Discontinued operations - Mexico project development (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total assets of discontinued operations	$ 22,319,927	$ 22,677,588
Discontinued Operations | Mexico Project Development
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash	750,048	154,130
Prepaid expenses and other current assets	82,783	88,978
Value added taxes receivable (net of allowance of $967,115 and $316,217, respectively)	340,910	1,267,991
Property, plant and equipment, net		5,682
Land	21,126,898	21,126,898
Other assets	19,288	33,909
Total assets of discontinued operations	22,319,927	22,677,588
Total liabilities of discontinued operations	190,141	190,933
Value added tax, net of allowance	$ 1,279,757	$ 316,217