Beacon Power on Monday said it has closed a $43 million loan guarantee with the Department of Energy for a project to use flywheels to buffer 20 megawatts of power on the grid.

The loan covers 62.5 percent of the estimated $69 million needed to construct the flywheel storage plant in Stephentown, N.Y. The New York Energy Research and Development Authority is also providing $2 million in funding for the plant which is now under construction.

Once done, Beacon Power said that the plant will be the only one of its kind in the world. Rather than use a large battery, it will use a network of 200 flywheels to store electricity from the grid as kinetic energy and disperse it in quick bursts of up to 15 minutes.

Right now, grid operators typically use natural gas power plants to maintain a balance between supply and demand and keep a steady frequency of 60 cycles per second. The Stephentown project, expected to be completed by the end of the first quarter next year, will be able to provide 10 percent of the frequency regulation services in New York needed on a typical day.

The project is significant step up for the technology, which so far has been used in smaller-scale installation of about one megawatt of power.

via Flywheel power grid storage project gets DOE loan | Green Tech – CNET News.