Short-Term Output Variations in Wind Farms--Implications for Ancillary Services in the United States: Preprint

With the advent of competition in the electric power marketplace, this paper reviews changes that affect wind and other renewable energy technologies, and discusses the role of federal and state policies in the recent wind installations in the United States. In particular, it reviews the implications of ancillary service requirements on a wind farm and presents initial operating results of monitoring one Midwest wind farm. Under federal energy policy, each generator must purchase, or otherwise provide for, ancillary services, such as dispatch, regulation, operation reserve, voltage regulation, and scheduling required to move power to load. As a renewable technology that depends on the forces of nature, short-term output variations are inherently greater for a wind farm than for a gas-fired combined cycle or a supercritical coal-fired unit.

Cadogan, J.; Milligan, M.; Wan, Y.; Kirby, B.
National Renewable Energy Laboratory
Market Analysis
Grid Integration & Transmission
Technical Report