Possibilities of the development of new anti-erosion coatings for wind turbine blade surface protection on the basis of nanoengineered polymers are explored. Coatings with graphene and hybrid nanoreinforcements are tested for their anti-erosion performance, using the single point impact fatigue testing (SPIFT) methodology. It is demonstrated that graphene and hybrid (graphene/silica) reinforced polymer coatings can provide better erosion protection with lifetimes up to 13 times longer than non-reinforced polyurethanes. Thermal effects and energy dissipation during the repeated soft impacts on the blade surface are discussed.

Leading edge erosion on a wind turbine blade from Vindeby offshore wind farm is characterized by X‐ray tomography, and air bubbles within the top coat are observed. Similar coating systems with and almost without air bubbles within the top coat are tested on a R&D Test Systems style whirling arm rain erosion tester (RET) and found to have different V–N curves. In general, the slope of the two curves was comparable. However, the absolute performance value with RET differs significantly with up to 2.6 times performance advantage to the coating with less bubbles. A micromechanical model of the coating system that takes the air bubbles into account has been developed, and air bubbles are found to have critical effect on the crack initialization in the coating.

Maintenance and repair of wind turbines contribute to the higher costs of wind energy. In this paper, various technologies of structural repair of damaged and broken wind turbine blades are compared. The composite plates, mimicking damaged blade parts, were damaged and repaired, using various available curing and bonding technologies. Technologies of repair with hand layup lamination, vacuum repair with hand layup and infusion, ultraviolet repair and high temperature thermal curing were compared. The repaired samples were tested under tensile static and fatigue tests, and subject to microscopic X-ray investigations. It was observed that both the strength of the repaired structures and the porosity depend on the repair technology used. Vacuum-based technologies lead to relatively stiff and lower-strength repaired plates, while ultraviolet-curing technologies lead to average stiffness and high strength. High-temperature vacuum curing leads to the highest maximum stress. Hand layup (both vacuum and without vacuum) leads to high post-repair porosity in the adhesive and scarf, while vacuum infusion leads to low porosity. Fatigue lifetime generally follows the trend of porosity. There exist risks of micro-damaging the parent laminate and the formation of residual stresses in the repaired structure.

The erosion of wind turbine blades is one of the most frequently observed mechanisms of wind turbine blade damage. In recent months and years, concerns about high volumes of eroded plastics and associated pollution risks have surfaced on social networks and in newspapers. In this scientific paper, we estimate the mass of plastic removed from blade surface erosion, using both a phenomenological model of blade erosion and the observed frequency of necessary repairs of blades. Our findings indicate that the mass of eroded plastic ranges from 30 to 540 g per year per blade. The mass loss is higher for wind turbines offshore (80–1000 g/year per blade) compared to onshore (8–50 g/year per blade). The estimations are compared with scientific literature data and other gray literature sources. Using the entire Danish wind farms portfolio, we quantify the yearly mass of plastic from blade erosion to be about 1.6 tons per year, which is an order of magnitude less than that from footwear and road marking and three orders of magnitude less than that from tires. While the contribution of wind blade erosion is small compared to other sources, the results of this work underline the importance of the (A) effective leading-edge protection of wind turbines, (B) regular and efficient maintenance, and (C) the optimal selection of materials used.