A new scientific paper has been published by AIRE’s partner DTU in collaboration with UiB. The objective of this paper is to talk about the effect of rain and high concurrent wind speed on the materials used in wind turbine blades. In this blog, we break down the essentials of these findings for anyone curious about scientific advances.

The basics

Wind turbines have big blades that spin to generate electricity from wind. These blades face a lot of challenges, including rain, hail, and other tiny particles in the air. Leading edge erosion happens when the front part of these blades (the “leading edge”) gets damaged due to these environmental factors.

 

Why is that a Problem?

When the leading edge erodes, it affects how well the wind turbine works. Erosion reduces the blade’s ability to capture wind energy, which means less electricity is produced.

Paper details

This study helps us understand how wind turbine blades erode and how different models predict erosion. It’s crucial for maintaining efficient wind energy production. Ásta, Charlotte and their colleagues studied erosion in Scandinavia and Finland, where wind turbines face strong winds and lots of rain. To do that, they used data from two models: ERA5 and NORA3. Think of these models as ‘weather time machines’ that let scientists travel back in time. By analyzing past weather data, they can see patterns like how intense the rain was or how strong the winds blew over the past years. This study focused on a specific type of wind turbine called the IEA 15 MW reference turbine. These models helped them understand rainfall intensity and wind speed over a period of five years. They looked at how rainwater hits the turbine blades and how quickly erosion starts. They also considered a special coating material used on the blades.

Process

The atlas layers are detailed maps calculated based on ERA5 and NORA3 data, which include information about rainfall and wind speed. This data covers a period of 5 years and is collected at different points within the studied regions Researchers use this data to calculate how much rain directly hits turbine blades (impinged rain) and the resulting damage increments are calculated from those time series. The python scripts used to create these layers can be found at: https://gitlab.windenergy.dtu.dk/astah/era5_erosion_atlas

Main results

This study is the first to create a rain erosion atlas for the Scandinavian region, including Denmark and Finland. The findings can be summarised as follows:

  • NORA3 data was more accurate than ERA5. It matched real-world measurements better.
  • NORA3 showed that erosion starts sooner over land (especially in complex areas) compared to ERA5.
  • ERA5 suggested erosion starts earlier offshore (away from land).
  • Using NORA3 data, they estimated that erosion begins after about 5 years for wind farms in the Baltic Sea.
  • For sites in the North Sea, it’s around 3.2 years.

This study delivers essential data on the rate at which wind turbines in Scandinavia experience erosion due to various weather conditions. These findings are critical for planning maintenance and protective measures, ensuring that energy production remains efficient, and that the infrastructure’s longevity is maintained.

For the full publication go to: https://www.sciencedirect.com/science/article/pii/S2590123024002639?via%3Dihub

Author: Laia Mencia & Ásta Hannésdottier
Editor: Lucia Salinas
September, 2024