Beacon Power Delivers Flywheel-Based Power System to Bechtel Bettis, Inc.

WILMINGTON, Mass. -- Company Will Also Speak at IEEE Electric Ship Technologies Symposium in July

Beacon Power Corporation (NASDAQ: BCON), a company that designs and develops advanced products for electric power and grid voltage and frequency regulation, announced that it has delivered a flywheel-based power system to Bechtel Bettis, Inc., under a contract that it announced in March 2005. The demonstration system, built using a Smart Energy 6 flywheel, is designed to provide a high cycle-life, reliable source of stored energy for a number of potential applications.

"This system we've delivered to Bechtel Bettis is an example of our strategy to address additional market opportunities beyond our primary business focus of providing advanced technology solutions for electric power systems," said Bill Capp, Beacon Power president and CEO. "We continue to seek ways to leverage Beacon technology as a viable alternative to conventional, non-sustainable energy storage. With this system in the hands of users who will evaluate its performance, we hope to both learn from their feedback and establish ourselves as a capable supplier."

Beacon Power also announced that it will present a paper, co-authored with personnel from the Naval Surface Warfare Center, entitled "Flywheel Energy Storage for Electric Start and an All-Electric Ship," at the IEEE Electric Ship Technologies Symposium in Philadelphia on July 27, 2005. The U.S. Navy's Electric Ship program is focused on development of next-generation vessels that make use of an integrated power system able to support more demanding electrical loads as well as reduce crew size and free up shipboard space. Beacon believes that there may be interest in its flywheel products for such applications because of certain inherent advantages over batteries, including long life, the ability to charge and discharge many thousands of times, the absence of hazardous materials and reduced maintenance requirements.

About Bechtel Bettis, Inc.

Bechtel Bettis, a Bechtel subsidiary, manages and operates the U.S. Navy Nuclear Propulsion Program's Bettis Atomic Power Laboratory for the U.S. Department of Energy. Bechtel is a global engineering-construction organization that provides premier technical management and directly related services to develop, engineer, build and operate installations for customers worldwide.

About Beacon Power

Beacon Power Corporation designs sustainable energy storage and power conversion solutions that would provide reliable electric power for the utility, renewable energy, and distributed generation markets. Beacon's Smart Energy Matrix is a design concept for a megawatt-level, utility-grade flywheel-based energy storage solution that would provide sustainable power quality services for frequency regulation, and support the demand for reliable, distributed electrical power. Beacon is a publicly traded company with its research, development and manufacturing facility in the U.S. For more information, visit www.beaconpower.com.

For more information, please contact James Spiezio, Chief Financial Officer; phone [phone]; fax [phone]; email [e-mail]; or write to Beacon Power Corporation, 234 Ballardvale Street, Wilmington, MA 01887.

Safe Harbor Statements under the Private Securities Litigation Reform Act of 1995:

Material contained in this press release may include statements that are not historical facts and are considered "forward-looking" within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements reflect Beacon Power Corporation's current views about future events and financial performances. These forward-looking statements are identified by the use of terms and phrases such as "believe," "expect," "plan," "anticipate," and similar expressions identifying forward-looking statements. Investors should not rely on forward-looking statements because they are subject to a variety of risks, uncertainties, and other factors that could cause actual results to differ materially from Beacon Power Corporation's expectation. These factors include: a short operating history; a history of losses and anticipated continued losses from operations; a need to raise additional capital combined with a questionable ability to do so; conditions in target markets; no experience manufacturing any product on a commercial basis; limited commercial contracts for sales to date; little experience managing operations in geographically dispersed locations; the dependence of sales on the achievement of product development and commercialization milestones; the uncertainty of the political and economic climate of any foreign countries into which Beacon hopes to sell or in which it operates, including the uncertainty of enforcing contracts and the potential substantial fluctuation in currency exchange rates in those countries; significant technological challenges to successfully complete product development; dependence on third-party suppliers; intense competition from companies with greater financial resources; possible government regulation that would impede the ability to market products; possible product liability claims and the negative publicity which could result; any failure to protect intellectual property; the possible need in the future to hire and retain key executives, particularly in light of the substantial workforce reductions during 2001 and 2002; the recent volatility in the stock price of companies operating in the same sector; the difficulties that often arise in integrating operations of companies after a merger or acquisition; the power of controlling shareholders and the limited ability of others to influence the outcome of matters put to the vote of shareholders. These factors are elaborated upon and other factors may be disclosed from time to time in Beacon Power Corporation's filings with the Securities and Exchange Commission. Beacon Power Corporation expressly does not undertake any duty to update forward-looking statements.