As the installed number of wind turbines grows, noise becomes one of the significant factors in the sitting and planning of wind farms. The emitted broadband sound-levels, as a function of wind speed, and sometimes the tonality of the noise, are crucial for the nearby dwellings.

The Laboratory for Wind Turbine Testing (LWTT) of CRES performs complete acoustic measurements with mobile units and according to international standards. Two main procedures are followed:

• The first is the noise emission measurement of a single wind-turbine at the source and it is used for certification/verification purposes or for the validation of different control modes during the R&D process of developing a new wind turbine model.
• The second is the noise immission measurement at the receptor site in order to evaluate the noise impact from wind parks at their vicinity.

Apart from the above, CRES has considerable experience in noise propagation measurements for the validation/modification of noise propagation models and is a founding member of the MEASNET International Network for Harmonised and Recognised Measurements in Wind Energy.

The Laboratory for Wind Turbine Testing of CRES is accredited according to the ELOT-EN ISO/IEC 17025:2005 by ESYD (Hellenic Accreditation System) under Certificate No 647 for Testing and Calibrations. The accreditation scope of the Laboratory includes both types of measurements (noise emission and noise immision).