Laboratory experiments on the energy extraction of a sealed ocean kinetic energy harvester for underwater mooring platforms

In order to extend the working time of underwater mooring platforms (UMPs) deployed in the East China Sea and explore the feasibility of energy harvesting from ocean, a laboratory experimental investigation on the energy extraction of a direct-driven Sealed Ocean Kinetic Energy Harvester (SOKEH) for UMPs was carried out. The present research investigates the influence of parameters including damping, inertia modification (ballasting), and coupled excitation motions on the performance of the SOKEH. Results indicate that this type of ocean kinetic energy harvester has two good performance resonant frequencies, 1 Hz (large amplitude) and 1.1 Hz (small amplitude). It is also demonstrated that the damping, inertia modification (ballasting), and coupled excitation motions significantly affect the energy extrication of the device. It is also shown that these parameters can be adjusted in response to the excitation motions to optimize the energy extrication. This work provides a preliminary step towards the development of a sealed ocean kinetic energy harvester for UMPs.