Line Items]
Total	100%	100%
Equity instruments (Level 1) | Level 1
Defined Benefit Plan, Plan Assets, Category [Line Items]
Total	47.30%	50.20%
Equity instruments (Level 1) | Minimum | Level 1
Defined Benefit Plan, Plan Assets, Category [Line Items]
Target	30%
Equity instruments (Level 1) | Maximum | Level 1
Defined Benefit Plan, Plan Assets, Category [Line Items]
Target	55%
Debt instruments (Level 2) | Level 2
Defined Benefit Plan, Plan Assets, Category [Line Items]
Total	9.70%	10.60%
Debt instruments (Level 2) | Minimum | Level 2
Defined Benefit Plan, Plan Assets, Category [Line Items]
Target	5%
Debt instruments (Level 2) | Maximum | Level 2
Defined Benefit Plan, Plan Assets, Category [Line Items]
Target	30%
Real estate (Level 3) | Level 3
Defined Benefit Plan, Plan Assets, Category [Line Items]
Total	30%	26.40%
Real estate (Level 3) | Minimum | Level 3
Defined Benefit Plan, Plan Assets, Category [Line Items]
Target	15%
Real estate (Level 3) | Maximum | Level 3
Defined Benefit Plan, Plan Assets, Category [Line Items]
Target	40%
Alternative investments (Level 3) | Level 3
Defined Benefit Plan, Plan Assets, Category [Line Items]
Total	7.70%	5.30%
Alternative investments (Level 3) | Minimum | Level 3
Defined Benefit Plan, Plan Assets, Category [Line Items]
Target	0%
Alternative investments (Level 3) | Maximum | Level 3
Defined Benefit Plan, Plan Assets, Category [Line Items]
Target	15%
Cash and equivalents (Level 1) | Level 1
Defined Benefit Plan, Plan Assets, Category [Line Items]
Total	5.30%	7.50%
Cash and equivalents (Level 1) | Minimum | Level 1
Defined Benefit Plan, Plan Assets, Category [Line Items]
Target	0%
Cash and equivalents (Level 1) | Maximum | Level 1
Defined Benefit Plan, Plan Assets, Category [Line Items]
Target	15%

DEFINED BENEFIT PENSION OBLIG_9

DEFINED BENEFIT PENSION OBLIGATION - Estimated Future Benefit Payments (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Retirement Benefits [Abstract]
2023	$ 42
2024	43
2025	43
2026	44
2027	45
Thereafter	227
Total	$ 444

DEFINED BENEFIT PENSION OBLI_10

DEFINED BENEFIT PENSION OBLIGATION - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Defined Contribution Plan Disclosure [Line Items]
Estimated employer contribution	$ 200,000
Matching contributions	$ 0	$ 0
Maximum
Defined Contribution Plan Disclosure [Line Items]
Matching participants’ contributions (up to)	3.50%

LEASES - Lease Expense (Details

LEASES - Lease Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating lease expense	$ 853	$ 647
Finance lease expense
Amortization of finance ROU assets	47	45
Interest on finance lease liabilities	2	3
Short-term lease expense	339	80
Variable lease expense	12	3
Sublease income	(9)	0
Total	$ 1,244	$ 778

LEASES - Other Lease Informatio

LEASES - Other Lease Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Weighted Average Remaining Lease Term (Years)
Operating leases	2 years 4 months 24 days	2 years 2 months 12 days
Finance leases	2 years 1 month 6 days	1 year 9 months 18 days
Weighted Average Discount Rate
Operating leases	8.60%	7.40%
Finance leases	4.40%	2.80%
Cash Paid for Amounts Included in the Measurement of Lease Liabilities
Operating cash flows used for operating leases	$ 836	$ 532
Operating cash flows used for finance leases	2	3
Financing cash flows used for finance leases	62	53
Total payments for lease liabilities	900	588
ROU Assets obtained in Exchange for Lease Liabilities
Operating leases	962	476
Finance leases	37	44
Total ROU assets obtained in exchange for lease liabilities	$ 999	$ 520

LEASES - Future Maturities of L

LEASES - Future Maturities of Leases (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Operating Leases
2023	$ 876
2024	482
2025	110
2026	105
2027	61
Thereafter	0
Total undiscounted cash flows	1,634
Less imputed interest	(138)
Present value of lease liabilities	1,496
Finance Leases
2023	40
2024	6
2025	6
2026	5
2027	0
Thereafter	0
Total undiscounted cash flows	57
Less imputed interest	(3)
Present value of lease liabilities	$ 54

WARRANTS - Narrative (Details)

WARRANTS - Narrative (Details) - $ / shares	Feb. 11, 2022	Dec. 31, 2022	Aug. 01, 2022	Mar. 08, 2022	Dec. 31, 2021
Class of Warrant or Right [Line Items]
Warrants outstanding (in shares)	14,700,000	5,167,000			14,750,000
Number of shares per warrant (in shares)	1
Warrant expiration period	5 years
Novus
Class of Warrant or Right [Line Items]
Common stock issuable upon exercise of warrants (in shares)				14,800,000
Public warrants
Class of Warrant or Right [Line Items]
Warrants outstanding (in shares)	9,600,000	0			9,583,000
Number of shares per warrant (in shares)			0.2526
Warrant exercise price per share (in usd per share)	$ 11.50		$ 11.50
Public warrants | Novus
Class of Warrant or Right [Line Items]
Warrants outstanding (in shares)	9,600,000
Private warrants
Class of Warrant or Right [Line Items]
Warrants outstanding (in shares)	5,200,000	5,167,000			5,167,000
Private warrants | Novus
Class of Warrant or Right [Line Items]
Warrants outstanding (in shares)	5,200,000

WARRANTS - Public Warrants Narr

WARRANTS - Public Warrants Narrative (Details) - $ / shares	1 Months Ended	12 Months Ended
	Jul. 31, 2022	Dec. 31, 2022	Aug. 01, 2022	Jun. 30, 2022	Feb. 11, 2022	Dec. 31, 2021
Class of Warrant or Right [Line Items]
Number of shares per warrant (in shares)					1
Warrants exercised (in shares)		9,348,000
Warrants outstanding (in shares)		5,167,000			14,700,000	14,750,000
Public warrants
Class of Warrant or Right [Line Items]
Warrant exercise price per share (in usd per share)			$ 11.50		$ 11.50
Number of shares per warrant (in shares)			0.2526
Warrants issued/redeemed (in shares)	2,200,000		200,000	700,000
Warrants exercised (in shares)	8,700,000	9,348,000
Warrants outstanding (in shares)		0			9,600,000	9,583,000
Public warrants | Redemption, stock equals or exceeds $10.00
Class of Warrant or Right [Line Items]
Redemption price per warrant (usd per share)			$ 0.10

WARRANTS - Warrants Rollforward

WARRANTS - Warrants Rollforward (Details) - shares	1 Months Ended	12 Months Ended
	Jul. 31, 2022	Dec. 31, 2022
Class of Warrant Or Right [Roll Forward]
Warrants assumed upon the Closing of the Merger (in shares)		14,750,000
Warrants exercised (in shares)		(9,348,000)
Warrants redeemed (in shares)		235,000
End of period (in shares)		5,167,000
Public warrants
Class of Warrant Or Right [Roll Forward]
Warrants assumed upon the Closing of the Merger (in shares)		9,583,000
Warrants exercised (in shares)	(8,700,000)	(9,348,000)
Warrants redeemed (in shares)		235,000
End of period (in shares)		0
Private warrants
Class of Warrant Or Right [Roll Forward]
Warrants assumed upon the Closing of the Merger (in shares)		5,167,000
Warrants exercised (in shares)		0
Warrants redeemed (in shares)		0
End of period (in shares)		5,167,000

WARRANTS - Private Warrants Nar

WARRANTS - Private Warrants Narrative (Details)	Dec. 31, 2022 $ / shares
Level 3 | Private warrants
Class of Warrant or Right [Line Items]
Warrant exercise price per share (in usd per share)	$ 0.01

WARRANTS - Estimate of Fair Val

WARRANTS - Estimate of Fair Value of Private Warrants (Details) - Private warrants	12 Months Ended
	Dec. 31, 2022 $ / shares
Class of Warrant or Right [Line Items]
Common stock price (in dollars per share)	$ 3,120
Exercise price (in dollars per share)	$ 11,500
Expected term (in years)	4 years 1 month 13 days
Expected volatility	17.40%
Risk-free interest rate	4.10%
Expected dividend yield	0%

WARRANTS - Warrants Liabilities

WARRANTS - Warrants Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Class of Warrant Or Right [Roll Forward]
Change in fair value	$ (2,330)	$ 0
Recurring basis
Class of Warrant Or Right [Roll Forward]
Warrant liability assumed upon the Closing of the Merger	19,838
Warrants exercised	(17,483)
Warrants redeemed	(23)
Change in fair value	(2,330)
Warrant liability at end of period	2	19,838
Public warrants | Recurring basis
Class of Warrant Or Right [Roll Forward]
Warrant liability assumed upon the Closing of the Merger	12,938
Warrants exercised	(17,483)
Warrants redeemed	(23)
Change in fair value	4,568
Warrant liability at end of period	0	12,938
Private warrants | Recurring basis
Class of Warrant Or Right [Roll Forward]
Warrant liability assumed upon the Closing of the Merger	6,900
Warrants exercised	0
Warrants redeemed	0
Change in fair value	(6,898)
Warrant liability at end of period	$ 2	$ 6,900

SUPPLEMENTAL BALANCE SHEETS D_3

SUPPLEMENTAL BALANCE SHEETS DETAIL (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Prepaid expenses and other current assets:
Deposits for project equipment and materials	$ 24,327	$ 0
Prepaid expenses	6,609	1,140
Tax refund receivable	454	121
Deferred merger costs	0	4,121
Other	179	156
Prepaid expenses and other current assets	31,569	5,538
Other assets:
Investment in equity securities	9,000	0
Convertible note receivable	2,080	654
Derivative asset —  conversion option	1,025	350
Other	1,795	521
Total	13,900	1,525
Accrued Expenses:
Employee costs	8,711	3,756
Taxes payable	4,168	0
Professional fees	1,671	81
Prototype costs	0	716
Other	199	151
Total	$ 14,749	$ 4,704

STOCKHOLDERS_ EQUITY - Narrativ

STOCKHOLDERS’ EQUITY - Narrative (Details) $ / shares in Units, shares in Millions	Feb. 11, 2022 USD ($) $ / shares shares
Dividends declared
Class of Stock [Line Items]
Dividends declared | $	$ 0
Common Stock
Class of Stock [Line Items]
Issue of new common stock shares (in shares)	27.6
Conversion of stock, shares converted (in shares)	3
Conversion of stock, new shares issued (in shares)	106.2
Redeemable convertible preferred stock
Class of Stock [Line Items]
Issued and outstanding redeemable convertible preferred stock cancelled (in shares)	85.7
Preferred stock exchange ratio	6.7735
Non-cumulative dividends (as a percent)	8%
Preferred stock conversion, sale of common stock per share minimum (in usd per share) | $ / shares	$ 49.0258
Preferred stock conversion, sale of common stock gross proceeds minimum | $	$ 50,000,000
Deemed liquidation event notification period	90 days
Conversion of stock, shares converted (in shares)	12.7
Redeemable convertible preferred stock | Common Stock
Class of Stock [Line Items]
Convertible preferred stock converted (in shares)	85.7
Redeemable convertible preferred stock | Common Stock Including Additional Paid in Capital
Class of Stock [Line Items]
Note payable conversion to preferred stock | $	$ 182,700,000

STOCKHOLDERS_ EQUITY - Converti

STOCKHOLDERS’ EQUITY - Convertible Preferred Stock (Details) - Convertible Preferred Stock shares in Thousands, $ in Thousands	Dec. 31, 2021 USD ($) shares
Class of Stock [Line Items]
Shares Designated (in shares)	85,741
Shares Issued (in shares)	85,741
Shares Outstanding (in shares)	85,741
Liquidation Preference | $	$ 171,349
Series C preferred stock
Class of Stock [Line Items]
Shares Designated (in shares)	14,787
Shares Issued (in shares)	14,787
Shares Outstanding (in shares)	14,787
Liquidation Preference | $	$ 107,000
Series B-1 preferred stock
Class of Stock [Line Items]
Shares Designated (in shares)	14,475
Shares Issued (in shares)	14,475
Shares Outstanding (in shares)	14,475
Liquidation Preference | $	$ 31,003
Series B preferred stock
Class of Stock [Line Items]
Shares Designated (in shares)	14,651
Shares Issued (in shares)	14,651
Shares Outstanding (in shares)	14,651
Liquidation Preference | $	$ 25,003
Series A-2 preferred stock
Class of Stock [Line Items]
Shares Designated (in shares)	5,087
Shares Issued (in shares)	5,087
Shares Outstanding (in shares)	5,087
Liquidation Preference | $	$ 3,555
Series A-1 preferred stock
Class of Stock [Line Items]
Shares Designated (in shares)	6,950
Shares Issued (in shares)	6,950
Shares Outstanding (in shares)	6,950
Liquidation Preference | $	$ 3,076
Series Seed 2 preferred stock
Class of Stock [Line Items]
Shares Designated (in shares)	4,240
Shares Issued (in shares)	4,240
Shares Outstanding (in shares)	4,240
Liquidation Preference | $	$ 934
Series Seed 1 preferred stock
Class of Stock [Line Items]
Shares Designated (in shares)	11,190
Shares Issued (in shares)	11,190
Shares Outstanding (in shares)	11,190
Liquidation Preference | $	$ 753
Series FR preferred stock
Class of Stock [Line Items]
Shares Designated (in shares)	14,361
Shares Issued (in shares)	14,361
Shares Outstanding (in shares)	14,361
Liquidation Preference | $	$ 25

STOCK-BASED COMPENSATION - Narr

STOCK-BASED COMPENSATION - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) d shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of training days to achieve target price	20 days
Number of training days | d	30
Number of options, stock options granted (in shares) | shares	0	1,142,000
Stock-based compensation expense	$ 41,058	$ 500
Merger
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	7,100
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized stock-based compensation expense	$ 600
Stock-based compensation expense expected recognized period	2 years 8 months 26 days
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense expected recognized period	3 years 3 days
Unrecognized stock-based compensation expense	$ 113,200
Restricted Stock Units | Merger
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 3,900
Restricted Stock Units | Cliff Vesting Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year
Restricted Stock | Merger
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 3,200
Minimum | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Maximum | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
2017 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award grant period				10 years
Voting rights in percentage				10%
Minimum percentage of exercise price for options granted for employees who hold more than 10%				110%
2017 Stock Incentive Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				1 year
2017 Stock Incentive Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				4 years
2020 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award grant period			10 years
Voting rights in percentage			10%
Minimum percentage of exercise price for options granted for employees who hold more than 10%			110%
2020 Stock Incentive Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			1 year
2020 Stock Incentive Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			4 years
2022 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved (in shares) | shares	15,500,000
Annual shares authorized increase, percent of outstanding shares	4%
2022 Equity Incentive Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual shares authorized increase, Board of Directors decision (in shares) | shares	0
2022 Equity Incentive Plan, Shares From Prior Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved (in shares) | shares	8,300,000
Twenty Twenty Two Equity Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved (in shares) | shares	8,000,000

STOCK-BASED COMPENSATION - Stoc

STOCK-BASED COMPENSATION - Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Feb. 11, 2022
Number of Options
Number of options, beginning balance (in shares) | shares	1,345	576
Number of options, stock options granted (in shares) | shares	0	1,142
Number of options, stock options exercised (in shares) | shares	(212)	(373)
Number of options, stock options forfeited, canceled, or expired (in shares) | shares	(40)
Number of options, ending balance (in shares) | shares	1,093	1,345	576
Number of options, options exercisable (in shares) | shares	796
Number of options, options vested and expected to vest (in shares) | shares	1,093
Weighted Average Exercise Price Per Share
Weighted average exercise price per share, beginning balance (in dollars per share) | $ / shares	$ 0.79	$ 0.09
Weighted average exercise price per share, stock options granted (in dollars per share) | $ / shares		0.89
Weighted average exercise price per share, stock options exercised (in dollars per share) | $ / shares	0.80	0.01
Weighted average exercise price per share, stock options forfeited, canceled, or expired (in dollars per share) | $ / shares	0.80
Weighted average exercise price per share, ending balance (in dollars per share) | $ / shares	0.79	$ 0.79	$ 0.09
Weighted average exercise price per share, options exercisable (in dollars per share) | $ / shares	0.69
Weighted average exercise price per share, options vested and expected to vest (in dollars per share) | $ / shares	$ 0.79
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term (in years)	8 years 1 month 6 days	9 years 1 month 9 days	7 years 5 months 23 days
Weighted average remaining contractual term (in years), options exercisable	7 years 10 months 20 days
Weighted average remaining contractual term (in years), options vested and expected to vest	8 years 1 month 6 days
Aggregate intrinsic value, beginning balance | $	$ 7,024	$ 423
Aggregate intrinsic value, ending balance | $	2,551	$ 7,024	$ 423
Aggregate intrinsic value, options exercisable | $	1,936
Aggregate intrinsic value, options vested and expected to vest | $	$ 2,551
Energy Vault Holdings Inc
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exchange ratio				6.7735

STOCK-BASED COMPENSATION - Summ

STOCK-BASED COMPENSATION - Summary of Weighted-average Assumptions (Details)	12 Months Ended
	Dec. 31, 2022 $ / shares
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years 3 months
Expected volatility	90%
Risk-free interest rate	0.10%
Expected dividend yield	0%
Stock options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock price (in dollars per share)	$ 930
Stock options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock price (in dollars per share)	$ 4,980
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	90%
Risk-free interest rate, minimum	3.60%
Risk-free interest rate, maximum	3.80%
Expected dividend yield	0%
Restricted stock units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock price (in dollars per share)	$ 2.93
Expected term (in years)	4 years
Restricted stock units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock price (in dollars per share)	$ 3.10
Expected term (in years)	6 years 3 months 7 days

STOCK-BASED COMPENSATION - Rest

STOCK-BASED COMPENSATION - Restricted Stock Units Activity (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2022 $ / shares shares	Dec. 31, 2021 $ / shares shares	Feb. 11, 2022
Energy Vault Holdings Inc
Weighted Average Grant Date Fair Value per Share
Exchange ratio			6.7735
Restricted stock units
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares) | shares	6,170	0
RSUs granted (in shares) | shares	23,412	6,170
RSUs forfeited (in shares) | shares	(561)
RSUs vested (in shares) | shares	(5,222)
Ending balance (in shares) | shares	23,799	6,170
Weighted Average Grant Date Fair Value per Share
Beginning balance (in dollars per share) | $ / shares	$ 2.11	$ 0
RSUs granted (in dollars per share) | $ / shares	6.31	2.11
RSUs forfeited (in dollars per share) | $ / shares	5.64
RSUs vested (in dollars per share) | $ / shares	1.55
Ending balance (in dollars per share) | $ / shares	$ 5.87	$ 2.11

STOCK-BASED COMPENSATION - Outs

STOCK-BASED COMPENSATION - Outstanding Unvested Stock Activities (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2022 shares	Dec. 31, 2021 shares	Feb. 11, 2022
Energy Vault Holdings Inc
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Exchange ratio			6.7735
Unvested Common Stock
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares)	5,520	3,051
New grants or issues (in shares)		5,655
RSUs forfeited (in shares)		(146)
Common stock vested (in shares)	(5,520)	(3,040)
Ending balance (in shares)	0	5,520

STOCK-BASED COMPENSATION - St_2

STOCK-BASED COMPENSATION - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 41,058	$ 500
Sales and marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	5,111	67
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	14,775	370
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 21,172	$ 63

INCOME TAXES - Pre-tax Loss (De

INCOME TAXES - Pre-tax Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
United States	$ (52,509)	$ (12,308)
Switzerland	(25,363)	(19,029)
Loss before income taxes	$ (77,872)	$ (31,337)

INCOME TAXES - Effective Income

INCOME TAXES - Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
US federal statutory income tax rate	21%	21%
State and local income taxes, net of Federal benefit	2.70%	0.30%
Non-deductible expenses	(6.50%)	(0.50%)
Credits	0.70%	0.40%
Foreign rate differential	(0.90%)	(0.60%)
Valuation allowance	(17.60%)	(20.60%)
Effective income tax rate	(0.60%)	0%

INCOME TAXES - Provision for In

INCOME TAXES - Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Current
Federal	$ 388	$ 0
State	39	1
Foreign	0	0
Total current tax provision	427	1
Deferred
Federal	0	0
State	0	0
Foreign	0	0
Total deferred tax provision	0	0
Provision for income taxes	$ 427	$ 1

INCOME TAXES - Deferred Tax Ass

INCOME TAXES - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Net operating loss carryforwards	$ 12,701	$ 10,905
Stock-based compensation	4,143	0
Revenue recognition	1,937	0
Accrued expense	1,324	425
Capitalized research and development	3,492	0
Credits	374	167
Operating lease liabilities	191	228
Other	289	139
Gross deferred tax assets	24,451	11,864
Less: valuation allowance	(24,043)	(11,405)
Net deferred tax assets	408	459
Deferred tax liabilities:
Depreciation and amortization	(229)	(89)
Right of use assets	(179)	(213)
Other	0	(157)
Net deferred tax assets (liabilities)	$ 0	$ 0

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Valuation allowance	$ 24,043,000	$ 11,405,000
Operating loss carryforwards, domestic	3,400,000
Operating loss carryforwards, state	21,900,000
Operating loss carryforwards, foreign	37,300,000
Unrecognized tax benefits	1,066,000	908,000	$ 882,000
Unrecognized tax benefits, income tax penalties and interest expense	0	0	$ 0
Unrecognized tax benefits that would impact effective tax rate	0	$ 0
United States
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	300,000
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	$ 300,000

INCOME TAXES - Unrecognized Tax

INCOME TAXES - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 908	$ 882
Increase related to prior year tax positions	31	13
Decrease related to prior year tax positions	0	(18)
Increase related to current year tax positions	127	31
Decrease related to lapsing status of limitation	0	0
Balance at end of year	$ 1,066	$ 908

NET LOSS PER SHARE OF COMMON _3

NET LOSS PER SHARE OF COMMON STOCK - Basic and Diluted Net Loss Per Share (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Feb. 11, 2022
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net loss, basic | $	$ (78,299)	$ (31,338)
Net loss, diluted | $	$ (78,299)	$ (31,338)
Weighted-average shares outstanding – basic (in shares) | shares	123,241	12,780
Weighted average shares of outstanding — diluted (in shares) | shares	123,241	12,780
Net loss per share — basic (in dollars per share) | $ / shares	$ (0.64)	$ (2.45)
Net loss per share — diluted (in dollars per share) | $ / shares	$ (0.64)	$ (2.45)
Energy Vault Holdings Inc
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Exchange ratio			6.7735

NET LOSS PER SHARE OF COMMON _4

NET LOSS PER SHARE OF COMMON STOCK - Narrative (Details) - shares	3 Months Ended		12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Feb. 11, 2022
Common Stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Number of dilutive shares	0	0	0	0
Number of earn-out shares (in shares)	9,000,000		9,000,000		9,000,000
Convertible preferred stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Number of dilutive shares	0	0	0	0

NET LOSS PER SHARE OF COMMON _5

NET LOSS PER SHARE OF COMMON STOCK - Common Share Equivalent Securities Excluded From Computation of Earnings Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	30,059	87,086
Private Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	5,167	0
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	1,093	1,345
Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	85,741
RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	23,799	0

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Non-cancellable purchase obligations	$ 50,200
Total refundable contributions to be made	25,000
Refundable contribution made	25,000	$ 0
Letters of credit issued	82,900
Outstanding performance and payment bonds	$ 0

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - USD ($) $ in Thousands		12 Months Ended
	Feb. 28, 2023	Dec. 31, 2022	Dec. 31, 2021
Subsequent Event [Line Items]
Purchase of equity securities		$ 9,000	$ 0
Subsequent Event | Energy Transition Industry Private Company
Subsequent Event [Line Items]
Purchase of equity securities	$ 6,000
Equity securities	$ 15,000