BWEC researchers conduct operational minimization and deterrence studies to evaluate the effectiveness of impact reduction strategies.
Patterns of bat fatality, relationships between weather and turbine variables, and observations with thermal imaging all corroborate and suggest bat fatalities occur primarily on low wind nights, but mostly when turbine blades are rotating at or near their maximum speed. Seasonal low-wind shutdowns during nights or periods of high bat kills have been shown to reduce bat mortality, with relatively little loss in power generation.
Experimentally test the effectiveness of changing turbine operations, based on bat activity and weather variables, to reduce bat mortality and determine the economic costs of curtailment.
Ultrasonic Attraction and Deterrence
- Experimentally test the effectiveness of changing turbine operations, based on bat activity and weather variables, to reduce bat mortality and determine the economic costs of curtailment.
- Develop high amplitude sonar (“jamming”) sound emission device.
- Experimentally test bat response to the acoustic deterring device under controlled conditions in a laboratory setting.
- Determine bat response to the acoustic deterrent in the field at sites with concentrated use by bats.
- Based on the behavioral response by bats from lab and field tests, pursue the development of a deterring mechanism prototype for field testing at wind facilities in 2007.
A wind turbine at a facility in Pennsylvania with blades in a “feathered” position, demonstrating the operational position turbines would be in during low wind shutdown experiments (Photo by Ed Arnett, BCI)
Dr. Joe Szewczak from Humboldt State University analyzes ultrasound recordings from a wind turbine using program SONOBAT (photo by Ed Arnett, BCI).
University of Maryland Ph.D. student Genni Spanjer prepares to release a captive big brown bat during lab experiments to evaluate the efficacy of acoustic deterrents (photo by Ed Arnett, BCI)
Jeremy Bowman, a windsmith with Iberdrola, installs a prototype acoustic deterrent device on a turbine at the Locust Ridge Wind Farm in Hazleton, PA. (photo by M. Baker, BCI)
Ultrasound emissions from wind turbines as a potential attractant to bats: a preliminary investigation (Arnett, Szewczak) May 2006
Responses of the big brown bat, Eptesicus fuscus, to an acoustic deterrent device in a lab setting (Spanjer, G. R.) December 2006
Preliminary field test results of an acoustic deterrent with the potential to reduce bat fatality from wind turbines (Szewczak and Arnett) December 2006
Field test results of a potential acoustic deterrent to reduce bat mortality from wind turbines (Szewczak and Arnett) July 2008
Testing the effectiveness of an experimental acoustic bat deterrent at the Maple Ridge wind farm (Horn et al.) July 2008
Evaluating the effectiveness of an ultrasonic acoustic deterrent for reducing bat fatalities at wind turbines” by Arnett et. al.
Altering turbine speed reduces bat mortality at wind-energy facilities. (Arnett et. al) 2010
Evaluating the effectiveness of an ultrasonic acoustic deterrent for reducing bat fatalities at wind turbines (Arnett et al. 2013)