Differences in wind farm energy production based on the atmospheric stability dissipation rate: Case study of a 30 MW onshore wind farm

Abstract

The physical characteristics of a wind field significantly influence the energy produced by a wind farm because they are related to the available kinetic energy in the wake region created by wind turbine generators; they also affect wake recovery. To understand the correlation between the external environment and the amount of energy produced, a study based on the interaction between the power characteristics of wind turbines and atmospheric factors is required. In this study, the distribution characteristics of the turbulence dissipation rate (ε) with the regime were analyzed after classifying atmospheric stability by regimes. In addition, the normalized power of wind turbines was analyzed, and the difference in annual energy production (AEP) with the regime was presented. The AEP showed the best value in the slightly unstable regime and the lowest value in the stable regime. Finally, considering the annual mean wind speed at the study site, a difference of approximately 5%–7% was observed between the AEP under the neutral atmospheric regime and other atmospheric regimes. Further, this study highlights the impact of atmospheric stability regimes and the turbulence dissipation rate on energy production, thereby indicating the necessity of integrating these factors to predict the AEP of wind farms.