The working group had worked on the subject since July, toward the revision of the national Strategic Energy Plan. The report was to be presented at a December 17 meeting of the Strategic Policy Committee, under the Advisory Committee for Natural Resources and Energy.
A model plant method was used to verify the data when comparing and evaluating the costs of 18 different power sources: solar, wind, hydro, geothermal, biomass, nuclear, LNG, hydrogen, ammonia, coal, and so forth. The per-kWh predictions for 2040, including political policy costs, were as follows (cheapest first):
- Large-scale solar, JPY7.0 to JPY8.9
- Nuclear, JPY12.5 or higher (assuming an NPP capacity factor of 70% and 40 years of service)
- Offshore wind, JPY14.4 to JPY15.1
- LNG-fired (single combustion), JPY16.0 to JPY21.0
- Coal-fired (combustion with 20% ammonia), JPY20.9 to JPY33.0
- Hydrogen (single combustion), JPY24.6 to JPY33.0
The results were slightly different from the figures obtained back in 2021, when the current Strategic Energy Plan was issued, and may be related to recent price increases, according to the Agency for Natural Resources and Energy (ANRE). Although the figures for nuclear power included costs for disaster measures, a member of the working group said that they reflected a frequence of core damage based on probabilistic risk assessments (PRAs).
With an eye on introducing “naturally variable power sources” (renewable energies), including solar and wind, the working group took integration costs into consideration when calculating power-generation costs, including additional costs for the entire power system, when verifying three scenarios: 40-percent installed NPP capacity, 50-percent installed capacity, and 60-percent installed capacity.
At the working group meeting on December 16, explanations of the analyses were given by several members, one of whom was OGIMOTO Kazuhiko, specially appointed professor of the Institute of Industrial Science at the University of Tokyo. They said that the extent of increase for “naturally variable” (i.e., renewable) power sources was distinctive in comparison with nuclear power and thermal power owing to the increased use of thermal fuel resulting from load-following operations, as well as the effects of output control.
For example, in the case of 40-percent installed NPP capacity, the costs were JPY15.3/kWh for large-scale solar and JPY16.4/kWh for nuclear, while in the case of 60-percent installed capacity, they were JPY36.9/kWh and JPY18.9/kWh, respectively, meaning that nuclear would be cheaper (i.e., the per-unit costs of generated power would be less) than solar the higher the installed capacity.
Professor Ogimoto et al. said that the usage of fuels increased in load-following operations according to “merit order,” based on the changes in output of the renewable energies. Another member of the working group suggested that the distinctive character of siting locations should also be considered.
Noting that the data demonstrated the “apparent superiority” of solar energy, and recognizing that various uncertainties could be looked at in multiple ways, working group chairman Akimoto suggested the need to examine the questions in more detail.
In previous working group discussions, industrial representatives had suggested various time spans for the introduction of new technology, such as “by 2030” or “by 2040.”
After the results were released by the working group, Deputy Commissioner HATAKEYAMA Yojiro made the following comment: “This is important basic material for discussions about Japan’s power-source composition and its energy mix.” He then urged the Strategic Policy Committee to deepen those discussions.
