Thursday, October 16, 2008
By Don Hopey, Pittsburgh Post-Gazette
A way to reduce the high number of deaths of migratory bats at wind turbine sites may lie in a groundbreaking study at Iberdrola Renewables' Casselman Wind Power Project in Somerset County. During the study, conducted at the 23-turbine project from late July to early October, selected wind turbines were stopped during low wind conditions to determine whether shutting down the big blades during low power production periods would reduce bat deaths while having a minimal impact on power generation.
"As responsible stewards of natural resources, we recognize there is an impact on bats that requires scientific study," said Andy Linehan, wind permitting director for Iberdrola, the world wind-power leader. "The new information generated by the Casselman project will be useful in improving many techniques for reducing wildlife risk at those wind power sites where there are significant impacts to bats." Iberdrola will dedicate the 34.5-megawatt Casselman turbine project today. The turbines have been operating since February. Gov. Ed Rendell, a vocal supporter of wind power, is scheduled to attend the noon ceremony at the project near Garrett.
Wind energy holds promise as a clean, renewable energy source. But there have been high numbers of bats killed at many wind-energy facilities and it remains unclear why some bat species seem susceptible to such collisions, especially in the eastern United States, and especially during low wind conditions. "We need to develop renewable energy resources, and we would like to develop those responsibly," said Ed Arnett, a principal wildlife investigator for Bat Conservation International, a conservation group that is part of the Bats and Wind Energy Cooperative. Other members of BWEC are the American Wind Energy Association, the U.S. Fish and Wildlife Service and the National Renewable Energy Laboratory. The cooperative's work since 2004 focuses on identifying and reducing the effects of wind energy on bats.
Previous BWEC research suggests that bat fatalities occur primarily on low wind nights when turbines are operating at low power but in some cases the turbine blades are rotating at or near maximum speed. Scientists think that shutting down those facilities during those low-wind periods could significantly reduce bat fatalities with only a modest reduction of power production. "The U.S. Fish and Wildlife Service is concerned that several species of bats, including potentially endangered bats, are killed each year by wind turbines," said Alex Hoar, the service's northeast coordinator for review of wind power projects. "The Service is pleased to be helping fund this precedent-setting study to test if slightly changing the way a wind turbine operates can substantially reduce or even avoid killing bats." The results of the Casselman study will be made public after they are reviewed by BWEC's scientific advisory committee.
Pennsylvania is the leading producer of wind energy east of the Mississippi River, generating more than 153 megawatts, enough to power 70,000 homes. The Rendell administration has been a major supporter of wind energy and has set a goal to boost wind power production to more than 3,000 megawatts, a twentyfold increase, over the next 15 years. But such a massive expansion of wind energy along Pennsylvania's windiest Appalachian ridges -- which also happen to be bat and bird migratory routes -- has the potential to kill thousands of bats and birds. In 2004, hundreds of migratory birds and up to 4,000 bats were killed by the whirling blades of 44 turbines in the Mountaineer Wind Energy Center on Backbone Mountain in West Virginia. And just down the road from Garrett in Meyersdale, Somerset County, hundreds of bats were killed at a 20-turbine wind power operation.
Don Hopey can be reached at firstname.lastname@example.org or 412-263-1983.
First published on October 16, 2008 at 12:00 am