Does wind power require back-up by fossil fuels on the grid?
Given the size of the U.S. mainland electric grid, even large amounts of wind power would require little backup by fossil fuel. In a 2004 study, the Minnesota Department of Commerce found that 1,500 MW of wind generation would require only eight MW of “spinning reserve.” Spinning reserve refers to generation resources that can come online immediately to make up for any sudden shortfall in supply. Furthermore, there is usually already more spinning reserve available on a system than would ever be required by any single wind farm or series of wind farms. Typically, the electricity grid operator maintains enough spinning reserve to insure there are no disruptions should a significant generation source experience a forced outage, for example a large nuclear or coal plant.
