Abstract
The Paris Agreement has prompted Japan to set a goal of zero net greenhouse gas (GHGs) emissions by 2050. This paper discussed the role of renewable energy toward carbon neutrality in Japan. In order to examine Japan's energy supply and demand in 2050, we used the TIMES-JAPAN optimization model, which is a bottom-up analysis of Japan's entire energy system. Employing this model, Japan’s long-term energy outlook is evaluated under the scenario on carbon regulation, variable renewable energy generation cost and negative emission technologies. In unconstrained CO2 emissions scenario, CO2 emissions in 2050 will be mitigated by approximately 50% from the level of emissions in 2015. In Net zero emission scenario which CO2 emissions sets zero in 2050, the share of renewable energy in primary energy will increase from 5% to 14% (UCE) and 38-51% (NZ) respectively in 2050.