Recent efforts to improve estimates of and mitigate potential wind turbine clutter impacts on WSR-88Ds

The Nation's use of wind turbine “farms” to generate electricity and diversify our energy sources has grown dramatically in recent years and is expected to continue to grow. These wind farms can have over 100 towers with turbine blade tip heights exceeding 400 feet above ground level.

As we have reported before, when wind farms are located in the radar line of sight of Weather Surveillance Radar-1988, Doppler (WSR-88D) systems, the towers and the interference due to rotating wind turbines blades, wind turbine clutter (WTC), can impact radar data quality and the performance of radar algorithms. During the last 4 years, the WSR-88D Radar Operations Center (ROC) on behalf of the Next Generation Weather Radar (NEXRAD Program) has analyzed over 700 wind farm proposals on a case-by-case basis for potential interference with the WSR-88D. Our analysis process, based in part on field experience, has matured over the last 4 years. The major change has been to estimate WTC impacts on WSR-88D data and forecast/severe weather warning performance separately. This change in particular has resulted in more realistic ROC estimates of “bottom line” impacts -- likelihood of operational forecast/warning impact, and increased credibility with the wind energy industry. However, the impacts of WTC leading to misinterpretations by other users; including emergency managers, the public and media, have led to misinterpretation of the data, created confusion and erroneous forecasts on some occasions.

This paper and presentation will discuss the updated ROC wind turbine clutter analysis procedures; outline recent efforts to mitigate impacts of WTC; provide an educational forum for external users (e.g., broadcasters, private industry and public); and examine possible trends regarding the siting of wind farms and that relation to WSR-88D operations and forecast/warning performance.