May 15, 2011

Wind turbines threaten Wisconsin bats

Written by Tony Walter, Green Bay Press-Gazette, 15 May 2011

Wind turbine industry reports filed with the Public Service Commission of Wisconsin indicate that a significant number of bats fall victim to the turbine blades every night, which could mean crop losses.

The rate of bat mortality has a major impact on the agricultural industry, according to a U.S. Geological study recently published in Science Magazine.

The study, conducted by Boston University’s biology department, estimated that insect-eating bats save the agricultural industry at least $3 billion a year.

“Because the agricultural value of bats in the Northeast is small compared with other parts of the country, such losses could be even more substantial in the extensive agricultural regions in the Midwest and the Great Plains where wind-energy development is booming and the fungus responsible for white-nose syndrome was recently detected,” said Tom Kunz, an ecology professor at Boston University and co-author of the study.

White nose syndrome is a disease believed to kill and sicken bats, which first was noticed in Albany, N.Y., in 2006, according to the U.S. Fish and Wildlife Service. The source of the condition remains unclear, the agency said.

According to studies by Current Biology, National Geographic and Science Daily, bats can be killed without being struck by a turbine blade. The studies concluded that air in low-pressure areas near the tips of the blades ruptures the bats’ lungs and causes internal hemorrhaging.

In PSC reports obtained by the Green Bay Press-Gazette, a post-construction bat mortality study of the Wisconsin Power and Light Company’s Cedar Ridge Wind Farm in Fond du Lac County, conducted by the power company, showed that 50 bats are killed annually by each of the project’s 41 turbines – about 2,050 each year.

Similarly, reports show that the 88 turbines in the Blue Sky Green Field Wind Energy Center in Fond du Lac County each kill an estimated 41 bats per year, which is a little more than 3,600 each year, according to the Wind Energy Center’s post-construction study.

Each turbine in the state kills about 41 bats each year, according to estimates compiled by the Wisconsin Department of Natural Resources.

“I can verify that bats are good natural predators of insects and definitely benefit agriculture,” said Mark Hagedorn, agricultural agent for the UW-Extension.

The largest known area for hibernating bats in Wisconsin is the Neda Mine State Natural Area in Dodge County, where a census found 143,000 bats, according to the DNR.

The construction of wind turbines in Brown County has been a controversial subject for years, but most of the complaints focused on the safety and health impact on humans. The impact on bats has not been part of the debate over wind turbine construction in Brown County.

Recently, Invenergy Inc. abandoned its plans to build a 100-turbine wind farm in four southern Brown County municipalities. The town of Glenmore last month approved permits for Cenergy to build eight turbines in the town.

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