IHI Corp. Toshiba Corp. and Mitsui & Co. have joined forces to develop a business based on generating power from ocean currents, exploiting specifically the Kuroshio current that flows in the seas around Japan.

Theplan is to build large, ocean-based power plants assembled from dozens of generators, each consisting of a pair of propeller-shaped impellors mounted on turbines anchored to the seabed, but floating at a depth of 30-50 metres and generating around 2 MW each.

The three partners have formed a consortium with the University of Tokyo and have plotted a schedule that calls for land-based operational testing of a 1:50 scale model in a water tank by 2012, and verification testing of a 1:3 scale model in the ocean by 2018. The goal is to have a commercial version ready in or soon after 2020 for a business that can generate yearly sales of several billion yen.

IHI will be responsible for manufacturing the turbines and anchoring the generators to the seabed. Toshiba will manufacture the power generators and Mitsui will conduct business feasibility analysis.

The Kuroshio current that flows past Japan is even broader than the Gulf Stream in the North Atlantic and presents a stable volume of moving water that can be tappe. The three partners calculate that as many as 2000 of their ocean current power generation systems could be stationed to tap the Kuroshio current, generating about 4 GWe in total.