CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
CONSOLIDATED STATEMENTS OF OPERATIONS
Total operating revenues	$ 3,990	$ 4,060
Operating expenses:
Cost of production	2,587	4,425
Depreciation and amortization	4,451	4,575
Research and development expense	1,548	1,198
General and administrative expense	12,150	10,761
Project development costs	5,319	2,959
Facility idling costs	1,076	999
Total operating expenses	27,131	24,917
Loss from operations	(23,141)	(20,857)
Other income (expense)
Interest expense	(542)	(539)
Interest and investment income	4,593	3,784
Other income (expense), net	215	(6)
Total other income, net	4,266	3,239
Net loss	$ (18,875)	$ (17,618)
Net loss per share - basic (in dollars per share)	$ (0.08)	$ (0.07)
Net loss per share - diluted (in dollars per share)	$ (0.08)	$ (0.07)
Weighted-average number of common shares outstanding - basic (in shares)	240,844,334	237,260,681
Weighted-average number of common shares outstanding - diluted (in shares)	240,844,334	237,260,681