CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net revenue:
Net revenue	$ 230,239	$ 174,632	$ 100,153
Cost of revenue:
Total cost of revenue	202,273	172,010	128,242
Gross profit (loss)	27,966	2,622	(28,089)
Operating expenses:
Research and development	33,675	33,907	28,693
Selling, general and administrative	44,333	38,198	45,010
Total operating expenses	78,008	72,105	73,703
Operating loss	(50,042)	(69,483)	(101,792)
Interest and other expense, net	(35,502)	(22,135)	(10,100)
Change in fair value of common stock warrant liability	79	4,286	(15,188)
Loss before income taxes	(85,465)	(87,332)	(127,080)
Income tax benefit		9,217
Net loss attributable to the Company	(85,465)	(78,115)	(127,080)
Preferred stock dividends declared and accretion of discount	(52)	(52)	(3,098)
Net loss attributable to common stockholders	$ (85,517)	$ (78,167)	$ (130,178)
Net loss per share:
Basic and diluted	$ (0.36)	$ (0.36)	$ (0.60)
Weighted average number of common stock outstanding	237,152,780	218,882,337	216,343,985
Sales of fuel cell systems and related infrastructure
Net revenue:
Net revenue	$ 149,884	$ 107,292	$ 62,631
Cost of revenue:
Total cost of revenue	96,859	84,439	54,815
Services performed on fuel cell systems and related infrastructure
Net revenue:
Net revenue	25,217	22,002	16,202
Cost of revenue:
Total cost of revenue	28,801	23,698	19,814
Power Purchase Agreements
Net revenue:
Net revenue	25,853	22,869	12,869
Cost of revenue:
Total cost of revenue	40,056	36,161	31,292
Fuel delivered to customers
Net revenue:
Net revenue	29,099	22,469	8,167
Cost of revenue:
Total cost of revenue	36,357	$ 27,712	22,013
Other
Net revenue:
Net revenue	186		284
Cost of revenue:
Total cost of revenue	$ 200		$ 308