Measuring The Swoosh
Noise associated with wind farms has been seen as a long-standing issue, so when The Institute of Acoustics (IOA) released its report on ‘Rating Amplitude Modulation (AM) in Wind Turbine Noise’ it was definitely a welcome step forward for most. The report details what IOA believe to be the ideal standard for measuring ‘swooshing noises’ from wind farms and focuses on reviewing the science and determining a metric for identifying amplitude modulation.
According to GE Reports, wind turbines in residential areas are placed no closer than 300 meters from the nearest house and will have a sound pressure level of 43 decibels – which is roughly the same amount of decibels as a refrigerator or air conditioning unit. However, there is still public concern over the noise from wind farms hence why there is a need for a robust way of measuring and assessing noises from wind farms to help evaluate complaints and to be included in planning conditions to control noises from new wind farm developments.
The aim of the new IOA report is to put forward new ways to measure and rate AM in wind turbine noise - amplitude Modulation is essentially the wave sound produced by the blades of the turbines turning.
Gavin Irvine, Amplitude Modulation Working Group (AMWG) chairman commented:
“This metric has been extensively tested on real, measured data, from wind farms and elsewhere, and the code is being provided so that all stakeholders involved in controlling noise from wind turbines can understand how the methodology works and evaluate their own data. This should ensure a level playing field in the area of AM, and has the potential to ensure that such noise is better controlled by wind farm operators.”
Geoff Offen, MD at Future Climate Info commented on the news:
“This is obviously a great step forward and helpful research not only for the planners who have the responsibility for controlling wind farm development, but also for consumers who are concerned about noise. As well as better controlling new wind farm development this new code should pave the way for testing existing installations to provide a more rational way of assessing noise complaints.”
The IOA plans to send the report to the Department of Business, Energy and Industrial Strategy (former DECC – Department of Energy & Climate Change) along with a request for the Government to endorse the noise condition derived from the metric. IOA also expect a further report on AM, originally commissioned by DECC to be released shortly which is likely to focus on what levels of AM are considered appropriate.
Read the full press release from IOA here.