Overview of Assessment by Power Generation Cost Verification Working Group

摘要

This report outlines the assessment by the Power Generation Cost Verification Working Group organized in the Japanese government in 2015. The working group sought to assess nuclear, thermal (fossil fuel-fired) and renewable energy power generation costs in Japan as fairly as possible while considering the latest data made available after the previous estimation by the Cost Estimation and Review Committee in 2011 and revising estimation methods. The 2011 Committee estimated the unit cost for nuclear power generation at 8.9 yen/kWh or more (with the discount rate at 3% and the capacity factor at 70%) covering decommissioning, additional safety measures, reprocessing of spent nuclear fuels, disposal of high-level radioactive wastes, plant location, R&D and accident risks. The working group revised the estimate upward to 10.1 yen/kWh or more reflecting additional damage compensation and safety measure costs after the Fukushima Daiichi Nuclear Power Station accident. The unit power generation cost estimate was also raised for fossil fuels due to exchange rate and other changes and for most renewable energy sources due to additional policy costs, while the estimate for solar photovoltaics was lowered due to an actual decline in solar panel prices. Given that the results change depending on preconditions, it is important to assess the economic efficiency of each power source not only by comparing numerical estimates alone, but also by understanding the changes in the estimates. Even after discussions at the working group, multiple problems are still left to be solved. For example, how to assess the grid stabilization cost accompanying the massive spread of volatile power sources such as solar photovoltaics and wind power, from which power output changes greatly within a short period of time, the accident risk cost for nuclear and other power sources, and various policy-related costs will have to be studied in the future. Efforts should be continued to refine the assessment taking into account the latest data, as well as other estimation results and the opinions of wide-ranging experts and citizens.