According to the Renewable Energy 3020 Implementation Plan announced in 2017 by the South Korean administration, the electricity share of renewable energy will be expanded to 20% of the total electricity generation by 2030. Given the intermittency of electricity generation from renewable energy, the realization of such a plan implies potentially large excess electricity generation in certain situations. The purpose of this study is to propose a model to accurately simulate the effects of excess energy generation from renewables which would arise during the transition to South Korea’s 8th Basic Plan for Long-term Electricity Supply and Demand. Our results show that the existence of excess power is highly likely when significant increases in generating capacity from PV and wind capacity are introduced, specifically in spring and fall. In addition, the planned ability to ramp down LNG plants will not be sufficient to cope with the excess energy produced by renewable intermittency. In this case, the role of coal-fired power plants through daily load-following operations could be essential to provide the grid system with additional operational flexibility. In addition, the role of nuclear energy would be vital to achieving both CO2 emissions and electricity cost reductions as an alternative to the fossil fuel generation capacity (i.e., LNG and Coal) outlined in the 8th Basic Plan.
Keywords renewable energy resources, nuclear energy, energy system modeling, excess electricity