Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Product sales	$ 4	$ 173
Operating cost and expense
Plant operations and clean up	3,959	7,017
Research and development cost	1,813	933
General and administrative expense	9,815	9,688
Total operating expense	15,587	17,638
Loss from operations	(15,583)	(17,465)
Other income and expense
Insurance proceeds net of related expenses	0	4,794
Impairment expense	(579)	(545)
PPP loan forgiveness	0	332
Gain (loss) on disposal of property and equipment	596	(5,665)
Interest expense	(125)	(21)
Interest and other income	262	379
Total other income (expense), net	154	(726)
Loss before income tax expense	(15,429)	(18,191)
Income tax expense	(2)	(2)
Net loss	$ (15,431)	$ (18,193)
Weighted average shares outstanding, basic and diluted (in shares)	75,811,034	70,002,180
Basic and diluted net loss per share (in dollars per share)	$ (0.20)	$ (0.26)