Changing wind speed distributions under future global climate

Abstract

Based on 12 global circulation models, the simulated changes in empirical 10 m wind speed distributions under the representative concentration pathway RCP8.5 were quantified. It is demonstrated that climate change leads to significant wind speed distribution changes around the world. It is very likely that mean wind speed increases in most parts of Brazil, South Africa and Eastern Australia whereas decreasing mean wind speed is projected for large parts of the USA and Eastern Russia. Changes in the other distribution moments (standard deviation, skewness and kurtosis) are simulated in almost every region of the world. The theoretical distributions Weibull, Kappa, Wakeby and Burr-Generalized Extreme Value were fitted to current and future empirical wind speed distributions. It was found that the simulated changes in distribution moments often lead to changes in the fitting accuracy. This fact highlights the great importance of considering the wind speed distribution as temporally highly variable. Based on these changes, the system of wind speed distributions (including the Burr-Generalized Extreme Value, Kappa and Wakeby distribution) was adapted to potential future climate conditions by optimizing a bagged trees classifier. The use of the system of wind speed distributions ensures a consistent wind speed distribution fitting by selecting the best fitting theoretical distribution under changing climate conditions. The results of this study are a valuable basis for planning future wind energy assessments from both the theoretical and practical perspective.