Discontinued operations - Mexico project development (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total assets of discontinued operations	$ 21,427,879	$ 21,660,768
Discontinued Operations. | Mexico Project Development
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash	189,613	442,252
Accounts receivable	12,675	12,675
Prepaid expenses and other current assets	96,303	76,553
Value added taxes receivable (net of allowance of $1,940,725 and $1,711,234, respectively)	21,126,898	21,126,898
Land	2,390	2,390
Other assets	$ 21,427,879	$ 21,660,768