Wind Farms useful but may kill birds and bats - Govt. Report

Wind farms, the massive arrays of giant windmills driving turbines, are becoming increasingly important means of generating electricity in the United States, but scientists are expressing worries that the large towers could harm wildlife.

By minimizing the need to burn fossil fuels, the turbines have been touted by some environmentalists as a boon to the environment but for some others the giant towers are posing as threat to birds and bats. Besides their effects on wildlife habitat, some see Wind facilities as blight on the scenery.

Now, a new congressionally mandated report from the National Research Council panel, Thursday criticized "the lack of any truly coordinated planning" in the rapid growth of wind farms across the country. The panel urged federal, state and local governments to pay more attention to the effects of turbines on wildlife and scenic landscapes.

Scientists sought more study of the threat spinning turbine blades pose to birds and bats. The towers appear most dangerous to night-migrating songbirds, bats and some hunting birds such as hawks and eagles.

"The United States is in the early stages of learning how to plan for and regulate wind-energy facilities," says the report. "A better analysis of the cumulative effects of various anthropogenic energy sources, including wind turbines, on bird and bat fatalities is needed, especially given projections of substantial increases in the numbers of wind turbines in coming decades."

However, the panel did not see any evidence that fatalities from existing wind facilities are causing significant changes in bird populations in the country.

Wind farms produce electricity by using the wind to turn giant blades that rotate turbines to make power. The blades have diameters ranging from 230 feet to 295 feet fixed on towers 197 feet to 295 feet tall.

A group of 10-50 wind turbines at a single site is known as a wind farm. Some farms contain hundreds of towers. A wind farm at Altamont Pass, Calif. has more than 5,000 towers.

Wind farms, the alternative methods of producing clean, renewable electrical energy, provide less than 1% of the nation's electricity, and more importantly produce no carbon dioxide (CO2), a major greenhouse gas that mainly contributes to global warming, or any other air pollutant.

A common objection to proposed wind projects in the United States is that they will have a negative aesthetic impact. "The human impacts of wind farms can be both positive and negative," said Paul Risser of the University of Oklahoma, who was chairman of the committee that prepared the report.

Although the Wind projects have beneficial and adverse economic effects on local areas, such as effects on landowners, the regional economy, and local government revenues, but at the same time they also can be disruptive because of noise and shadow flicker, a strobe-like effect caused by rotating turbine blades.

As a case study, the panel examined the mid-Atlantic highlands, a mountainous area that spans parts of West Virginia, Virginia, Maryland, and Pennsylvania.

Wind farms operate in 36 states. Growing from almost nothing in 1980, wind-powered turbines generated 11,605 megawatts of electricity in the U.S. in 2006, though that was still less than 1 percent of the nation’s electricity.

Based on U.S. Department of Energy projections for wind-energy development in the country, the committee estimated that by 2020, wind energy will offset approximately 4.5 percent of the CO2 that would otherwise be emitted by other electricity sources.

In 2005, electricity generation accounted for 39 percent of the United State's total carbon dioxide emissions. The committee estimates that wind farms could generate 2 percent to 7 percent of U.S. power within 15 years.

The recent report was sponsored by the White House Council on Environmental Quality. The National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council, which make up the National Academies, are private, nonprofit institutions that provide science, technology, and health policy advice under a congressional charter. The Research Council is the principal operating agency of the National Academy of Sciences and the National Academy of Engineering.