Renewable Energy Demand, Wind Turbines, Killing Bats

Published January 3, 2017

Government mandates and subsidies to produce increasing amounts of renewable energy is harming multiple species. For instance, in a November 2016 study published in Current Biology, researchers in Britain found the demand for wind power is killing bats despite efforts to reduce bat deaths.

The study examining the efficacy of Environmental Impact Assessments (EIAs) in reducing bat deaths from wind turbines found each wind turbine in the United Kingdom kills one to two bats each month on average, with some killing more than 60. They also found in many countries the efforts required to assess the environmental effect of planned wind farms have proven flawed and inadequate in measuring the risk to bats.

The risks posed by the more than 300,000 wind turbines around the world to birds flying into the blades are becoming better understood, however, turbines risk to bats, while recognized, is less well understood.

Fiona Mathews, an assistant professor of mammalian biology at the University of Exeter in England and a co-author of the study, told The New York Times, bats seem to be attracted to turbines, whether because of the noise the machines make or because bugs, bats main source of food, get trapped in the air currents created by the turbines spinning.

“It’s a ready food supply,” Mathews said.

Minimize Bat Deaths

The authors fear, with demand for renewable energy rising, the threat to biodiversity, particularly bats and other avian species, is growing as well. Unfortunately, according to the researchers, EIAs, the main tool used across the world to predict the overall positive and negative effects of renewable energy developments have failed to prevent bat deaths. The study indicates EIAs do not accurately predict the sources and types of risks bats face from wind installations. For instance, the researchers found bat casualties from the turbines in unexpected places like locations at high-altitudes. According to the study, however, even in instances where EIAs show risks to bats is high, the steps taken to mitigate harm and prevent bat deaths have failed.

Mathews told Scientific American magazine the causes and repercussions of bat fatalities at wind farms needs further study, with the goal of minimizing deaths over time even as wind energy proliferates.

Kenneth Artz ([email protected]) writes from Dallas, Texas.


Paul R. Lintott, et al., “Ecological impact assessments fail to reduce risk of bat casualties at wind farms,” Current Biology, Volume 26, Issue 21, November 7, 2016: