Performance Evaluation of Scanning Doppler Lidar and its Application to Wind Field Measurement

Abstract

This study evaluates scanning Doppler Lidar-based wind field measurement and analysis techniques for wind energy applications. The Lidar measurements are first validated against measurements from existing V1 Lidar. It is found that the availability of 20% (30 data per 10 minutes) is sufficient to produce fairly good 10 minutes averaged wind speed and direction. The vertical profile measurements for wind blowing from land and that from sea are then performed using DBS configuration. The averaged wind speed for the former is lower than for the later. Two more scan modes, RHI and PPI, are employed to investigate the effect of coastal terrain on the near shore velocity profiles and to characterize the wind turbine wake. An internal boundary layer develops from the shore and persists up to 2000 m offshore. Lidar measurement data are also used to validate numerical simulations by a mesoscale model. The measured and predicted wind speeds agree well up to the height of 500 m. Finally, measurements of flow field around wind turbine shows the velocity deficit in the wind turbine wake and agree with those predicted by a wake model.