Annual report pursuant to Section 13 and 15(d)

Stockholders' equity - Restricted Stock Activity (Details)

v2.4.0.6
Stockholders' equity - Restricted Stock Activity (Details) (Restricted stock, USD $)
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Tecogen
   
Unvested Restricted Stock [Roll Forward]    
Unvested, Beginning (shares) 1,933,268 1,733,268
Granted (shares) 0 200,000
Vested (shares) 0 0
Forfeited (shares) (336,988) 0
Unvested, Ending (shares) 1,596,280 1,933,268
Weighted Average Grant Date Fair Value [Roll Forward]    
Unvested, Beginning (usd per share) $ 0.36 $ 0.32
Granted (usd per share) $ 0.00 $ 0.65
Vested (usd per share) $ 0.00 $ 0.00
Forfeited (usd per share) $ 0.34 $ 0.00
Unvested, Ending (usd per share) $ 0.36 $ 0.36
Ilois
   
Unvested Restricted Stock [Roll Forward]    
Unvested, Beginning (shares) 560,000 360,000
Granted (shares) 0 200,000
Vested (shares) 0 0
Forfeited (shares) (50,000) 0
Unvested, Ending (shares) 510,000 560,000
Weighted Average Grant Date Fair Value [Roll Forward]    
Unvested, Beginning (usd per share) $ 0.24 $ 0.10
Granted (usd per share) $ 0.00 $ 0.50
Vested (usd per share) $ 0.00 $ 0.00
Forfeited (usd per share) $ 0.10 $ 0.00
Unvested, Ending (usd per share) $ 0.26 $ 0.24