Wind towers vs. birds and bats – information is controversial
My viewpoint was, and still is, that the huge towers (260 feet high), gigantic blades (add another 150 feet), blinking strobe lights, permanent removal of wind-hindering vegetation, and highly visible road and transmission infrastructures are totally inappropriate for wild, undeveloped, scenic and highly visible settings. And I said I thought that opponents should focus on those issues, as well as the small return in electricity for the massive public price paid, aesthetically and otherwise, and should perhaps stay away from the issue of bird mortality caused by the rapidly spinning blades. The jury is still out on that, I said, and conventional wisdom is that vastly more birds are killed by high-rise windows and free-running cats......Well, so much for conventional wisdom.
Editor's Note This opinion piece was written in response to a letter received from Lisa Linowes that is available via the link below.
January 4, 2006
by John Harrigan
in North Country Notebook, Littleton Courier, Salmon Press, Meredith, NH
Every now and then it’s good for even the most grizzled and veteran writer to be reminded of an old axiom, which is “Don’t be too quick to dismiss what might be someone else’s cause.” In a recent column about the controversy over wind towers, I did just that concerning bird mortality, and earned some excellent, polite, informative, and yes, mollifying mail.
My viewpoint was, and still is, that the huge towers (260 feet high), gigantic blades (add another 150 feet), blinking strobe lights, permanent removal of wind-hindering vegetation, and highly visible road and transmission infrastructures are totally inappropriate for wild, undeveloped, scenic and highly visible settings. And I said I thought that opponents should focus on those issues, as well as the small return in electricity for the massive public price paid, aesthetically and otherwise, and should perhaps stay away from the issue of bird mortality caused by the rapidly spinning blades. The jury is still out on that, I said, and conventional wisdom is that vastly more birds are killed by high-rise windows and free-running cats.
Well, so much for conventional wisdom.
First, a mea culpa. I obtained my impression of the relative ranking of bird mortality from my steady dose of reading an eclectic and extensive mix of magazines, periodicals and newspapers, plus opinions gleamed from a couple of friends in the wildlife field. Everything I’d seen or heard indicated that birds tended to avoid the towers and mortality did not seem to be a big issue.
It all depends, of course, on your sources of information, and it turns out there’s a ton of controversy out there on the effects the towers will have on birds, not to mention bats.
A reader from the Littleton area good-naturedly walked me to the woodshed on all this, and acquainted me with an organization called National Wind Watch (windwatch.org), whose stated mission is to “promote awareness of the risks and related impacts of industrial wind energy development on our environment, economy and quality of life.” The group’s Web site offers a lot of information on current and proposed wind projects, and lists papers and news articles as well as links to other sites on the subject.
“In your column, you state bird mortality is a subject that wind energy opponents should stand down from,” the reader wrote. “However, there is good reason for us to continue to shed light on this problem. To our knowledge, no commercial scale wind facility in the United States has been subject to pre-construction avian risk assessments that included remote sensing (radar or acoustical). The U.S. Fish and Wildlife guidelines recommend a minimum of three years of remote study, since bird migration periods vary year to year. This assessment will give us a good understanding of the number of birds that fly within the path of the spinning blades.”
The notion that the massive blades spin slowly, giving winged creatures plenty of time to get out of the way, is a fallacy, she said. “The wind companies have argued the point that modern turbines spin more slowly than the older models, thus they are less deadly to birds. The ‘slower’ spin rate is a complete misnomer. The fact is, the new towers have a blade length of 115-plus feet. The three-blade assembly sweeps an area of 1-plus acre in size. In order to cover this distance at 15-18 revolutions per minute, the blades are spinning at 150-200 mph at the tips. This is a law of motion (rate x time = distance). At a distance, the blades look like they’re dancing slowly in the breeze. This is an illusion. If a bird clears one blade, the next is traveling right at him at 150 mph. Since the blades are moving, birds do not judge distances well. (Also) the newer towers are taller, spinning quickly at altitudes where migratory birds fly.
After reading up on the this issue, I got hold of Eric Orff, a wildlife biologist with the New Hampshire Fish and Game Department and an old friend. Eric wears a lot of hats, but one of his areas of expertise is bats. “There are really high mortality rates on bats, I can tell you that,” he said, and probably birds as well, and he concurred on the need for much more data.
To date, two or three sites have been talked about in New Hampshire, but the major projects are underway or being planned in Maine and Vermont. One of the articles I perused on Wind Watch’s Web site concerned a proposal to erect 29 wind turbines on 260-foot towers with 150-foot blades on Redington Pod Range and Black Nubble in the remote 300,000-acre section of Northwestern Maine. The developers would upgrade or build 18 miles of high-grade road to accommodate the huge vehicles, cranes and other equipment needed to support and erect the towers and turbines.
The developers have estimated that the “wind farm” would create enough electricity to power 44,000 Maine homes. But the electricity, opponents note, would go into a regional New England grid to be directed to where needed at the time, and Maine has no current power deficit.
And so it all comes down to the same old question. Is it worth it, not just to tourists and hikers, but to Mainers who love their landscape? And it is worth it in terms of an unknown price not just to wildness, aesthetics, and the darkness of the nighttime sky, but yes, in birds and bats as well?