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Fairer noise assessment needed for a rural turbine

As someone who, for 15 years, carried out investigations into noise complaints from electrical equipment throughout the South West, I am horrified at the current rash of applications for large wind turbines in Devon. Companies as far away as Glasgow are scouring our beautiful countryside looking for hilly sites where they can install a machine. They are racing to get turbines installed because sensible politicians are now realising that the subsidies paid are far too high (up to 86% of the annual revenue) and that the Bill going through the Lords, which will require a 1,500 metre separation to the nearest property, will stop them in their tracks.

As I understand it, current planning policy on wind turbines makes use of the guideline ETSU R 97. Many people think that this is flawed because it fails to allow for the very low background noise levels to be found in our rural areas – as low as 20 dbA. It is the background noise that masks the turbine noise, and the higher the background noise is, the higher the turbine noise can be before it is audible.

ETSU R 97 cuts off the lower limit level of turbine noise at a property at 35 dbA. This is 15 dbA above a typical background level in our area and is therefore set far too high. In reality, anything above 5 dbA over background noise would be audible. Also the noise surveys carried out for the turbine developers often appear biased in favour of the turbine as they quote high background levels taken near rustling hedges etc and with little proof of the actual turbine noise to be found at a certain distance.

There is the psychological effect of intrusive turbine noise that makes even low levels of noise unbearable. It can be called “The Ticking Clock Syndrome”: We will happily tolerate a ticking clock in a bedroom because we put it there. If a neighbour installed a machine in his garden, without our permission, which produced exactly the same noise in our bedroom we would find it intolerable! Amazingly, the ticking clock would only raise the measured sound level by 1 decibel in the bedroom or 21 dbA over a background of 20 dbA. This is long way below the planners’ guideline of 35 dbA. So if a turbine is going in near you please ask the right questions before it is too late.