EXHIBIT 11 ENVIRONMENTAL POWER CORPORATION COMPUTATION OF EARNINGS PER SHARE MARCH 31, 1999 INCOME SHARES PER SHARE (NUMERATOR) (DENOMINATOR) AMOUNTS ------------------ -------------------- --------------- Three Months Ended March 31, 1999: Income available to shareholders $1,010,801 11,406,783 $.09 Effect of dividends to preferred stockholders (1,250) ------------------ -------------------- --------------- Basic EPS - income available to common shareholders 1,009,551 11,406,783 .09 Effect of dilutive securities: Assumed exercise of dilutive stock options ------------------ -------------------- --------------- Diluted EPS - income available to common shareholders $1,009,551 11,406,783 $.09 ================== ==================== =============== THREE MONTHS ENDED MARCH 31, 1998: Income available to shareholders $ 580,593 11,406,783 $.05 Effect of dividends to preferred stockholders (1,250) ------------------ -------------------- --------------- Basic EPS - income available to common shareholders 579,343 11,406,783 .05 Effect of dilutive securities: Assumed exercise of dilutive stock options 16,827 ------------------ -------------------- --------------- Diluted EPS - income available to common shareholders $ 579,343 11,423,610 $.05 ================== ==================== ===============