Abstract:In recent years, reanalysis data are more and more used in wind energy resource assessment. In this paper, the observation data from 40 ground stations in China are used to evaluate the ground wind speed error of ERA5 and ERA5-Land reanalysis data with different resolutions. The results show that the mean Bias Error (BE) of multi-year mean wind speed of ERA5 and ERA5-Land data is 0.08 m s-1 and -0.06 m s-1 respectively, the maximum BE is 0.46 m s-1 and -0.19 m s-1 respectively, the Relative Bias Error (RBE) is 4.4% and -2.0%, and the maximum RBE is 33.0% and -10.1% respectively; The slope of the linear fitting equation of monthly mean wind speed is 0.93 and 0.97 respectively, the intercept is 0.29 m s-1 and 0.02 m s-1 respectively, and the correlation coefficient is 0.98 and 0.99 respectively; The mean Root Mean Square Error (RMSE) of monthly mean wind speed is 0.17 m s-1 and 0.14 m s-1 respectively, the maximum RMSE is 0.49 m s-1 and 0.22 m s-1 respectively, the Relative Root Mean Square Error (RRMSE) is 7.4% and 5.7%, and the maximum RRMSE is 35.2% and 13.3% respectively. The error of ground wind speed of ERA5-Land high-resolution data is relatively low, which is conducive to improving the accuracy of wind energy resource assessment.
