Initially, the hybrid generator will combine 100 MW of wind energy with air and natural gas and use electric generators that are similar to combustion turbines, but use one-third to a half less natural gas. Eventually, Wind says, the project could "green up" by adding more wind capacity and it may add a biomass component if the price of natural gas rises above $7.50/million cubic feet.
Public utilities in the state of Iowa, helped by wind power consultant Tom Wind, may have found a way to store wind's intermittent energy for when it is needed most and is valued highest. Wind says he and others have engineered a hybrid wind and gas turbine system that can compress air during the night, store it in an underground aquifer and combine it with natural gas in a turbine to produce electricity during peak hours. This is not a pie in the sky idea, Wind says. An aquifer has been located 1200 feet below ground in north central Iowa, $700,000 has been raised for feasibility studies and utilities are lining up to participate. The project, says Wind, could be up and running in 2007.