City-owned utilities in Iowa and three other states are a step closer to building the world’s first wind energy storage facility deep underground at an unspecified location in northern Iowa. Robert Haug , executive director of the Iowa Association of Municipal Utilities, explains how the quarter-billion dollar project would work. Electricity from wind turbines would be used to compress air 12-hundred feet underground in an aquifer. For it to work, Haug says there needs to be a layer of sandstone or sand in a dome shape with a cap rock above it that will hold the air. He says the concept is already being used to hold another precious commodity. Natural gas is stored in underground aquifers all over the U.S., including in Iowa. A just-completed study, taking years of data into account, concludes the proposed facility will hold the air and is “actually ideally suited” as a storage facility for compressed air. Haug says one problem with wind power is that the wind doesn’t always blow when you need it to. This underground air storage facility would help solve that problem. There are times, usually at night and on weekends, when electricity from the wind turbines isn’t needed — there’s no market for it. Haug says that off-peak energy can be used to store potential electricity in the form of compressed air and create a large “battery” for wind power. That compressed air can be bled off later during calm weather or during peak times to spin turbines in ground-based generators. The research was funded by 70 municipal utilities in Iowa, Minnesota and the Dakotas. This week, Congress voted to put one-and-a-half million dollars toward further development of the project. For more information, surf to “www.iamu.org”.