An international expert in noise has advised the Department of the Environment that new guidelines on acceptable noise emissions from wind turbines must take account of existing ambient noise levels in individual communities.
Acoustic consultant and chartered engineer Dick Bowdler said the current guidelines, introduced in 2006, contain “inaccurate or misleading statements” and that existing guidance “is not evidence based”, and “in some cases contrary to best evidence”.
Meanwhile, the Sustainable Energy Authority of Ireland is seeking consultants to carry out a review of all international academic studies completed on noise from onshore windfarms. The invitation to tender was posted on the eTenders website this week. The review will form part of the overall updating of statutory wind energy development guidelines which is under way.
In his submission, which formed part of an earlier public consultation process, Mr Bowdler warned that the use of fixed limits or set-back distances from the turbines “without consideration of individual local circumstances cannot provide a measure of the significance of the impact of noise”.
“We can compare two houses where turbines are producing a noise level of 43dB. At one windfarm site, perhaps near a main road system, the background noise level could be 38dB and so the margin of turbine noise over background noise would be 5dB — turbines 40% louder than background noise.
“At another site the background noise might be 28dB and the margin would therefore be 15dB — turbines three times as loud.
“Clearly the significance of the impact is more in the second case than in the first.”
He is opposed to prescriptive or “one size fits all” noise limits being used, as he says each planning application needs to be examined individually and their existing level of background noise measured. He says acceptable noise limits will have to vary depending on the size of a windfarm.
Mr Bowdler has been asked by the Ardglass Wind Turbine Action Awareness Group in East Cork and others to make a submission to the wind energy guidelines review.
He describes himself as a “supporter of renewable energy for 45 years” and says he has worked “for all sides of the industry”, including local authorities in Britain, and was contracted to RenewableUK, the UK equivalent of the Irish Wind Energy Association, in 2010 and 2011.
The Ardglass Wind Turbine Action Awareness Group was set up last year when plans were announced for an 11-turbine windfarm between the villages of Dungourney, Castlelyons, Lisgoold, and Ballynoe.
The turbines, which would dwarf the Elysian in Cork City, are being proposed by Ardglass Windfarm Ltd and are within 2.5km of 323 homes.
The group opposes the project on grounds of visual impact, noise impact, and shadow flicker. It has also questioned its ability to create many jobs.
Ardglass is yet to lodge planning permission with Cork County Council.
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