Q: What is your opinion of wind
energy’s environmental and health effects?
A:
First let us say that we very much favor wind power and all other
sources of environmentally friendly, renewable energy. They are
crucial alternatives to fossil fuels, which are major contributors
to global warming, and to nuclear reactors, which, among other
problems like heavy water usage, have an unsolved dangerous waste
hazard. We have found that many of the criticisms of wind energy are
inflated. And a much greater threat to birds, animals and humans
comes from allowing climate change to create floods, drought, forest
fires, severe storms and other catastrophic occurrences.
The controversy that sometimes surrounds wind
energy often relates to scale. As in many situations, small is often
better. For the past few decades, there have been many research
studies about the effects of wind farms on bird mortality and the
quality of life for nearby residents.
In the U.S., these studies were prompted by the
relatively high number of raptors that were found dead at the
Altamont Pass Wind Farms near San Francisco – a situation that even
prompted an unsuccessful lawsuit by the Center for Biological
Diversity in 2004.
A much greater threat than
wind energy to birds, animals and humans comes from doing nothing and allowing
climate change to decrease habitat worldwide through drought, forest fires,
severe storms and other catastrophic occurrences.
The Altamont Pass site was one of the first
locations in the U.S. to be developed for commercial wind energy
generation. Recent research indicates that the large-scale bird
kills at that site are an unusual and possibly unique phenomenon
caused by a number of factors, including bad siting and the
particular wind turbine and tower technology used when it was built
in the early 1980s. The wind farm consists of lattice-like towers,
which provide attractive perches for birds, supporting 4,800 small
turbines, as opposed to newer farms consisting of larger turbines
constructed on taller tubular towers.
Properly sited, today’s wind farms seem to present
much less danger to bird populations. Nevertheless, studies show
that in the U.S., turbines kill between 40,000 and 70,000 birds per
year. However, these numbers must be put into perspective with the
generally far greater hazards posed by land clearing due to
residential sprawl, road traffic, large buildings, power lines,
traffic, hunting and agricultural pesticides, which together account
for billions of bird deaths annually. One study estimates that each
year 57 million birds are killed by cars and 97.5 million by
collisions with plate glass. Domestic cats are reported to be
responsible for the demise of hundreds of millions of songbirds and
other species every year. The numbers must also be compared to the
dangers from other forms of energy generation – for instance, the
Exxon Valdez oil spill alone is estimated to have killed between
375,000 and 500,000 birds.
In other parts of the world, where the wind industry is better
developed, the research is relatively positive. Danish radar research, for
instance, shows that most birds tend to change their flight route some 100 to
200 meters (109 to 219 yards) before they arrive at a turbine, passing above at
a safe distance, research that has been confirmed at several Australian wind
farms. One of the more comprehensive pieces of research is the eight-year Danish
Offshore Wind Study on Key Environmental Issues, which looked at
pre-construction and post-construction data on the effects of off-shore wind
farms on birds, marine mammals, fish and the people living in neighboring
coastal communities. It found that there were virtually no negative impacts of
the offshore wind farms to birds, and noted that tagged birds altered their
flight paths around the turbines.
In the U.K., the Royal Society for the Protection of Birds
supports wind farms, concluding that, “The available evidence suggests that
appropriately positioned wind farms do not pose a significant hazard for birds.”
A new report, issued in May of 2007 by the National Academy of
Sciences in the U.S., suggests that bats have far more to fear from wind
generators than birds do. The scientists suggested that the wind-power turbines
generate sounds and, possibly, electromagnetic fields that lure the acoustically
sensitive creatures into the spinning blades. A reduction in bird and bat
impacts is expected to evolve as research results in improvements in turbine
design and wind farm location.
As the number of offshore wind farms increases and they move
further into deeper water, there is a concern that the noise and vibrations
generated by the turbines could be transmitted via the tower structure to the
water...and that that could become significant enough to harm sea mammals. The
Danish Offshore Wind study found no impact on seals and fish in shallow waters.
However sound injected into deeper water will travel much further and will be
more likely to impact bigger creatures like whales, which tend to use lower
frequencies than porpoises and seals. A recent study found that wind farms add
around 100 decibels to the existing low-frequency ambient noise and this could
impact baleen whales’ communication and stress levels.
In some areas, nearby residents have complained of noise that
causes high levels of human stress. However, it’s in manufacturers’ best
interests to design blades that are increasingly aerodynamic because that
increases turbine efficiency, with the side benefit of reducing noise. One
report from Greece’s Centre for Renewable Energy Sources claims that the level
of audible noise from a modern wind turbine is, at a distance of 200 meters (219
yards,) “lower than the background noise level of a small town in the
countryside.” In December 2006, a jury in Texas denied a suit for private
nuisance against FPL Energy for noise pollution after the company demonstrated
that noise readings were not excessive, with the highest reading reaching 44
decibels, which was characterized as approximately the same noise level as a
light wind.
Concerns are sometimes expressed about the health effects from
electromagnetic fields. The electrical generator and transformer do emit
electromagnetic radiation, but it’s confined to a very short distance from the
turbine housing, which is located high above the ground. If there is any danger
on that score, it’s likely from the power lines rather than the turbines, and
power lines are a necessity of any sort of power distribution.
The National Academy of Sciences addressed the aesthetic downside of wind farms
in its report. “Not everyone considers [turbines] beautiful,” the authors wrote.
They cited marred mountain ridges and disrupted views, and other complaints that
have related to the industrialization or rural areas due to the concentration of
wind turbines.
For a variety of reasons, wind farms – like most other
large-scale developments – have a tendency to divide communities. For instance,
residents of the eastern Ontario community of Wolfe Island are currently split
about a wind power project that will earn millions of dollars annually for their
township, but that some fear will industrialize their rural landscape. Dozens of
residents have agreed to allow wind turbines on their property in exchange for
royalties worth thousands of dollars per turbine, and claim that most people
opposed to the project are either newcomers or don’t even live there.
The Greek report Environmental Impacts of Wind Farms: Myth
and Reality cites EU research that found people who are favorably disposed
to the development of wind energy accept wind turbines much more easily than
people who are opposed. In the same studies, it was also found that wind farms
are visually more acceptable to people who have been informed of the benefits
derived from their use.
While there have been many studies conducted on the effects of
commercial- scale wind installations, we haven’t been able to find any on the
impact of home-sized wind systems. Wind energy advocate and entrepreneur Mick
Sagrillo, who writes regularly for the American Wind Energy Association (AWEA,)
says that’s because it’s just not an issue, “especially when ‘big’ wind’s impact
on birds is considered biologically insignificant [to birds].” As for noise
pollution, a typical residential- scale turbine is estimated by the AWEA to make
less noise than the average washing machine.
As for those large-scale wind farms, there is no doubt they need
to be planned and constructed carefully. The National Academy of Sciences report
criticized “the lack of any truly coordinated planning” in the rapid growth of
wind farms and called on federal, state and local governments to pay more
attention to the effects of turbines on wildlife and scenic landscapes. And that
seems prudent.
However, problems with wind turbines must also be compared to
the damage wrought by other power sources. For instance, a 2004 Irish study
found that wind-generated electricity reduces carbon dioxide emissions between
0.59 and 0.33 tonnes per megawatt hour (MWh) over other methods of electricity
generation.
Of course, conservation is the most desirable way to mitigate
global warming. But wind energy appears to us to be a safe, clean and
sustainable replacement for some of the energy generated by non-renewable,
greenhouse gas generating technologies.
Update, June 2011: As the popularity for
renewable energy grows, some activists have ramped up their campaigns
against wind power, often playing on people's NIMBY tendencies and fear, and using unsubstantiated information. Here is a recently published explanation of the
scientific evidence that answers critics' concerns and updates the research
presented in this article.
Wendy Priesnitz is the Editor of
Natural Life Magazine and a journalist with over 30 years of experience.
She has
also authored nine
books.
Read her
blog.
This is one of a limited number of articles
from Natural Life Magazine available for free on this website. To read more articles like
this, please
subscribe to Natural Life Magazine.
