Windfarms in General: Noise

The Department for Business Enterprise & Regulatory Reform, which seem to be responsible for guidelines regarding renewable energy states on their website: "In low noise environments the daytime level of the LA90, 10 min of the wind farm noise should be limited to an absolute level within the range of 35-40dBA". and 'a modern turbine has to be placed at a distance of between 200 and 300 metres from the receptor to reach a sound pressure level of between 45 and 50dBA.' As well, the noise level seems to decrease by 6dBA when doubling the distance. (click here for full report)

An article in the magazine 'NewScientist' is investigating the effects of noise on health. Under the headline: 'Thousands of people around the world may be dying prematurely or succumbing to disease through the effects of noise exposure' (NewScientist, 25 Aug 2007, pages 6 - 9).

While this article refers mainly to traffic noise, airports and building sites, it gives some interesting numbers: Threshold for cardiovascular problems for chronic night-time exposure of 50dB and above, sleep disturbance 42dB....

While I believe, that even the closest properties in Longhirst will be below these sound levels I will be discussing this (and reports of the WHO) further on the relevant webpage in the Longhirst Windfarm section. (Click here)

Some internet links:

  • Article by British Wind Energy, measuring noise levels of wind turbines and comparing them with natural sounds. Not surprisingly they compare the turbine noise level at 350m distance to the noise in a quiet bedroom....
    here the link: http://www.britishwindenergy.co.uk/ref/noise.html
  • Barrhil Windfarms website. Probably a more objective report with some interesting links (e.g.: Calculators to work out the noise yourself) http://www.barrhill.org.uk/windfarm/noise/index.html
  • An article of Selford University regading amplitude modulation of aerodynamic noise (AM). The term AM indicates aerodynamic noise from wind turbines, but with a greater than normal degree of regular fluctuation at blade passing frequency,typically once per second. An interesting article, but considering that out of 133 windfarms investigated, in only 4 (possibly 8 others) AM seemed to be the main cause of complaint. http://www.berr.gov.uk/files/file40570.pdf