By Sarah Doty
Post-Bulletin, Rochester MN
Wind turbines' ability to displace carbon dioxide has been equated with planting acres of trees and taking thousands of cars off the roads, but they have also been blamed with killing hundreds of birds and bats each year.
It is that give-and-take that has left people with mixed opinions on the benefits of wind energy.
Jeff Cook-Coyle is the vice president of development of Nature Energies in Rochester. He has been intrigued with clean energy since he was 8 years old.
"With wind we aren't depleting anything," Cook-Coyle said. "There isn't less wind because we are generating electricity, like there is with coal for example."
The ability to always have wind and never exhaust the resource is a positive on many fronts, according to the American Wind Energy Association.
In a report issued by the AWEA, they stated that, "Wind energy offsets other, more polluting sources of energy. That is important because electricity generation is the largest industrial source of air pollution in the U.S."
It would take 23 million tons of coal to generate the same amount of energy that U.S. wind farms create, the report said.
Decreasing pollution is needed to slow global warming, according to Cook-Coyle, a physicist by training.
"Climate change, it's a big deal," he said. "The evidence of it is compelling. It's extraordinary and it's a big deal. We need to be doing things differently, and this (wind) is local energy and it's clean energy."
Dan Juhl, who built the first wind farm in Minnesota, also strongly believes in the need for clean energy.
"You have to remember we need clean energy, and we haven't built hardly any power plants in the last 20 years, but the demand keeps going up and up and the cost keeps going up and up," Juhl said. "With wind, there is no fuel, no waste, no emissions. We want clean energy and carbon-free energy. We need carbon-free energy. Wind power and solar power are the sources of energy in the future."
Even with the positives of wind energy, the impact on birds and bats cannot be overlooked. According to the AWEA, an average of one to six bird deaths occur every year for each megawatt of wind energy created.
That number is down significantly from the original turbines, which had lattice towers where the birds would nest.
"The first wind project that I ever saw was out in Palm Springs, Calif., years and years and years ago," said Peter Tangren of Austin, who has 10 turbines on his land. "In those first projects the turbines were smaller and very close together. So I could see how that could be an issue with killing birds, because there wasn't a lot of places you could fly without getting hit by a blade, but they (developers) have learned a lot."
Nowadays, the towers are made of tubular steel and have no place for the birds to nest. Slower-turning blades have also eliminated some of the problems, so birds can see and avoid them.
The tower and blade changes have made a significant difference, and Garwin McNeilus, who has a 56-turbine wind farm in Dodge County, will vouch for their updated design.
"I have never seen a dead bird or bat out here, not a one."
He says that the reason for that might be because of the way the blade is built.
"A turbine (blade) is like a bug shield on a car. If a bird or something would come along, the current would bring them right up and over the blade."
McNeilus' experience, however, doesn't comfort the North American Society for Bat Research. Last year it adopted a resolution that recognized the issues of climate change but concluded "... the fact that large numbers of bats are being killed by wind turbines cannot be ignored."
Currently it is researching and developing methods to solve the problem.
The National Audubon Society, has taken a slightly different stance.
The group released a statement supporting "properly-sited wind power," in order to reduce the threat of global warming and minimize the negative impacts on bird and wildlife populations.