Transition from fossil fuels to nuclear and renewable energy: Evidence from Japan

Japan has pledged carbon neutrality by 2050, yet energy production still accounts for 84% of its greenhouse-gas emissions, and only 33.4% (328.48 TWh) of its 2023 electricity generation came from nuclear and renewable sources. This paper asks how Japan’s electricity generation can complete the transition from fossil fuels to nuclear and renewable energy. Using annual data for 1980–2023 from the World Bank, IMF, and the Statistics Bureau of Japan, we estimate an autoregressive log-growth model of electricity consumption driven by GDP per capita, median age, and population change, and project Japan’s 2050 electricity consumption at approximately 1,000 TWh (999 TWh; range 900–1,000 TWh across specifications, sample horizons, and population paths). Closing the resulting clean-energy gap of roughly 469 TWh would require the equivalent of about 56 additional nuclear reactors of average current capability (8.41 TWh each), rising to about 67 at the capacity factors Japan has realized since Fukushima. Applying machine-learning facility-location methods (genetic and NSGA-II algorithms) to a benchmark 21-plant configuration, we show that siting new plants on Japan’s least-populated coastlines reduces the population inside their emergency planning zones by roughly two orders of magnitude relative to naive placement, at an additional transmission cost of a few hundred million US dollars per year. Public acceptance, rather than engineering capacity, is the binding constraint on Japan’s nuclear future, and siting policy that takes safety over efficiency directly addresses it. Hydrogen-based generation, whose commercial viability at scale by 2050 remains unconfirmed, lies outside the scope of the quantitative analysis.