Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenue:
Sales of fuel cell systems and related infrastructure	$ 8,560	$ 9,121	$ 10,757	$ 14,339
Services performed on fuel cell systems and related infrastructure	5,049	5,360	10,198	10,633
Power Purchase Agreements	4,945	3,062	9,256	5,768
Fuel delivered to customers	3,986	2,638	7,477	4,648
Other	64	278	151	403
Grossl revenue	22,604	20,459	37,839	35,791
Provision for common stock warrants	(1,820)		(1,820)
Net revenue	20,784	20,459	36,019	35,791
Cost of revenue:
Sales of fuel cell systems and related infrastructure	6,441	8,043	8,727	11,941
Services performed on fuel cell systems and related infrastructure	5,068	5,926	11,634	11,709
Provision for loss contracts related to service		(1,071)		(1,071)
Power Purchase Agreements	7,450	3,616	14,065	6,497
Fuel delivered to customers	5,303	3,208	9,452	5,619
Other	65	353	163	542
Total cost of revenue	24,327	20,075	44,041	35,237
Gross (loss) profit	(3,543)	384	(8,022)	554
Operating expenses:
Research and development	6,625	5,201	12,623	10,031
Selling, general and administrative	17,904	8,559	27,049	16,849
Total operating expenses	24,529	13,760	39,672	26,880
Operating loss	(28,072)	(13,376)	(47,694)	(26,326)
Interest and other expense, net	(2,251)	(1,208)	(4,388)	(1,682)
Change in fair value of common stock warrant liability	(12,296)	1,456	(14,576)	2,734
Loss before income taxes	(42,619)	(13,128)	(66,658)	(25,274)
Income tax benefit				392
Net loss attributable to the Company	(42,619)	(13,128)	(66,658)	(24,882)
Preferred stock dividends declared and accretion of discount	(26)	(26)	(3,061)	(52)
Net loss attributable to common shareholders	$ (42,645)	$ (13,154)	$ (69,719)	$ (24,934)
Net loss per share:
Basic and diluted (in dollars per share)	$ (0.19)	$ (0.07)	$ (0.34)	$ (0.14)
Weighted average number of common shares outstanding	220,310,678	180,282,904	205,748,184	180,204,334