Analysis of the impacts of nuclear phase-out on energy systems in Japan

Nuclear power is likely to be widely recognized as one of the few options that can help countries meet base load electricity demand with virtually no greenhouse gas emissions. In Japan, the deregulation of Electricity Supply Industry (ESI) is expected to introduce competition into the electricity market and change market structures to lower electricity prices. As investors assume the risk of their investments, incentives to invest in nuclear power become conservative. This research examines the impacts of nuclear phase-out on both energy systems and carbon dioxide emission in Japan. A partial equilibrium model of the Japanese energy sector has been developed to forecast changes in the energy system until the year 2040. This model can account for the changes in energy technology capacities, fuels, and consumption in response to policy initiatives, such as taxes. We find that the nuclear phase-out results in an 8% increase in carbon dioxide emissions by the year 2040. To achieve the same level of carbon dioxide emissions without nuclear power in the future, it will be necessary to charge a 30% higher carbon tax than in a similar scenario with nuclear power.