The renewable energy sector plays a key part in Japan’s growth strategy. Among options such as solar and geothermal, wind power may be the most suitable for Japan as it is surrounded by the ocean.
Winds are strong and stable at the ocean due to the absence of structures blocking the wind. The noise and vibrations from wind turbines disturbing residents is another reason the ocean is preferable.
The challenge is that the ocean floor around Japan is steep, so it would only make sense if wind turbines float. But there are no floating offshore wind farms in the world.
Japan’s answer is to create the world’s first wind farm off the coast of Fukushima Prefecture.
“It’s the best solution for Japan,” said Takeshi Ishihara, a professor in the Department of Civil Engineering at the University of Tokyo’s Graduate School of Engineering. The university, along with several manufacturing companies, formed a consortium to build the wind farm.
Potential for wind power generation is huge in Japan, he said. According to the Environment Ministry, the amount of offshore wind energy that can be potentially generated in Japan is 1.6 billion kilowatts, 10 times that of solar power and 100 times that of thermal power and small and mid-size hydraulic power. It is also eight times the current capacity of Japan’s power companies.
Japan lags very much behind European countries in wind power generation. Wind power accounts for less than 1 percent of power generation in Japan, Ishihara said.
Meanwhile, Britain, for example, aims to increase wind power and its goal is to have a third of its power generated from wind.
“Japan should also have a similar goal,” Ishihara said.
There have been legitimate reasons, however, for Japan to have stayed away from wind power.
One of the reasons is that Japan has not had the experience and know-how of building and maintaining wind turbines in the ocean and cannot simply apply European methods as the climate and geology are very different.
To solve the problem, the New Energy and Industrial Technology Development Organization (NEDO) built fixed-bottom offshore wind turbines to collect data in waters off Choshi, Chiba Prefecture, in October 2012 and Kitakyushu in March 2013.
Another reason is the high cost. Construction costs for wind turbines, foundations and undersea cables are said to be twice as much as a wind farm on land, Ishihara said. Maintenance costs are also higher than on land.
To counter the challenge, the consortium is building large wind turbines to increase power-generating efficiency. The consortium is working on developing light but strong materials to make large-size wind turbines.
The consortium is planning to start operation of a 2,000 kW floating offshore wind turbine as well as a floating substation and observation station in October. It is also planning to add two 7,000 kW floating offshore wind turbines by 2015.
The consortium’s goal is to raise power generating capacity of the wind farm to 1 million kW (1 gigawatt).
Currently, there are two floating offshore wind turbines in the world. Norway has one with 2,300 kW of capacity and Portugal has the other with 2,000 kW of capacity. Those two countries still need to solve some technical challenges to build a floating offshore wind farm, Ishihara said.
One challenge for Japan is gaining the support of the fisheries industry. The consortium has thoroughly researched the ecosystem in the ocean to choose the optimal location for the wind farm to minimize the negative impact on the industry.
Also, the consortium and local fishery cooperatives have worked together to come up with various measures. For example, the flotation devices for the wind turbine and substation will have automatic feed dispersal functions to create fishing spots.
“The difference between solar power and wind power is the contribution to the local economy,” Ishihara said. “In solar power, simple power generation can be performed by purchasing solar panels and placing them on a building. But for wind power, they have to have a local factory.”