Erosive wear of tidal turbine blades in sea water: Mapping pre-exposure effects of GFRP polymer-based composites

The ongoing depletion of global fossil fuel resources and the intensification of the greenhouse effect have made the development of renewable energy a universally prioritised objective. Tidal energy is one of the renewable energy sources that offers a viable alternative due to its excellent predictability, high energy density, and long-term stability. However, one of the primary challenges in tidal turbine applications is the erosion of turbine blades caused by challenging marine environmental conditions. This study investigates the erosion behaviour of glass fibre-reinforced polymer (GFRP) in aquatic conditions over an extended pre-exposure period of 183 days (4,380 hours). To achieve this, a custom-designed slurry erosion impingement rig was developed and is detailed in this paper. The results reveal serious changes in the erosive mechanisms of GFRP as a function of prolonged pre-exposure, with critical implications for the suitability of the material in tidal turbine blades for tidal energy applications. Advanced characterisation techniques, including erosion wastage maps, micro-profiling, and SEM, were employed to analyse surface degradation and erosion patterns. These tools provide insight into material performance and support the optimisation of GFRP for reliable, long-term operation in tidal energy environments.