Public
Country Guardian misquotes ETSU
It is typical of Country Guardian to misunderstand technical information, but be happy to use the material in inappropriate ways. One example of this is their persistent misuse of material on noise.
At the 20th British Wind Energy Association annual conference, held in Cardiff in September 1998, the author of an ETSU report on noise from wind turbines, explained how Country Guardian had misquoted ETSU. This misquote was taken seriously, as, unfortunately, it made its way into the Trade and Industry Select Committee Report on Energy Policy. This report was published on the 9th June 1998 and included a review of the environmental impacts of nuclear energy, mining and renewables.
Two of the three paragraphs on wind energy related to visual impact and construction and the third addressed the aural impact as reprinted below.
"108(b) The aural impact of wind turbines. Rotating wind turbine blades create a "penetrating, low-frequency" noise, the volume of which the Energy Technology Support Unit has confirmed cannot be predicted when a wind farm is planned. Noisy wind turbines have been a significant source of complaint from adjacent residents, particularly because wind farms tend to be sited in quiet rural areas. [280]"
Reference 280 is an unprinted memorandum from Country Guardian
At the conference Mark Legerton from ETSU showed delegates an overhead of the paragraph. He pointed out that it was inaccurate and stated that:
"ETSU has not made any such statements regarding the prediction of wind turbine noise"
He thought it likely that the unpublished memorandum (reference 280) had a similar content to an article on their web site, where they say
"The noise is a penetrating, low-frequency one - a "thump" reminiscent of the low frequency bass notes of a discotheque or a neighbour's noisy party...........
...........The difficulty at the planning stage is that no developer can say with any certainty what noise levels will be created by a proposed windfarm, although he will claim that he can. The Energy Technology Support Unit has written: "At present there is no established method for the prediction of wind turbine noise and basic understanding of wind turbine noise is low. Not enough is known of the basic mechanisms which control the noise radiation process to allow the development of detailed prediction methods. (Assessment & Prediction of Wind Turbine Noise 1993)."
As regards the statement taken from their website, Mark Legerton made three key observations:
- It is not an ETSU quote. The quote on the prediction of wind turbine noise is not from ETSU but from one of ETSU's contractor's reports. All contractor reports have a disclaimer stating that the views and judgements expressed in the report are those of the contractor and do not necessarily reflect those of ETSU or the DTI.
- It is on a different subject. The report Country Guardian is referring to is not about predicting noise levels at nearest residences, but about predicting the "sound power level" of a turbine. The sound power level of a turbine is a theoretical number used to aid turbine manufacturers at the turbine design stage. It should not be confused with audible sound. Wind farm developers use a measured sound power level for predicting how sound will propagate from a proposed development. From a planning perspective, it is of little importance that predicting this theoretical number is difficult, since it can be measured using international standards or recommended practices and therefore does not have to be predicted.
- It is very old anyway. Since 1993 a great deal of research has been done in understanding the mechanisms by which aerodynamic noise is created by wind turbines and it is now better understood.
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