Understanding Leading Edge Erosion, Its Impact on Turbine Efficiency, and the Path to Sustainable Solutions

Wind energy is a crucial component of our transition to cleaner power sources. However, to maximize its environmental impact as discussed in our previous blog “The Winds of Change”, we must address challenges such as blade erosion. In this blog, we delve deeper into the issue of leading edge erosion and explore its effects on wind turbine efficiency.

Leading Edge Erosion: The Problem

Let’s start by clarifying what we mean by “leading edge”. The Leading Edge (LE) is the longitudinal edge of the blade that first encounters the air during operation. When we talk about LE erosion, we refer to the fact that this edge delaminates, meaning its layers separate.[1]

This leading edge erosion or LEE is a major challenge for the wind turbine industry. While wind turbines rotate at seemingly modest speeds (approximately 12-15 RPM), the blades move at astonishing velocities. The blades of a typical 5 MW turbine can stretch up to 62 meters in length, causing their tips to move at speeds exceeding 400 km/h. When rain, hail, or sand dust strike these blades, the leading edge gradually wears away. According to various observations, the first effects of erosion processes on the blades appear already 2-3 years after the turbine begins operation.[2]

On erosion issues associated with the leading edge of wind turbine blades – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Example-of-leading-edge-erosion-Source-14_fig3_258261403 [accessed 19 Aug 2024]

This issue significantly diminishes the lifespan of wind turbines. The problem becomes even more acute for offshore installations, where larger blades are exposed to more severe environmental conditions.[3]

LEP impact: Efficiency Loss and Repair Costs & Sustainability

The efficiency loss of a wind turbine with leading edges as eroded as that in the previous image can exceed 50% under certain conditions. Moreover, the cost of repairing the blade is prohibitively high. It involves dismantling the turbine, transporting the blade for additional protection application, and reinstalling it.[4] As a result, a significant portion of wind turbine repair expenses stem from leading edge damage. Additionally, there is the cost associated with the turbine being out of operation during the repair period.

Beyond efficiency and cost concerns, wind turbine blades pose an environmental challenge. With a typical lifespan of 20 to 25 years[5], these blades eventually need replacement. However, recycling them is not easy due to their composition. The blades are made from composite materials that combine different physical and chemical properties, providing the necessary stiffness, reduced weight, and corrosion resistance. While these characteristics are crucial for the blades’ performance, they also make the materials extremely difficult to break down or reuse. As a result, many of these blades end up in landfills, creating what are known as “wind turbine blade graveyards.”[6]

According to a statement from the European Technology and Innovation Platform on Wind Energy (ETIPWind), there will be around 66,000 tonnes of end-of-life wind turbine blades in Europe in 2025.[7] It is therefore crucial not only to seek ways to reuse or at least recycle the blades but also to extend their lifespan through new models, improved protection materials or optimal placement strategues, thereby increasing their environmental sustainability.

AIRE – Tackling Erosion for Increased Production and Reduced Costs

At AIRE, we’re developing new approaches to tackle these challenges. With a focus on extending the operational lifespan and enhancing the performance of these giants of renewable energy, we are following a multi-pronged approach:

Creating an erosion risk atlas tool to help the industry optimize wind farm location choice.
Developing a wind turbine erosion safe mode operation tool to provide the industry with tools to control and protect their wind turbines against climate hazards.
Designing a new blade to create longer-lasting more productive turbines.
Building realistic computational models for eroded blades to improve airfoil performance models under worn surface conditions.

By addressing erosion, we contribute to truly clean and sustainable wind energy for our planet.

In the upcoming blog, we will share with you the latest studies being conducted to identify areas prone to erosion from liquid precipitation, an essential fact for reducing erosion on the blades and thereby enhancing the sustainability of wind energy.