The State of Victoria (Australia) has enacted new wind farm siting guidelines that prohibit construction within 2km (1.25 miles) of a home unless the owner has signed off on the nearby turbine(s). In addition, the new guidelines prohibit wind farms within 5km of many existing villages, in order to allow for future growth. And, several areas with “a high degree of amenity, environmental value, or are a significant tourist destination” are excluded from development. (In Australia and New Zealand, the term “amenity” is often a factor in planning decisions; it largely corresponds to what we might also term rural quality of life.)
The new guidelines set a 40dB noise limit, reduced to 35dB in areas of “high amenity.” It may be of interest to note that the Victoria planning authorities seem to equate 35dB to about a 2km setback, whereas an Oregon noise standard of 36dB has more often led to roughly half-mile, or 1km, setbacks. It appears that the noise modeling is using different parameters in Oregon than in Victoria. It’s also possible that the 2km buffer is designed to protect “visual amenity,” with the noise limit being a secondary feature of the guidelines.
Already, some wind farm developers have cancelled plans to build in Victoria, while locals who have experienced quality of life or health impacts praise the moves. I was especially struck by the reports of Adrian and Helen Lyons, who have 15 turbines within about 3km of their home, with the closest about 1.7km (just over a mile) away; both have reported a feeling of sustained pressure in their ears when the wind comes from the north. The ear pressure has disturbed their sleep. This spurs my ongoing question as to whether some of the physical sensations may have more to do with air pressure downwind of turbines, rather than noise levels. To my knowledge, factors creating pressure differentials have not been investigated, although the related investigation of turbulence effects is on the research agenda of agencies and companies seeking to optimize turbine layout in wind farms.