A Study on Energy Mix in 2050

Abstract

Both Variable Renewable Energy (VRE) such as Solar and Wind and Nuclear Energy are crucial energy sources to reach decarbonization target in 2050 and later. However, VRE is non-dispatchable energy, namely the electric power is highly depending on the weather. This study aims to clarify the degree of excess or lack of electric power when the amount of electric power by VRE becomes 20%, 40% and 85% of annual electricity generation, where the electric power of VRE is estimated based on the VRE capacity factors recorded hourly in FY2018. As a result, there are some negligible excess electric power and no lack of electric power can be estimated up to 20% of the VRE fraction, where the fraction of solar and wind should be even. On the other hand when the VRE fraction would be 85%, there occurs the excess electricity and lack of electricity almost every day and its values become hundreds of TWh. It is found that the VRE fraction of 40% can be a development target under even power generation capability by solar and wind power. The lack of electricity can be adjusted by a large scale battery system around 70GWh. Based on this estimation, it is inevitable that the dispatchable energy sources such as fossil power with Carbon Capture, Utilization and Storage (CCUS) and nuclear power have to occupy the rest of the electric power generation．