Remote Monitoring of the Growth of Biofouling on Dynamic Electrical Cables and Mooring Lines of Floating Wind Turbine

Abstract Marine biocolonization, or biofouling, on submarine dynamic electrical cables presents a significant challenge for offshore wind energy systems. The accumulation of marine organisms, such as algae and mollusks, alters the surface characteristics of the cables, increasing both their mass and roughness. This results in higher hydrodynamic forces and accelerates mechanical fatigue, ultimately reducing the service life of the cables. Additionally, biofouling creates a thermal insulation layer, which hinders heat exchange between the cable and the surrounding seawater. This reduced heat dissipation leads to elevated operating temperatures, which can degrade cable performance and reliability. Given these mechanical and thermal impacts, real-time monitoring of biofouling is essential to ensure the safety, efficiency, and longevity of offshore electrical systems. In this study, we present a novel external flux-metric thermal sensor designed to monitor biofouling indirectly by estimating the global heat transfer coefficient around the cable. This sensor operates independently of environmental conditions such as water turbidity and weather, providing consistent and reliable measurements. By detecting changes in heat transfer efficiency, the system allows for continuous, remote assessment of biofouling growth, enabling predictive maintenance and reducing the risk of unexpected failure in floating offshore wind turbine infrastructure.