Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 25,552	$ 22,608
Prepaid expenses and other current assets	835	670
Total current assets	26,387	23,278
Property, plant and equipment, net	173,816	161,662
Operating lease right-of-use assets, net	590	429
Other non current assets	21,312	16,299
Total assets	222,105	201,668
Current liabilities
Accounts payable	281	207
Share-based compensation liability	182	182
Accrued liabilities and other current liabilities	5,791	1,032
Current Common Stock Warrant liabilities	1,376	3,290
Current operating lease liabilities	596	432
Total current liabilities	8,226	5,143
Non-current Common Stock Warrant liabilities	2,587	874
Other non-current liabilities	23,000	22,916
Total liabilities	33,813	28,933
Commitments and contingencies (Note 14)
Stockholders’ equity
Common stock, $0.0001 par value Authorized: 480.0 million shares at December 31, 2021 and 2020, Issued and outstanding: 120.8 million shares and 117.8 million shares at December 31, 2021 and 2020, respectively	12	12
Treasury stock: 346,126 shares and 249,742 shares at December 31, 2021 and 2020, respectively, at cost	(1,315)	(1,031)
Preferred stock, $0.0001 par value Authorized: 0.5 million, after designation of the Convertible Preferred Stock, Issued and outstanding: none at December 31, 2021 and 2020	0	0
Additional paid-in-capital	191,264	209,481
Accumulated deficit	(170,069)	(148,030)
Total stockholders’ equity	19,892	60,432
Total liabilities, Convertible Preferred Stock and stockholders’ equity	222,105	201,668
Series A Convertible Preferred Stock [Member]
Current liabilities
Convertible Preferred Stock	63,791	55,522
Series B Convertible Preferred Stock [Member]
Current liabilities
Convertible Preferred Stock	64,602	56,781
Series C Convertible Preferred Stock [Member]
Current liabilities
Convertible Preferred Stock	$ 40,007	$ 0