Development of mooring-less robotic buoy system using wave powered renewable energy

For long-term operation, a wave-energy harvesting robotic buoy system that holds position automatically without anchoring line is proposed. We made a prototypes which consists of the propulsion system and power generation system. We adopted the Wave glider platform to hold the buoy position without mooring, and developed a flip-type self-rectifying wave turbine system (WTS). We developed modeling equations to describe the proposed system and simulated them using numerical software, then tested their station-keeping ability and energy-harvesting power in wave tank. Developed prototype patrolled within a 3-m diameter area, and the WTS generated 10.1 W of power. The station-keeping area was smaller than that of the existing mooring buoy, which means that the robotic buoy system can obtain precise and accurate observation data in the ocean without additional costs for mooring systems, and its wave-harvested energy can provide sufficient electric power to maintain the whole system.