Q: What is your opinion of wind
energy’s environmental and health effects?
A: Along with other
sources of environmentally friendly, renewable energy, wind is a
crucial alternative to fossil fuels, which are major contributors
to global warming. They are also an alternative to nuclear reactors, which, among other
problems like heavy water usage, have an unsolved dangerous waste
hazard.
My research shows that many of the
criticisms of wind energy are inflated. And, arguably, a much greater threat to birds,
animals, and humans results 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.
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 designed and 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 windows and building cladding. In
addition, 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 1989 Exxon Valdez oil spill
off the coast of Alaska 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 report issued early in 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.
However, 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. One 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.
Some people living near wind farms also can be impacted by the weak noise
produced by the rapidly spinning blades and perhaps from the turbine
machinery, as well as by vibrations and disruptions in air pressure. In some areas, nearby residents have
complained of this noise, which is called
“infrasound”
– that which is lower
in frequency than 20Hz per second. This noise reportedly can cause sleep
disturbances, headaches, hearing problems, and concentration issues.
The newer wind turbines are considerably quieter than the first
models built and the technology has evolved to include
sound-dampening systems. The noise from gears and generators has also been
reduced, and insulation added to the turbine mechanical areas. In many
areas, guidelines have been developed to restrict siting to include buffer
zones between residential areas and wind farms.
It’s also 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.
A
2018 study by a team of researchers from the University of Toronto found
no direct link between residents’
distance from wind turbines and sleep disturbances, blood pressure, or
stress.
Concerns are sometimes also expressed
about the health effects from electromagnetic fields. The electrical
generator and transformer do emit electromagnetic radiation, but it’s
confined to a 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, in 2007, residents a community in eastern
Ontario, Canada, were split about a wind power project predicted to earn
millions of dollars annually for their township, but that some fear will
industrialize their rural landscape. Dozens of residents agreed to
allow wind turbines on their property in exchange for royalties worth
thousands of dollars per turbine, and claimed that most people opposed to the
project were either newcomers or didn’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, I 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].” Regarding 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 an excellent way to mitigate global warming. But wind energy appears to
me to
be a safe, clean, and sustainable replacement for some of the energy
generated by non-renewable, greenhouse gas generating technologies.
Wendy Priesnitz
is the Editor of Natural Life Magazine and a journalist with over 40 years of experience.
She has also authored 13 books. This article was published in Natural Life Magazine in 2007
and updated in 2018.
