A floating wind farm?

Overlooking a mountain lake a few hours drive from Tokyo, dozens of tall wind turbines spin in the breeze creating carbon-free power for the world's fifth-biggest emitter of greenhouse gases. A sudden change in breeze spins the turbines in a different direction, an apt symbol of Japan's efforts to shift away from fossil fuels for renewable energy such as wind power to help cut its greenhouse gas emissions under the Kyoto Protocol.

Wind farms such as the Nunobiki Plateau Wind Farm on a hill north of Tokyo, which generates enough electricity to power some 35,000 homes a year, have failed to make a dent in Japan's obligations to cut carbon gas emissions under the Kyoto Protocol. But Japan is now looking towards the sea, following in the footsteps of Europe which is the world's leader in wind energy, by planning a network of offshore wind farms to tap into the gales of the Pacific Ocean.

"It's worthwhile entering the sector now as offshore technology is at the cutting-edge," said Mitsutoshi Yamashita, a Ministry of Economy, Trade and Industry official in charge of promoting wind power. "Once we obtain the technology needed, the kilowatts are limitless," he added.

Japan hopes that wind power will provide around 0.2% of the country's primary energy supply by March 2011. That figure might rise dramatically if major electric companies follow through with plans to build offshore wind farms near coastal power stations.

The northern Japanese town of Hokkaido, which is the first offshore wind-for-power system outside of Europe, has since 2003 been harnessing the sea breeze with two 600-kilowatt turbines located inside a breakwater less than one km off the coast. That's enough to power an average of 1,000 homes per year.

"Maintenance is tough," said Shinya Ono, a town official, explaining the waves were sometimes too high to reach the turbines by boat.

He said that offshore wind energy was double in power to that harnessed on land, but the power it generated was unpredictable when compared with conventional thermal electricity generation. Nevertheless, sea breezes are seen as more reliable than solar power and wind turbines require less space and lower investment than nuclear and solar plants.

"There's a good wind year and a bad wind year, and when added up so far, it just breaks even," Ono said, adding the central government had subsidised construction costs, including turbines the town purchased from Denmark's Vestas.

In Europe it costs about 50 to 100% more to build offshore wind farms to those based on land. In Japan, it could cost even more as the island nation is surrounded by deeper seas.

Japan is set to study the feasibility of offshore wind energy this year. One option might be to follow the example of Scotland, which installed offshore turbines in deep water in 2006. As part of the study, the government is expected to install an offshore wind turbine to determine best engineering practices for the widespread use of the technology. The domestic industry is expected to make a push towards offshore wind turbines by 2012. Toru Nakao, an engineering consultant at E&E Solutions, a unit of a Japanese non-ferrous smelter Dowa Holdings, envisages that Japan might exploit locations several miles off its coastline in the not too distant future.

What are the possible strategies that Japan will implement in order to make the offshore wind energy work?