Annual report pursuant to Section 13 and 15(d)

Property, plant and equipment - Summary of Property and Equipment (Details)

v3.20.1
Property, plant and equipment - Summary of Property and Equipment (Details) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 6,672,201 $ 14,939,567
Less: accumulated depreciation and amortization (3,206,253) (3,666,452)
Net property, plant and equipment $ 3,465,948 11,273,115
Minimum    
Property, Plant and Equipment [Line Items]    
Useful life - years 3 years  
Maximum    
Property, Plant and Equipment [Line Items]    
Useful life - years 15 years  
Energy systems    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 4,372,638 12,709,990
Energy systems | Minimum    
Property, Plant and Equipment [Line Items]    
Useful life - years 10 years  
Energy systems | Maximum    
Property, Plant and Equipment [Line Items]    
Useful life - years 15 years  
Machinery and Equipment    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 1,462,208 1,355,617
Machinery and Equipment | Minimum    
Property, Plant and Equipment [Line Items]    
Useful life - years 5 years  
Machinery and Equipment | Maximum    
Property, Plant and Equipment [Line Items]    
Useful life - years 7 years  
Furniture and Fixtures    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 193,698 222,542
Useful life - years 5 years  
Computer software    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 192,865 200,626
Computer software | Minimum    
Property, Plant and Equipment [Line Items]    
Useful life - years 3 years  
Computer software | Maximum    
Property, Plant and Equipment [Line Items]    
Useful life - years 5 years  
Leasehold improvements    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross [1] $ 450,792 $ 450,792
[1] Lesser of estimated useful life of asset or lease term