Annual report pursuant to Section 13 and 15(d)

Related party transactions (Details)

v3.20.1
Related party transactions (Details) - USD ($)
12 Months Ended
May 04, 2018
Mar. 27, 2018
Dec. 31, 2019
Dec. 31, 2018
May 18, 2017
May 19, 2016
Related Party Transaction [Line Items]            
Payment made to terminate senior convertible promissory note     $ 0 $ 850,000    
TTcogen, LLC            
Related Party Transaction [Line Items]            
Equity interest in joint venture (percent)           50.00%
Tedom USA            
Related Party Transaction [Line Items]            
Equity interest in joint venture (percent)           50.00%
Chief Executive Officer (John N. Hatsopoulos)            
Related Party Transaction [Line Items]            
Loan from related party         $ 850,000  
Chief Executive Officer (John N. Hatsopoulos) | Demand notes            
Related Party Transaction [Line Items]            
Stated interest rate (percent)         6.00%  
Tedom USA            
Related Party Transaction [Line Items]            
Equity interest in joint venture (percent)           50.00%
Initial payment to acquire productive assets   $ 1        
Payments to acquire equity method investments   72,597        
Payments to acquire productive assets   $ 72,598        
Chief Executive Officer (John N. Hatsopoulos)            
Related Party Transaction [Line Items]            
Loan from related party         $ 850,000  
Payment made to terminate senior convertible promissory note $ 919,590          
Chief Executive Officer (John N. Hatsopoulos) | Demand notes            
Related Party Transaction [Line Items]            
Stated interest rate (percent)         6.00%