A Swarm of Floating Breakwaters to Protect a Floating OTEC Plant

Abstract Floating breakwaters are essential for reducing wave loads on a diverse range of marine structures, such as marinas and ports. Also, applications like protecting other floating structures, as in this case, Ocean Thermal Energy Conversion (OTEC) plants. These plants, which harness the temperature difference between surface and deep seawater, may be sensitive to wave-induced motions that can affect their operation due to the CWP-Platform (Cold Water Pipe) connection. This study investigates the use of a swarm of floating breakwaters as a protective system for a floating 5MW OTEC platform. Unlike single-breakwater systems, a swarm configuration, composed of multiple smaller units, offers greater adaptability and enhanced wave attenuation capabilities. Numerical simulations were conducted using OrcaWave, a three-dimensional potential flow-based software, to evaluate the hydrodynamic performance of the swarm under various wave conditions. Key performance metrics, such as the wave transmission coefficient (Kt), were analyzed, and sheltered regions around the OTEC plant were also assessed. Results show that the swarm approach significantly reduces wave transmission compared to the case without protection, with an average 70% of reduction, providing good wave attenuation and consequently minimizing loads on the OTEC platform. Also, the presence of the swarm of FBs (Floating Breakwaters) significantly changed the surge, heave, and pitch motion amplitudes of the OTEC platform, which had 40% less motion. These findings suggest that a swarm of floating breakwaters is a promising solution for protecting floating OTEC plants.