Wind Power Plant Monitoring Project Annual Report

The intermittent nature of the wind resource, together with short-term power fluctuations, are the two principal issues facing a utility with wind power plants in its power grid. To mitigate these issues, utilities, wind power plant developers, and operators need to understand the nature of wind power fluctuations and how they affect the electrical power system, as well as to analyze ancillaryservice requirements with real wind power plant output data. To provide the necessary data, NREL conducted a study to collect at least 2 years of long-term, high-frequency (1-hertz [Hz]) data from several medium- to large-scale wind power plants with different wind resources, terrain features, and turbine types. Researchers then analyzed the data for power fluctuations, frequency distribution ofwind power (by deriving a probability distribution function of wind power plant output variations), spatial and temporal diversity of wind power, and wind power capacity credit issues. Results of these analyses can provide data on the potential effects of wind power plants on power system regulation.