During 2009, the AEI has been tracking public concerns about wind farm noise, while also studying new research papers and industry trade journals and reports in order to get up to speed on this emerging issue.
AEI’s approach has been the same as it has taken with ocean noise issues since 2004: “to do our best to cut through the rhetoric and hyperbole from advocates on both sides of the issue and get a clearer sense of the state of understanding of these noise impacts”, in order to help inform emerging public policy choices.
Most wind farms not a disturbance
According to the AEI, with wind farm noise, as with ocean noise, “the more we learn, the more obvious it is that there is much we still do not know. And, it’s not nearly as simple as either side in this increasingly rancorous debate appears to think it is”. While the focus of the report is to digest what was learned in 2009, it also include some over-arching themes and bigger-picture context that serves as a useful introduction to those who are new to the consideration of the effects of wind farm noise on people living nearby.
The report balances sensitivity to the experiences of some wind farm neighbours who have been affected by higher than expected noise levels (including some cases of excessive sleep disruption and even abandonment of homes) within a larger context that recognises that most wind farms do not trigger noise complaints, and that many or most wind farm neighbours who can hear the turbines are not especially bothered by the noise.
An extended section of the report addresses noise limits, introducing the many metrics used to measure and analyse sound, and considering several factors that seem to confound well-designed noise models, including quiet rural night-time conditions, amplitude modulation, and wind shear and other related atmospheric conditions.
Ten pages of the report centres on brief lay summaries of recent research and comprehensive reports, including studies of sound propagation, wind shear, and acoustic modelling, effects on wildlife, and annoyance responses among neighbours.
To conclude, the report suggests that both the industry and local activist groups are contributing to the current polarity of denial and fear about noise impacts, and that part of the problem may be that we are facing a situation that includes some fundamental paradoxes that lead scientific studies to come to reassuring conclusions despite negative impacts on a significant minority of people within earshot.
“We must directly face some social choices about how much impact is considered acceptable,” says the AEI.
Finally, the report looks ahead at key themes likely to play out in 2010 and beyond.
New Zealand wind farm noise standard
The timing of this report coincides with the release by the New Zealand government of a new Acoustics – Wind farm noise Standard (NZS 6808:2010), which Fraser Clark, Chief Executive of the New Zealand Wind Energy Association, says “replaces the 1998 version, provides communities, councils and developers with robust, up-to-date methods for the prediction, measurement and assessment of sound from wind turbines, and recommends noise limits that ensure people will continue to enjoy their homes and other locations near wind farms”.
“Wind power is expected to be supplying up to 20% of New Zealand’s electricity within 20 years,” noted Mr Clark, adding that: “It is important that this growth is managed in a way that does not create unreasonable effects on local communities”.
“This new Standard will be key to managing the noise-related effects of newly consented wind farms. While they will be audible at times, the Standard will ensure their sound will not be unreasonable and that it will be at a level that is consistent with existing environmental sound,” he concluded. For additional information:
