X0303 4 2011-06-30 0001103345 BEACON POWER CORP BCON 0001278525 CAPP F WILLIAM C/O BEACON POWER CORPORATION 65 MIDDLESEX ROAD TYNGSBORO MA 01879 1 1 0 0 President and CEO Common Stock 2011-06-30 4 A 0 37500 0 A 118124 D The securities described represent the maximum amount of shares of common stock that can be awarded upon conversion of restricted stock units ("RSU's") granted as of the date of this report. The RSU's will only vest and be converted into common stock to the extent certain performance goals are met, including a specific adjusted EBITDA target, as of the last day of the Issuer's 2013 fiscal year. In the event the specific goals are not met, the RSU's will vest on a pro rata basis, if at all. The number of shares that would be awarded upon vesting if the target is achieved is 25,000. /s/ Albert L. Sokol as attorney-in-fact 2011-06-30