Aspen Aerogels (ASPN) 10-Q 7 Nov 24 2024 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Nov. 07, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Trading Symbol	ASPN
Entity Registrant Name	ASPEN AEROGELS, INC.
Entity Central Index Key	0001145986
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		82,047,288
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-36481
Entity Tax Identification Number	04-3559972
Entity Address, Address Line One	30 Forbes Road
Entity Address, Address Line Two	Building B
Entity Address, State or Province	MA
Entity Address, City or Town	Northborough
Entity Address, Postal Zip Code	01532
City Area Code	508
Local Phone Number	691-1111
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, par value $0.00001 per share
Security Exchange Name	NYSE
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 113,489	$ 139,723
Restricted cash	394	248
Accounts receivable, net of allowances of $898 and $230	115,199	69,995
Inventories	47,430	39,189
Prepaid expenses and other current assets	29,344	17,176
Total current assets	305,856	266,331
Property, plant and equipment, net	451,569	417,227
Operating lease right-of-use assets	20,373	17,212
Other long-term assets	4,789	2,278
Total assets	782,587	703,048
Current liabilities:
Accounts payable	42,280	51,094
Accrued expenses	26,531	22,811
Deferred revenue	2,405	2,316
Finance obligation for sale and leaseback transactions	3,653
Operating lease liabilities	3,181	1,874
Long term debt - current portion	26,250
Total current liabilities	104,300	78,095
Revolving line of credit	42,735
Long term debt	93,674
Convertible note - related party		114,992
Finance obligation for sale and leaseback transactions long-term	10,486
Operating lease liabilities long-term	23,742	21,906
Total liabilities	274,937	214,993
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock, $0.00001 par value; 5,000,000 shares authorized, no shares issued and outstanding at September 30, 2024 and December 31, 2023
Common stock, $0.00001 par value; 250,000,000 shares authorized, 77,155,896 and 76,503,151 shares issued and outstanding at September 30, 2024 and December 31, 2023, respectively	0	0
Additional paid-in capital	1,179,239	1,161,657
Accumulated deficit	(671,589)	(673,602)
Total stockholders’ equity	507,650	488,055
Total liabilities and stockholders’ equity	$ 782,587	$ 703,048

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Allowance for accounts receivable and contract assets	$ 898	$ 230
Preferred stock, par value	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	77,155,896	76,503,151
Common stock, shares outstanding	77,155,896	76,503,151

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
Revenue	$ 117,340	$ 60,755	$ 329,611	$ 154,499
Cost of revenue	68,297	46,945	193,847	127,196
Gross profit	49,043	13,810	135,764	27,303
Operating expenses:
Research and development	4,591	4,218	13,645	12,281
Sales and marketing	9,306	8,386	27,130	24,226
General and administrative	17,746	15,840	52,465	41,382
Impairment of equipment under development			2,702
Total operating expenses	31,643	28,444	95,942	77,889
Income (loss) from operations	17,400	(14,634)	39,822	(50,586)
Other income (expense)
Interest expense, convertible note - related party	(1,469)	(1,938)	(7,550)	(2,424)
Interest income (expense)	(1,147)	1,313	(883)	5,532
Income from Employee Retention Credits		2,186		2,186
Loss on extinguishment of debt	(27,487)		(27,487)
Total other income (expense)	(30,103)	1,561	(35,920)	5,294
Income (loss) before income tax expense	(12,703)	(13,073)	3,902	(45,292)
Income tax expense	(267)		(1,889)
Net income (loss)	$ (12,970)	$ (13,073)	$ 2,013	$ (45,292)
Net income (loss) per share:
Basic	$ (0.17)	$ (0.19)	$ 0.03	$ (0.65)
Diluted	$ (0.17)	$ (0.19)	$ 0.03	$ (0.65)
Weighted-average common shares outstanding:
Basic	76,261,294	69,317,805	76,402,123	69,243,843
Diluted	76,261,294	69,317,805	79,149,193	69,243,843

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2022	$ 447,435		$ 1,075,226	$ (627,791)
Beginning balance, shares at Dec. 31, 2022		69,994,963
Net Income (Loss)	(16,796)			(16,796)
Stock-based compensation expense	2,267		2,267
Vesting of restricted stock units	(385)		(385)
Vesting of restricted stock units, shares		71,643
Proceeds from employee stock option exercises	21		21
Proceeds from employee stock option exercises, shares		2,554
Ending balance at Mar. 31, 2023	432,542		1,077,129	(644,587)
Ending balance, shares at Mar. 31, 2023		70,069,160
Beginning balance at Dec. 31, 2022	447,435		1,075,226	(627,791)
Beginning balance, shares at Dec. 31, 2022		69,994,963
Net Income (Loss)	(45,292)
Ending balance at Sep. 30, 2023	409,813		1,082,896	(673,083)
Ending balance, shares at Sep. 30, 2023		70,226,633
Beginning balance at Mar. 31, 2023	432,542		1,077,129	(644,587)
Beginning balance, shares at Mar. 31, 2023		70,069,160
Net Income (Loss)	(15,423)			(15,423)
Stock-based compensation expense	2,710		2,710
Issuance of restricted stock, shares		44,928
Vesting of restricted stock units	(8)		(8)
Vesting of restricted stock units, shares		2,464
Proceeds from employee stock option exercises	150		150
Proceeds from employee stock option exercises, shares		41,591
Ending balance at Jun. 30, 2023	419,971		1,079,981	(660,010)
Ending balance, shares at Jun. 30, 2023		70,158,143
Net Income (Loss)	(13,073)			(13,073)
Stock-based compensation expense	2,789		2,789
Vesting of restricted stock units	(9)		(9)
Vesting of restricted stock units, shares		2,662
Proceeds from employee stock option exercises	274		274
Proceeds from employee stock option exercises, shares		65,828
Issuance costs from underwritten public offering	(139)		(139)
Ending balance at Sep. 30, 2023	409,813		1,082,896	(673,083)
Ending balance, shares at Sep. 30, 2023		70,226,633
Beginning balance at Dec. 31, 2023	488,055		1,161,657	(673,602)
Beginning balance, shares at Dec. 31, 2023		76,503,151
Net Income (Loss)	(1,835)			(1,835)
Stock-based compensation expense	2,532
Issuance costs from private placement of common stock	(28)		(28)
Vesting of restricted stock units	(1,081)		(1,081)
Vesting of restricted stock units, shares		118,289
Cancellation of restricted stock	2,174		2,174
Cancellation of restricted stock, shares		(679,796)
Proceeds from employee stock option exercises	1,386		1,386
Proceeds from employee stock option exercises, shares		136,286
Ending balance at Mar. 31, 2024	491,203		1,166,640	(675,437)
Ending balance, shares at Mar. 31, 2024		76,077,930
Beginning balance at Dec. 31, 2023	488,055		1,161,657	(673,602)
Beginning balance, shares at Dec. 31, 2023		76,503,151
Net Income (Loss)	2,013
Ending balance at Sep. 30, 2024	507,650		1,179,239	(671,589)
Ending balance, shares at Sep. 30, 2024		77,155,896
Beginning balance at Mar. 31, 2024	491,203		1,166,640	(675,437)
Beginning balance, shares at Mar. 31, 2024		76,077,930
Net Income (Loss)	16,818			16,818
Stock-based compensation expense	2,971		2,971
Issuance of restricted stock, shares		11,388
Employee restricted stock awards withheld for tax	(1,810)		(1,810)
Employee restricted stock awards withheld for tax, shares		(75,885)
Vesting of restricted stock units	(53)		(53)
Vesting of restricted stock units, shares		3,790
Proceeds from employee stock option exercises	8,698		8,698
Proceeds from employee stock option exercises, shares		1,063,816
Ending balance at Jun. 30, 2024	517,827		1,176,446	(658,619)
Ending balance, shares at Jun. 30, 2024		77,081,039
Net Income (Loss)	(12,970)			(12,970)
Stock-based compensation expense	2,630		2,630
Vesting of restricted stock units	(124)		(124)
Vesting of restricted stock units, shares		11,784
Proceeds from employee stock option exercises	287		287
Proceeds from employee stock option exercises, shares		63,073
Ending balance at Sep. 30, 2024	$ 507,650		$ 1,179,239	$ (671,589)
Ending balance, shares at Sep. 30, 2024		77,155,896

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities:
Net income (loss)	$ 2,013,000	$ (45,292,000)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation	17,093,000	10,757,000
Accretion of interest on convertible note - related party	7,083,000	1,721,000
Amortization of debt discount due to modification of convertible note - related party	443,000	675,000
Loss on extinguishment of debt	27,487,000
Deferred financing costs written off	1,829,000
Provision for bad debt	139,000	(89,000)
Stock-based compensation expense	10,307,000	7,766,000
Impairment of property, plant and equipment	6,810,000	0
Reduction in the carrying amount of operating lease right-of-use assets	1,990,000	2,186,000
Changes in operating assets and liabilities:
Accounts receivable	(45,343,000)	3,026,000
Inventories	(8,241,000)	(11,883,000)
Prepaid expenses and other assets	(16,786,000)	(6,771,000)
Accounts payable	4,452,000	(420,000)
Accrued expenses	1,890,000	691,000
Deferred revenue	89,000	(383,000)
Operating lease liabilities	(1,710,000)	(1,845,000)
Net cash provided (use) in operating activities	9,865,000	(39,833,000)
Cash flows from investing activities:
Capital expenditures	(71,511,000)	(147,669,000)
Net cash used in investing activities	(71,511,000)	(147,669,000)
Cash flows from financing activities:
Proceeds from employee stock option exercises	10,371,000	445,000
Proceeds from sale and leaseback transactions	14,982,000
Repayment of finance obligation for sale and leaseback transactions	(843,000)
Payments made for employee restricted stock tax withholdings	(1,258,000)	(402,000)
Repayment of convertible note	(150,029,000)
Proceeds from term loan	125,000,000
Issuance costs from term loan	(5,337,000)
Proceeds from revolver	43,000,000
Issuance costs from revolver	(300,000)
Fees and issuance costs from private placement of common stock	(28,000)	(139,000)
Net cash provided by (used in) financing activities	35,558,000	(96,000)
Net decrease in cash, cash equivalents and restricted cash	(26,088,000)	(187,598,000)
Cash, cash equivalents and restricted cash at beginning of period	139,971,000	282,561,000
Cash, cash equivalents and restricted cash at end of period	113,883,000	94,963,000
Supplemental disclosures of cash flow information:
Interest paid	2,328,000	1,000
Supplemental disclosures of non-cash activities:
Right-of-use assets obtained in exchange for new operating lease liabilities	4,853,000	9,994,000
Capitalized interest		6,084,000
Changes in accrued capital expenditures	(13,266,000)	(17,193,000)
Convertible Note [Member]
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Amortization of convertible note issuance costs	$ 320,000	$ 28,000

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (12,970)	$ 16,818	$ (1,835)	$ (13,073)	$ (15,423)	$ (16,796)	$ 2,013	$ (45,292)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	None of our directors or executive officers adopted , modified or terminated any contract, instruction or written plan for the purchase or sale of our securities that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) or any “non-Rule 10b5-1 trading arrangement” as such term is defined in Item 408(a) of Regulation S-K, during the fiscal quarter ended September 30, 2024 .
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Rule 10b5-1 Arr Modified Flag	false
Non Rule10B51 Arr Modified Flag	false

Description of Business and Bas

Description of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	(1) Description of Business and Basis of Presentation Nature of Business Aspen Aerogels, Inc. (the Company) is an aerogel technology company that has introduced a line of aerogel thermal barriers for use in battery packs in the electric vehicle market. In addition, the Company designs, develops and manufactures innovative, high-performance aerogel insulation used in the energy industrial and sustainable insulation materials markets. The Company is also developing applications for its aerogel technology in the battery materials and a number of other high-potential markets. The Company maintains its corporate offices in Northborough, Massachusetts. The Company has three wholly owned subsidiaries: Aspen Aerogels Rhode Island, LLC (Aspen RI), Aspen Aerogels Germany, GmbH and Aspen Aerogels Georgia, LLC (Aspen Georgia). Additionally, we engaged Prodensa Servicios de Consultora to establish OPE Manufacturer Mexico S de RL de CV, a maquiladora located in Mexico (OPE), which manufactures thermal barrier PyroThin products and operates an automated fabrication facility for PyroThin. OPE is currently owned by Prodensa, which charges a management fee. There is an option for OPE to be purchased by the Company after a period of 18 months. During the period between inception and the exercise of the purchase option, OPE operations are consolidated within the Company financial statements. Liquidity During the nine months ended September 30, 2024, the Company earned net income of $ 2.0 million, provided $ 9.9 million of cash in operations and used $ 71.5 million of cash for capital expenditures. The Company had unrestricted cash and cash equivalents of $ 113.5 million as of September 30, 2024. In January 2024 and September 2024 , the Company entered i nto sale and leaseback arrangements, pursuant to which the Company sold certain equipment to an equipment leasing company for one-time cash payments of $ 5.0 and $ 10.0 million, respectively, and leased back such equipment from the leasing company. The associated monthly lease rents will be paid over the lease term of three years . On August 19, 2024, the Company and Aspen RI (each, a Borrower and collectively, the Borrowers) entered into a Credit, Security and Guaranty Agreement (the Credit Agreement and the facilities provided thereunder, collectively, the MidCap Loan Facility) with MidCap Funding IV Trust, as agent (the Agent), MidCap Financial Trust, as term loan servicer, the financial institutions or other entities from time to time party thereto as lenders (the Lenders), and the other parties party thereto as additional guarantors and/or borrowers from time to time, for a term loan facility in an aggregate principal amount of $ 125.0 million and an asset-based revolving credit facility in an aggregate principal amount not to exceed the lesser of $ 100.0 million or the borrowing base. At closing the Company drew $ 125.0 million from the term loan facility and $ 43.0 million from the revolving loan facility. The proceeds of the borrowings, net of fees and costs, were used for repurchasing of the 2022 Convertible Notes (as defined below) for $ 150.0 million and for general corporate purposes. The amount available to the Company at September 30, 2024 under the revolving loan facility was $ 25.7 million. The Company is increasing investment in the research and development of next-generation aerogel products and manufacturing process technologies. In addition, the Company has developed a number of promising aerogel products and technologies for the electric vehicle market. The Company believes that the commercial potential for the Company’s products and technology in the electric vehicle market is significant. Accordingly, the Company is hiring additional personnel, incurring additional operating expenses, incurring significant capital expenditures to expand aerogel manufacturing capacity and automated thermal barrier fabrication operations, and enhancing research and development resources, among other items. The Company expects its existing cash balance and the amount anticipated to be available under the existing revolving loan facility will be sufficient to support current operating requirements, current research and development activities and the initial capital expenditures required to support the evolving commercial opportunity in the electric vehicle market and other strategic business initiatives. However, the Company plans to supplement its cash balance and available credit with equity financings, debt financings, equipment leasing, sale and leaseback transactions, c ustomer prepayments, or government grant and loan programs to provide the additional capital necessary to purchase the capital equipment, construct the new facilities, establish the operations and complete the aerogel capacity expansions required to support these evolving commercial opportunities and strategic business initiatives. Unaudited Interim Financial Information The accompanying unaudited interim consolidated financial statements include the accounts of the Company and have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Certain information and disclosures normally included in the consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this Quarterly Report on Form 10-Q should be read in conjunction with the audited consolidated financial statements and accompanying notes in our Annual Report on Form 10-K for the year ended December 31, 2023 (the Annual Report), filed with the U.S. Securities and Exchange Commission on March 7, 2024. In the opinion of the Company’s management, the unaudited interim consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and include all adjustments that are of a normal recurring nature and necessary for the fair statement of the Company’s financial position as of September 30, 2024 and the results of its operations and stockholders’ equity for the three and nine months ended September 30, 2024 and 2023 and the cash flows for the nine-month periods then ended. The Company has evaluated subsequent events through the date of this filing. The Company’s results of operations for the three and nine months ended September 30, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024 or any other period.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Significant Accounting Policies	(2) Significant Accounting Policies Please refer to "Note 2. Summary of Basis of Presentation and Significant Accounting Policies," to the Company's consolidated financial statements from the Annual Report for the discussion of the Company's significant accounting policies. Use of Estimates The preparation of the consolidated financial statements requires the Company to make a number of estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant items subject to such estimates and assumptions include allowances for doubtful accounts, sales returns and allowances, product warranty costs, inventory valuation, the carrying amount of property and equipment, right-of-use assets, lease liabilities, stock-based compensation, and deferred income taxes. The Company evaluates its estimates and assumptions on an on-going basis using historical experience and other factors, including current economic conditions, which are believed to be reasonable under the circumstances. Management adjusts such estimates and assumptions when facts and circumstances warrant. Illiquid credit markets, volatile equity markets and declines in business investment can increase the uncertainty inherent in such estimates and assumptions. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Changes in these estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods. Restricted Cash As of September 30, 2024, the Company had $ 0.4 million of restricted cash to support its outstanding letters of credit. Concentration of Credit Risk Financial instruments, which potentially expose the Company to concentrations of credit risk, consist principally of accounts receivable. The Company’s customers are primarily insulation distributors, insulation contractors, insulation fabricators and select energy and automotive end-users located throughout the world. The Company performs ongoing credit evaluations of its customers’ financial condition and generally requires no collateral to secure accounts receivable. The Company maintains an allowance for doubtful accounts based on its assessment of the collectability of accounts receivable. The Company reviews the allowance for doubtful accounts quarterly. During the nine months ended September 30, 2024, the Company recorded an increase for estimated customer uncollectible accounts receivable of $ 0.1 million. During the nine months ended September 30, 2023, the Company recorded a reduction for estimated customer uncollectible accounts receivable of less than $ 0.1 million. For the nine months ended September 30, 2024 and 2023 , two customers represented 74 % and 50 % of total revenue, respectively. At September 30, 2024 , the Company had one customer which accounted for 79 % of accounts receivable. At December 31, 2023, the Company had two customers which accounted for 60 % and 6 % of accounts receivable, respectively. Revenue Recognition The Company recognizes revenue in accordance with Accounting Standards Codification 606, Revenue from Contracts with Customers (ASC 606). See note 3 for further details. Sale and Leaseback Accounting The Company has entered into sale and leaseback transactions for certain equipment within its plants. Due to the Company not meeting criteria to account for the transfer of the assets as a sale, sale accounting is precluded. Accordingly, the Company uses the financing method to account for these transactions. Under the financing method of accounting for a sale and leaseback, the Company does not derecognize the assets and does not recognize as revenue any of the sale proceeds received from the lessor that contractually constitutes payment to acquire the assets subject to these arrangements. Instead, the sale proceeds received are accounted for as finance obligations and leaseback payments made by the Company are allocated between interest expense and a reduction to the finance obligation. Interest on the finance obligation is calculated using the Company’s incremental borrowing rate at the inception of the arrangement on the outstanding finance obligation. Recently Issued Accounting Standards From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board or other standard setting bodies. Recently issued standards typically do not require adoption until a future effective date. Prior to their effective date, the Company evaluates the pronouncements to determine the potential effects of adoption to its consolidated financial statements. Standards Implemented Since December 31, 2023 The Company has not implemented any accounting standards that had a material impact on its consolidated financial statements during the nine months ended September 30, 2024. Standards to be Implemented In November 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) 2023-07 Segment Reporting (Topic 280) Improvements to Reportable Segment Disclosures to enhance disclosures about significant segment expenses. This ASU is effective for the Company’s fiscal year 2024 and interim periods in fiscal year 2025. Early adoption is permitted. The Company is currently evaluating segment expense disclosures related to its annual report for fiscal year 2024. In December 2023, the FASB issued ASU 2023-09 Income Taxes (Topic 740) Improvements to Income Tax Disclosures that requires disclosure of disaggregated income taxes paid, prescribes standard categories for the components of the effective tax rate reconciliation, and modifies other income tax-related disclosures. This ASU is effective for the Company’s fiscal year 2025. Early adoption is permitted. The Company is currently evaluating income tax disclosures related to its annual report for fiscal year 2025. Although there are several other new accounting pronouncements issued by the FASB, the Company does not believe any of these accounting pronouncements had or will have a material impact on its Consolidated Financial Statements. The Company believes that the impact of recently issued accounting standards that are not yet effective will not have a material impact on its consolidated financial statements.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	9 Months Ended
	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	(3) Revenue from Contracts with Customers Revenue Recognition Revenue is recognized when a customer obtains control of promised goods or services in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements within the scope of ASC 606, the Company performs the following five steps: (i) identification of the contract with a customer; (ii) identification of the performance obligations in the contract; (iii) determination of the transaction price; (iv) allocation of the transaction price to the separate performance obligations in the contract; and (v) recognition of the revenue associated with performance obligations as they are satisfied. The Company applies the five-step model to contracts when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the 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 and assesses whether each promised good or service is distinct. If the contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. Contracts that contain multiple performance obligations require an allocation of the transaction price based on the estimated relative standalone-selling prices of the promised products or services underlying each performance obligation. The Company determines standalone-selling prices based on the price at which the performance obligation is sold separately. If the standalone-selling price is not observable through past transactions, the Company estimates the standalone-selling price considering available information such as market conditions and internally approved pricing guidelines related to the performance obligations. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. When determining the transaction price of a contract, an adjustment is made if payment from a customer occurs either significantly before or significantly after performance, resulting in a significant financing component. Applying the practical expedient in paragraph ASC 606-10-32-18, the Company does not assess whether a significant financing component exists if the period between when the Company performs its obligations under the contract and when the customer pays is one year or less. The Company did not have any contracts outstanding at December 31, 2023 and did not enter into any contracts during the nine months ended September 30, 2024 that contained a significant financing component. The Company records deferred revenue for product sales when (i) the Company has delivered products, but other revenue recognition criteria have not been satisfied, or (ii) payments have been received in advance of the completion of required performance obligations. Thermal Barriers The Company supplies fabricated, multi-part thermal barriers for use in battery packs in the electric vehicle market. These thermal barriers are customized to meet customer specifications. Although thermal barrier products are customized with no alternative use to the Company, the Company does not always have an enforceable right to payment. Under the provisions of ASC 606, the Company recognizes revenue at a point in time when transfer of the control of the products is passed to the customer according to the terms of the contract, including under bill and hold arrangements. The timing of revenue recognition is assessed on a contract-by-contract basis. Energy Industrial The Company generally enters into contracts containing one type of performance obligation. For a majority of the contracts, the Company recognizes revenue at a point in time when transfer of control of the products is passed to the customer, which is generally upon delivery according to contractual shipping terms within customer purchase orders. For a limited number of customer arrangements for customized products with no alternative use to the Company and an enforceable right to payment for progress completed to date, the Company recognizes revenue over time using units of production to measure progress toward satisfying the performance obligations. Units of production represent work performed as we do not generate significant work in process and thereby best depicts the transfer of control to the customer. Customer invoicing terms for contracts for which revenue is recognized under the over time methodology are typically based on certain milestones within the production and delivery schedule. The timing of revenue recognition is assessed on a contract-by-contract basis. The Company also enters into rebate agreements with certain customers. These agreements may be considered an additional performance obligation of the Company or variable consideration within a contract. Rebates are recorded as a reduction of revenue in the period the related revenue is recognized. A corresponding liability is recorded as a component of deferred revenue on the consolidated balance sheets. These arrangements are primarily based on the customer attaining contractually specified sales volumes. The Company estimates the amount of its sales that may be returned by its customers and records this estimate as a reduction of revenue in the period the related revenue is recognized. The Company currently estimates return liabilities using historical rates of return, current quarter credit sales, and specific items of exposure on a contract-by-contract basis. Sales return reserves were approximately $ 0.7 million and $ 0.2 million as of September 30, 2024 and December 31, 2023, respectively. Shipping and Handling Costs Shipping and handling costs associated with outbound freight after control over a product has transferred to a customer are accounted for as fulfillment costs and are included in the cost of product revenue. The associated amount of revenue recognized includes the consideration to which the Company expects to be entitled to receive in exchange for incurring these shipping and handling costs. Disaggregation of Revenue In the following tables, revenue is disaggregated by primary geographical region and source of revenue: Three Months Ended September 30, 2024 2023 U.S. International Total U.S. International Total (In thousands) Geographical region Asia $ — $ 4,439 $ 4,439 $ — $ 5,801 $ 5,801 Canada — 6,125 6,125 — 633 633 Europe — 8,455 8,455 — 11,361 11,361 Latin America — 25,012 25,012 — 1,176 1,176 U.S. 73,309 — 73,309 41,784 — 41,784 Total revenue $ 73,309 $ 44,031 $ 117,340 $ 41,784 $ 18,971 $ 60,755 Source of revenue Energy industrial $ 13,679 $ 13,097 $ 26,776 $ 12,249 $ 15,663 $ 27,912 Thermal barrier 59,630 30,934 90,564 29,535 3,308 32,843 Total revenue $ 73,309 $ 44,031 $ 117,340 $ 41,784 $ 18,971 $ 60,755 Nine Months Ended September 30, 2024 2023 U.S. International Total U.S. International Total (In thousands) Geographical region Asia $ — $ 18,071 $ 18,071 $ — $ 27,522 $ 27,522 Canada — 11,599 11,599 — 1,519 1,519 Europe — 26,926 26,926 — 26,735 26,735 Latin America — 74,614 74,614 — 5,065 5,065 U.S. 198,401 — 198,401 93,658 — 93,658 Total revenue $ 198,401 $ 131,210 $ 329,611 $ 93,658 $ 60,841 $ 154,499 Source of revenue Energy industrial $ 41,853 $ 50,928 $ 92,781 $ 43,994 $ 53,317 $ 97,311 Thermal barrier 156,548 80,282 236,830 49,664 7,524 57,188 Total revenue $ 198,401 $ 131,210 $ 329,611 $ 93,658 $ 60,841 $ 154,499 Contract Balances The following table presents changes in the Company’s contract liabilities during the nine months ended September 30, 2024: Balance at Additions Deductions Balance at (In thousands) Contract liabilities Deferred revenue Energy industrial $ 2,316 $ 5,686 $ ( 5,597 ) $ 2,405 Total contract liabilities $ 2,316 $ 5,686 $ ( 5,597 ) $ 2,405 During the nine months ended September 30, 2024, the Company recognized $ 2.3 million of revenue that was included in deferred revenue as of December 31, 2023. A contract asset is recorded when the Company satisfies a performance obligation by transferring a promised good or service and has earned the right to consideration from its customer. These assets may represent a conditional right to consideration and are included within accounts receivable and other current assets on the consolidated balance sheets. A contract liability is recorded when consideration is received, or such consideration is unconditionally due, from a customer prior to transferring goods or services under the terms of the contract. Contract liabilities are recognized as revenue after control of the products or services is transferred to the customer and all revenue recognition criteria have been met.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2024
Inventory Disclosure [Abstract]
Inventories	(4) Inventories Inventories consist of the following: September 30, December 31, 2024 2023 (In thousands) Raw materials $ 16,054 $ 24,735 Work in process 12,226 7,936 Finished goods 19,150 6,518 Total $ 47,430 $ 39,189

Property, Plant and Equipment,

Property, Plant and Equipment, Net	9 Months Ended
	Sep. 30, 2024
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Net	(5) Property, Plant and Equipment, Net Property, plant and equipment consist of the following: September 30, December 31, Useful 2024 2023 life (In thousands) Construction in progress $ 344,063 $ 314,695 — Buildings 26,914 25,473 30 years Machinery and equipment 197,657 185,339 3 - 10 years Computer equipment and software 9,703 9,495 3 years Leasehold improvements 24,570 23,514 Shorter of useful life or lease term Total 602,907 558,516 Accumulated depreciation ( 151,338 ) ( 141,289 ) Property, plant and equipment, net $ 451,569 $ 417,227 Depreciation expense was $ 17.1 million and $ 10.8 million for the nine months ended September 30, 2024 and 2023, respectively. The Company recorded impairment charges of approximately $ 6.8 million during the nine months ended September 30, 2024, respectively, for equipment that will no longer be needed in manufacturing following customer directed engineering changes to a part it manufactures and for other property, plant and equipment that have become obsolete following development of new and more efficient equipment. Refer to Note 9 – Commitments and Contingencies for a discussion of the claim that the Company has submitted with a customer for reimbursement of losses incurred in connection with the customer directed engineering changes. The impairment charges of $ 6.8 million during the nine months ended September 30, 2024 consist of $ 4.1 million impairment included in cost of revenue and $ 2.7 million included in impairment of equipment under development on the Company's consolidated statement of operations. There were no impairments of property, plant and equipment during the nine months ended September 30, 2023. The construction in progress balance at September 30, 2024 and December 31, 2023 included engineering designs and construction costs, and capitalized interest totaling $ 325.1 million and $ 288.5 million, respectively, for a planned aerogel manufacturing facility in Bulloch County, Georgia. The Company incurred $ 8.8 million in capitalized interest for the construction in progress in Bulloch County, Georgia. The Company capitalized interest of $ 0.0 million and $ 8.8 million for the nine months ended September 30, 2024 and 2023 , respectively.

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2024
Payables and Accruals [Abstract]
Accrued Expenses	(6) Accrued Expenses Accrued expenses consist of the following: September 30, December 31, 2024 2023 (In thousands) Employee compensation $ 15,003 $ 16,876 Other accrued expenses 11,528 5,935 Total $ 26,531 $ 22,811

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2024
Related Party Transactions [Abstract]
Related Party Transactions	(7) Related Party Transactions Convertible Note During the year ended December 31, 2022, the Company issued a $ 100.0 million aggregate principal amount convertible note (the 2022 Convertible Note) to Wood River Capital, LLC (Wood River), an entity affiliated with Koch Disruptive Technologies, LLC (Koch), for the planned manufacturing facility in Bulloch County, Georgia, pursuant to that certain Note Purchase Agreement, dated as of February 15, 2022, as amended by that certain Amendment No. 1 to Note Purchase Agreement, dated November 28, 2022 (together, the Note Purchase Agreement). The Company repurchased the 2022 Convertible Note on August 19, 2024. See Note (8) Convertible Note – Related Party for additional detail. During the nine months ended September 30, 2024, the Company incurred $ 7.1 million of interest from the 2022 Convertible Note. Other The Company had $ 2.8 million in accounts payable as o f December 31, 2023, due to an entity affiliated with Koch for project management service. On March 27, 2024, we entered into a Settlement and Release Agreement with the affiliate of Koch to settle the accounts payable for $ 1.2 million, which was paid during the three months ended, June 30, 2024.

Convertible Note - Related Part

Convertible Note - Related Party	9 Months Ended
	Sep. 30, 2024
Convertible Notes [Abstract]
Convertible Note - Related Party	(8) Convertible Note – Related Party 2022 Convertible Note On February 15, 2022, the Company entered into the Note Purchase Agreement with Wood River, an entity affiliated with Koch, relating to the issuance and sale to Wood River of the 2022 Convertible Note in the aggregate principal amount of $ 100.0 million. The transactions contemplated by the Note Purchase Agreement closed on February 18, 2022. The maturity date of the 2022 Convertible Note is February 18, 2027 , subject to earlier conversion, redemption, or repurchase. The 2022 Convertible Note is a senior unsecured obligation of the Company and ranks equal in right of payment to all senior unsecured indebtedness of the Company and will rank senior in right of payment to any indebtedness that is contractually subordinated to the 2022 Convertible Note. On August 19, 2024, the Company entered into a note purchase and sale agreement with Wood River (the Note Repurchase Agreement), pursuant to which the Company repurchased from Wood River $ 123.9 million in aggregate capitalized principal amount (inclusive of PIK interest paid through June 30, 2024) of the 2022 Convertible Note, such aggregate amount being the entire outstanding amount of the 2022 Convertible Note, for a total purchase price of $ 150.1 million in cash, which amount equals to the Redemption Price (as defined in the 2022 Convertible Note). Pursuant to the Note Repurchase Agreement, all rights and obligations, covenants and agreements under the 2022 Convertible Note and the Note Purchase Agreement were satisfied and discharged. The Redemption Price less capitalized principal amount and accrued interest to redemption date, of $ 24.6 million along with unamortized deferred issuance costs was classified in the income statement as Loss on Extinguishment of Debt. In accordance with ASU 2020-06, the 2022 Convertible Note is accounted for as a single unit of account and consists of the following: September 30, December 31, 2024 2023 (In thousands) Convertible note, principal $ — $ 100,000 Payment in-kind — 18,318 Discount on convertible note, net of accumulated amortization — ( 3,209 ) Debt issuance costs, net of accumulated amortization — ( 117 ) Convertible note $ — $ 114,992 The 2022 Convertible Note does not have current observable inputs such as recent trading prices (Level 1) and was measured at fair value using a combination of option pricing and discounted cash flow models and incorporate management’s assumptions for stock price, volatility and risk rate. In general, fair values determined by Level 1 inputs utilize observable inputs such as quoted prices in active markets for identical assets or liabilities. Fair values determined by Level 2 inputs utilize data points that are either directly or indirectly observable, such as quoted prices for similar instruments in active markets, interest rates and yield curves. Fair values determined by Level 3 inputs utilize unobservable data points in which there is little or no market data, which require the Company to develop its own assumptions for the asset or liability. The Company estimated the fair value of the 2022 Convertible Note was approximately $ 118.2 million as of December 31, 2023. However, as the Company did not elect to utilize the fair value option, it was carried at amortized cost of $ 115.0 million.

Debt

Debt	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Debt	(9) Debt On August 19, 2024, the Borrowers entered into the Credit Agreement, by and among the Borrowers, the Agent, the Lenders and the other parties party thereto as additional guarantors and/or borrowers from time to time. Loans borrowed under the MidCap Loan Facility mature on August 19, 2029. The MidCap Loan Facility is comprised of (i) a term loan facility in an aggregate principal amount of $ 125 million (the Term Loan Facility) and (ii) an asset-based revolving credit facility in an aggregate principal amount not to exceed the lesser of (A) a $ 100 million commitment amount and (B) the value of the borrowing base (defined as the sum of (x) 85 % of certain eligible accounts of the Borrowers and (y) the lesser of 85 % of the NOLV or 85 % of the cost of certain eligible inventory of the Borrowers) (the “Revolving Facility”). Loans borrowed under the Term Loan Facility will bear interest rate equal to Term SOFR (as defined in the Credit Agreement) for a one-month interest period plus 4.50 % per year, subject to a Term SOFR floor of 4.50 % and a Term SOFR cap of 7.50 %. Loans borrowed under the Revolving Facility will bear an interest rate equal to Term SOFR plus 4.60 % per year, subject to a Term SOFR floor of 2.50 %. The Term Loan Facility is subject to amortization of principal, payable quarterly on the last day of each quarter, commencing September 30, 2024, in an amount as set forth in the Credit Agreement with the remaining aggregate principal amount payable on the maturity date. The Borrowers are required to pay the Lenders an exit fee of $ 2.5 million on the maturity date. The Revolving Facility has a required minimum balance set at 30 % of the average borrowing base during the immediate preceding month. The Borrowers are required to pay the Lenders under the Revolving Facility an unused line fee of 0.30 % of the average unused availability under the Revolving Facility, subject to the aforementioned minimum balance. The MidCap Loan Facility is guaranteed by the Loan Parties and is secured by a lien on substantially all existing and after-acquired assets of the Loan Parties, including the equity interest in Aspen RI and Aspen Georgia, owned by the Company, in each case, subject to customary exceptions. Aspen Georgia is not a guarantor and its assets are excluded from the collateral under the Credit Agreement, subject to its entrance into a loan facility within one year from the closing date of the MidCap Loan Facility. Once Aspen Georgia enters into the loan facility within such one-year period, the lien granted by the Company on the equity interest of Aspen Georgia will be released. If Aspen Georgia does not enter into the loan facility within such one-year period, Aspen Georgia will be obligated to become a Loan Party under the MidCap Loan Facility and pledge substantially all of its assets as security for the obligations thereunder. The Credit Agreement includes representations and warranties, affirmative covenants (including reporting obligations), negative covenants and events of default that are usual and customary for facilities of this type, in each case, subject to certain permitted exceptions as set forth therein. The Credit Agreement includes financial covenants for the benefit of the Lenders, including (i) a covenant to maintain Liquidity (as defined therein) equal to or greater than $ 75 million at all times and (ii) a covenant to maintain EBITDA (as defined therein) equal to or greater than the specified applicable amount set forth in the Credit Agreement, tested quarterly with the first test set at $ 45 million commencing with the fiscal quarter ended September 30, 2024. The Borrowers will have the right to prepay the loans outstanding under the MidCap Loan Facility (or, with respect to the Revolving Facility, terminate the commitments thereunder), subject to a premium equal to 3.0 % of the amount prepaid or terminated, as applicable, during the first year after the closing date, which premium will be decreased to 2.0 % during the second year after the closing date and to 1.0 % thereafter. The Borrowers will be required to mandatorily prepay the loans outstanding under the Term Loan Facility with, among other things, certain casualty insurance proceeds or proceeds from non-ordinary course assets sales (which will also be subject to the aforementioned premium). The Borrowers will be required to mandatorily prepay the balance outstanding under the Revolving Facility (i) if the outstandings exceed the borrowing base in an aggregate amount equal to that excess or (ii) upon a cash dominion event of all the funds deposited in the lockbox account during the cash dominion period. A cash dominion event is triggered upon an event of default or if the Liquidity is less than $ 100 million. MidCap debt consists of the following: September 30, 2024 (In thousands) Term loan 125,000 Exit fee 85 Term loan issuance costs ( 5,161 ) Total debt 119,924 Current portion 26,250 Long term portion 93,674 The revolving line of credit had an outstanding balance of $ 42.7 million as of September 30, 2024 , net of unamortized issuance costs.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	(10) Commitments and Contingencies Cloud Computing Agreement The Company is party to multiple cloud computing agreements that are service contracts for enterprise resource planning software and payroll services. The amortization period of a cloud computing agreement was adjusted during the three months ended March 31, 2024 to align with implementation of a new agreement that will begin to amortize during 2025. The amortization associated with the payroll services agreement began during the three months ended September 30, 2024 and will amortize over a period of five years . The capitalized implementation costs are classified on the consolidated balance sheets as follows: September 30, December 31, 2024 2023 (In thousands) Cloud computing costs included in other current assets $ 780 $ 420 Cloud computing costs included in other assets 2,691 1,590 Amortization of cloud computing costs ( 578 ) ( 662 ) Total capitalized cloud computing costs $ 2,893 $ 1,348 Thermal Barrier Contracts The Company is party to production contracts with General Motors to supply fabricated, multi-part thermal barriers (Barriers) for use in the battery system of its next-generation electric vehicles (Contracts). Pursuant to the Contracts, the Company is obligated to supply Barriers at fixed annual prices and at volumes to be specified by General Motors up to a daily maximum quantity through the respective terms of the agreements, which expire at various times from 2026 through 2034. While General Motors has agreed to purchase its requirement for Barriers from the Company for locations to be designated from time to time by General Motors, it has no obligation to purchase any minimum quantity of Barriers under the Contracts. In addition, General Motors may terminate the Contracts at any time and for any or no reason. All other terms of the Contracts are generally consistent with General Motors' standard purchase terms, including quality and warranty provisions customary in automotive industry. Charges for Engineering Change In January 2024, the Company was notified by a customer of an engineering change to one of the parts the Company manufactures for that customer to enable incremental productivity and support a set of broader system level changes that could drive higher demand for its parts. The Company has submitted claims to the customer for reimbursement for estimated inventory and equipment losses incurred by the Company and its vendors due to potential obsolescence. In connection with the same, during the three months ended March 31, 2024, the Company recognized a charge of $ 6.8 million, net of contractual recoverable of $ 1.9 million, in cost of revenues for inventory obsolescence and impairment of equipment. During the three months ended June 30, 2024, the customer approved reimbursement of parts of the claim totaling $ 4.2 million for equipment losses incurred by the Company and its vendors, which is recognized as an offset to the charge the Company recognized in the three months ended, March 31, 2024 in cost of revenues. During the three months ended September 30, 2024, the customer approved the remaining claims related to inventory obsolescence of $ 2.2 million, in addition to the contractual recoverable amount, which is recognized as an offset to the charge recognized in the three months ended, March 31, 2024 in cost of revenues. Federal, State and Local Environmental Regulations The Company is subject to federal, state and local environmental laws and regulations. These laws generally provide for control of pollutants released into the environment and require responsible parties to undertake remediation. Penalties may be imposed for noncompliance. Litigation The Company is, from time to time, a party to litigation that arises in the normal course of its business operations. See Part II, Item 1 “Legal Proceedings” of this Quarterly Report on Form 10-Q for a description of certain of the Company’s current legal proceedings. The Company is not presently a party to any litigation for which it believes a loss is probable requiring an amount to be accrued or a possible loss contingency requiring disclosure. Purchase Commitments As of September 30, 2024, the Company had purchase commitments of approximately $ 240.0 million, which included capital commitments of $ 175.3 million. Purchase commitments related to capital expenditures are anticipated to be spent over the next three years , while the Company's remaining purchase commitments are anticipated to be spent throughout 2024. Purchase obligations relate primarily to open purchase orders for capital expenditures, inventories, and goods and services. Purchase obligations are entered into with various vendors in the normal course of business and are consistent with the Company's expected requirements. Warranty The Company offers warranties to its customers depending upon the specific product. The Company’s standard warranty period for energy industrial products extends to one year from the date of shipment. This standard warranty provides that the Company’s products will be free from defects in material and workmanship, and will, under normal use, conform to the specifications for the product. The Company’s thermal barrier products provide quality and warranty provisions customary in the automotive industry. The Company recorded warranty reserves related to its thermal barrier products of $ 1.1 million during the nine months ended September 30, 2024 and $ 0.2 million during the nine months ended September 30, 2023 .

Leases and sale and leaseback

Leases and sale and leaseback	9 Months Ended
	Sep. 30, 2024
Leases [Abstract]
Leases and sale and leaseback	(11) Leases and sale and leaseback The Company leases office, laboratory, warehouse and fabrication space in Massachusetts, Rhode Island and Monterrey, Mexico under operating leases. Under these agreements, the Company is obligated to pay annual rent, real estate taxes, and certain other operating expenses. The Company also leases equipment under operating leases. The Company’s operating leases expire at various dates through 2034 . The Company determines if an arrangement is a lease at inception. 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 payment obligations under the lease. Operating lease ROU assets and liabilities are recognized based on the present value of lease payments over the lease term. To measure its lease liabilities, the Company uses its incremental borrowing rate or the rate implicit in the lease, if available. The Company calculates its incremental borrowing rate using a synthetic credit rating analysis based on Moody’s Building Materials Industry Rating Methodology. ROU assets also include any direct costs and prepaid lease payments but exclude any lease incentives received. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. The Company elected the short-term lease recognition exemption for all leases that qualify. For leases that qualify for this exemption, the Company does not recognize ROU assets or lease liabilities. For lease agreements with lease and non-lease components, the Company accounts for each component separately. However, in the case of equipment leases, the Company accounts for lease and non-lease components as a single component. Maturities of operating lease liabilities as of September 30, 2024 are as follows: Year Operating (In thousands) 2024 (excluding the nine months ended September 30, 2024) $ 1,523 2025 6,110 2026 5,598 2027 4,695 2028 4,599 Thereafter 19,338 Total lease payments 41,863 Less imputed interest ( 14,940 ) Total lease liabilities $ 26,923 The Company incurred operating lease costs of $ 4.3 million and $ 4.2 million during the nine months ended September 30, 2024 and 2023, respectively. Cash payments related to operating lease liabilities were $ 4.0 million and $ 3.6 million during the nine months ended September 30, 2024 and 2023, respectively. As of September 30, 2024, the weighted average remaining lease term for operating leases was 7.8 years. As of September 30, 2024, the weighted average discount rate for operating leases was 12.0 % . As of September 30, 2024, the Company had an additional operating equipment lease that will commence during 2024 with total lease payments of $ 0.3 million and a weighted average lease term of 5.0 years. As of September 30, 2024, the Company had no additional operating real estate leases that would commence during 2024. Sale and leaseback transaction In January 2024, the Company entered into a sale and leaseback arrangement, pursuant to which the Company sold certain equipment to an equipment leasing company for a one-time cash payment of $ 5.0 million and leased back such equipment from the leasing company. The transaction was considered as a failed sale and leaseback transaction and accordingly, was accounted as a financing transaction. The Company did not recognize a gain on any of the proceeds received from the lessor that contractually constitute payments to acquire the assets subject to these arrangements. Instead, the sale proceeds received were accounted for as finance obligations. The monthly lease rents will be paid over the term of three years and will be allocated between interest expense and principal repayment of the financial liability. In September 2024 , the Company entered into a sale and leaseback arrangement, pursuant to which the Company sold certain equipment to an equipment leasing company for a one-time cash payment of $ 10.0 million and leased back such equipment from the leasing company. The transaction was considered as a failed sale and leaseback transaction and accordingly, was accounted as a financing transaction. The Company did not recognize a gain on any of the proceeds received from the lessor that contractually constitute payments to acquire the assets subject to these arrangements. Instead, the sale proceeds received were accounted for as finance obligations. The monthly lease rents will be paid over the term of three years and will be allocated between interest expense and principal repayment of the financial liability. The outstanding finance obligation balance as of September 30, 2024 was $ 14.1 million

Stock Based Compensation

Stock Based Compensation	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock based compensation	(12) Stock based compensation During the nine months ended September 30, 2024, the Company granted 242,279 restricted common stock units (RSUs) with an aggregate grant date fair value of $ 4.0 million and non-qualified stock options (NSOs) to purchase 569,301 shares of common stock with an aggregate grant date fair value of $ 6.4 millio n to employees under its equity incentive plans. The restricted common stock and NSOs granted to employees will typically vest over a three-year period. During the nine months ended September 30, 2024, the Company also granted 13,264 shares of restricted common stock with a grant date fair value of $ 0.4 million and NSOs to purchase 11,618 shares of common stock with a grant date fair value of $ 0.2 million to its non-employee directors under the 2023 Equity Plan. The RSUs and NSOs granted to non-employee directors will typically vest over a one-year period. Stock-based compensation is included in cost of revenue or operating expenses, as applicable, and consists of the following: Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 (In thousands) (In thousands) Cost of product revenue $ 186 $ 93 $ 545 $ 420 Research and development expenses 188 255 891 510 Sales and marketing expenses 456 378 1,241 1,110 General and administrative expenses 1,800 2,063 7,630 5,726 Total stock-based compensation $ 2,630 $ 2,789 $ 10,307 $ 7,766 The 2023 Equity Plan was approved by stockholders at the Company’s annual meeting of stockholders on June 1, 2023 as the successor to the Company’s 2014 Employee, Director and Consultant Equity Incentive Plan (the 2014 Equity Plan), and no further awards may be made under the 2014 Equity Plan after that date. As of September 30, 2024, 5,012,394 shares of common stock were reserved for issuance upon the exercise or vesting of outstanding stock-based awards granted under the Company’s equity incentive plans. Any cancellations or forfeitures of awards outstanding under the 2023 Equity Plan, the 2014 Equity Plan or the 2001 Equity Incentive Plan, as amended (the 2001 Equity Plan) will result in the shares reserved for issuance pursuant to such awards becoming available for grant under the 2023 Equity Plan. As of September 30, 2024, the Company has either reserved in connection with statutory tax withholdings or issued a total of 6,609,298 shares under the Company’s equity incentive plans. As of September 30, 2024, there were 2,180,098 shares of common stock available for future grant under the 2023 Equity Plan. On March 5, 2024, the Compensation and Leadership Development Committee (the Committee) of the Board of Directors of the Company approved the cancellation of the outstanding, unearned portion of the performance-based restricted shares granted to certain employees pursuant to the 2014 Equity Plan on June 29, 2021 (to Donald R. Young) and June 2, 2022 (to certain other employees). The Committee determined that based on current market conditions, the likelihood of achievement of any of the remaining performance hurdles applicable to the unearned restricted shares is remote, and that the unearned restricted shares therefore had ceased to have incentive value for the grantees. On March 6, 2024, the Company entered into cancellation agreements, pursuant to which the applicable employees agreed to such cancellation. The cancelled unearned restricted shares were added to the number of shares available for awards under the Company’s 2023 Equity Incentive Plan. For financial accounting purposes, the cancellation of the unearned restricted shares resulted in the immediate charge of approximately $ 2.2 million of unamortized stock compensation costs of which $ 2.0 million is included in the general and administrative expenses and $ 0.2 million is included in research and development expenses in the accompanying consolidated statement of operations.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	(13) Net Income (Loss) Per Share The computation of basic and diluted net income (loss) per share consists of the following: Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 (In thousands, except Numerator: Net income (loss) $ ( 12,970 ) $ ( 13,073 ) $ 2,013 $ ( 45,292 ) Denominator: Weighted average shares outstanding, basic 76,261,294 69,317,805 76,402,123 69,243,843 Weighted average shares outstanding, diluted 76,261,294 69,317,805 79,149,193 69,243,843 Net income (loss) per share, basic $ ( 0.17 ) $ ( 0.19 ) $ 0.03 $ ( 0.65 ) Net income (loss) per share, diluted $ ( 0.17 ) $ ( 0.19 ) $ 0.03 $ ( 0.65 ) Potentially dilutive common shares that were excluded from the computation of diluted net (loss) income per share because they were anti-dilutive consist of the following: Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Common stock options 4,453,006 5,462,015 110,900 5,462,015 Restricted common stock units 559,389 568,469 1,957 568,469 Restricted common stock awards 13,264 889,366 824 889,366 Convertible note, if converted — 3,862,221 — 3,862,221 Total 5,025,659 10,782,071 113,681 10,782,071 The potential dilutive shares from common stock options, restricted common stock units, restricted common stock awards, and the convertible note were excluded from the calculation of diluted net income (loss) per share because their effect would have been anti-dilutive for the periods presented. The Company excludes the shares issued in connection with restricted stock awards from the calculation of basic weighted average common shares outstanding until the restrictions lapse.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	(14) Income Taxes The Company incurred net operating loss and income for the three and nine months ended September 30, 2024, respectively. The Company incurred net operating losses and recorded a full valuation allowance against net deferred tax assets for all prior periods. Accordingly, the Company has not recorded a provision for federal or state income taxes for the three and nine months ended September 30, 2024. The Company has provided $ 0.3 million of income tax expense related to its Mexican maquiladora operations for the three months ended September 30, 2024. The Company has provided $ 1.9 million of income tax expense related to its Mexican maquiladora operations for the nine months ended September 30, 2024 .

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2024
Segment Reporting [Abstract]
Segment Information	(15) Segment Information Operating segments are identified as components of an enterprise about which separate, discrete financial information is available for evaluation by the chief operating decision maker in making decisions on how to allocate resources and assess performance. The Company’s chief operating decision maker is the Chief Executive Officer. The Company’s chief operating decision maker reviews consolidated operating results to make decisions about allocating resources and assessing performance for the entire Company. The Company reports two segments: Energy Industrial and Thermal Barrier. The Company evaluates segment performance based on the segment profit (loss) before corporate expenses. Summarized below are the Revenue and Segment Operating Profit for each reporting segment: Revenue Segment Operating Profit (Loss) Revenue Segment Operating Profit (Loss) Three Months Ended Three Months Ended Nine Months Ended Nine Months Ended September 30, September 30, September 30, September 30, 2024 2023 2024 2023 2024 2023 2024 2023 (In thousands) (In thousands) Energy industrial $ 26,776 $ 27,912 $ 10,733 $ 5,825 $ 92,781 $ 97,311 $ 37,750 $ 24,246 Thermal barrier 90,564 32,843 38,310 7,985 236,830 57,188 98,014 3,057 Total $ 117,340 $ 60,755 $ 49,043 $ 13,810 $ 329,611 $ 154,499 $ 135,764 $ 27,303 Corporate expenses 31,643 28,444 95,942 77,889 Operating profit (loss) 17,400 ( 14,634 ) 39,822 ( 50,586 ) Other (expense) income, net ( 30,103 ) 1,561 ( 35,920 ) 5,294 Income tax expense ( 267 ) - ( 1,889 ) - Net income (loss) $ ( 12,970 ) $ ( 13,073 ) $ 2,013 $ ( 45,292 ) Total Assets September 30, December 31, 2024 2023 (In thousands) Energy industrial $ 97,575 $ 93,168 Thermal barrier 172,582 118,565 Total assets of reportable segments 270,157 211,733 Construction in progress 344,041 314,678 All other corporate assets 168,389 176,637 $ 782,587 $ 703,048

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2024
Subsequent Events [Abstract]
Subsequent Events	(16) Subsequent Events The Company has evaluated subsequent events through November 7, 2024, the date of issuance of the consolidated financial statements for the three and nine months ended September 30, 2024. In October 2024, the Company entered into an underwriting agreement (the Underwriting Agreement) with Goldman Sachs & Co. LLC and Morgan Stanley & Co. LLC (collectively, the Underwriters), pursuant to which the Company issued and sold an aggregate of 4,887,500 shares of the Company’s common stock, which included 637,500 shares pursuant to the Underwriters’ option to purchase additional shares of common stock of the Company, to the Underwriters in a registered underwritten offering (the “Offering”). The price to the public in the Offering was $ 20.00 per share. The net proceeds to the Company from the Offering were approximately $ 93.2 million, after deducting underwriting discounts and commissions and estimated offering expenses payable by the Company.

Description of Business and B_2

Description of Business and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Nature of Business	Nature of Business Aspen Aerogels, Inc. (the Company) is an aerogel technology company that has introduced a line of aerogel thermal barriers for use in battery packs in the electric vehicle market. In addition, the Company designs, develops and manufactures innovative, high-performance aerogel insulation used in the energy industrial and sustainable insulation materials markets. The Company is also developing applications for its aerogel technology in the battery materials and a number of other high-potential markets. The Company maintains its corporate offices in Northborough, Massachusetts. The Company has three wholly owned subsidiaries: Aspen Aerogels Rhode Island, LLC (Aspen RI), Aspen Aerogels Germany, GmbH and Aspen Aerogels Georgia, LLC (Aspen Georgia). Additionally, we engaged Prodensa Servicios de Consultora to establish OPE Manufacturer Mexico S de RL de CV, a maquiladora located in Mexico (OPE), which manufactures thermal barrier PyroThin products and operates an automated fabrication facility for PyroThin. OPE is currently owned by Prodensa, which charges a management fee. There is an option for OPE to be purchased by the Company after a period of 18 months. During the period between inception and the exercise of the purchase option, OPE operations are consolidated within the Company financial statements.
Liquidity	Liquidity During the nine months ended September 30, 2024, the Company earned net income of $ 2.0 million, provided $ 9.9 million of cash in operations and used $ 71.5 million of cash for capital expenditures. The Company had unrestricted cash and cash equivalents of $ 113.5 million as of September 30, 2024. In January 2024 and September 2024 , the Company entered i nto sale and leaseback arrangements, pursuant to which the Company sold certain equipment to an equipment leasing company for one-time cash payments of $ 5.0 and $ 10.0 million, respectively, and leased back such equipment from the leasing company. The associated monthly lease rents will be paid over the lease term of three years . On August 19, 2024, the Company and Aspen RI (each, a Borrower and collectively, the Borrowers) entered into a Credit, Security and Guaranty Agreement (the Credit Agreement and the facilities provided thereunder, collectively, the MidCap Loan Facility) with MidCap Funding IV Trust, as agent (the Agent), MidCap Financial Trust, as term loan servicer, the financial institutions or other entities from time to time party thereto as lenders (the Lenders), and the other parties party thereto as additional guarantors and/or borrowers from time to time, for a term loan facility in an aggregate principal amount of $ 125.0 million and an asset-based revolving credit facility in an aggregate principal amount not to exceed the lesser of $ 100.0 million or the borrowing base. At closing the Company drew $ 125.0 million from the term loan facility and $ 43.0 million from the revolving loan facility. The proceeds of the borrowings, net of fees and costs, were used for repurchasing of the 2022 Convertible Notes (as defined below) for $ 150.0 million and for general corporate purposes. The amount available to the Company at September 30, 2024 under the revolving loan facility was $ 25.7 million. The Company is increasing investment in the research and development of next-generation aerogel products and manufacturing process technologies. In addition, the Company has developed a number of promising aerogel products and technologies for the electric vehicle market. The Company believes that the commercial potential for the Company’s products and technology in the electric vehicle market is significant. Accordingly, the Company is hiring additional personnel, incurring additional operating expenses, incurring significant capital expenditures to expand aerogel manufacturing capacity and automated thermal barrier fabrication operations, and enhancing research and development resources, among other items. The Company expects its existing cash balance and the amount anticipated to be available under the existing revolving loan facility will be sufficient to support current operating requirements, current research and development activities and the initial capital expenditures required to support the evolving commercial opportunity in the electric vehicle market and other strategic business initiatives. However, the Company plans to supplement its cash balance and available credit with equity financings, debt financings, equipment leasing, sale and leaseback transactions, c ustomer prepayments, or government grant and loan programs to provide the additional capital necessary to purchase the capital equipment, construct the new facilities, establish the operations and complete the aerogel capacity expansions required to support these evolving commercial opportunities and strategic business initiatives.
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying unaudited interim consolidated financial statements include the accounts of the Company and have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Certain information and disclosures normally included in the consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this Quarterly Report on Form 10-Q should be read in conjunction with the audited consolidated financial statements and accompanying notes in our Annual Report on Form 10-K for the year ended December 31, 2023 (the Annual Report), filed with the U.S. Securities and Exchange Commission on March 7, 2024. In the opinion of the Company’s management, the unaudited interim consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and include all adjustments that are of a normal recurring nature and necessary for the fair statement of the Company’s financial position as of September 30, 2024 and the results of its operations and stockholders’ equity for the three and nine months ended September 30, 2024 and 2023 and the cash flows for the nine-month periods then ended. The Company has evaluated subsequent events through the date of this filing. The Company’s results of operations for the three and nine months ended September 30, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024 or any other period.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements requires the Company to make a number of estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant items subject to such estimates and assumptions include allowances for doubtful accounts, sales returns and allowances, product warranty costs, inventory valuation, the carrying amount of property and equipment, right-of-use assets, lease liabilities, stock-based compensation, and deferred income taxes. The Company evaluates its estimates and assumptions on an on-going basis using historical experience and other factors, including current economic conditions, which are believed to be reasonable under the circumstances. Management adjusts such estimates and assumptions when facts and circumstances warrant. Illiquid credit markets, volatile equity markets and declines in business investment can increase the uncertainty inherent in such estimates and assumptions. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Changes in these estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods.
Restricted Cash	Restricted Cash As of September 30, 2024, the Company had $ 0.4 million of restricted cash to support its outstanding letters of credit.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially expose the Company to concentrations of credit risk, consist principally of accounts receivable. The Company’s customers are primarily insulation distributors, insulation contractors, insulation fabricators and select energy and automotive end-users located throughout the world. The Company performs ongoing credit evaluations of its customers’ financial condition and generally requires no collateral to secure accounts receivable. The Company maintains an allowance for doubtful accounts based on its assessment of the collectability of accounts receivable. The Company reviews the allowance for doubtful accounts quarterly. During the nine months ended September 30, 2024, the Company recorded an increase for estimated customer uncollectible accounts receivable of $ 0.1 million. During the nine months ended September 30, 2023, the Company recorded a reduction for estimated customer uncollectible accounts receivable of less than $ 0.1 million. For the nine months ended September 30, 2024 and 2023 , two customers represented 74 % and 50 % of total revenue, respectively. At September 30, 2024 , the Company had one customer which accounted for 79 % of accounts receivable. At December 31, 2023, the Company had two customers which accounted for 60 % and 6 % of accounts receivable, respectively.
Revenue Recognition	Revenue Recognition The Company recognizes revenue in accordance with Accounting Standards Codification 606, Revenue from Contracts with Customers (ASC 606). See note 3 for further details.
Sale and Leaseback Accounting	Sale and Leaseback Accounting The Company has entered into sale and leaseback transactions for certain equipment within its plants. Due to the Company not meeting criteria to account for the transfer of the assets as a sale, sale accounting is precluded. Accordingly, the Company uses the financing method to account for these transactions. Under the financing method of accounting for a sale and leaseback, the Company does not derecognize the assets and does not recognize as revenue any of the sale proceeds received from the lessor that contractually constitutes payment to acquire the assets subject to these arrangements. Instead, the sale proceeds received are accounted for as finance obligations and leaseback payments made by the Company are allocated between interest expense and a reduction to the finance obligation. Interest on the finance obligation is calculated using the Company’s incremental borrowing rate at the inception of the arrangement on the outstanding finance obligation.
Recently Issued Accounting Standards	Recently Issued Accounting Standards From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board or other standard setting bodies. Recently issued standards typically do not require adoption until a future effective date. Prior to their effective date, the Company evaluates the pronouncements to determine the potential effects of adoption to its consolidated financial statements. Standards Implemented Since December 31, 2023 The Company has not implemented any accounting standards that had a material impact on its consolidated financial statements during the nine months ended September 30, 2024. Standards to be Implemented In November 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) 2023-07 Segment Reporting (Topic 280) Improvements to Reportable Segment Disclosures to enhance disclosures about significant segment expenses. This ASU is effective for the Company’s fiscal year 2024 and interim periods in fiscal year 2025. Early adoption is permitted. The Company is currently evaluating segment expense disclosures related to its annual report for fiscal year 2024. In December 2023, the FASB issued ASU 2023-09 Income Taxes (Topic 740) Improvements to Income Tax Disclosures that requires disclosure of disaggregated income taxes paid, prescribes standard categories for the components of the effective tax rate reconciliation, and modifies other income tax-related disclosures. This ASU is effective for the Company’s fiscal year 2025. Early adoption is permitted. The Company is currently evaluating income tax disclosures related to its annual report for fiscal year 2025. Although there are several other new accounting pronouncements issued by the FASB, the Company does not believe any of these accounting pronouncements had or will have a material impact on its Consolidated Financial Statements. The Company believes that the impact of recently issued accounting standards that are not yet effective will not have a material impact on its consolidated financial statements.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Summary of Revenue Disaggregated by Geographical Region and Source of Revenue	In the following tables, revenue is disaggregated by primary geographical region and source of revenue: Three Months Ended September 30, 2024 2023 U.S. International Total U.S. International Total (In thousands) Geographical region Asia $ — $ 4,439 $ 4,439 $ — $ 5,801 $ 5,801 Canada — 6,125 6,125 — 633 633 Europe — 8,455 8,455 — 11,361 11,361 Latin America — 25,012 25,012 — 1,176 1,176 U.S. 73,309 — 73,309 41,784 — 41,784 Total revenue $ 73,309 $ 44,031 $ 117,340 $ 41,784 $ 18,971 $ 60,755 Source of revenue Energy industrial $ 13,679 $ 13,097 $ 26,776 $ 12,249 $ 15,663 $ 27,912 Thermal barrier 59,630 30,934 90,564 29,535 3,308 32,843 Total revenue $ 73,309 $ 44,031 $ 117,340 $ 41,784 $ 18,971 $ 60,755 Nine Months Ended September 30, 2024 2023 U.S. International Total U.S. International Total (In thousands) Geographical region Asia $ — $ 18,071 $ 18,071 $ — $ 27,522 $ 27,522 Canada — 11,599 11,599 — 1,519 1,519 Europe — 26,926 26,926 — 26,735 26,735 Latin America — 74,614 74,614 — 5,065 5,065 U.S. 198,401 — 198,401 93,658 — 93,658 Total revenue $ 198,401 $ 131,210 $ 329,611 $ 93,658 $ 60,841 $ 154,499 Source of revenue Energy industrial $ 41,853 $ 50,928 $ 92,781 $ 43,994 $ 53,317 $ 97,311 Thermal barrier 156,548 80,282 236,830 49,664 7,524 57,188 Total revenue $ 198,401 $ 131,210 $ 329,611 $ 93,658 $ 60,841 $ 154,499
Summary of Changes in Contract Assets and Contract Liabilities	The following table presents changes in the Company’s contract liabilities during the nine months ended September 30, 2024: Balance at Additions Deductions Balance at (In thousands) Contract liabilities Deferred revenue Energy industrial $ 2,316 $ 5,686 $ ( 5,597 ) $ 2,405 Total contract liabilities $ 2,316 $ 5,686 $ ( 5,597 ) $ 2,405

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2024
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consist of the following: September 30, December 31, 2024 2023 (In thousands) Raw materials $ 16,054 $ 24,735 Work in process 12,226 7,936 Finished goods 19,150 6,518 Total $ 47,430 $ 39,189

Property, Plant and Equipment_2

Property, Plant and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2024
Property, Plant and Equipment [Abstract]
Summary of Property, Plant and Equipment	Property, plant and equipment consist of the following: September 30, December 31, Useful 2024 2023 life (In thousands) Construction in progress $ 344,063 $ 314,695 — Buildings 26,914 25,473 30 years Machinery and equipment 197,657 185,339 3 - 10 years Computer equipment and software 9,703 9,495 3 years Leasehold improvements 24,570 23,514 Shorter of useful life or lease term Total 602,907 558,516 Accumulated depreciation ( 151,338 ) ( 141,289 ) Property, plant and equipment, net $ 451,569 $ 417,227

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2024
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of the following: September 30, December 31, 2024 2023 (In thousands) Employee compensation $ 15,003 $ 16,876 Other accrued expenses 11,528 5,935 Total $ 26,531 $ 22,811

Convertible Note - Related Pa_2

Convertible Note - Related Party (Tables)	9 Months Ended
	Sep. 30, 2024
Convertible Notes [Abstract]
Summary of Convertible Notes	In accordance with ASU 2020-06, the 2022 Convertible Note is accounted for as a single unit of account and consists of the following: September 30, December 31, 2024 2023 (In thousands) Convertible note, principal $ — $ 100,000 Payment in-kind — 18,318 Discount on convertible note, net of accumulated amortization — ( 3,209 ) Debt issuance costs, net of accumulated amortization — ( 117 ) Convertible note $ — $ 114,992

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Schedule of MidCap Debt	MidCap debt consists of the following: September 30, 2024 (In thousands) Term loan 125,000 Exit fee 85 Term loan issuance costs ( 5,161 ) Total debt 119,924 Current portion 26,250 Long term portion 93,674

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Summary of Capitalized Implementation Costs are Classified on the Consolidated Balance Sheets	The capitalized implementation costs are classified on the consolidated balance sheets as follows: September 30, December 31, 2024 2023 (In thousands) Cloud computing costs included in other current assets $ 780 $ 420 Cloud computing costs included in other assets 2,691 1,590 Amortization of cloud computing costs ( 578 ) ( 662 ) Total capitalized cloud computing costs $ 2,893 $ 1,348

Leases and sale and leaseback (

Leases and sale and leaseback (Tables)	9 Months Ended
	Sep. 30, 2024
Leases [Abstract]
Summary of Maturities of Operating Lease Liabilities	Maturities of operating lease liabilities as of September 30, 2024 are as follows: Year Operating (In thousands) 2024 (excluding the nine months ended September 30, 2024) $ 1,523 2025 6,110 2026 5,598 2027 4,695 2028 4,599 Thereafter 19,338 Total lease payments 41,863 Less imputed interest ( 14,940 ) Total lease liabilities $ 26,923

Stock Based Compensation (Table

Stock Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Summary of Stock Based Compensation Included in Cost of Revenue or Operating Expenses	Stock-based compensation is included in cost of revenue or operating expenses, as applicable, and consists of the following: Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 (In thousands) (In thousands) Cost of product revenue $ 186 $ 93 $ 545 $ 420 Research and development expenses 188 255 891 510 Sales and marketing expenses 456 378 1,241 1,110 General and administrative expenses 1,800 2,063 7,630 5,726 Total stock-based compensation $ 2,630 $ 2,789 $ 10,307 $ 7,766

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Income (Loss) Per Share	The computation of basic and diluted net income (loss) per share consists of the following: Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 (In thousands, except Numerator: Net income (loss) $ ( 12,970 ) $ ( 13,073 ) $ 2,013 $ ( 45,292 ) Denominator: Weighted average shares outstanding, basic 76,261,294 69,317,805 76,402,123 69,243,843 Weighted average shares outstanding, diluted 76,261,294 69,317,805 79,149,193 69,243,843 Net income (loss) per share, basic $ ( 0.17 ) $ ( 0.19 ) $ 0.03 $ ( 0.65 ) Net income (loss) per share, diluted $ ( 0.17 ) $ ( 0.19 ) $ 0.03 $ ( 0.65 )
Summary of Potentially Dilutive Common Shares Excluded from Computation of Diluted Net Loss Per Share	Potentially dilutive common shares that were excluded from the computation of diluted net (loss) income per share because they were anti-dilutive consist of the following: Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Common stock options 4,453,006 5,462,015 110,900 5,462,015 Restricted common stock units 559,389 568,469 1,957 568,469 Restricted common stock awards 13,264 889,366 824 889,366 Convertible note, if converted — 3,862,221 — 3,862,221 Total 5,025,659 10,782,071 113,681 10,782,071

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2024
Segment Reporting [Abstract]
Summary of Revenue and Segment Operating Profit	Summarized below are the Revenue and Segment Operating Profit for each reporting segment: Revenue Segment Operating Profit (Loss) Revenue Segment Operating Profit (Loss) Three Months Ended Three Months Ended Nine Months Ended Nine Months Ended September 30, September 30, September 30, September 30, 2024 2023 2024 2023 2024 2023 2024 2023 (In thousands) (In thousands) Energy industrial $ 26,776 $ 27,912 $ 10,733 $ 5,825 $ 92,781 $ 97,311 $ 37,750 $ 24,246 Thermal barrier 90,564 32,843 38,310 7,985 236,830 57,188 98,014 3,057 Total $ 117,340 $ 60,755 $ 49,043 $ 13,810 $ 329,611 $ 154,499 $ 135,764 $ 27,303 Corporate expenses 31,643 28,444 95,942 77,889 Operating profit (loss) 17,400 ( 14,634 ) 39,822 ( 50,586 ) Other (expense) income, net ( 30,103 ) 1,561 ( 35,920 ) 5,294 Income tax expense ( 267 ) - ( 1,889 ) - Net income (loss) $ ( 12,970 ) $ ( 13,073 ) $ 2,013 $ ( 45,292 ) Total Assets September 30, December 31, 2024 2023 (In thousands) Energy industrial $ 97,575 $ 93,168 Thermal barrier 172,582 118,565 Total assets of reportable segments 270,157 211,733 Construction in progress 344,041 314,678 All other corporate assets 168,389 176,637 $ 782,587 $ 703,048

Description of Business and B_3

Description of Business and Basis of Presentation - Additional Information (Detail)

1 Months Ended

3 Months Ended

9 Months Ended

Aug. 19, 2024 USD ($)

Sep. 30, 2024 USD ($)

Jan. 31, 2024 USD ($)

Sep. 30, 2024 USD ($)

Jun. 30, 2024 USD ($)

Mar. 31, 2024 USD ($)

Sep. 30, 2023 USD ($)

Jun. 30, 2023 USD ($)

Mar. 31, 2023 USD ($)

Sep. 30, 2024 USD ($) Subsidiary

Sep. 30, 2023 USD ($)

Dec. 31, 2023 USD ($)

Basis Of Presentation [Line Items]

Number of Subsidiaries | Subsidiary

3

Period of option to purchase

18 months

Net income earned

$ (12,970,000)

$ 16,818,000

$ (1,835,000)

$ (13,073,000)

$ (15,423,000)

$ (16,796,000)

$ 2,013,000

$ (45,292,000)

Cash used in operations

(9,865,000)

$ 39,833,000

Cash for capital expenditures

$ 71,500,000

Sale and leaseback arrangement date

September 2024

January 2024

September 2024

Sale and leaseback equipment value

$ 10,000,000

$ 5,000,000

10,000,000

$ 10,000,000

Sale and leaseback rent payment term

3 years

3 years

Unrestricted cash and cash equivalents

$ 113,489,000

113,489,000

113,489,000

$ 139,723,000

2022 Convertible Notes [Member] | Credit, Security and Guaranty Agreement with MidCap Financial [Member]

Basis Of Presentation [Line Items]

Proceeds of the borrowings

$ 150,000,000

Revolving Credit Facility [Member] | Credit, Security and Guaranty Agreement with MidCap Financial [Member]

Basis Of Presentation [Line Items]

Line of credit facility amount withdrawn

43,000,000

Available borrowing capacity

$ 25,700,000

$ 25,700,000

$ 25,700,000

Term Loan Facility [Member] | Credit, Security and Guaranty Agreement with MidCap Financial [Member]

Basis Of Presentation [Line Items]

Aggregate principal amount

125,000,000

Line of credit facility amount withdrawn

125,000,000

Asset Based Revolving Credit Facility [Member] | Maximum [Member] | Credit, Security and Guaranty Agreement with MidCap Financial [Member]

Basis Of Presentation [Line Items]

Aggregate principal amount

$ 100,000,000

Significant Accounting Polici_2

Significant Accounting Policies - Additional Information (Detail) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2024 USD ($) Customer	Sep. 30, 2023 USD ($) Customer	Dec. 31, 2023 USD ($) Customer
Summary Of Significant Accounting Policies [Line Items]
Reduction/Charge for uncollectible accounts receivable | $	$ 139	$ (89)
Restricted cash to support our outstanding letters of credit | $	$ 394		$ 248
Revenue [Member] | Customer Concentration Risk [Memeber] | Two Customers [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of customers | Customer	2	2
Revenue [Member] | Customer Concentration Risk [Memeber] | Customer A [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	74%	74%
Revenue [Member] | Customer Concentration Risk [Memeber] | Customer B [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	50%
Accounts Receivable [Member] | Customer Concentration Risk [Memeber] | Two Customers [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of customers | Customer			2
Accounts Receivable [Member] | Customer Concentration Risk [Memeber] | One Customer [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	79%
Number of customers | Customer	1
Accounts Receivable [Member] | Customer Concentration Risk [Memeber] | Customer A [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage			60%
Accounts Receivable [Member] | Customer Concentration Risk [Memeber] | Customer B [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage			6%
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Reduction/Charge for uncollectible accounts receivable | $		$ 100

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Additional Information (Details) $ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($) Agreement	Dec. 31, 2023 USD ($)
Revenue Recognition [Line Items]
Deferred revenue, revenue recognized	$ 2.3
Maximum [Member]
Revenue Recognition [Line Items]
Sales return reserves	$ 0.7	$ 0.2
Energy Industrial [Member]
Revenue Recognition [Line Items]
Number of performance obligations | Agreement	1

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Summary of Revenue Disaggregated by Geographical Region and Source of Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation Of Revenue [Line Items]
Total revenue	$ 117,340	$ 60,755	$ 329,611	$ 154,499
Energy Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	26,776	27,912	92,781	97,311
Thermal Barrier [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	90,564	32,843	236,830	57,188
Asia [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	4,439	5,801	18,071	27,522
Canada [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	6,125	633	11,599	1,519
Europe [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	8,455	11,361	26,926	26,735
Latin America [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	25,012	1,176	74,614	5,065
U.S. [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	73,309	41,784	198,401	93,658
U.S. [Member] | Energy Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	13,679	12,249	41,853	43,994
U.S. [Member] | Thermal Barrier [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	59,630	29,535	156,548	49,664
International [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	44,031	18,971	131,210	60,841
International [Member] | Energy Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	13,097	15,663	50,928	53,317
International [Member] | Thermal Barrier [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	$ 30,934	$ 3,308	$ 80,282	$ 7,524

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Summary of Changes in Contract Assets and Contract Liabilities (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($)
Contract liabilities
Beginning Balance	$ 2,316
Additions	5,686
Deductions	(5,597)
Ending Balance	2,405
Energy Industrial [Member]
Contract liabilities
Beginning Balance	2,316
Additions	5,686
Deductions	(5,597)
Ending Balance	$ 2,405

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Raw materials	$ 16,054	$ 24,735
Work in process	12,226	7,936
Finished goods	19,150	6,518
Total	$ 47,430	$ 39,189

Property, Plant and Equipment_3

Property, Plant and Equipment, Net - Summary of Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 602,907	$ 558,516
Accumulated depreciation	(151,338)	(141,289)
Property, plant and equipment, net	451,569	417,227
Construction in Progress [Member]
Property Plant and Equipment [Line Items]
Property, plant and equipment, gross	344,063	314,695
Buildings [Member]
Property Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 26,914	25,473
Property, plant and equipment, Useful life	30 years
Machinery and Equipment [Member]
Property Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 197,657	185,339
Machinery and Equipment [Member] | Minimum [Member]
Property Plant and Equipment [Line Items]
Property, plant and equipment, Useful life	3 years
Machinery and Equipment [Member] | Maximum [Member]
Property Plant and Equipment [Line Items]
Property, plant and equipment, Useful life	10 years
Computer Equipment and Software [Member]
Property Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 9,703	9,495
Property, plant and equipment, Useful life	3 years
Leasehold Improvements [Member]
Property Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 24,570	$ 23,514
Property, Plant, and Equipment, Useful Life, Term, Description [Extensible Enumeration]	us-gaap:UsefulLifeShorterOfTermOfLeaseOrAssetUtilityMember

Property, Plant and Equipment_4

Property, Plant and Equipment, Net - Additional Information (Detail) - USD ($)	9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Property Plant and Equipment [Line Items]
Depreciation	$ 17,093,000	$ 10,757,000
Impairment charges of property, plant and equipment	6,810,000	0
Impairment of equipment under development	2,702,000
Capitalized interest		6,084,000
Cost of Revenue [Member]
Property Plant and Equipment [Line Items]
Impairment charges of property, plant and equipment	4,100,000
Georgia [Member]
Property Plant and Equipment [Line Items]
Pre-construction costs	325,100,000		$ 288,500,000
Capitalized interest	0	$ 8,800,000
Georgia [Member] | Construction in Progress [Member]
Property Plant and Equipment [Line Items]
Capitalized interest	$ 8,800,000

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Accrued Liabilities, Current [Abstract]
Employee compensation	$ 15,003	$ 16,876
Other accrued expenses	11,528	5,935
Total	$ 26,531	$ 22,811

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Accounts Payable	$ 42,280		$ 51,094
Koch Disruptive Technologies LLC [Member]
Related Party Transaction [Line Items]
Accounts Payable			$ 2,800
Accounts Paid		$ 1,200
2022 Convertible Notes [Member]
Related Party Transaction [Line Items]
Accrued interest	$ 7,100
2022 Convertible Notes [Member] | Wood River Capital, LLC [Member]
Related Party Transaction [Line Items]
Issuance and sale of convertible notes				$ 100,000

Convertible Note - Related Pa_3

Convertible Note - Related Party - Additional Information (Detail) - USD ($) $ in Thousands	Aug. 19, 2024	Feb. 15, 2022	Sep. 30, 2024	Dec. 31, 2023
Convertible Notes [Line Items]
Issuance and sale of convertible notes				$ 100,000
Debt issuance costs, net of accumulated amortization			$ 5,161	117
2022 Convertible Notes [Member]
Convertible Notes [Line Items]
Aggregate capitalized principal amount repurchased	$ 123,900
Redemption price less capitalized principal amount and accrued interest	24,600
Purchase price	$ 150,100
Convertible notes, fair value				$ 118,200
Convertible debt carried at amortized cost			115,000
Accrued interest			$ 7,100
2022 Convertible Notes [Member] | Wood River Capital, LLC [Member]
Convertible Notes [Line Items]
Issuance and sale of convertible notes		$ 100,000
Existing maturity date		Feb. 18, 2027

Convertible Note - Related Pa_4

Convertible Note - Related Party - Summary of Convertible Notes (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Convertible Notes [Abstract]
Convertible note, principal		$ 100,000
Payment in-kind		18,318
Discount on convertible note, net of accumulated amortization		(3,209)
Debt issuance costs, net of accumulated amortization	$ (5,161)	(117)
Convertible note		$ 114,992

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($)		3 Months Ended	9 Months Ended
	Aug. 19, 2024	Sep. 30, 2024	Sep. 30, 2024
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving line of credit outstanding amount		$ 42,700,000	$ 42,700,000
Mid Cap Loan Facility [Member] | Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Aggregate principal amount	$ 125,000,000
Exit fee amount	$ 2,500,000
Mid Cap Loan Facility [Member] | Term Loan Facility [Member] | SOFR [Member]
Line of Credit Facility [Line Items]
Term loan facility interest rate	4.50%
Mid Cap Loan Facility [Member] | Term Loan Facility [Member] | SOFR Floor [Member]
Line of Credit Facility [Line Items]
Term loan facility interest rate	4.50%
Mid Cap Loan Facility [Member] | Term Loan Facility [Member] | SOFR Cap [Member]
Line of Credit Facility [Line Items]
Term loan facility interest rate	7.50%
Mid Cap Loan Facility [Member] | Asset Based Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Minimum borrowing capacity as percentage of available borrowing capacity	30%
Percentage of unused portion of facility, monthly fee	0.30%
Debt instrument covenant description			The Credit Agreement includes representations and warranties, affirmative covenants (including reporting obligations), negative covenants and events of default that are usual and customary for facilities of this type, in each case, subject to certain permitted exceptions as set forth therein. The Credit Agreement includes financial covenants for the benefit of the Lenders, including (i) a covenant to maintain Liquidity (as defined therein) equal to or greater than $75 million at all times and (ii) a covenant to maintain EBITDA (as defined therein) equal to or greater than the specified applicable amount set forth in the Credit Agreement, tested quarterly with the first test set at $45 million commencing with the fiscal quarter ended September 30, 2024.
Debt instrument covenant liquidity	$ 100,000,000
Mid Cap Loan Facility [Member] | Asset Based Revolving Credit Facility [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Debt instrument EBITDA covenant liquidity		45,000,000
Debt instrument covenant liquidity		$ 75,000,000
Mid Cap Loan Facility [Member] | Asset Based Revolving Credit Facility [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Aggregate principal amount	$ 100,000,000
Mid Cap Loan Facility [Member] | Asset Based Revolving Credit Facility [Member] | SOFR [Member]
Line of Credit Facility [Line Items]
Term loan facility interest rate	4.60%
Mid Cap Loan Facility [Member] | Asset Based Revolving Credit Facility [Member] | SOFR Floor [Member]
Line of Credit Facility [Line Items]
Term loan facility interest rate	2.50%
Mid Cap Loan Facility [Member] | First Year After the Closing Date [Member] | Asset Based Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Prepayment of loan percentage	3%
Mid Cap Loan Facility [Member] | Second Year After the Closing Date [Member] | Asset Based Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Prepayment of loan percentage	2%
Mid Cap Loan Facility [Member] | Thereafter [Member] | Asset Based Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Prepayment of loan percentage	1%
Mid Cap Loan Facility [Member] | Accounts of Borrowers [Member] | Asset Based Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility percentage	85%
Mid Cap Loan Facility [Member] | Inventory of Borrowers [Member] | Asset Based Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility percentage	85%
Mid Cap Loan Facility [Member] | Nolv [Member] | Asset Based Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility percentage	85%

Debt - Schedule of Mid Cap Debt

Debt - Schedule of Mid Cap Debt (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Exit fee	$ 85
Term loan issuance costs	(5,161)	$ (117)
Total debt	119,924
Current portion	26,250
Long term portion	93,674
Term Loan [Member]
Debt Instrument [Line Items]
Term loan	$ 125,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2024	Sep. 30, 2023
Commitments And Contingencies [Line Items]
Charge recognized in cost of revenues for inventory obsolescence and impairment of equipment			$ 6.8
Contractual recoverable, net			$ 1.9
Reimbursement received from cost of revenues for inventory obsolescence and impairment of equipment		$ 4.2
Inventory obsolescence	$ 2.2
Purchase commitments				$ 240
Capital commitments				$ 175.3
Purchase commitments spent over period				3 years
Thermal Barrier [Member]
Commitments And Contingencies [Line Items]
Warranty reserves				$ 1.1	$ 0.2
Energy Industrial [Member]
Commitments And Contingencies [Line Items]
Standard product warranty period				1 year
Cloud Computing Agreement [Member] | Payroll Services Agreement [Member]
Commitments And Contingencies [Line Items]
Adjusted amortization period	5 years			5 years
Thermal Barrier Contracts [Member] | General Motors
Commitments And Contingencies [Line Items]
Purchase commitment, description				While General Motors has agreed to purchase its requirement for Barriers from the Company for locations to be designated from time to time by General Motors, it has no obligation to purchase any minimum quantity of Barriers under the Contracts.

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Capitalized Implementation Costs are Classified on the Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Cloud computing costs included in other current assets	$ 780	$ 420
Cloud computing costs included in other assets	2,691	1,590
Amortization of cloud computing costs	(578)	(662)
Total capitalized cloud computing costs	$ 2,893	$ 1,348

Leases and sale and leaseback -

Leases and sale and leaseback - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended		9 Months Ended
	Sep. 30, 2024	Jan. 31, 2024	Sep. 30, 2024	Sep. 30, 2023
Lessee Lease Description [Line Items]
Operating lease expiry year			2034
Operating lease cost			$ 4.3	$ 4.2
Cash payments related to operating lease liabilities			$ 4	$ 3.6
Operating lease, weighted average remaining lease term	7 years 9 months 18 days		7 years 9 months 18 days
Operating lease, weighted average discount rate, percent	12%		12%
Sale and leaseback equipment value	$ 10	$ 5	$ 10
Sale and leaseback arrangement date	September 2024	January 2024	September 2024
Operating real estate lease liability payments not yet commenced			$ 0.3
Operating real estate lease liability payments not yet commenced, term			5 years
Sale and leaseback transaction one-time cash payment		$ 5
Outstanding finance obligation	$ 14.1		$ 14.1
Sale and leaseback rent payment term	3 years	3 years

Leases and sale and leaseback_2

Leases and sale and leaseback - Summary of Maturities of Operating Lease Liabilities (Detail) $ in Thousands	Sep. 30, 2024 USD ($)
Leases [Abstract]
2024 (excluding the nine months ended September 30, 2024)	$ 1,523
2025	6,110
2026	5,598
2027	4,695
2028	4,599
Thereafter	19,338
Total lease payments	41,863
Less imputed interest	(14,940)
Total lease liabilities	$ 26,923

Stock Based Compensation - Addi

Stock Based Compensation - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($) shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unamortized stock compensation costs | $	$ 2.2
Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares reserved for issuance | shares	5,012,394
Number of shares either issued or reserved in connection with statutory tax withholdings | shares	6,609,298
Equity Incentive Plan [Member] | Restricted Stock Units [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based awards granted to purchase common stock | shares	242,279
Stock-based awards granted to purchase common stock, grant date fair value | $	$ 4
Stock-based award vesting period	3 years
Equity Incentive Plan [Member] | Non-Qualified Stock Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based awards granted to purchase common stock | shares	569,301
Stock-based awards granted to purchase common stock, grant date fair value | $	$ 6.4
Stock-based award vesting period	3 years
2023 Equity Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Increased number of shares available for grant | shares	2,180,098
General and Administrative Expenses [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unamortized stock compensation costs | $	$ 2
Research and Development Expenses [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unamortized stock compensation costs | $	$ 0.2
Non-Employee Directors [Member] | 2023 Equity Plan [Member] | Restricted Stock Units [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based awards granted to purchase common stock | shares	13,264
Stock-based awards granted to purchase common stock, grant date fair value | $	$ 0.4
Stock-based award vesting period	1 year
Non-Employee Directors [Member] | 2023 Equity Plan [Member] | Non-Qualified Stock Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based awards granted to purchase common stock | shares	11,618
Stock-based awards granted to purchase common stock, grant date fair value | $	$ 0.2
Stock-based award vesting period	1 year

Stock Based Compensation - Summ

Stock Based Compensation - Summary of Stock Based Compensation Included in Cost of Revenue or Operating Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 2,630	$ 2,789	$ 10,307	$ 7,766
Cost of Product Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	186	93	545	420
Research and Development Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	188	255	891	510
Sales and Marketing Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	456	378	1,241	1,110
General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 1,800	$ 2,063	$ 7,630	$ 5,726

Net Income (Loss) Per Share - C

Net Income (Loss) Per Share - Computation of Basic and Diluted Net Income (Loss) Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator:
Net Income (Loss)	$ (12,970)	$ 16,818	$ (1,835)	$ (13,073)	$ (15,423)	$ (16,796)	$ 2,013	$ (45,292)
Denominator:
Weighted average shares outstanding, basic	76,261,294			69,317,805			76,402,123	69,243,843
Weighted average shares outstanding, diluted	76,261,294			69,317,805			79,149,193	69,243,843
Net income (loss) per share, basic	$ (0.17)			$ (0.19)			$ 0.03	$ (0.65)
Net income (loss) per share, diluted	$ (0.17)			$ (0.19)			$ 0.03	$ (0.65)

Net Income (Loss) Per Share - S

Net Income (Loss) Per Share - Summary of Potentially Dilutive Common Shares Excluded from Computation of Diluted Net Loss Per Share (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive Securities	5,025,659	10,782,071	113,681	10,782,071
Common Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive Securities	4,453,006	5,462,015	110,900	5,462,015
Restricted Common Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive Securities	559,389	568,469	1,957	568,469
Restricted Common Stock Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive Securities	13,264	889,366	824	889,366
Convertible Note If Converted [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive Securities	0	3,862,221	0	3,862,221

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2024
Income Taxes [Line Items]
Income tax expense	$ 267	$ 1,889
Mexican Maquiladora Operations [Member]
Income Taxes [Line Items]
Income tax expense	$ 300	$ 1,900

Segment Information - Additiona

Segment Information - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2024 Segment
Segment Reporting [Abstract]
Number of reportable segments	2

Segment Information - Summary o

Segment Information - Summary of Revenue and Segment Operating Profit (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Revenue	$ 117,340			$ 60,755			$ 329,611	$ 154,499
Segment Operating Profit (Loss)	49,043			13,810			135,764	27,303
Corporate expenses	31,643			28,444			95,942	77,889
Operating profit (loss)	17,400			(14,634)			39,822	(50,586)
Other (expense) income, net	(30,103)			1,561			(35,920)	5,294
Income tax expense	(267)						(1,889)
Net Income (Loss)	(12,970)	$ 16,818	$ (1,835)	(13,073)	$ (15,423)	$ (16,796)	2,013	(45,292)
Total assets	782,587						782,587		$ 703,048
Construction in Progress [Member]
Segment Reporting Information [Line Items]
Total assets	344,041						344,041		314,678
All Other Corporate Assets [Member]
Segment Reporting Information [Line Items]
Total assets	168,389						168,389		176,637
Operating Segment
Segment Reporting Information [Line Items]
Total assets	270,157						270,157		211,733
Operating Segment | Energy Industrial [Member]
Segment Reporting Information [Line Items]
Revenue	26,776			27,912			92,781	97,311
Segment Operating Profit (Loss)	10,733			5,825			37,750	24,246
Total assets	97,575						97,575		93,168
Operating Segment | Thermal Barrier [Member]
Segment Reporting Information [Line Items]
Revenue	90,564			32,843			236,830	57,188
Segment Operating Profit (Loss)	38,310			$ 7,985			98,014	$ 3,057
Total assets	$ 172,582						$ 172,582		$ 118,565

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Oct. 31, 2024	Sep. 30, 2024	Dec. 31, 2023
Subsequent Event [Line Items]
Common stock, shares issued		77,155,896	76,503,151
Subsequent Event [Member] | Underwriting Agreement [Member]
Subsequent Event [Line Items]
Common stock, shares issued	4,887,500
Purchase of additional shares of common stock	637,500
Price to the public per share	$ 20
Proceeds from offering, net	$ 93.2