The principle purpose in regulating the noise emissions of industrial wind turbines is the protection of the sleep of those living nearby. Adequate sleep is essential for human health and well being.
Current guidance, ETSU-R-97, was formulated in 1997 and has never been revised despite considerable research and evidence of harm. Wind turbine noise differs from other sources of noise, such as traffic, in character and in causing annoyance. Annoyance" in this context constitutes a degree of stress sufficient to impair health. Wind turbine noise cannot be treated in the same way as other noise sources. Evidence from a range of sources, set out in this paper, shows that current guidance permits industrial wind turbines to be sited too close to residential properties for the preservation of sleep and health of the residents. My expert opinion is that the minimum setback of large (>2MW) industrial wind turbines should be at least 1.5km from residential properties.
Legal opinion is clear that guidance such as ETSU-R-97 can be set aside if relevant evidence is presented that was not available to those that framed the guidance. The evidence presented constitute material considerations and it is therefore entirely reasonable for a planning authority to enforce a minimum setback distance on the grounds of noise and health.
The evidence provided here leads me answer the following questions from the Northumberland Council Core Strategy Issues and Options report thus: Question 58 - Public health impact must be considered when assessing renewable and low carbon energy schemes.
Question 61- The council should have a recommended separation distance for turbines from houses on health grounds and the current body of evidence would support a distance of at least 1.5km