A National Academy of Sciences report Thursday criticized "the lack of any truly coordinated planning" in the rapid growth of wind farms across the country, and called on federal, state and local governments to pay more attention to the effects of turbines on wildlife and scenic landscapes.
Wind provides less than 1% of the nation's electricity, but it is one of the fastest-growing alternatives to fossil-fuelproduced power, a major contributor to global warming.
In the last six years, U.S. wind capacity has more than quadrupled. And by 2020, the report predicts, it could offset as much as 4.5% of the planet-warming carbon dioxide that American utilities would otherwise spew into the atmosphere.
But wind, the report notes, "is surprisingly controversial.... Not everyone considers [turbines] beautiful." The effect on wildlife could escalate as wind power grows, with bat and raptor populations especially at risk due to their slow reproductive rates. Wind farms should be located away from major migration flyways and from habitats that attract birds of prey. Projects should be reevaluated by government officials "at all states of planning and operation," said Paul Risser of the University of Oklahoma, chairman of the study group.
Evaluating wind projects, the report noted, is complicated by the fact that the benefits tend to be regional and global -- less air pollution and less reliance on foreign oil -- whereas the costs are felt at a local level: marred mountain ridges, intermittent humming noise and disrupted wildlife habitat.
Nonetheless, the danger from newer wind farms appears to be less than from some earlier projects, especially in California's Altamont Pass and San Gorgonio Pass, which have thousands of smaller turbines on lattices. Up to 37,000 birds are killed by turbines annually, the report noted, more than half of them in California.
Newer, larger turbines on single poles "appear to kill fewer birds," said study director David Policansky, "but we can't be sure yet because the research hasn't been adequate." Far more birds are killed by hitting vehicles or buildings than by turbines, the report noted.
Julia Levin, policy director for Audubon California, agreed with the report that more research was needed. "In some parts of the country," she said, "wind power may increase more than tenfold, yet we don't know what the cumulative impacts of that will be on wildlife."
California has nearly completed new guidelines to reduce the environmental impact of wind farms, but many other states have yet to address the issue -- though 36 states now have turbines.
The report's call for better evaluation of the costs and benefits of individual projects comes as Congress considers an extension of tax credits for wind development. At a House subcommittee hearing this week, the American Bird Conservancy called for any new tax credit to be tied to requirements that developers minimize the impact on wildlife.
Voluntary guidelines are being ignored by the wind industry, according to the conservancy's Michael Fry. He estimated that by 2030, more than 1 million birds, including 50 species of songbirds, could be killed by turbines each year unless government stepped in to regulate wind farm development. One possibility: installing radar so turbines could shut down if bird flocks approached.
Nonetheless, bird advocacy groups support wind power as a way to reduce global warming, which they view as a far greater threat to wildlife.
The congressionally mandated report, 267 pages long, was drafted by a group of academics and experts assembled by the National Research Council, an arm of the National Academy of Sciences.
The group projected that wind could account for a maximum of 7% of the nation's electricity in 15 years, a more conservative estimate than the industry goal of 20%. The report addressed only onshore projects, although offshore wind farms are under consideration in Massachusetts and other states.