Chapter 6: Wind Energy: Effects on Bats

Utility-scale wind energy facilities require no fuel, consume no water, and produce no greenhouse gas emissions or other pollutants during energy production. Wind power currently supplies approximately 6.4% of the electricity consumed in the United States (U.S.), with continued growth expected in the coming years. Although further expansion of wind power is anticipated to provide environmental and economic benefits, there are increasing concerns about bat fatalities occurring at wind energy facilities across North America. Recent estimates place the number of bat fatalities in the several hundreds of thousands on an annual basis, and that number is projected to rise. As a result, population-level impacts of wind turbine-caused mortality are of increasing concern. For example, modeling efforts for a widespread species, the hoary bat (Lasiurus cinereus), indicate that the population could decline by 90% within 50 years, assuming no growth in installed wind power capacity and no significant implementation of conservation measures. Given increasing demand for wind energy and increasing evidence suggesting that bats are attracted to wind turbines, the need to develop cost-effective and practical impact minimization strategies is a high priority. Current strategies include siting restrictions and operational minimization, both of which limit wind power generation. Potential solutions that do not limit power generation include broadcasting ultrasound from wind turbines or using ultraviolet (UV) light to deter bats from approaching and entering the rotor-swept area where fatalities occur. Another possible solution is the development of turbine-surface materials that reduce the relative attractiveness of wind turbine towers to bats. In this chapter, we provide a succinct summary of known impacts of wind energy on bats and present current and future research priorities. We also describe the challenges and opportunities associated with developing and implementing effective solutions to minimize wind turbine-caused bat fatality.