
<PAGE>
 
                                  EXHIBIT 11



Environmental Power Corporation
Computation of Loss Per Share
September 30, 1995

<TABLE> 
<CAPTION> 
FOR THE THREE MONTHS ENDED SEPTEMBER 30, 1995 :
- - -----------------------------------------------

<S>                                             <C> 
Weighted average number
of shares outstanding                            10,662,179

Net loss                                       $(1,033,075)
                                               =============

Loss per share - primary and fully diluted     $       (.10)
                                               =============



FOR THE NINE MONTHS ENDED SEPTEMBER 30, 1995 :
- - ----------------------------------------------

Weighted average number
of shares outstanding                            10,653,095

Net loss                                       $(4,065,563)
                                               =============

Loss per share - primary and fully diluted     $       (.38)
                                               =============
</TABLE> 
