Discontinued operations - Mexico project development (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total assets of discontinued operations	$ 22,677,588	$ 29,289,022
Discontinued Operations | Mexico Project Development
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash	154,130	831,586
Prepaid expenses and other current assets	88,978	111,220
Value added taxes receivable	1,267,991	676,250
Property, plant and equipment, net	5,682	10,227
Land and rights of way	21,126,898	24,162,523
Other assets	33,909	3,497,216
Total assets of discontinued operations	22,677,588	29,289,022
Total liabilities of discontinued operations	$ 190,933	$ 2,858,314