Cost of revenues and general and administrative expenses (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cost of revenues and general and administrative expenses [Line Items]
Cost of Revenue	$ 38,977,570	$ 35,368,461
Electricity [Member]
Cost of revenues and general and administrative expenses [Line Items]
Cost of Revenue	11,087,214	9,722,210
Depreciation [Member]
Cost of revenues and general and administrative expenses [Line Items]
Cost of Revenue	5,328,091	5,553,423
Fuel oil [Member]
Cost of revenues and general and administrative expenses [Line Items]
Cost of Revenue	5,434,995	4,423,264
Employee costs [Member]
Cost of revenues and general and administrative expenses [Line Items]
Cost of Revenue	5,127,831	5,344,251
Cost of plant sales [Member]
Cost of revenues and general and administrative expenses [Line Items]
Cost of Revenue	1,059,520	0
Maintenance [Member]
Cost of revenues and general and administrative expenses [Line Items]
Cost of Revenue	2,481,095	2,443,629
Retail license royalties [Member]
Cost of revenues and general and administrative expenses [Line Items]
Cost of Revenue	1,687,010	1,537,879
Insurance [Member]
Cost of revenues and general and administrative expenses [Line Items]
Cost of Revenue	996,563	944,366
Materials [Member]
Cost of revenues and general and administrative expenses [Line Items]
Cost of Revenue	3,102,533	2,836,240
Other [Member]
Cost of revenues and general and administrative expenses [Line Items]
Cost of Revenue	$ 2,672,718	$ 2,563,199