Japan Institute for National Fundamentals

　
On December 17, the draft Seventh Strategic Energy Plan was released by the Japanese government. Earlier, on September 9, an energy study group of the Japan Institute for National Fundamentals issued a policy proposal urging the government to change course to make maximum use of nuclear power without expanding renewable energy into a mainstay power source. The Study group explained the proposal to the ruling Liberal Democratic Party’s federation of Diet members for promoting nuclear power generation. I checked how the JINF policy proposal is reflected in the government draft energy plan.

Remaining dependency on renewable energy while vowing to utilize nuclear power

JINF proposed that the government change course to make maximum use of nuclear power and construct new and additional innovative light-water nuclear reactors at an early date. The draft energy plan deleted the wording of “reducing dependence on nuclear energy as much as possible” under the current Sixth Plan and clarified the policy of making maximum use of nuclear power as well as renewable energy. In order to promote the construction of new and additional nuclear power plants and the replacement of existing ones, the draft allowed an electric power company to construct an innovative light-water reactor at a different nuclear plant site of the same company if it decommissioned an existing reactor. These policies are very commendable.

The draft also urged that the operation of a spent nuclear fuel reprocessing facility be expedited, that relevant agencies actively work to promote understanding about geological disposal of high-level radioactive waste towards the selection of disposal sites, that the nuclear fuel cycle for fast breeder reactors be focused on, and that plutonium fuel be effectively utilized. These measures are also commendable.

On the other hand, against the JINF proposal that renewable energy, which increases the national burden and squeezes public finances, should not be expanded into a mainstay power source, the draft plan raised renewable energy’s share of the power generation mix from 36-38% for fiscal 2030 under the current Sixth Plan to 40-50% for fiscal 2040. As the raise was reported before the release of the draft plan, the JINF energy study group met and called on the government to prevent electricity prices from skyrocketing. The following explains why the renewable energy expansion into a mainstay power source would lead to the substantial rise of electricity prices.

High cost of expanding renewable energy into a mainstay power source

The problem here is the capacity factor for power generation facilities. The capacity factor means the ratio of actually generated electricity to the facility’s capacity. The capacity factor for nuclear power plants usually stands at 100%. Even if a two-month regular checkup is taken into account, the capacity factor comes to 83%. In contrast, the factor is as low as 13% for solar power plants that can generate electricity only during daytime and on sunny days. The factor for wind power plants is about 25%. Solar and wind power plant factors are added up to only 38%. Even if 12% for hydro and biomass power plants is added to solar and wind power plant factors, the combined factor manages to reach 50%.

In cloudy and windless weather, however, solar and wind power plants can generate almost no electricity, meaning that hydro, thermal, and nuclear power plants would be required to cover 100% of Japan’s electricity demand. In other words, the 50% share for renewable energy means that Japan must have power generation capacity that is three times as large as its electricity demand. Solar panels occupying one-third of Japan’s Honshu main island and offshore wind farms filling Japan’s exclusive economic zone will be required. Their construction is unfeasible from a national financial perspective.

For this reason, the draft plan cites the need for developing low-cost batteries, systems for storing electricity as heat energy, and synthetic fuels such as methane and methanol. However, their technologies are still under development.

Tadashi Narabayashi is a specially appointed professor at the Institute of Science Tokyo and a director at the Japan Institute for National Fundamentals.