In Japan, deep-down ocean currents in coastal waters can be exploited to generate energy, as the IHI company and the New Energy and ­Industrial Technology Development Organisation have shown in a new project. Kairyu is the first plant to take advantage of the Kuroshio current. The machinery is located 50m below the water surface off the southeast coast of Japan. If it were stationed closer to the surface, it would produce more than the 100kW it generates now, but the ­generator would be in jeopardy from the frequent tornadoes in the area. IHI now intends to install a 2-MW turbine near the prototype. The company estimates the ocean currents off the Japanese coasts can be harnessed to produce around 205 gigawatts of power. The ­efficiency of these systems is excellent at 70 percent.