South Korea has raised its projected 2040 target peak electricity demand by 26.6 to 26.8 GW in a revised preliminary proposal, reflecting the formal inclusion of large-scale semiconductor and artificial-intelligence data-center investments. The forecast now stands at 158.4 GW in the baseline scenario and 165.0 GW in the upside scenario, compared with April estimates of 131.8 GW and 138.2 GW. Annual target electricity consumption was also lifted to 847.3 TWh and 885.1 TWh, respectively, from 657.6 TWh and 694.1 TWh. The revisions were driven mainly by advanced-industry projects: semiconductor-related demand increased by about 141 TWh, while data-center demand rose by 58.4 TWh. Authorities said the higher outlook could require 19 additional 1.4 GW large-scale nuclear reactors if met through nuclear capacity, adding pressure to the debate over new reactors, renewable generation, transmission infrastructure and demand management. The forecasts remain contested because many artificial-intelligence data-center projects are not yet fully confirmed. The government plans to finalize the 12th Basic Plan for Long-term Electricity Supply and Demand by year-end.