Beacon Power Announces $10 Million Investment Commitment.

WILMINGTON, Mass. -- Beacon Power Corporation (NASDAQ: BCON) today announced that it has received a commitment for $10 million of new investment in the Company. The capital will be used to fund ongoing operations, including improvements to Beacon's new manufacturing facility in Tyngsboro, Massachusetts, as well as procurement of materials related to the deployment of the Company's first megawatt of commercial flywheel frequency regulation service. The transaction is expected to close on September 10, 2007.

The investment was made by a single institutional investor that had previously participated in an earlier round of fundraising that Beacon completed. The transaction is an at-market purchase of approximately 5.1 million units for $1.96 per unit, based on the closing bid price of Beacon stock on September 4, 2007. Each unit consists of one share of the Company's common stock, par value $0.01 per share, and one warrant to purchase 1.2 shares of the Company's common stock at an exercise price of $1.99 per share. The warrants are immediately separable from the units, and will be exercisable beginning six months and one day after the date of their issuance, and will expire on five and one-half years after the date of their issuance. All of the units are being offered by Beacon Power under an effective shelf registration statement previously filed with the Securities and Exchange Commission.

The net proceeds to the Company are expected to be approximately $9.3 million after deducting placement agency fees and estimated expenses. Merriman Curhan Ford & Co. acted as sole placement agent in this transaction.

About Beacon Power

Beacon Power Corporation designs, develops and is taking steps to commercialize advanced products and services to support stable, reliable and efficient electricity grid operation. The Company's primary business strategy is to commercialize its patented flywheel energy storage technology to perform frequency regulation services on the grid. Beacon's Smart Energy Matrix, now in development following approval for use in three of the country's five open-bid regulation markets, is being designed to be a non-polluting, megawatt-level, utility-grade flywheel-based solution that would provide sustainable frequency regulation services. Beacon is a publicly traded company with its research, development and manufacturing facility in the U.S. For more information, visit www.beaconpower.com.

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 or supplying frequency regulation services on a commercial basis; limited commercial contracts for sales to date; our ability to obtain site interconnection or other construction approvals in a timely manner; the dependence of sales on the achievement of product development and commercialization milestones, including design modifications that have been implemented following a malfunction that occurred at the end of 2006 while testing a prototype flywheel; the uncertainty of the political and economic climate, and the different electrical grid characteristics and requirements of any foreign countries into which Beacon hopes to sell or operate, including the uncertainty of enforcing contracts, the different market structures, and the potential substantial fluctuation in currency exchange rates in those countries; dependence on third-party suppliers; intense competition from companies with greater financial resources, especially from companies that are already in the frequency regulation market; possible government regulation that would impede the ability to market products or services or affect market size; the complexity and other challenges of arranging project finance and resources for one or more frequency regulation power plants; possible product liability claims and the negative publicity which could result; any failure to protect intellectual property; retaining key executives and the possible need in the future to hire and retain key executives; the historical volatility of the Company's stock price, as well as volatility of the stock price of other companies in the energy sector. 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.

Additional Note

This press release does not and shall not constitute an offer to sell or the solicitation of an offer to buy any of the securities, nor shall there be any sale of the securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration of qualification under the securities laws of any state.