Erosion of Wind Turbine Blades

Objectives

The purpose of Task 46 Erosion is to improve understanding of erosion driving factors, develop datasets and model tools to enhance prediction of leading-edge erosion likelihood, identify damage at the earliest possible stage, and advance potential solutions. The Task is structured around three technical work packages:

WP2 — Climatic conditions driving blade erosion: The scientific goals of this work package are to provide a priori assessments of wind sites regarding the potential for excess leading-edge erosion and to inform wind farm operation to optimise blade lifetimes. The long-term objective is to characterise erosion-relevant properties geospatially and temporally, and generate GIS layers for inclusion in an erosion risk atlas.

WP3 — Wind turbine operations with erosion: This work package has three key objectives: to promote collaborative research to mitigate erosion using wind turbine control and assess the viability of erosion-safe mode; to improve understanding of droplet impingement in the context of erosion; and to improve understanding of wind turbine performance with eroded blades, especially the effect of leading-edge erosion (LEE) surface roughness on aerodynamics.

WP4 — Laboratory testing of erosion: The objective of this work package is to facilitate convergence in laboratory erosion testing practices to achieve a high-fidelity test setup representative of erosion phenomena observed in the field, and to reduce uncertainty associated with sample preparation, testing, and data analysis.

Participation

Progress, Results, and Impact in 2025

Key outcomes of the work on climatic conditions driving blade erosion (WP2) included new knowledge on precipitation measurement practices, raindrop-size data, data processing methods, analysis of joint distributions of rain and wind, and the variability of these quantities across different geographies. The work evolved into a roadmap for preparing a leading-edge erosion risk atlas, and precipitation datasets were shared openly.

Key outcomes of the work on wind turbine operations with erosion (WP3) were threefold. First, erosion classes and their estimated impact on annual energy production (AEP) loss were established based on a comprehensive dataset and structured methodology. Second, the potential of using wind turbine control to mitigate erosion was addressed at the theoretical level and confirmed as a viable mitigation method. Third, the understanding of droplet impingement and wind turbine performance with rough eroded blades was addressed in a benchmark study.

Key outcomes of the work on laboratory testing of erosion (WP4) included novel methods for analysing whirling-arm rain-erosion test data, including open-access software, and a thorough description and discussion of laboratory testing methods and options for pre-testing specimens. Whirling arm rain erosion testing is a standard recommended testing practice. Figure 1 shows a photo of an R&D rain erosion tester and a diagram indicating the specimen structure.

Key outcomes of the work on erosion mechanics and material properties included a novel method to relate leading-edge erosion observed at wind turbines in the field to laboratory test data, linked to the prevailing meteorology. A thorough study of the damage mechanisms and the identification of appropriate damage models for accumulative droplet impact erosion was conducted for multilayer systems, including failure modes such as surface wear, interface debonding, and cracking of underlying layers.

Next Steps

A large-scale comparison and round robin using the same type of specimen across several rain erosion test facilities is ongoing, with the objective of evaluating the consistency and reliability of rain erosion test methods across different testing setups. Work on bridging the gap between durability testing and material properties will also continue. An updated erosion classification system covering aerodynamics, together with results from an aerodynamic benchmark, will be presented at the Torque 2026 conference. A recommendation report for measurement of leading-edge erosion drivers — including droplet size and fall velocity — is in planning.

References

1. Maniaci, D.C., MacDonald, H., Paquette, J., Clarke, R. (2023). Leading Edge Erosion Classification System. IEA Wind Task 46 – Erosion Classification System.
2. Simon, J. E. and Johansen, N. F.-J. (2024). Rain erosion test data analysis, damage accumulation and VN curves. IEA-Task46-D4.3-VN-curves.
3. Campobasso, M. S., Rose, M. S., Shende, S., Adirosi, E., Pace, G., De Silvestri, L., Dimitriadou, K., Vinod, A., Hasager, C. B., Sánchez, F., & Castorrini, A. (2026). Development, performance and energy trade-off analyses of wind turbine precipitation-reactive control at offshore and onshore sites in Western Europe. Renewable Energy, 262, Article 125357. https://doi.org/10.1016/j.renene.2026.125357
4. Pryor, S.C. and Barthelmie, R.J. (2026). Hail as a damage vector for renewable energy. iScience, 29, 114439. https://doi.org/10.1016/j.isci.2025.114439
5. Pryor, S.C. and Barthelmie, R.J. (2025). Hail as a damage vector for renewable energy [software]. Zenodo. https://zenodo.org/records/16420233