Katsutoshi Shirasawa
Okinawa Institute of Science and Techonology Graduate University, Japan
Title: Development of a floating ocean-current turbine for the Kuroshio current
Biography
Biography: Katsutoshi Shirasawa
Abstract
Ocean currents have an important potential for future renewable energy. Japan is in suitable location for harnessing the power of ocean currents because the Kuroshio ocean current runs steadily near the Japanese seaside. The Kuroshio current is a strong ocean current in the western North Pacific Ocean. The current flow is approximately 500 m deep and 100 km wide with a flow speed of 1—1.5 m/s. This seems to be rather slow flow, but it is sufficient for generating electricity because the water density is 800 times higher than air. In order to harness the kinetic energy of ocean currents, we propose a novel ocean-current turbine [1]. The turbines are moored to the seabed and function like kites in the water flow. To operate a turbine at the middle layer of a marine current, it is necessary to cancel the rotor torque. Therefore, our turbine is designed with a float at the top and a counterweight at the bottom. Owing the buoyancy and gravity, the turbine maintains a stable body. In this presentation, we describe laboratory and at-sea towing experiments and show that results confirm the float and counterweight configuration’s high hydrostatic stability and reliable electric power generation.