Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue:
Sales of fuel cell systems and related infrastructure	$ 5,653	$ 24,777	$ 19,992	$ 48,530
Services performed on fuel cell systems and related infrastructure	4,763	3,555	15,396	9,083
Power Purchase Agreements	3,858	1,546	9,626	3,600
Fuel delivered to customers	2,909	1,544	7,557	3,331
Other	376	10	779	313
Total revenue	17,559	31,432	53,350	64,857
Cost of revenue:
Sales of fuel cell systems and related infrastructure	4,241	22,271	16,182	42,103
Services performed on fuel cell systems and related infrastructure	4,481	5,510	16,190	15,648
Change in estimate			(1,071)
Power Purchase Agreements	4,464	1,417	10,961	3,101
Fuel delivered to customers	3,679	2,148	9,298	4,107
Other	313	10	855	371
Total cost of revenue	17,178	31,356	52,415	65,330
Gross profit (loss)	381	76	935	(473)
Operating expenses:
Research and development	5,001	4,131	15,032	10,457
Selling, general and administrative	8,636	8,201	25,485	23,952
Total operating expenses	13,637	12,332	40,517	34,409
Operating loss	(13,256)	(12,256)	(39,582)	(34,882)
Interest and other expense, net	(2,113)	(8)	(3,795)	(95)
Loss on acquisition activity, net		(116)		(116)
Change in fair value of common stock warrant liability	1,975	2,167	4,709	4,603
Loss before income taxes	(13,394)	(10,213)	(38,668)	(30,490)
Income tax benefit			392
Net loss attributable to the Company	(13,394)	(10,213)	(38,276)	(30,490)
Preferred stock dividends declared	(26)	(25)	(78)	(78)
Net loss attributable to common shareholders	$ (13,420)	$ (10,238)	$ (38,354)	$ (30,568)
Net loss per share:
Basic and diluted (in dollars per share)	$ (0.07)	$ (0.06)	$ (0.21)	$ (0.17)
Weighted average number of common shares outstanding	180,375,680	177,369,017	180,261,449	174,724,746