Noise optimization - A sucessful case study
Martin Peters, Head of Measurement Technology
Operating noise from wind turbines must be reduced to a minimum in order to ensure the acceptance of wind energy in neighboring residential areas. Our case study shows the successful noise reduction through blade angle optimization, which is also manufacturer-independent and does not require the installation of blade elements.
In Germany, a noise immission prediction is therefore already used in the approval process for wind turbines to assess whether the specified sound pressure levels in accordance with the Federal Immission Control Act are observed. If the limit value is exceeded during actual operation of the wind turbine, the authorities can impose noise-reduced operation or even night-time shutdown. In the case presented, due to complaints from local residents about night-time noise from the wind farm (operating already in a noise-reduced mode), the authority required a noise emission measurement on a multi-megawatt wind turbine. The determined sound pressure level of 102.4 dB(A) exceeded the approved sound pressure level of 102.0 dB(A) at the site. The operator was requested by the authorities to take measures to reduce noise, or a shutdown of the entire wind farm at night would be imposed.
There are various approaches to reducing noise emissions:
- On the hardware side, blade elements such as trailing edge serrations can be retrofitted or fitted at the factory during rotor blade production.
- The operational management can set adapted night modes that strike a compromise between noise and power generation.
