Noise from wind turbines is produced by the blades cutting through the air and by the machinery in the turbine used to generate electricity. The noise generated by the blade cutting though the air results in the characteristic swish-swish noise that can be heard when you are very close to a wind turbine, but tends to be masked by background noise at greater distances. Noise produced by the machinery, however, tends have a specific tone which is capable of travelling large distances and can be an annoyance to local populations. For this reason tonal noise emitted by wind turbines is heavily penalised by regulatory authorities. By removing tonal noise the impact of wind turbines on the public is reduced and the market for wind turbine manufacturers and potential sires for developers can be increased.
Xi take the approach of removing tonal noise at its source; the vibrating component that is responsible for problematic noise. Xi use field measurements combined with numerical modelling to identify the source of vibration and the pathway that vibrations takes to the surface of the wind turbine where it is released to the air as noise. By understanding the source and vibration pathway it becomes possible to intervene with anti-vibration techniques that remove the tonal noise. Xi use numerical models to test and optimise the effectiveness of anti-vibration technique leading to a cost effective solution for our clients and the best outcome for both the general public and wind farm developers.