Yellow light for a 'green' energy source
Soaring on the wings of new wind-turbine technology, tax breaks, and rising fossil fuel costs, the US wind-power growth picture looks great - except to Edward Arnett, a wildlife biologist who sees a dead bat in it - many thousands of dead bats, actually.Skip to next paragraph
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Swatted by wind-turbine blades perhaps 300 feet long and traveling up to 200 miles per hour at the tips, bats in some US regions may be killed by wind farms in greater numbers than previously thought, his industry-funded research shows.
Dead bats are just one of a growing list of concerns that threaten to tarnish wind power's reputation as one of the nation's most promising renewable energy sources. Concerns over the potential impact on migratory songbirds, aesthetic issues like the "shutter effect" of flickering turbine blade shadows, and "view shed" damage from turbines on scenic skylines are growing, observers say.
The nation's first offshore wind farm looks as though it could be blown away. An amendment to a US Coast Guard reauthorization bill, which may be taken up in Congress this week, would ban the big turbines within 1.5 nautical miles of shipping and ferry lanes. Amendment supporters say the turbines are a shipping hazard. Supporters say the real concern is that rich folk on the island of Martha's Vineyard don't want ocean views disrupted.
A nest of other problems that may seem small today could hatch into much bigger ones. Consider the many bird lovers in the United States. How happy would they be if wind turbines killed songbirds?
Birds killed by turbines are now only a tiny fraction of the hundreds of millions killed in collisions with skyscrapers, and by house cats. Yet the wind, wildlife, and aesthetics clash could intensify. The US wind power market is expected to grow by 40 percent this year, according to Emerging Energy Research, a Cambridge, Mass., research firm. The 3,400 megawatts of new capacity could power between 816,000 and 1,020,000 US homes, based on American Wind Energy Association estimates.
"It is now recognized that wind power facilities can have adverse impacts - particularly on wildlife, and most significantly on birds and bats," the General Accountability Office (GAO) reported in September.
Mr. Arnett, a research biologist with Bat Conservation International in Austin, Texas, coordinates an industry-funded research effort. "There's no question the industry will face some tough choices in order to maintain the 'green' image of wind energy," he says.
Where to put wind farms is a big one. As wind farms sprout from the Appalachian Mountains to coastal waters to the vast expanse of North Dakota, signs of resistance are also appearing. A threat to scenic vistas may have undone the Cape Wind project in Massachusetts, but a sterner concern, a lawsuit citing adverse impact on migratory birds, has hit a proposed Virginia wind farm.
Industry officials say such concerns are misplaced, since other forms of power generation do far more harm to the environment. Little is known about bat and bird mortality from wind turbines, they say, and industry studies should help stanch the problem. "We have a better understanding of the nature of the risk today," says Randall Swisher, executive director of the American Wind Energy Association in Washington, D.C. "We're working with turbine manufacturers and developers to learn how to minimize the risk and ensure that, as we build, we're not unduly harming birds and other wildlife."
The same GAO report that cites birds and bat problems concludes ambiguously that, "it does not appear that wind power is responsible for a significant number of bird deaths."