There are not a lot of shallow offshore locations in Japan, so they are looking into the prospects for floating wind turbines. This has been in the news lately.
See: http://www.bloomberg.com/news/2012-03-29/floating-windmills-in-japan-help-wind-down-nuclear-power-energy.html QUOTES: Japan, whose island geography and earthquake risk have long shaped its economy, is lagging behind developed nations including the U.S., Germany and Spain in wind energy, which supplied just 0.4 percent of its electricity demand in 2010, according to the International Energy Agency Wind 2010 Annual Report. Ranking as the world’s fifth-largest carbon emitter, Japan is trying to elevate its wind-energy capacity from 2,500 megawatts, the 13th-highest among all nations, according to the Global Wind Energy Council. Land-based wind-energy development is limited by Japan’s mountains, making offshore developments more viable. The depths of its oceans creates a bigger potential for floating turbine technology, still in its infancy compared with the more conventional method of deploying fixed versions of the machines. . . . The industry group has set a wind-power installation target of 50,000 megawatts by March 2051, including 17,500 megawatts and 7,500 megawatts in floating and fixed offshore wind respectively. That compares with the 49,000 megawatts of nuclear power, which is being debated by government officials after the Fukushima meltdowns. JWPA estimates Japan’s potential for wind is 144,000 megawatts for onshore and 608,000 for offshore. . . . - Jed