Low Air Pressure from Wind Turbines Killing Bats

August 29, 2008 02:16 PM
by findingDulcinea Staff
Scientists say they have discovered the true killer of the animals, after assuming for years that it was the turbines' blades that were at fault.

The Truth Behind Wind Turbines and Bats

Scientists have known for years that wind farms are killing bats in large numbers, just as they kill birds, but had always believed thought that the spinning blades of the wind turbines were smashing the animals to death.

A study released in Current Biology this month reports the results of a study of 188 bats killed near a wind farm in Alberta, Canada last year. Researchers found that almost half of the animals had no external injuries, and that most of those that they dissected had suffered burst blood vessels in their lungs, suggesting that their deaths were caused by a condition called barotrauma.

When wind moves through a turbine's blades, air pressure drops behind them. The lungs and blood vessels of bats quickly expand and burst when they wander into the low-pressure zones.

"As turbine height increases, bat deaths increase exponentially," said ecologist Erin Baerwald of the University of Calgary in Alberta, to Scientific American. "What we found is a lot of internal hemorrhaging."

Baerwald notes that while birds are also killed by wind farms, their lungs are stronger and more resistant to pressure changes. They are typically killed after being hit by turbine blades, and not because of the air pressure difference.

Scientific American reports that it is not clear what can be done to prevent the bats' deaths, other than stopping the turbines from operating at night, when the animals are most active.

Related Topic: Wind power in the United States and worldwide

Billionaire oil tycoon T. Boone Pickens is hoping to steer the United States away from fossil fuels and toward wind power. The owner of Mesa Power LLP suggests that wind power could be used to provide 20 percent of the country's electricity, freeing up more natural gas to be used to power cars. Cutting dependence on foreign oil in this way could save the country $230 billion a year, Pickens says.

General Electric, as well, is looking to alternative energy sources and has announced a multimillion-dollar plan to invest in a wind turbine project. The company's Financial Services division has announced that it is buying up a major stake in Houston-based turbine company Horizon Wind.

European researchers are looking into harnessing wind energy with kites. Scientists from Delft University of Technology in the Netherlands have successfully used a giant kite to produce 10 kilowatts of power—enough to provide electricity to 10 family homes. They hope to produce enough to power 100,000 homes through further development of their experiment.

Scotland has major plans for wind energy. The country is planning to build Europe's biggest wind farm, positioning the country as a leader in the worldwide push for renewable energy. Ministers of the country have approved the plan to construct a 152-turbine wind farm in Clyde, South Lenarkshire. The Clyde wind farm will provide electrical power for 320,000 homes, generate 200 jobs during construction and 30 permanent positions once completed.

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