Email message to Scottish Power and Force9

On behalf of the community council, I have tried to be specific about the information we need but it is probable that further questions will arise as time goes on. If you are able to make a start at supplying these data it would be much appreciated, as the sooner we can begin to allay any fears about noise the better.

With regard to visual impact: if we were to give the co-ordinates and elevation of viewing points, would you create an image to show the extent to which turbines would be visible.

The data sought concerning noise are:

(1) Sound power level of the turbine you propose to use.

This will probably be shown graphically for different wind speeds. Confidence intervals would make any averages more meaningful.

If the data was also available in dB(C) or unweighted , and given as a frequency analysis, it would be of most use.

(2) Noise at locations around a wind farm.

We look forward to receiving your calculations of sound pressure levels, meanwhile, could let us know a little about the mathematical models you intend to use. It would be helpful if you could let us know how you intend to determine the increase in sound pressure level that occurs downwind. (possibly caused by refraction of sound within the layers of air where there is a vertical velocity gradient.)

(3) Background noise.

Could you please let us know the locations where these measurements are being made. We appreciate that at exposed locations, the background noise created by the wind might be sufficient to mask noise from the turbines (if the noise is neither tonal or pulsating). We are however, also concerned that you have included locations, sheltered from the wind and therefor likely to have a low background noise, even though the wind speed at hub height, may be sufficient for the turbines to work.

We look forward to learning more about the proposed windfarm.

Kind regards

Dave

Dave Holtom, on behalf of Barrhill Community Council