Wind turbines (WTGs) generate a substantial proportion of the electricity from renewable energies in Germany, especially in the north. The majority of wind turbines are built on land ‒ preferably in windy locations on flat terrain, near the coast or the mountains. Considering the high density of WTGs in northern Germany and the lack of unused land that is still available for the further expansion of WTGs, the focus will shift more to the south in future. However, there are fewer productive sites in the south than in the north. In order to be able to use wind turbines in these locations economically, ecologically and in a manner that is acceptable for the local population, factors such as sound propagation and its influence on local residents, efficiency and turbulence as well as the natural and topographical conditions of the site must be taken into consideration and optimised.
As part of a collaborative project funded by the Federal Ministry for Economic Affairs and Energy (BWMi), three project partners are working together to develop a reliable model for optimising sound insulation for individual wind turbines as well as wind farms in regions with simple and complex terrain. Sound propagation models are being used to study the influence of complex terrain structures (valleys, street canyons, vegetation, etc.) under realistic meteorological conditions. However, noise predictions of wind turbines are difficult due to other noise sources and the interaction of the wind turbines with the atmosphere. The Institute for Atmospheric Physics of the German Aerospace Center e.V. (DLR) carries out simulations of meteorological flow and sound propagation in the atmospheric boundary layer and has developed a simple acoustic beam model of sound propagation. Together with the University of Stuttgart and the Wobben Research & Development GmbH of the Enercon Group, the second step will be to evaluate the existing measurements taken and to analyse and evaluate the overall results.
The project has a duration of three years and is funded by the BMWi until the end of November 2021.