Last spring, a red tail hawk was hit and killed by Rhode Island's one functioning wind turbine at Portsmouth Abbey School. Brother Joseph Byron says the bird was the first animal fatality he has seen since the 241-foot-high structure started producing 660 kilowatts in March 2006.
An internationally known bat researcher, however, says tens of thousands of bats are killed annually by wind turbines in the US. Unless researchers are monitoring a site, says Boston University professor Thomas Kunz, bat fatalities often go undetected, because their bodies are lost in the brush or eaten by scavengers.
In a November 19 lecture sponsored by the Rhode Island National History Survey, Kunz, director of BU's Center for Ecology and Conservation Biology, labeled wind energy "brown," not green. He also warned that high numbers of bat fatalities may cause populations of insects to increase dramatically.
Concerns about the environmental hazards of wind power have been muted as Rhode Island promotes wind power as a major way to meet its legally mandated goal of producing 16 percent of its energy from renewable sources by 2020.
Rhode Island environmental groups have pushed for wind power to reduce burning fossil fuels, which produce carbon dioxide, one of the principal causes of global warming. Noting that global warming may be a greater risk to animals than wind turbines, Eugenia Marks, senior director of policy for the Audubon Society of Rhode Island, says, "There are risks and benefits to any course we take. What we need to do is increase the benefits and decrease the risks." But Kunz says not enough is known about the dangers of wind turbines, especially to bats.
Kunz reports that wind turbines currently produce 21,000 megawatts of electricity nationally, with another 8000 megawatts planned. "Whether the fauna can withstand that development is certainly not clear," he says. Solar, nuclear, and underwater generation are better ways, he argues, to meet rising energy demands and to reduce carbon dioxide emissions.
Bats appear to be attracted to wind turbines, Kunz says, but since they fly at 25 to 30 mph they cannot always avoid turbine blades whose tips may move at 125 mph. Pregnant bats, carrying babies that comprise 25 percent of their body weight, have an especially difficult time maneuvering around turbines' rotating blades. Many bats also die when their lungs explode due to rapid air pressure changes caused by whooshing turbine blades.
To reduce bat deaths by as much as 50 percent, Kunz advocates stopping low wind speed turbines, which generate little electricity. Fatalities are rare when wind speeds exceed six meters per second, he notes, because insects — the food supply of bats — take cover at higher wind speeds. He also wants companies that receive government subsidies to be required to fund environmental studies. Finally, he calls for carefully locating turbines to avoid key animal habitats.
Sheila Dormody, Rhode Island director for Clean Water Action, adds that alternative energy producers, like all new traditional power plants, should be required to submit environmental impact statements.
