CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue and cost of goods sold
Total operating revenues	$ 4,528	$ 309	$ 12,826	$ 630
Operating expenses:
Cost of production	2,480	575	8,836	5,499
Depreciation and amortization	4,994	1,657	14,323	4,573
Research and development expense	1,558	1,562	4,716	4,720
General and administrative expense	10,522	11,144	31,891	29,205
Project development costs	4,789	2,218	10,635	5,550
Facility idling costs	911	2,330	2,923	2,330
Impairment loss	0	24,749	0	24,749
Total operating expenses	25,254	44,235	73,324	76,626
Loss from operations	(20,726)	(43,926)	(60,498)	(75,996)
Other income (expense)
Interest expense	(540)	(455)	(1,615)	(459)
Interest and investment income	5,261	896	14,083	1,226
Other income (expense), net	305	(301)	292	2,609
Total other income, net	5,026	140	12,760	3,376
Net loss	$ (15,700)	$ (43,786)	$ (47,738)	$ (72,620)
Net loss per share - basic (in dollars per share)	$ (0.07)	$ (0.19)	$ (0.20)	$ (0.34)
Net loss per share - diluted (in dollars per share)	$ (0.07)	$ (0.19)	$ (0.20)	$ (0.34)
Weighted-average number of common shares outstanding - basic (in shares)	239,537,811	236,649,805	238,100,986	216,255,710
Weighted-average number of common shares outstanding - diluted (in shares)	239,537,811	236,649,805	238,100,986	216,255,710