Noise

The noise created by a wind turbine sounds like a "swooshing" as the rotor blades pass through the air. The degree of noise perceived by an observer depends on the location of the observer (upwind or downwind); wind speed, since higher speeds tend to mask the rotor noise; the level of background noise, which affects the perceived additional noise caused by the windfarm; and distance from the windfarm, since sound is absorbed as it passes through the air.

The predicted noise from Curraheen Windfarm has been conservatively estimated, and compared to measured background levels and DoEHLG Guidelines criteria.

The results show that the noise from the windfarm will certainly not exceed the DoEHLG threshold values at any third party property during the day; and that it will only exceed the night-time threshold values for two third party dwellings. At these properties, sound could exceed night-time thresholds with the wrong combination of windspeed and direction. However, this is a predictable phenomenon, and measures can be taken, such as reducing the power configuration of the wind farm to reduce the noise in this situation, if in fact it occurs when the windfarm is constructed.

The relevant noise modelling results are illustrated below. The most sensitive windspeed is about 8 metres per second, since the degree of background noise masking is low at that speed, and results are shown for that windspeed.

NOISE MAP WITH 8 m/s CONTOURS

For details view the 2465 300 EIS Figure 10.3.pdf from the Curraheen Windfarm Environmental Impact Statement.