Noise levels wind turbines
The results of sound intensity level dB(A) calculations for the proposed wind turbines: Based on wind speeds of 8 m/s, at a height of 2 m.
Wind turbine manufacturers generally claim a maximum noise rating of 106 dB at 8 m/s. This means that noise levels reach over 70 dB within a 20 m radius of the wind turbines at mast height, but the noise level drops as it reaches ground height. The noise levels from the Búrfell wind turbines will be under the defined limit for industrial zones of 70 dB (A) and will probably not surpass 60 dB. Noise levels will reach 50 - 55 dB at wind speeds of 8 m/s at a distance of 250 - 300 m from each wind turbine. Noise levels will reach 45 - 50 dB at longer distances within the wind farm. Noise levels will drop below 40 dB at a distance of 1 – 1.5 km from the wind farm. The regulations would define this as a ‘quiet area’. The effects of the wind turbines on noise levels outside the area can be classified as insignificant.
Calculated values are shown on the map. Noise levels were specifically calculated for four ‘noise sensitive’ areas:
- Stöng Farm in the Þjórsárdalur Valley
- Area by the Háafoss Waterfall
- Hólaskógur hut
The results show that noise levels from the wind farm do not have a significant acoustic impact on the aforementioned areas.
Noise levels from the wind turbines are within the reference limit for industrial zones, and remain well below the limit, in the entire wind farm area. The noise generated by the wind turbines within the Búrfell Wind Farm will be obvious and the dominant noise source in the area. Noise levels will drop below the limit required for ‘quiet areas’, areas suitable for recreation, at a distance of 1.5 km.
The noise created by the wind turbines is lower outside of the demarcated wind farm area than the noise that exists within. As the distance from the turbines increases, the noise levels will continually decrease. The acoustic impact is therefore considered to be negligible in all three proposals.
The difference between the three proposals with regard to noise levels is attributed to the Þjórsárdalsvegur Road (32), which will run through the wind farm in proposals 2 and 3. Thus, there will be a greater impact than in proposal 1. Noise levels on the Landvegur Road (26) will be higher in the section that runs through the Búrfell Wind Farm in proposals 1 and 3 than in proposal 2. The proposed relocation of the Landvegur Road would move the road to the periphery of the Búrfell Wind Farm where noise levels would then be similar to those in proposal 2. Overall, the impact is considered to be similar in all three proposals.