The heavily fossil-fuel dependent country of Japan has successfully tested a system that could provide a consistent source of renewable energy, regardless of the sun or the wind. For more than a decade, IHI Corp. has been developing a subsea turbine which harnesses the power in deep ocean currents and converts it into a steady and reliable source of electricity.
The turbine is called Kairyu and is a 330-ton prototype designed to be anchored to the sea floor at 30-50 meters (100-160 feet). The giant machine resembles an airplane, with two counter-rotating turbine fans in place of jets and a central ‘fuselage’ housing a buoyancy adjustment system. In commercial production, the plan is to site the turbines in the Kuroshio Current, one of the world’s most robust, which runs along Japan’s eastern coast and transmits the power via seabed cables to Japan.
“Ocean currents have an advantage in terms of their accessibility in Japan,” said Ken Takagi, a professor of ocean technology policy at the University of Tokyo Graduate School of Frontier Sciences. “Wind power is more geographically suited to Europe, which is exposed to predominant westerly winds and is located at higher latitudes.”
