Mapping raindrop erosion of GFRP composite wind turbine blade materials : perspectives on degradation effects in offshore and acidic environmental conditions

Climate change is rapidly forcing the world to create renewable energy that is capable of sustaining future energy requirements globally. The generation of renewable energy at a comparatively lower cost is a major challenge for this industry. Unforeseen weather conditions and environments such as offshore conditions or involving acid rain have a significant effect on the degradation of structural materials of renewable energy devices. For the investigation of droplet erosion behavior of the advanced material for the wind turbine blades, experimental work was carried out on a glass fiber-reinforced epoxy (GFRE) composite in different environments. A whirling arm rig was used for this experimental work in a laboratory-simulated rainfall conditions at a constant tip speed of the rotor blade. Three types of rainwater were used for a range of angles of attack from 15 to 90 deg in an increment of 15 deg. Erosive wear maps have been constructed to show the weather, location, environment, and raindrop erosion effects on the degradation of the wind turbine blade material. This map predicts that erosion in saline and acidic rain conditions acts synergistically on the blade material, which results in delamination between the fiber layers, pit formation, and development of micro stresses leading to loss of adhesion of reinforcement fibers.