EXHIBIT 11 ENVIRONMENTAL POWER CORPORATION COMPUTATION OF EARNINGS PER SHARE March 31, 1998 INCOME SHARES PER SHARE (NUMERATOR) (DENOMINATOR) AMOUNTS ------------------ -------------------- --------------- 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 ================== ==================== =============== THREE MONTHS ENDED MARCH 31, 1997: - ---------------------------------- Income available to shareholders $ 311,430 11,076,783 $ .03 Effect of dividends to preferred stockholders (26,428) ------------------ -------------------- --------------- Basic EPS - income available to common shareholders 285,002 11,076,783 .03 Effect of dilutive securities: Assumed exercise of dilutive stock options 144,208 ------------------ -------------------- --------------- Diluted EPS - income available to common shareholders $ 285,002 11,220,991 $ .03 ================== ==================== ===============