AEP based on rotor equivalent wind speed measured from a floating LiDAR

Abstract

During the last years, the wind turbines rotor area and the hub height have been increasing gradually. This has entailed new challenges for the measuring atmospheric boundary layer techniques which must be able to measure wind speeds over 200m height and also the use of the hub height wind speed for estimating the rotor power has been questioned. In this study, three boundary layer estimation methods have been compared with wind data from a floating LIDAR buoy, in order to analyze their behaviour and their reliability. Subsequently, the REWS theory for the energy estimation has been tested against the hub height wind speed in order to determine the power production difference. From the three boundary layer estimation methods studied, the logarithm law and the power law get excellent results when they were compared to long term average LIDAR measurements are estimated, obtaining MSE of 0:0031 and 0:0087 respectively. However the results from 10-minute average boundary layer were very inaccurate with maximum MSE of 19. On the other hand, the energy estimation results show that the use of hub height wind speed overestimates the wind turbine power production around 0.2% for LL and PL and, 0.4% when LIDAR measurements are used. Thus, it can be concluded that REWS method implementation does not imply big changes on AEP.