Evaluation of the Impact of Environmentally Driven Curtailment Regulations on Wind Farm Energy Production

Environmentally driven curtailment strategies—based on increasing wind turbine cut-in speeds during high bat activity—are increasingly adopted in wind energy regulations worldwide. These measures, typically enforced during summer nights, aim to reduce bat mortality but lead to energy losses that can compromise the economic performance of wind farms. This study assesses the impact of such regulations by analyzing three key variables that influence curtailed energy: mean wind speed, wind variability, and turbine design, characterized through specific power (the ratio of rated power to rotor swept area). A combined approach is proposed, integrating a theoretical energy model with real performance data from 130 commercial wind turbines, enabling a comprehensive evaluation across a wide range of wind regimes and turbine configurations. The results show that curtailed energy increases significantly at low-wind sites and for turbines with lower specific power. Wind variability also has a notable influence, with contrasting effects depending on the wind class. Although the study is based on the regulatory framework under development in Spain, the methodology is generalizable to other regions. The findings provide valuable insights for developers and policymakers, supporting the design of strategies that balance biodiversity conservation with the economic sustainability of wind energy deployment.