Posters
Come meet the poster presenters to ask them questions and discuss their work
We would like to invite you to come and see the posters at our upcoming conference. The posters will showcase a diverse range of research topics, and will give delegates an opportunity to engage with the authors and learn more about their work. Whether you are a seasoned researcher or simply curious about the latest developments in your field, we believe that the posters will offer something of interest to everyone. So please join us at the conference and take advantage of this opportunity to learn and engage with your peers in the academic community. We look forward to seeing you there!
PO064: Why omitting directional effects in sound propagation kills optimal yield of wind farms
Henriette Labsch, Senior Project Engineer Noise Compatibility, WRD GmbH (Enercon)
Abstract
It is crucial for Europe to obtain energy independence. Thereby, the optimal use of wind energy areas whilst protecting neighbours is pivotal for harnessing wind power. In many countries, the prognosis for wind turbine noise immission is carried out as a worst-case scenario following the ISO 9613-2 without directivity correction. However, measurements indicate a significant underestimation of wind farm noise compared to this prognosis. Two of the main influencing factors resulting in this conservativism are neglecting the turbine's emission directivity and the assumption of an "always downwind" propagation. Noise from wind turbines (WT) is assumed as a point source with an omnidirectional emission. However, in reality they show an eight-shaped directivity pattern with less sound in crosswind direction. Additionally, when the wind direction is taken into account, the propagation is slightly stronger downwind than upwind. It is shown in this work based on simulations that this leads to an increasing overestimation of sound immission with increasing size of the wind farm. In order to address this, a directional prognosis approach is proposed: In the current measurement standard for WTs (IEC 61400-11:2019) the measurements points are defined not only for downwind, but also for up- and crosswind. This provides an ideal starting point to consider the WEC's directivity pattern. The potential of considering directivity and wind direction dependency is analysed for two exemplary sites with different complexity with respect to the noise situation. To ensure an industrial applicability, the calculation is restricted to four sectors. It can be shown that utilizing a directional prognosis approach can significantly increase the yield of a wind farm while at the same time maintaining the good protection of the neighbouring dwellings. Further, the directional approach supports also the application of sector specific high-yield modes with increased sound level.
