Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue:
Sales of fuel cell systems and related infrastructure	$ 78,002	$ 48,306	$ 18,446
Services performed on fuel cell systems and related infrastructure	14,012	9,909	6,659
Power Purchase Agreements	5,718	2,137
Fuel delivered to customers	5,075	1,959
Other	481	1,919	1,496
Total revenue	103,288	64,230	26,601
Cost of revenue:
Sales of fuel cell systems and related infrastructure	67,703	43,378	20,414
Services performed on fuel cell systems and related infrastructure	22,937	19,256	14,929
Provision for loss contracts related to service	10,050
Power Purchase Agreements	5,253	1,052
Fuel delivered to customers	6,695	2,204
Other	540	3,202	2,506
Total cost of revenue	113,178	69,092	37,849
Gross loss	(9,890)	(4,862)	(11,248)
Operating expenses:
Research and development	14,948	6,469	3,121
Selling, general and administrative	34,164	26,601	14,596
Total operating expenses	49,112	33,070	17,717
Operating loss	(59,002)	(37,932)	(28,965)
Interest and other income	157	752	150
(Loss) gain on acquisition activity, net	(116)	1,014
Change in fair value of common stock warrant liability	3,661	(52,260)	(37,102)
Interest and other expense	(390)	(387)	(398)
Gain on sale of equity interest in joint venture			3,235
Loss before income taxes	(55,690)	(88,813)	(63,080)
Income tax benefit		325	410
Net loss attributable to the Company	(55,690)	(88,488)	(62,670)
Preferred stock dividends declared	(105)	(156)	(121)
Net loss attributable to common shareholders	$ (55,795)	$ (88,644)	$ (62,791)
Net loss per share:
Basic and diluted (in dollars per share)	$ (0.32)	$ (0.56)	$ (0.82)
Weighted average number of common shares outstanding	176,067,231	159,228,815	76,436,408