The Ministry of Economy, Trade and Industry (METI) plans to install submarine power cables between Hokkaido and Honshu. The project is to be finished by FY2030 to enable transmission of mainly wind-generated power from Hokkaido to the Tokyo Metropolitan area. Although it is a large scale one-trillion yen project, the additional power it will generate in 2030 is expected to be limited. Wind power is far from becoming the primary source of power because the cost of wind power generation is high and technology is still in development.
One plan is to install a submarine cable in the Sea of Japan along the Hokuriku coast, and another plan is to install a cable in the Pacific Ocean. Each cable would be 800 kilometers in length, making it the longest in Japan to date. METI plans to include survey costs in the FY2022 budgetary proposal, and a decision on vendors will be made in FY2023.
Maintenance costs may exceed one trillion yen for power transmission of 4 million kilowatts. METI will consider financing the project through government financial institutions. Part of the cost will be defrayed by increasing power charges, and also by the renewable energy levy on power consumers nationwide, to commence when the cables start operation.
The aim of this large-scale submarine cable project is to support the introduction of wind and other renewable energy sources. METI’s revised draft of the Basic Energy Plan seeks to raise the proportion of renewable energy to 36-38% of total power generated. The plan also aims to increase the proportion of renewable energy to more than twice the 2019 figure of 18%.
The exact source of 3% of the 36-38% in renewable energy has not been determined. METI expects that the submarine cables will be a promising means. To meet METI’s goal, the cables will need to start operation by FY2030.
It has been noted that introduction of renewable energy needs to be in concert with the reinforcement of the power grid.
Renewable energy has been introduced in Hokkaido and Kyushu, which have locations suitable for solar and wind power generation. Because the power lines connecting different regions are not adequate, power cannot be transmitted to urban areas. There have been situations where generator output was reduced.
METI concluded that a direct-current submarine cable would be less costly than a land-based cable. METI will start discussions on installing submarine cables between Kyushu and the Kansai area, going forward.
Boosting power generation will only have a limited effect by 2030. The project will only generate an additional 10 billion kilowatts from both land-based and offshore wind power, according to METI. This is just 1% of the 930-940 billion kilowatts of total power generated in Japan. Wind power comprises only 6% of overall power, which is less than solar power’s 15%.
The draft Basic Energy Plan says that the government promotes off-shore wind power as “a trump card in making renewable energy a primary energy source.” Although expectations [for wind power] are growing, cost and technology issues need to be resolved.
About eight years is necessary, from conducting environmental surveys to construction of wind power generators. Wind power is realistically expected to become more common after 2030.
Fixed wind power generators, which are fixed to the seabed in shallow waters, are becoming more common in Europe. Japan’s coastal waters are deep, necessitating the use of “floating” offshore generators for mass introduction of wind power. METI is providing assistance for floating offshore generators, which are still under development.
Cost is an issue. METI estimates that the cost of power generation in 2030 will be 26.1 yen per kilowatt for wind power. This figure is two to three times the cost of commercial solar power. METI aims to lay groundwork for technology that enables the introduction of fixed wind power generators for eight to nine yen by 2030.