Revenue

3 Months Ended

Mar. 31, 2024

Revenue

Revenue

12. Revenue

Disaggregation of revenue

The following table provides information about disaggregation of revenue (in thousands):

Major products/services lines	Three months ended
	March 31,
	2024		2023
Sales of fuel cell systems	$	19,003	$	28,852
Sales of hydrogen infrastructure		12,295		48,868
Sales of electrolyzers		1,351		40,032
Sales of engineered equipment		4,216		7,753
Services performed on fuel cell systems and related infrastructure		13,023		9,097
Power purchase agreements		18,304		7,937
Fuel delivered to customers and related equipment		18,286		10,142
Sales of cryogenic equipment and other		31,430		56,589
Other		2,356		1,016
Net revenue	$	120,264	$	210,286

Contract balances

The following table provides information about receivables, contract assets and deferred revenue and contract liabilities from contracts with customers (in thousands):

	March 31,		December 31,
	2024		2023
Accounts receivable	$	148,822	$	243,811
Contract assets		160,374		155,989
Deferred revenue and contract liabilities		255,802		288,302

Contract assets primarily relate to contracts for which revenue is recognized on a straight-line basis; however, billings escalate over the life of a contract. Contract assets also include amounts recognized as revenue in advance of billings to customers, which are dependent upon the satisfaction of another performance obligation. These amounts are included in contract assets on the accompanying unaudited interim condensed consolidated balance sheets.

The deferred revenue and contract liabilities relate to the advance consideration received from customers for services that will be recognized over time (primarily fuel cell and related infrastructure services and electrolyzer systems and solutions). Deferred revenue and contract liabilities also include advance consideration received from customers prior to delivery of products. These amounts are included within deferred revenue and other contract liabilities on the unaudited interim condensed consolidated balance sheets.

Significant changes in the contract assets and the deferred revenue and contract liabilities balances during the period are as follows (in thousands):

Contract assets	Three months ended		Year ended
	March 31, 2024		December 31, 2023
Transferred to receivables from contract assets recognized at the beginning of the period	$	(9,082)	$	(94,860)
Change in contract assets related to warrants		5,850		14,260
Impairment		—		(2,375)
Revenue recognized and not billed as of the end of the period		7,617		134,677
Net change in contract assets	$	4,385	$	51,702

Deferred revenue and contract liabilities	Three months ended		Year ended
	March 31, 2024		December 31, 2023
Increases due to customer billings, net of amounts recognized as revenue during the period	$	12,057	$	151,965
Change in contract liabilities related to warrants		110		440
Revenue recognized that was included in the contract liability balance as of the beginning of the period		(44,667)		(94,001)
Net change in deferred revenue and contract liabilities	$	(32,500)	$	58,404

Estimated future revenue

The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied (or partially unsatisfied) at the end of the reporting period, including provision for common stock warrants (in thousands):

	March 31,		Expected recognition
	2024		period (years)
Sales of fuel cell systems	$	55,671		1 - 2
Sales of hydrogen installations and other infrastructure		31,039		1
Sales of electrolyzers		303,127		1 - 2
Sales of engineered equipment		14,559		1
Services performed on fuel cell systems and related infrastructure		142,111		5 - 10
Power purchase agreements		419,406		5 - 10
Fuel delivered to customers and related equipment		93,685		5 - 10
Sales of cryogenic equipment and other		77,105		1
Total estimated future revenue	$	1,136,703