Arnett’s second solution is to increase the minimum wind speed necessary for wind turbine blades to start turning. Research shows that bats are more likely to be hit on calm nights in late summer and fall. Because this could cause a drop in a wind facility’s energy production, Arnett had trouble getting a company to sign on to study this solution. It was the world’s leading provider of wind power, Iberdrola Renewables, that finally agreed to collaborate, giving Arnett access to all 23 turbines on its Casselman Wind Power Project in Pennsylvania. According to Andy Linehan, the company’s wind permitting director, the benefits of finding a solution to the bat fatality problem outweighed the costs of producing slightly less energy. “We market ourselves as a green industry,” he says. “If we’re going to continue to take that seriously, we’ve got to continue to show it.“
The experiment was a success. By curtailing production during low wind conditions, and increasing the wind speed threshold required to jump-start the turbines, bat fatalities dropped between 56 and 92 percent. The costs to the company were small: a less than one percent overall power loss for the year. Arnett now wants to test this strategy at several more sites.
“This is a worldwide issue,” says Barclay, who is also a science advisor for BWEC. “Most of the research is being done in North America, but wind turbines are going up at an incredible rate in other parts of the world, and so the research we do here can have a potentially bigger impact.”