Significant bat mortality at wind energy facilities first became widely known in the United States in 2003 when research scientists observed alarming numbers of bats killed at FPL Energy's Mountaineer wind energy plant in West Virginia. The forty-four turbine site located along the forested Backbone mountaintop was found to be slaughtering bats at annual rates of over 50 bats per turbine with some estimates placing the count at close to 100 bats. High mortality was also observed that year at the Meyersdale wind farm in Pennsylvania, another FPL project.
Researchers from Texas-based Bat Conservation International ("BCI") were invited to investigate the cause for the high mortality with the intent of trying to minimize and/or avoid the impact. FPL (now Next Era) initially agreed to cooperate, but in 2004 abruptly changed course and banned further visits by scientists to the sites. To our knowledge, bat kills are continuing unabated and Windaction.org has no independent information to suggest anyone is even monitoring the problem.
In 2007, renown bat expert Dr. Thomas H. Kunz and others published "Ecological impacts of wind energy development on bats: questions, research needs, and hypotheses", which detailed the significant risk that industrial-scale wind turbines posed for migratory and local bat populations in the Mid-Atlantic region of the United States. The authors projected that by 2020, annual bat fatalities at wind energy facilities in this area alone could reach 111,000 bats.
The authors also made clear that their preliminary projections of cumulative bat fatalities were likely unrealistically low.
And developers' own consultants agree. During court proceedings before the U.S. District Court involving the Beech Ridge wind energy facility proposed for West Virginia, experts predicted that more than 135,000 bats would be killed by the turbines through a combination of direct collision with the turbine blades and barotrama. The Beech Ridge project is close geographically to the Mountaineer facility.
Dr. Kunz elaborated on his concerns in written testimony submitted to the court as follows:
"the most severe threats facing bats in eastern United States are habitat loss, White Nose Syndrome, and proliferation of poorly sited industrial wind developments. Habitat loss and degradation as a result of human activity has been occurring for a long time, but the recent threats of White Nose Syndrome and industrial wind developments - and particularly the cumulative effects of the two simultaneous threats -could have especially deleterious effects on a number of bat species in the eastern United States, including the endangered Indiana bat."
Vermont's Agency for Natural Resources is taking bat mortality very seriously. In recommendations to the Vermont Public Service Board involving a 5-turbine project along Vermont's Georgia Mountain, the agency proffered maximum allowed mortality thresholds:
"Adverse impacts to bat populations may occur as a result of the new wind facility and should be addressed when estimated bat fatalities for the period July 1 through September 30 at the Green Mountain site exceed 0.0 threatened and endangered bat species/ turbine (Indiana or small footed bat), 3.0 migratory bats/ turbine (combinations of red bat, hoary bat and silver- haired bat) or 5.0 bats/turbine of other species (combinations of little brown bat, big brown bat, northern long-eared bat, and tri-colored bat)."
But wind developers building in agriculture areas or areas away from forests essentially ignored the bat problem believing it only applied to a few projects along ridgelines in eastern States.
In proceedings before the Wisconsin Public Service Commission on the Blue Sky Green Field Wind Energy Center (88 turbines), developer We Energies dismissed recommendations by the State's Department of Natural Resources (DNR) that pre- and post- construction studies be conducted to understand the effect on resident and migratory bats. Their witness testified that the "project's bat mortality rate is reasonably likely to compare with the published mortality rates at wind farms located in similar agriculturally-dominated landscapes."
Still, the Commission required the project conduct post-construction studies and the results were staggering. Bat mortality was found to be over 40 bats per turbine per year with counts nearly split between migratory and resident species. In an expected 20-year project life, over 70,000 bats will be decimated by this single project.
Scientists at the DNR made it clear to the Commission that there were too few scientific studies completed nationwide for anyone to understand the estimated potential for impacts for a particular wind farm simply by performing a literature review and extrapolating the results from wind farms located in similar environments. And they were right!
The State of Wisconsin now has a decision to make on what to do about bat mortality. Windaction.org hopes Wisconsin and We Energies will act more responsibly than NextEra and the State of West Virginia. An important step is to first acknowledge that the problem exists.