Quarterly report pursuant to Section 13 or 15(d)

Related party transactions (Details)

v3.7.0.1
Related party transactions (Details)
 1 Months Ended 6 Months Ended
Aug. 02, 2016
USD ($)
$ / shares
shares
Jan. 31, 2017
USD ($)
Jul. 31, 2016
USD ($)
$ / shares
shares
Jun. 30, 2017
USD ($)
company
May 19, 2016
Dec. 28, 2015
USD ($)
Schedule of Equity Method Investments [Line Items]            
Number of affiliated companies | company       2    
Equity interest in joint venture (percent)       43.00%    
Warrant exercise price (per share) | $ / shares     $ 4.00      
Proceeds from the exercise of warrants     $ 2,700,000      
Investments in joint venture       $ 13,500,000    
Ultra Emissions Technology Ltd.            
Schedule of Equity Method Investments [Line Items]            
Equity interest in joint venture (percent)           50.00%
Warrants exercised for investment in joint venture $ 2,000,000          
Due from affiliate       94,407    
TTcogen, LLC            
Schedule of Equity Method Investments [Line Items]            
Equity interest in joint venture (percent)         50.00%  
Due from affiliate       279,069    
Offshore Investors            
Schedule of Equity Method Investments [Line Items]            
Investment by other party to joint venture           $ 3,000,000
Tedom a.s.            
Schedule of Equity Method Investments [Line Items]            
Equity interest in joint venture (percent)         50.00%  
Warrant            
Schedule of Equity Method Investments [Line Items]            
Warrants exercised (shares) | shares     675,000      
Warrant | Ultra Emissions Technology Ltd.            
Schedule of Equity Method Investments [Line Items]            
Warrants exercised (shares) | shares 2,000,000          
Warrant exercise price (per share) | $ / shares $ 1.00          
American DG Energy            
Schedule of Equity Method Investments [Line Items]            
Equipment purchase   $ 985,000        
Co-venturer            
Schedule of Equity Method Investments [Line Items]            
Investments in joint venture       8,500,000    
Co-Chief Executive Officer            
Schedule of Equity Method Investments [Line Items]            
Loan from related party       $ 850,000    
Notes Payable | Co-Chief Executive Officer            
Schedule of Equity Method Investments [Line Items]            
Stated interest rate (percent)       6.00%