Wind turbine noise

Noise is often considered the most important environmental impact when planning wind farms or single wind turbines. In most countries there are noise requirements to comply with. In the planning process it is important to have reliable data for the noise emission and accurate prediction models and software tools.

New prediction models like Nord2000 makes it possible to optimize the design of wind farms, both with regard to noise and the power generated.

Apart from the standardized tests, measurements and predictions, DELTA also works with more detailed consultancy when specific problems arise.

Documentation of the noise

Documentation of the noise impact is most often carried out by measuring the noise emission from the individual turbines, followed by a calculation of the noise impact at the neighbours' properties. Therefore it is important to ensure that both the noise measurements and calculations are of high quality and use the latest knowledge and methods.

Measurement methods

DELTA has participated in the development of the generally accepted measurement method IEC 61400-11 thus having first hand knowledge of the difficulties when making noise measurements. For the measurements DELTA uses a dedicated measurement system for wind turbine noise measurements. This ensures that measurements are handled in a simple and efficient process from the planning of the measurements to reporting the results.

Prediction of noise impact

The Nord2000 model predicts the noise impact from a wind farm taking into account the terrain in more details and the meteorological parameters influencing the noise propagation. The wind speed, wind speed gradient, the temperature and the temperature gradient are the most important parameters. DELTA has in cooperation with Sinteff in Norway and Statens Provningsanstalt in Sweden developed the Nord2000 model. In a new in part publicly funded project DELTA has in cooperation with EMD International developed a prototype of Nord2000 for wind turbines to be implemented in WindPRO.

Danish and international standards

DELTA has taken part in the development of the international measuring method IEC 61400-11 and has a central role in the current revision of the standard.

We know what we are talking about

For over 40 years, DELTA has been working with acoustics, noise and vibration. Credibility is the key, and DELTA has more than 30 acousticians at its disposal, all with their unique knowledge. We take an active part internationally in working towards standardisation and we are accredited by DANAK to carry out measurements and calculations in all branches of acoustics.

Our customers are:

• Companies
• Building owners
• Authorities
• Individuals