Expectation for renewable energy is increasing. There are several studies that have considered renewable energy installation in Japanese power grids as a whole. However, renewable energy presents problems with regard to load following capability and regional geographic characteristics. This study presents the optimal installation region of renewable energy in Japan by using a multi-regional optimal generation planning model. Additionally, a renewable energy installation strategy to reduce CO2 emission by Japan’s electricity sector is proposed. First, a CO2 emission constraint scenario is executed. Next, two scenarios are implemented: a Natural Gas Combined Cycle plants constraint scenario and a residential photovoltaics constraint scenario. The result shows three important factors for the selection of an installation region for renewable energy, i.e., the composition of energy resources of each regional electricity power supplier, the plan of power generation plants of each regional electricity power supplier and the introduction amount of residential photovoltaics. Results indicate that information-sharing among electricity power suppliers, renewable energy suppliers and government is important to achieve a low-carbon grid.
