Melbourne, Australia, 16-19 November 2014
The noise characteristics of ‘compliant’ wind farms that adversely affect its neighbours
Sarah Large, Mike Stigwood
MAS Environmental, UK
In the UK many wind farms cause complaints of noise despite complying with control limits. Problems relate to reliance on the LA90 index, failure to consider or apply ratings on the context of the sound characteristics and actual human responses due to complex characteristics. In general in the UK low frequency and very low frequency sound effects are either ignored or denied.
Mike Stigwood, Duncan Stigwood, Sarah Large
MAS Environmental, UK
This paper provides early results of a long term study of community impact from wind farm noise and uses of the data obtained. A continuously recorded database of noise collected under different meteorological conditions has allowed detailed analysis of particular characteristics such as amplitude modulation and also the reliability of assessment methodologies for predicting and quantifying impact. Surprising outcomes are explored including upwind impact.
David Mcbride, Daniel Shepherd, Robert Thorne
University of Otago, New Zealand; Auckland University of Technology, New Zealand; Noise Measurement Services, Australia
The WHO considers noise pollution to be of sufficient threat to public health to justify the publication of guidelines on noise effects and mitigation. ‘Community noise’ has largely been studied in the context of transportation and general neighbourhood noise, with exposure to wind turbine noise relatively understudied for historical, methodological, and political reasons. There also appears to be a general uncoupling of wind turbine noise from the other sources, which endows upon it an exclusivity that excuses it from the methods, guidelines, and critique used for other noise sources.
Professor Emeritus, The University of Tokyo
In Japan, serious complaints about wind turbine noise have arisen from nearby residents since the commencement of large-scale construction of wind generation plants in about 2000. Regarding this new type of environmental noise problem, scientific knowledge is insufficient and no standard methods for measuring and assessing the noise have been established in Japan.
Valeri V. Lenchine, Jonathan Song
SA Environment Protection Authority, Australia
Noise produced by wind farms may exhibit a multitude of different noise characters, ranging from amplitude modulation, tonality and low frequency noise. The presence of the noise characters is able to increase the annoyance factor caused by a noise source significantly. A penalty to the noise levels is applied in accordance with some regulations when a noise character is detected. This paper discusses a noise character that can be described as “rumbling” that was detected during a long term monitoring program which was conducted in an area adjacent to a wind farm.
Helge Aa. Madsen, Franck Bertagnolio, Andreas Fischer, Christian Bak
DTU Wind Energy, Technical University of Denmark
Amplitude modulation (AM) of noise from wind turbines and its more extreme version named “other amplitude modulation” OAM have been investigated intensively during the last few years due to the additional annoyance impact this type of noise has compared to broad band noise. In a recent published research by RenewableUK the hypothesis has been that one of the causes of OAM is transient stall on the blade due to non uniform inflow such as shear.
Hayes McKenzie Partnership Ltd, United Kingdom
With the increasing number of operational wind farms/turbines, the requirement for noise measurements required to demonstrate compliance with planning conditions is increasing as well. The British ETSU-R-97 noise limits are often set relative to measured or standardised 10 m height wind speeds and therefore the assessment of noise from wind turbines requires simultaneous noise and wind speed/direction measurements.
Frank Butera, Kym Burgemeister, Kai Fisher, David Mounter
Arup, Melbourne, Australia, and Singapore; Hydro Tasmania, Hobart, Australia
Two of the most common questions that wind farm developers face during community consultation are ‘what will the wind farm look like’ and ‘what noise will it make?’ A lot of work has been undertaken recently to develop ‘visualisations’ or ‘photomontages’ to answer the first question. However, there has not been an equivalent tool available to enable local communities to understand what a wind farm actually sounds like.
Noise Measurement Services Pty Ltd, Australia
Wind farms consist of clusters of industrial wind turbines which, when placed in rural areas, are associated with intrusive and unwanted sound. Wind turbine noise has characteristics sufficiently different from other, more extensively studied, noise sources to suggest that standard industrial noise standards are not appropriate for measurement and assessment purposes. A seven year study is reported and, although limited in population size, it is clear that there are definite adverse health effects related to wind farm noise.
Conny Larsson, Olof Öhlund
Uppsala University, Sweden
The meteorological conditions vary over the globe but also change over the day and the year and vary a lot depending on the terrain for a certain location. The meteorological parameters govern both the wind turbine emission sound levels and the sound propagation conditions and therefore gives rise to different sound immission levels. Long-time measurements of meteorological effects on sound propagation from wind turbines over forest areas have been performed at two sites in Sweden for more than two years.
Colin Novak, Anders Sjöström, Helen Ule, Delphine Bard, Göran Sandberg
University of Windsor, Canada; Lund University, Sweden; Akoustik Engineering Limited, Canada
The use of diaphragm type microphones with the typical foam windscreen ball for outdoor noise measurement applications are mostly restricted to wind speeds below 4 to 6 m/s. This is due to the extra noise induced into the microphone, particularly at low and infrasonic frequencies, as a result of the wind excitation on the diaphragm.