The Iowa Stored Energy Plant (ISEP) will be the first plant in the world that will use energy from a wind farm plus supplemental off peak electricity to produce compressed air to be stored in an underground aquifer until it is need to produce electricity on demand. When demand for electricity is high, the air will be released and used in combination with a small amount of natural gas to drive combustion turbines to generate electricity. Wind power is undependable and not always available when needed, compressed air energy storage (CAES) mitigates this intermittency. This method will save one-third to one-half the natural gas that would otherwise be needed. CAES has been used in Alabama and Germany, but at these locations the energy for storage does not come from wind.
A separate section of the underground aquifer will also be used for storing natural gas. Gas storage will allow the facility and other gas utilities to buy natural gas when prices are lower. This type of gas storage is widely used in the U.S.
Senator Tom Harkin (D-IA), a senior member of the Senate Appropriations committee, announced on November 24 that he secured $1.5 million for the development of ISEP in the final FY 2006 Senate Energy and Water Appropriations Bill. This money will be used to fund further studies, DOE contracts for studies are nearly complete.
Plans are to build a 200MW CAES and a 100 MW wind farm. ISEP plans to have the plant in completed 3 years from final approval, operation is currently anticipated to be in 2010.
Iowa Stored Energy Plant to deliver Wind Energy on Demand, The Messenger, Fort Dodge, Iowa, Nov 24, 2005
ISEP Project Review and Update, May, 2005
Iowa Stored Energy Project (ISEP), website
Transforming Wind-power into a Reliable Resource, ISEP fact sheet, February 2003