Electricity planning in Japan by 2030 through scenario analysis

Under continuing policies of the mitigation of GHG (Green House Gases) emission, it is crucial to consider scenarios for Japan to realize a safe and clean future electricity system after the Fukushima nuclear accident. The development plans of nuclear power and renewable energy - mainly PV and wind power - need to be reconsidered. Therefore, in the present study, three electricity supply scenarios in 2030 are proposed according to different future nuclear power development strategies: (1) negative nuclear power; (2) conservative nuclear power; and (3) active pursuit of nuclear power. On the other side, three electricity demand scenarios are also proposed considering energy saving. The purpose of the study is to propose electricity supply systems with maximum renewable energy penetration under different nuclear power development strategies and demand situations through scenario analysis. The scenario analysis is conducted using an input-output hour-by-hour simulation model subject to constraints from technological, economic and environmental perspectives. The obtained installed capacity mix, power generation mix and CO2 emissions of the scenarios were compared and analyzed with each other and with historical data. The results show that (1) penetration level of renewable energy is subject to the share of nuclear power as base load; (2) it is very difficult to remove nuclear power absolutely from the electricity system even when a high level of penetration of renewable energy is realized; (3) high level penetration of renewable energy can reduce the dependence on nuclear and thermal power, but there is a need for more flexible power sources to absorb fluctuations; (4) CO2 emissions reduction compared to 1990 levels can be readily achieved with the help of renewable energy, nuclear power and energy saving in 2030. This is a revised version of the paper that was published in [1]. (author)