Environmentalists and animal lovers are facing a conundrum when it comes to wind power. Wind turbines, with their long blades that rotate at high speeds, kill birds and bats. On the other hand, they are a cleaner alternative to fossil fuels that pollute the environment and destroy habitats. A resolution may be at hand: an inventor claims that his new wind turbine design will not kill birds or bats, will generate more power than existing turbines and will be quieter to boot.
Raymond Green, an 89-year-old World War II veteran, is collecting patents around the globe for his new turbine design. Gizmag offers illustrations and a video about the new turbine, called the Compressed Air Enclosed Wind Turbine. Gizmag explains that the machine, which is shaped like a megaphone,”draws in wind through its wide entrance, pushing it into the more confined space where the turbine blades” are safely ensconced.
Windmills in the U.S. currently produce enough power for 1.6 million homes. (China produces three times as much wind power.) According to the Pennsylvania Wind Working Group, compared to traditional energy sources, running a one megawatt wind turbine for one year saves 1,500 tons of carbon dioxide, 6.5 tons of sulfur dioxide, 3.2 tons of nitrogen oxides and 60 pounds of mercury. There seems to be no debate that wind energy is cleaner than conventional power sources.
There does seem to be debate about everything else. Supporters of wind energy deny that it kills birds in large numbers, or argue that it kills fewer of them than traditional energy sources and other man-made structures do. And there is dispute that Green’s Compressed Air Enclosed Wind Turbine can supply as much energy as the conventional style currently in use.
The U.S. Department of Energy produced a sheet titled “Wind Energy Myths” that downplays the dangers of wind turbines to birds. “Wind farms and wildlife can and do coexist successfully. Wind energy development’s overall impact on birds is extremely low (<1 of 30,000) compared to other human-related causes, such as buildings, communications towers, traffic, and house cats.” The DOE goes on to argue that even though turbines do kill birds, “conventional fuels contribute to air and water pollution that can have far greater impact on wildlife and their habitat, as well as the environment and human health.”
“Windmills kill nearly half a million birds a year, according to a Fish and Wildlife estimate,” the Washington Post reports. The American Wind Energy Association, however, contends that “the current bird kill is about 150,000 annually.” Whichever number is closer to the truth, it appears to have included six golden eagles last year.
A further wrinkle in the situation is the discovery that bats may be at even higher risk than birds. TreeHugger discusses a study reported in Science Daily which found that “bat fatalities at wind turbines far outnumber bird fatalities at most sites.” The study, performed by scientists at the University of Calgary, stated that most of the affected bats are migratory. TreeHugger explains that migratory bats “eat thousands of insects per night (including crop pests) as they move from one region to another. Bat losses in one region could have negative effects on ecosystems far away from the site of wind turbines. Also, because bats have long lives and reproduce slowly, their ability to recover from population crashes is limited.”
Extrapolating from the University of Calgary report’s findings, the Compressed Air Enclosed Wind Turbine may not reduce bat fatalities. The study concluded that bats die on wind farms because of reduced air pressure around each turbine. The researchers found that “90% of the dead bats they examined showed signs of internal hemorrhaging such as could happen with a sudden drop in air pressure,” TreeHugger reported. There is no indication in the descriptions of the new turbine design that it would not reduce the air pressure around it.
The Calgary study also found that about half the dead bats had direct contact with the blades of the windmills, which the proposed design would prevent. A turbine without exposed blades, like the new one, would protect birds more than bats, as birds’ lungs are less susceptible to damage from drops in air pressure and they are more at risk from collision.
In addition to the uncertainty about the numbers of wildlife windmills kill, there is disagreement about the effectiveness of the Compressed Air Enclosed Wind Turbine. Commenters on Gizmag’s article engaged in lively debate about whether the proposed design would be more efficient than the turbines currently in use and even whether it had already been invented. Nevertheless, designer Green has partnered with Sigma Design Company to bring the new design to market.
Photo credit: jerryoldenettell