South Korea announced an energy transition roadmap, CO₂ roadmap, and national greenhouse gas reduction target of nationally determined contribution (NDC) for the Paris Agreement. Furthermore, the government has also set a goal of reducing its CO₂ emissions to reach net-zero carbon emissions by 2050. Additionally, the Korean government submitted an enhanced update of the first NDC at the end of 2021. In the electricity sector, the updated NDC proposed the GHG emissions target of 149.9 million tons in 2030. In this study, we model eight scenarios based on future energy mix and demand forecast considering the government’s latest plans to evaluate the possible emission reduction and impacts in the electricity sector. The scenario-based analysis is conducted to check whether it can satisfy the CO₂ reduction target by using PLEXOS, a production simulation model. The results show that emission reduction targets are difficult to accomplish in the short term and can lead to significant changes in the operation of generators and increased costs to realize the decarbonization pathway.