The need for additional generation to compensate for wind variations is disappearing.
Ronald Lehr practices law and consults for the National Renewable Energy Laboratory, American Wind Energy Association, and other clients. He has served as chairman and commissioner of the Colorado PUC.
Utility-based studies have laid to rest the concern that a wind plant needs to be backed up with an equal amount of dispatchable generation. Even at moderate penetrations, ancillary services to back up new wind power need not be more than is required of a system as a whole.
An initial report on utility integration of wind, compiled by the Utility Wind Interest Group (UWIG), an organization of more than 50 utilities with wind power on their systems, looked at a series of studies from Xcel Energy, PacifiCorp, Bonneville Power Administration, We Energies, and consultant Eric Hirst, and concluded that the need for additional generation to compensate for wind variations by backing up a wind plant with an equal amount of dispatchable generation "is substantially less than one-for-one and often closer to zero."
The 162-MW Colorado Green wind farm, completed in 2003, illustrates not only that wind can be economic against other fuels, but also that the need for additional generation to compensate for wind variations is, as the UWIG report says, much less than one-to-one.