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IHI's deep-ocean Kairyu has two counterrotating turbines.

IHI's deep-ocean Kairyu has two counterrotating turbines.

Source: IHI Corp./NEDO

Cleaner Tech

Giant Deep Ocean Turbine Trial Offers Hope of Endless Green Power

Tested in one of the world’s strongest ocean currents, a prototype generator could herald the start of a new stream of renewable energy

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Power-hungry, fossil-fuel dependent Japan has successfully tested a system that could provide a constant, steady form of renewable energy, regardless of the wind or the sun. 

For more than a decade, Japanese heavy machinery maker IHI Corp. has been developing a subsea turbine that harnesses the energy in deep ocean currents and converts it into a steady and reliable source of electricity. 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. Called Kairyu, the 330-ton prototype is designed to be anchored to the sea floor at a depth of 30-50 meters (100-160 feet).