High bat mortality at wind turbines, and the vulnerability of rare bat populations, has led to recognition of the need for effective strategies to reduce bat mortality at wind development sites. Curtailment of turbine operation during periods of high bat activity is one strategy which can successfully reduce mortality. However, cut-in speed adjustments reduce power production and revenue, and may cause warranty and maintenance issues for turbines not designed with this practice in mind. A successful deterrent has the potential to reduce impacts on bats, without altering turbine operation or limiting power production. We propose the design of a series of ultrasonic pulse generators, or whistles, to be affixed to a wind turbine blade, which produce ultrasound through mechanical means. The whistles will produce sounds mimicking the spectrotemporal patterns of bat echolocation pulses, thereby enhancing the bats’ ability to detect, localize and avoid the moving blades. We intend to model the internal structure of the whistles after that of a bat larynx, which responds in a non-linear fashion to small changes in air pressure, allowing for chaotic changes in frequency of sound produced. Our devices represent a significant improvement over current technology, which is not effective over the full rotor-swept zone, is limited in placement due to size and power requirements, and is expected to require much more maintenance than a simple mechanical device.
Whistling Like a Bat: Development of an Ultrasonic Whistle to Deter Bats From Wind Turbines
Thursday, February 18, 2016 - 4:00pm
E-Lab 2 Rm. 118 (Kellogg Room)