LATELY MORE AND MORE homeowners are thinking about installing small turbines to generate power primarily for their own homes.
The advantages of wind power are obvious. The disadvantages are mostly a concern for people living near the turbines, who may complain about noise, vibration, or changed views. But for me the overriding worry is the potential effect on wildlife. It hardly makes sense to attract wildlife into your garden, then batter them with windmill blades, now does it?
FIRST, SOME BACKGROUND
Most of the concern about wildlife and windpower comes from research done on big, big turbines. Thus far there is plenty of evidence that collisions with the blades do kill birds and bats. There are also concerns about the effect of wind turbines on wildlife habitat. The area around the turbines, as well as the area under transmission lines, is usually cleared of vegetation. Also, some wild animals simply avoid areas where there are man-made structures. But research on the relationship between wildlife and big wind is only just beginning.
Wind proponents argue that the design of wind turbines has been improved to a point where the impact on birds is small. My reading suggests that we need more research to be sure of this.
It looks as though there is even more reason to worry about bats. Apparently nobody thought much about the effect of windpower on these animals until fairly recently. Now it turns out that bats may actually be attracted to wind turbines or to the areas around wind turbines. (Nobody knows why, though there is a lot of speculation.) They are very slow to reproduce, so the death of breeding-age animals could have a signficant impact on their populations. Research on this topic is even scantier than research on wildlife-impacts as a whole.
Researchers are continuing to try to improve the design of big wind turbines so that they’ll have less impact on wildlife, as well as on how to place them so that they’ll have less of an effect. The Nature Conservancy, an organization I respect, seems to be in favor of wind energy as long as turbines are sited properly. But personally I’m going to have trouble supporting big wind until more has been done to prevent injury to wildlife.
THINKING ABOUT ADDING A Small WIND TURBINE?
So what about small wind? First keep in mind that typical “small wind” isn’t all that small. Though you can buy tiny turbines that install on the roof of a house, when people talk about residential or small wind installations they are usually talking about a fairly large turbine (they look big to me, anyway) that installs on a tower somewhere near your home.
There are a lot of nonwildlife issues to consider before putting in one of these turbines, the upfront cost being just one. If you haven’t already done everything possible to make your home energy efficient, installing a smaller turbine is almost certainly not the best use of your money. If you are already energy efficient, CanWea’s Small Wind Energy site is a good place to look for resources that would help you explore this complicated decision.
What about wildlife? According to the CanWEA site, “migrating birds tend to fly well above small wind turbine height,” so at least one wildlife population is probably safe from a smaller turbine. But backyard birds and bats do appear to be at risk. In fact, CanWEA recommends against placing a smaller turbine “in areas where birds concentrate,” which would appear to rule out a home surrounded by wildlife-friendly landscaping … unless you happen to be an exceptionally bad gardener!
The CanWEA site argues that wind turbines “are far less of a danger to birds than buildings or household cats.” This is currently true, but it’s hardly an excuse for adding to the hazards our local wildlife already face. Besides, if homeowners continue to add turbines to their properties, the kill rates will increase.
HOW ABOUT ROOFTOP TURBINES?
Rooftop turbines are more interesting from a wildlife-impact point of view. Although they have moving blades that could potentially injure birds or bats, the hazard area is smaller because the turbines themselves are small. Also some of the designs look as though they would be much less hazardous to wildlife than the conventional vertical-blade (aka wildlife whacker) design. On the other hand, anything with moving blades might be hazardous. I wonder whether it would be possible to enclose a rooftop turbine in a cage?
The tiny turbines are controversial, however, and not just for the usual reasons (noise, etc.). Some critics contend that they do not work, or at least do not work well. The Wind Turbines Now website seems to provide a fairly balanced overview of the issues surrounding rooftop turbines.
I would like to see more research done on rooftop turbines before investing money in them. In June 2009 it was announced that the Boston Museum of Science had set up a Wind Turbine Lab for precisely that purpose, and it will be interesting to see what they (or other researchers) turn up.
IMHO, wind turbines will not not a good choice for wildlife-friendly gardeners until someone can come up with a design that's been shown to be wildlife-safe. It’s hard enough protecting your birds and other wildlife from window strikes and neighborhood cats. We don’t need any more hazards in the backyard.
In the meantime, I’m going to be taking a closer look at solar power. The technology keeps improving. You can use solar to heat water and air directly, but if you would like to try using it to generate electricity, you'll be glad to know that the price of solar panels has dropped dramatically. Solar panels are quiet and inconspicuous, and above all ... they don't move.
Additional sources used in writing this post
“Assessing Impacts of Wind-Energy Development on Nocturnally Active Birds and Bats: A Guidance Document.” (pdf) Journal of Wildlife Management 71(8) 2007.
“Mitigation Toolbox.” Compiled by National Wind Coordinating Collaborative Mitigation Subgroup and Jennie Rectenwald.
“Wind Energy and Wildlife Concerns 101” (PowerPoint presentation). Dale Strickland. Presented at the Wind Wildlife Research Meeting VII, October 28, 2008, Milwaukee, WI.
“Wind & Wildlife: Key Research Topics.” Prepared by the National Wind Coordinating Collaborative Wildlife Workgroup. May 2008.
“Wind and Wildlife: Let’s Keep it Green” (PowerPoint presentation). The Nature Conservancy. Presented at the Wind Wildlife Research Meeting VII, October 28, 2008, Milwaukee, WI.
The art at the top of this post is from Dover Books’ Vintage Label Art, modified by me to add the “D” to “Win.”