The last few weeks have been busy ones on wind turbine sound, with new developments continuing to cast doubt on anti-wind groups’ claims.Perhaps the most telling is a new study from Canada’s Pembina Institute, looking at wind farm complaints (or rather, the lack of wind farm complaints) in the province of Alberta, where some of the earliest wind farms in Canada were installed.
In a blog post about the study, Pembina’s Benjamin Thibault explains, “[U]nlike some parts of the country, we don’t tend to hear much about [wind power in Alberta], so my colleagues and I wondered whether, in fact, we were just missing something.”
In fact, it turned out, while the Alberta Utilities Commission, which regulates electricity in the province, has a 13-year-old database with the records of 31,000 contacts from members of the public, not one of those 31,000 contacts has been about the sound of operating wind turbines. That’s a very striking finding, but it lends credence to the work of Australian Prof. Simon Chapman of the University of Sydney, who has a pending study finding that complaints about turbine sound in Australia are heavily focused on areas where anti-wind groups have been conducting public campaigns.
Pembina researchers went further to unearth evidence of complaints, Mr. Thibault says, contacting:
- “Operators of existing wind energy projects;
- Municipalities (municipal districts and counties) where operating wind energy projects are located;
- Local and provincial health authorities; and
- Municipal agricultural fieldmen.”
“The operators of the wind farms did report some complaints during operations, noting eight unique complaints, most of which were resolved noise complaints (five), along with a few generalized complaints about wind energy broadly.
“Only three complaints about operating wind farms came to the seven Alberta municipalities with wind energy projects: one about ice throw that was investigated and dismissed, one about the density of wind turbines offering a terrorism opportunity, and one about noise, which was referred to the operator.
“No more complaints were found with the health contacts surveyed (two regional health inspectors covering municipal districts with over half of Alberta’s wind energy) or the livestock contacts (five agricultural fieldmen also covering the majority of the experience).”In other news: The co-owner of the largest wind farm in Australia, AGL Energy Ltd., released the results of a voluntarily commissioned, detailed study of infrasound and low-frequency sound emissions at its facility.The study, conducted by consulting firm Resonate Acoustics, measured infrasound and low-frequency sound levels at two residences located 1.1 and 1.7 miles from the wind farm — before any turbines were operating, when 105 turbines were operating, and when all 140 machines were running. It found the infrasound and low-frequency sound levels unchanged.
- Wind farms are widespread have been around for many years, but there were no complaints about health effects until 2002, with a large increase (in Australia) in 2009 after anti-wind groups began focusing on the topic.
- While anti-wind groups claim that impacts are immediate and long-term, no complaints have been raised about many (65 percent) of the wind farms on the continent.
- The number of individuals complaining to date is 129, or approximately 1 of 254 of all residents within 5 kilometers of wind farms.
- Some of the most typical complaints ascribed to turbine sound, such as high blood pressure and difficulty sleeping, are common among the broader Australian population regardless of the proximity of wind farms.
- Millions of people live in areas with higher levels of sound, including the inaudible infrasound some blame for a variety of ailments (common sources of infrasound include waves, motors, storms and the human circulatory system).
Ketan Joshi, a research and communications officer at Infigen Energy, an Australian wind farm developer, is featured in a radio interview with ABC Australia News, in which he discusses the problem of pseudoscience as applied to wind turbine sound and other phenomena: “Far from the fringe paranoia often attributed to people who believe wind turbines are doing them harm, we mostly see honest individuals who have been taken in by a calculated campaign, designed to exploit several key vulnerabilities of the way we perceive danger.” Mr. Joshi talks about how he himself has personally experienced such concerns (e.g., about using his cell phone) and the strong tendency, called “confirmation bias,” for people to unconsciously select perceptions that conform to their opinions.
Mr. Joshi also has a new blog post on work that is being done to develop a computer program that will allow people to hear very accurate representations of wind turbine sounds. After seeing the program in action himself, he concludes: “It’s an established truth that experiences are more memorable than numbers. When was the last time you decided that a light was bright by measuring its luminosity? You didn’t — you looked at it through your own trusted (and well-tested) machinery of perception. I suspect it’s very much the same with the experience of sound. If we’re told of a decibel output, it’s not really that memorable. But if we can experience an accurate representation of wind farm noise ourselves, it sticks with us.
“Visiting a wind farm is great, and you get to experience it first hand, but you’re limited to one wind speed, and one wind direction. This ‘Auralisation’ tool seems to be able to accurately represent a variety of conditions, and I think the engineers at Arup deserve some credit for the rigour they’ve put into the science behind it.”
This article was originally published on AWEA’s Into the Wind blog and was republished with permission.
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