This is an excerpt from EERE Network News, a weekly electronic newsletter.

June 04, 2003

Iowa Utilities Propose a Wind-Powered Energy Storage Plant

A group of municipal utilities in Iowa are proposing to build a unique power plant that will combine wind power with a compressed-air energy storage (CAES) facility. The proposed Iowa Stored Energy Plant (ISEP) will use a 100-megawatt wind power facility to pump air into an underground aquifer, compressing the air. During times of peak power demand, the compressed air will be supplied to 200 megawatts of combustion turbines that are fired with natural gas, allowing the turbines to operate at high efficiencies. The group places the cost of the ISEP at $215 million and hopes to launch the project this fall, with a startup date in mid-2006. See the ISEP Web site and Background page.

CAES plants work by replacing a combustion turbine's compressor with a source of compressed air. Nearly two-thirds of the natural gas supplied to a conventional combustion turbine is used to drive the compressor, so a CAES plant burns much less natural gas than a conventional combustion-turbine plant. Currently, two CAES plants exist: a 290-megawatt plant in Germany and a 110-megawatt plant in Alabama. A 2,700-megawatt CAES plant has also been proposed by CAES Development Company, LLC for construction in Norton, Ohio. See DOE's Distributed Energy Resources Web site and the CAES Development Company Web site.