A single wind turbine can change air currents, creating dangerous winds for birds and other airborne wildlife. (Photo by Michael Tyas)
Wind energy is one of the fastest growing sources of new electricity in the United States. For some environmentalists, that’s
good news. Wind turbines don’t spew smoke into the air. There’s no nuclear by-product. But there is an environmental risk. To see it, you have to view the wind turbines through the eyes of a bird.
The GLRC’s Dustin Dwyer has more:
Transcript
Wind energy is one of the fastest growing sources of new electricity in the United States.
For some environmentalists, that’s good news. Wind turbines don’t spew smoke into the
air. There’s no nuclear byproduct. But there is an environmental risk. To see it, you
have to view the wind turbines through the eyes of a bird. The GLRC’s Dustin Dwyer
has more:
Chandler Robbins has spent a lot of time studying how birds kill themselves. He says he
would go out on windy nights to the Washington Monument in Washington, D.C. He’d
stand at the bottom of the 555 foot tall obelisk and watch the birds at the top:
“Just as they get to the tower, they just go around the edge of it and bang, the turbulence
from the winds going around the tower, sweeps those birds against the tower, and they’re
killed.”
Speaking at a conference, Robbins tells the crowd he once watched more than 500 birds
slam into the monument in one night, and that monument is standing still. Now imagine
wind turbines, some of them about as tall as the Washington Monument, with spinning
blades that reach nearly a football field in diameter.
Alex Hoar is with the U.S. Fish and Wildlife Service. He says a single turbine can now
change air currents for three acres around the turbine itself:
“So, if you put up a hundred turbines, the blades are sweeping 300 acres. So, that’s a large
space. And what we don’t know is when are birds and bats at risk.”
We don’t know because no one has really studied it. Both Alex Hoar and Chandler
Robbins say scientists know a lot about where birds take off and where they land. They
know about migration patterns, but they don’t know about what birds do, or where they
go while they’re in the air.
So, with more wind farms being built across the country, it’s not clear what affect they
might have on bird populations, but some suspect it won’t be good. Peter Kailing works
with an environmental consulting company. He recently did an environmental impact
study for a new 47 hundred acre commercial wind farm in Michigan. He says scientists
can learn a lot from the wind farms that have already been built. He says the ones that
have done the most damage to wildlife have a few things in common:
“The turbine was in a narrow valley, or a mountain-pass, or on the edge of a large
water body with steep wooded cover that was used by migrating songbirds, there’s almost
always a topographical association.”
Weather also plays a role. Peter Kailing and others say that birds tend to avoid cloud
banks by flying under them. That could put them in the path of turbine blades. So, one
way to limit damage would be to shut the turbines down on cloudy days.
Chandler Robbins says better technology could also limit damage. He says turbine blades
could be equipped with sensors:
“If a bird or a bat collided with that blade, it would set up enough vibration so that the
blade could be feathered temporarily to avoid other birds striking until the immediate
problem is over.”
Feathering essentially means that you twist the angle of the blade so that wind passes
over it, rather than pushing the blade into a spin. That way, birds aren’t sucked into it.
It’s basically the turbine’s braking system. Some say you don’t even need a sensor on the
turbine. They say engineers could monitor radar and thermal imaging. That would tell
them if any migrating birds are in the area, and if they are, feather the blades.
Of course, the absolute safest solution in the short term might be just to stop building
wind farms, but you’d be hard-pressed to find anyone who thinks that’s a good idea.
Most seem to realize that any way of making electricity will have some impact on the
environment. The question is what can be done with each of them to minimize the risk.
With wind energy, that work is just getting started.
For the GLRC, I’m Dustin Dwyer.
