Minimising Environmental Impact and Preventing Energy Loss
During wind turbine operation, the gearbox, generator and rotor blades generate noise that is emitted to the environment. The noise from the rotor blades is mainly caused by air turbulence at their trailing edge and blade tip. These operating noises can be perceived as disturbing by residents. Reducing them to a minimum therefore plays an important role in the acceptance of wind energy in the population. This article describes ways of reducing noise at wind turbines using the example of a multimegawatt wind farm in Germany. The focus is on the blade angle adjustment, which ultimately led to compliance with the limit values.
By Martin Peters, Head of Measurement Department, Green Wind Engineering, Germany
In Germany, the limit values for the permissible sound pressure level are regulated in the Federal Immission Control Act, and compliance is assessed in the approval procedure for wind turbines by means of noise emission forecasting. If the limit values are exceeded during wind turbine operation, the authorities can order power reductions and even night-time shutdowns. Noise reduction is therefore important in order to maximise the performance of a wind farm and avoid fines.
