The days of shoddy noise assessments are thankfully well and truly past. Nowhere is this more evident than in planning applications for wind farms. In the last few years, the assessment methodology for wind farms has become particularly detailed, more so than for any other sector. The assessment and rating of noise from wind farms (report ETSU-R-97 prepared by ETSU for the UK Department of Trade and Industry, 1996) continues to form the basis of wind farm noise assessments, which in turn has informed the DOEHLG (now DOECLG) document Planning guidelines on wind energy development (2006). The DOEHLG document is currently under review, while ETSU-R-97 is likely to be reviewed in the next few years. In the meantime, the Institute of Acoustics has issued A good practice guide to the application of ETSU-R-97 for the assessment and rating of wind turbine noise (2013), and several supplementary guidance documents.
The collective guidance above sets out the measurement methodology to be applied in assessing noise impacts associated with a proposed wind farm, and when measuring emissions from an existing wind farm. The methodology is detailed and complicated, requiring synchronised measurement of noise levels, wind speed and precipitation. The resulting data analysis is quite complex. Predictive modelling of noise levels at receptors requires an in-depth knowledge of noise modelling.
For this reason, measurement of wind farm noise levels and prediction of impacts cannot be left to inexperienced consultants. Few noise consultants in Ireland have the necessary experience in managing wind farm noise projects. Damian Brosnan Acoustics (dBA) is one of the few.