Annual report pursuant to Section 13 and 15(d)

Consolidated Statements of Stockholders' Equity (Deficit)

Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Officers and Directors Plan	Officers and Directors Plan Common Stock	Officers and Directors Plan Additional Paid-in Capital	Over-Allotment Option	Over-Allotment Option Common Stock	Over-Allotment Option Additional Paid-in Capital	2018 Public Offering	2018 Public Offering Common Stock	2018 Public Offering Additional Paid-in Capital	January 2019 Public Offering	January 2019 Public Offering Common Stock	January 2019 Public Offering Additional Paid-in Capital	May 2019 Public Offering	May 2019 Public Offering Common Stock	May 2019 Public Offering Additional Paid-in Capital	Restricted Stock Units (RSUs) Common Stock
Balance at beginning (in shares) at Dec. 31, 2017		27,554,076
Balance at beginning at Dec. 31, 2017	$ 58,965	$ 27	$ 113,780	$ (54,842)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	1,201		1,201
Common stock issued (in shares)						2,034			1,072,500			10,085,500								65,600
Proceeds from common stock issued					$ 4		$ 4	$ 2,103	$ 2	$ 2,101	$ 26,646	$ 10	$ 26,636
Common stock issued for consulting services (in shares)		152,727
Common stock issued for consulting services	423		423
Modification of Interstate Batteries warrant #1	1,002		1,002
Net loss	(40,254)			(40,254)
Balance at end (in shares) at Dec. 31, 2018		38,932,437
Balance at end at Dec. 31, 2018	50,090	$ 39	145,147	(95,096)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	4,206		4,206
Warrants issued related to Veolia agreement	5,780		5,780
Common stock issued (in shares)															5,175,000			11,000,000		854,064
Proceeds from common stock issued	1	$ 1												$ 9,063	$ 5	$ 9,058	$ 20,317	$ 11	$ 20,306
Common stock issued for consulting services (in shares)		2,036,279
Common stock issued for consulting services	4,927	$ 2	4,925
Net loss	(44,795)			(44,795)
Balance at end (in shares) at Dec. 31, 2019		57,997,780
Balance at end at Dec. 31, 2019	$ 49,589	$ 58	$ 189,422	$ (139,891)