Sonus Report 2010 – noise and infrasound
15 December 2010
Pacific Hydro commissioned a report in 2010 to measure and compare infrasound levels from wind farms and common environment infrasound sources, both natural and manmade.
The noise measurements were recorded for Pacific Hydro by an independent acoustic consulting firm, Sonus, with the aim of helping us to better understand the levels of infrasound that exist in the environment (both natural and man-made).
For the purposes of the report, infrasound was measured at two of our Australian wind farms, Clements Gap in South Australia and Cape Bridgewater in Victoria (while operating and while off), at a beach, a cliff top along the coastline, in the Adelaide CBD close to two busy roads, in an Adelaide suburb, and near a gas-fired power station.
The results show that infrasound is not unique to wind farms. The levels of infrasound produced by wind turbines is well below established perception thresholds and, importantly, is also below levels produced by other natural and man-made sources. Interestingly one of the highest levels of infrasound that was recorded was at a beach.
Whilst this report is by no means exhaustive it does provide further support to existing overseas data which shows that infrasound emissions from operational wind farms is significantly below recognised perception thresholds of 85dB(G). It also reaffirms that infrasound is not unique to wind farms and is, in fact, produced by many sources, both natural and man-made.