Bats & Wind Energy

Bats are being killed in alarming numbers at many wind energy facilities around the world. In the U.S. and Canada, nearly 1.7 million bats were estimated to have been killed prior to 2011. Additionally, as many as 1.3 million estimated fatalities may have occurred in 2012.

Wind energy development negatively impacts 23 of the 45 species north of Mexico. Of these, hoary bats (Lasiurus cinereus), eastern red bats (Lasiurus borealis), and silver-haired bats (Lasionycteris noctivagans) account for approximately 70% of those killed. However, at some wind energy facilities little brown bats (Myotis lucifugus), tri-colored bats (Perimyotis subflavus), and other species battered by White-nose Syndrome are frequently killed.

The northern long-eared bat (M. septentrionalis), a species proposed for listing as endangered and two federally endangered species, the Indiana bat (M. sodalis) and the Hawaiian hoary bat (Lasiurus cinereus semotus) are also killed by turbines, although only a few individuals have been recovered to date. With wind energy development in the U.S. expected to expand from the current 60,000 MW to 350,000 MW by 2030, the impact on bat populations could be devastating.

In 2003, Bat Conservation International became a founding member of the Bats and Wind Energy Cooperative, an alliance of state and federal agencies, private industry, academic institutions and nongovernmental organizations designed to provide scientifically credible recommendations for standardizing protocols, methodologies and research to reduce the risk of bats and support long-term, responsible wind energy development. BCI also has served on the Federal Advisory Committee to develop the U.S. Fish and Wildlife Service Land-based Wind Energy Guidelines, provided expert testimony, published peer-reviewed articles, and conducted specialized training sessions for studying the impacts of wind energy development on bats.

In 2008-;2009, BCI conducted the 1st U.S.-based operational minimization study to test the effectiveness of reducing bat fatalities by changing turbine operations. We documented a 44–93% reduction in fatalities with only a 0.3–1% annual loss of energy production. In 2009–2010, BCI conducted the 1st-ever study investigating the ability to deter bats from wind turbines. Using ultrasonic acoustic deterrents, we observed as high as a 64% reduction in bat fatalities. BCI continues to refine operational minimization and optimize ultrasonic acoustic deterrents to provide ecologically sound and economically feasible strategies that minimize bat fatalities and maximize wind energy production. More recently, BCI has contributed to studies integrating multiple technologies, including ultrasonic acoustic detectors, thermal imaging cameras, and radar to better understand bat and wind turbine interactions, and identify the specific timing and conditions under which bats are most at risk.

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