The Sandia National Laboratory and Houston-based CAES Development Co are jointly investigating a 2700 MW compressed air energy storage (CAES) project in Ohio. Construction is due to start later this year, with the project ready to enter service in 2003. The plant will be built in units brought on line in increments of 300 MWe.

A compressed air energy storage plant uses off-peak power to compress air, using the compressor stage of a gas turbine, to around 1600 psi. The high pressure air is stored in an underground cavern until needed, when it is expanded through the latter stages of a gas turbine, generating electricity.

The Ohio project is being built using an abandoned limestone mine in Norton, Ohio, and is the first compressed air system to use such a mine. The two existing schemes – McIntosh and Huntorf – use caverns in salt deposits. Permits are currently being sought through the state’s regulatory agencies. The Ohio Power Siting Board has already recommended approval of the facility.