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Are Wind Turbines Actually Bird Blenders?

The criticism of wind power generators from way back in the dawn of the wind energy age lives on despite all of the progress made in renewable energy.
 
 
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Wind turbines are blenders for endangered bird species, and wind energy itself way too expensive -- at least that's the way some critics would have us view the technology that is now the most successful of all modern types of renewable energy. For more than 20 years, the wind power industry has been reacting to such accusations and improving technology. The result: the criticism hasn't changed, and some comparisons are eye-opening.

The two oil crises of 1973 and 1979 revealed the dependency of the U.S. on oil to be a critical weakness of the U.S. economy. President Carter responded by implementing the nation's first wind and solar programs. One of the largest wind energy projects began in 1982 at Altamont Pass east of San Francisco. By 1987, a total of 7340 turbines had been installed -- right where a number of endangered raptors flew. In the 60s, the population of one of the species, the bald eagle, had already been decimated to around 30 birds due to the thinning of their eggshells from the effects of DDT. Without DDT, we may never have thought of wind turbines as dangerous to birds.

The first study on the effects of the wind turbines in Altamont was published in 1992. 1169 of the total 7340 turbines were studied for a period of two years (1989-91), but the study was limited to endangered raptors, with other species only being recorded haphazardly. The study found that these 1169 turbines had killed 182 raptors, i.e. one bird per 13 turbines per annum. That's 0.07 per turbine p.a. However, the number of all of the birds killed by the rotor blades is much higher. A study published by the U.S. National Wind Coordinating Committee (NWCC) in August 2001 estimates that the roughly 15,000 wind turbines then operating in the U.S. kill around 33,000 birds annually, i.e. some 2.2 birds per turbine/year, though this figure fluctuates greatly from one location to another.

How many are too many?

The report emphasizes that even if 1 million wind turbines were installed, the number of birds that would then be killed by the blades -- an estimated 2.2 million -- would still only a fraction of the damage that other man-made structures already cause. Buildings (windows) kill an estimated 500 million birds every year, cars and trucks 70 million, and telecommunication antennas about 27million.

The estimated maximum of 2.2 million birds that may be killed nationwide by wind turbines in the distant future pales in comparison, not to mention the estimated 33,000 for 2001. But has anyone ever called cars -- or buildings, for that matter -- blenders? It should be noted that bird protection groups are now taking the Federal Communications Commission to court because environmental impact assessments (EIAs) have not even been mandatory for many communications facilities.

In contrast, EIAs have long been required for wind turbines, despite the drastically lower danger they pose for birds. Would we have had this requirement -- and this confusion -- without DDT? The NWCC manual for wind turbine permits from 2002 pushes the comparison even further when it points out that the Audubon Society estimates that cats (wild and domestic) kill some 100 million birds each year nationwide.

Indeed, the Audubon Society -- the largest bird protection group in the USA -- is hardly an enemy of wind energy as some (such as a speaker from the right-wing Cato Institute on the Diane Rehm show in November 2001) would have us believe. In June 2001 -- five months before the broadcast above -- Audubon's spokesperson John Bianchi answered my query about the Society's position on wind power as follows:

"At Audubon, we believe wind power is a great, non-polluting alternative to fossil fuels. We have only one reservation: wind generation plants must be located away from habitats for endangered birds, especially raptors, which have a higher chance of impacting with wind turbines. With the proper EIS work, wind plants should be a great benefit to people and the environment."

This positive attitude is mostly based on the understanding that wind power does not cause any air or soil pollution (acid rain), which affects birds directly and severely. Indeed, once the number of birds whose lives are saved by wind turbines is entered into the calculation, the results are incredibly positive. A recent study for a new wind farm in Ontario, Canada estimates that the power from coal-fired plants that wind power would replace would reduce pollution so much that 1710 birds per turbine would be saved annually. Take away the 2.2 birds killed by the rotors, and the balance for wind energy, +1707.8 birds per turbine a year, is not bad. No wonder bird protection groups are in favor of wind power.

Wind Turbines

These are the first wind turbines on Altamont Pass at the beginning of the 80s. Today, a single modern wind turbine would produce several times more power than all of the turbines shown above. The first wind turbines there were often less than 10 yards apart; today, turbines are several hundred meters apart. Also, notice the "open" towers, where birds are able to land or even build nests.

From the USA to Europe

Wind farms in the USA thus do not seem to have any negative effect on bird populations: Since Altamont, bird studies have been conducted in over a dozen states ranging from Tennessee to Minnesota and not one has shown that bird populations have been affected. Nor do they pose a threat to birds in Europe. The Danish Wind Industry Association (whose website offers an exhaustive history and current overview of wind power which can be downloaded in its entirety) puts it this way on its website:

"Birds often collide with high voltage overhead lines, masts, poles, and windows of buildings. They are also killed by cars in the traffic. Birds are seldom bothered by wind turbines, however. Radar studies from Tjaereborg in the western part of Denmark, where a 2 megawatt wind turbine with 60 metre rotor diameter is installed, show that birds -- by day or night -- tend to change their flight route some 100-200 metres before the turbine and pass above the turbine at a safe distance."

A German dissertation came to similar findings for that country: "The effects of wind turbines on small birds observed during the day at four locations are estimated to be low. The danger of birds being killed by rotating rotor blades was also found to be low at the five turbines studied."

And in the offshore field, which will be booming in the next few years in Europe, no danger is expected to emanate from the turbines. In the Netherlands, mussels will even be farmed under the offshore turbines.

Learning from mistakes

As one would expect with a large pilot project, researchers learned a lot from the mistakes made at Altamont. First, EIAs were made mandatory to see whether any animals, especially birds, would be affected. Then, the design of the wind turbines was changed to make them less dangerous for birds. There were mainly two approaches to this end. On the one hand, the closed towers replaced the open ones (that look like power pylons) so that birds would not be able to build nests on them and land when no wind was blowing; on the other, the speed of the rotor blades was reduced.

This slower speed did not, however, lead to lower energy generation. On the contrary, the first turbines at had a capacity of 55kW. Now, 2 MW turbines (that's 2,000 kW) are on the market. And the first 5 MW turbines are being developed for offshore. Not bad: an increase of over 18,000 percent in less than 25 years. At the same time, the price of a kilowatt-hour of wind energy has fallen from over 30 cents to less than five cents in good locations. Wind power is thus cheaper than nuclear and can compete with coal and oil -- even if we do not include the great external costs for these energy carriers. Indeed, wind energy has become so cheap so fast that Germany -- the world's wind leader in terms of installed capacity -- will be revising its Energy Feed-In Act later this year to reduce the guaranteed prices that wind turbine owners get for power they sell to the grid. Wind energy just doesn't need that much support anymore. Wind power is quite a success story. And, my fellow Americans, it's a European success story, not an American one.

Craig Morris directs Petite Planète Translations, which specializes in translations for technologies and policies to keep life on our small planet going.