TNEI’s noise team can now provide expert consulting services for the measurement, analysis and reporting to characterise the noise emissions from wind turbines of various sizes.
In March 2013, BS EN 61400-11:2013 was issued. It is the UK implementation of IEC 61400-11:2012 ed3.0 and superseded BS EN 61400-11:2003. This new version of the standard includes a number of changes and aims to provides more accuracy in collecting wind turbine source data; typically used for wind turbine predictions.
Characterising the sound power level, the frequency spectrum and the tonal component of a wind turbine are the three main objectives of an IEC 61400-11 test. Other characteristics such as low frequency and directivity may be assessed too, however these are optional. The sound power level usually varies with wind speed and this information is used as input data to undertake predictions of wind turbine noise.
Notably in this new version of the standard, a statistical approach based on 1/3 octaves band is considered and measurements are taken every 10 seconds, with the aim of providing increased confidence in the resulting sound power levels. Historically, the IEC 61400-11 tests were often only undertaken for larger scale turbines but this new version also considers smaller scale turbines. In fact, on the 15th of January 2014 RenewableUK released a Small Wind Turbine Standard in which the latest IEC 61400-11 is recommended as appropriate guidance which should be used to test noise from small turbines.
TNEI’s nine strong noise team has significant experience in wind farm noise at every stage of the development process from initial feasibility assessments, ETSU-R-97 noise reports through to sound power level testing and post construction compliance monitoring.
James Mackay, TNEI’s Technical Services Manager “ Planning & Environmental said: “We are delighted to be able to offer full IEC sound power tests in accordance with the new standard. The service fits perfectly along side our existing service offering at a time where lots of turbine manufacturers and developers are looking for robust noise data to enable accurate assessment of wind turbines.”
TNEI recently developed bespoke noise software and acquired a range of ground boards in order to offer quick turn around for IEC 61400-11:2013 test reports. Our team can assess turbines of all sizes and relate the results back to current good practice used to predict noise levels for proposed wind farms as part of a planning application.
For further information on TNEI’s noise team please click here. For an IEC 61400-11 quote or an informal chat, please contact Moise Coulon on moise.coulon@tnei.co.uk or 0191 211 1408.
