Annual report pursuant to Section 13 and 15(d)

Summary of significant accounting policies - Revenue (Details)

v3.22.0.1
Summary of significant accounting policies - Revenue (Details) - USD ($)
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Disaggregation of Revenue [Line Items]    
Revenue $ 24,398,073 $ 28,254,579
Payment Term on Energy Production Contract Invoices 30 days  
Unbilled revenue recognized $ 806,218  
Revenue billed that was recognized in previous periods 1,078,332  
Deferred revenue recognized 1,731,965  
Remaining performance obligations $ 2,166,208  
Performance obligation recognized over next 24 months (percent) 93.00%  
Performance obligation recognized over next 12 months (percent) 3.00%  
Performance obligation recognized in subsequent 12 months (percent) 90.00%  
Products    
Disaggregation of Revenue [Line Items]    
Revenue $ 10,133,329 11,466,716
Installation Services [Member]    
Disaggregation of Revenue [Line Items]    
Revenue 938,831 4,872,877
Maintenance Service [Member]    
Disaggregation of Revenue [Line Items]    
Revenue 11,586,763 10,077,805
Energy Production    
Disaggregation of Revenue [Line Items]    
Revenue $ 1,739,150 1,837,181
Turnkey Installation [Member]    
Disaggregation of Revenue [Line Items]    
Payment Term on Installation Services 30 days  
Energy Production    
Disaggregation of Revenue [Line Items]    
Revenue $ 1,739,150 1,837,181
Energy Production | Products    
Disaggregation of Revenue [Line Items]    
Revenue 0 0
Energy Production | Installation Services [Member]    
Disaggregation of Revenue [Line Items]    
Revenue 0 0
Energy Production | Maintenance Service [Member]    
Disaggregation of Revenue [Line Items]    
Revenue 0 0
Energy Production | Energy Production    
Disaggregation of Revenue [Line Items]    
Revenue 1,739,150 1,837,181
Product and Service    
Disaggregation of Revenue [Line Items]    
Revenue 22,980,541 26,817,142
Product and Service | Products    
Disaggregation of Revenue [Line Items]    
Revenue 10,133,329 11,466,716
Product and Service | Installation Services [Member]    
Disaggregation of Revenue [Line Items]    
Revenue 938,831 4,872,877
Product and Service | Maintenance Service [Member]    
Disaggregation of Revenue [Line Items]    
Revenue 11,586,763 10,077,805
Product and Service | Energy Production    
Disaggregation of Revenue [Line Items]    
Revenue 0 0
General and Administrative Expense    
Disaggregation of Revenue [Line Items]    
Shipping and handling expenses 385,351 418,180
Operating Segments    
Disaggregation of Revenue [Line Items]    
Revenue 24,398,073 28,254,579
Operating Segments | Energy Production    
Disaggregation of Revenue [Line Items]    
Revenue 1,739,150 1,837,181
Operating Segments | Product and Service    
Disaggregation of Revenue [Line Items]    
Revenue $ 22,658,923 $ 26,417,398