Researchers look for ways to eliminate bird, bat deaths from wind turbines
09/07/09 7:35AM David Chanatry
(Host) Every state in the Northeast has set a target for increasing the amount of renewable energy it produces.
Wind power is a big part of this push, but it may pose a danger to birds and bats.
As part of a collaboration of northeast public radio stations, David Chanatry reports from the site of the biggest wind farm in the region.
(Chanatry) Bill Burke is walking through the alfalfa field behind his farmhouse, right on the edge of New York's Tug Hill Plateau.
There's an old barn next door, some rusty farm equipment in the yard, and the day's laundry is on the clothesline, whipping in the wind.
(Burke) "I'm the fifith generation on the farm right here."
(Chanatry) But Burke no longer works the land. Instead he leases some of it to the Maple Ridge Wind Farm, enough for 6 large turbines. And he works for the companies running the project. One task was to mow the fields so they could count dead birds.
(Burke) "1940 I don't miss much from the tractor seat, and from the tractor seat, myself, I might have observed 5 or 6 birds."
(Chanatry)The wind industry loves low numbers like that, and points to estimates that turbines kill only 60,000 to 100,000 birds a year, a tiny fraction of the millions killed by other common hazards like cars and household cats.
But many projects are proposed for prime bird habitat including ridgetops, and on the coast all the way from Rhode Island to Maine. And that could impact -more- birds.
(Rosenberg) "We know that there is potentially large mortality."
(Chanatry) Ken Rosenberg is the director of conservation science at the Cornell University lab of Ornithology.
(Rosenberg) "What they call the buildout of windpower in the U.S. could involve millions, upwards of more than 2 million turbines. And we just have no idea what that large number of structures on the landscape, especially concentrated in certain areas might mean for birds."
(Chanatry) To find out, industry and scientists are now working together to figure out whether they can site turbines in places that are safer for birds.
Their work comes as the U.S. Fish and Wildlife Service is preparing to issue voluntary guidelines next year on where to locate new wind farms.
At Cornell, they're recording the sounds of birds as they migrate at night. And they're developing software to identify them.
(Rosenberg) "Everyone of those individual little fuzzy calls is a thrush that is flying overhead giving its call. When you hear this cacophony of sounds there are hundreds probably thousands of birds in the air."
(Chanatry) That kind of information is helping scientists to come up with solutions to protect birds.. Moving a turbine just a couple hundred yards may significantly cut down on collisions. Other researchers are attaching mini-GPS units to eagles to pinpoint exactly where they fly. Even radar is being used. Michael Fry of the American Bird Conservancy says bad weather often forces bird down lower in the sky, closer to turbines, where they can be hit by spinning blades. Fry suggests using high resolution radar to spot birds in the danger zone.
(Fry) "Then it would be possible to really fine tune the system to shut down wind farms for short periods of time, perhaps an hour at dawn and dusk."
(Chanatry) This idea of curtailing operations is especially important when it comes to bats.
They appear to be attracted to wind turbines, says Ed Arnett of Bat Conservation, International.
(Arnett) "They may be misconstruing this structure as a place to roost, to secure a mate, a meal."
(Chanatry) Bats and the insects they prey on are most active when there's not much wind, and that's also when the vast majority are killed. So at two windfarms Ed Arnett changed the blades' start-up speed just a little bit. Bat deaths fell as much as 87 percent.
(Arnett) "What it suggests to us is that during these high periods of fatalaties we can target nights for mitigation when we can// change the speeds and feather the blades so they're not moving during the periods when the bats are most active and reduce fatalities considerably."
(Chanatry) The loss of power production is minimal...less than 1 percent says Ed Arnett. That's caught industry's eye. Laurie Jodziewicz of the American Wind Energy Association says -some- wind farms might change their start up speeds.
(Jodziewicz) "We want to be the environmentally friendly choice for renewable energy and electricity generation ... but we do want to make sure we are not putting the wind industry out of business at the same time."
(Chanatry)With so much emphasis on renewable energy, there's little risk of that.
For VPR News, I'm David Chanatry
(Host) Northeast environmental coverage is part of NPR's Local News Initiative. The reporting is funded, in part, with a grant from United Technologies.