South Korea's government has unveiled a roadmap to phase out all 60 currently operating coal-fired power units (39.5 GW) from the generation market by 2040.

Under the proposal, 39 of the country's 60 operating coal plants would be replaced by LNG and pumped-storage hydroelectricity by 2038, while the remaining 21 units would be phased out between 2037 and 2039.

The plan was presented by Professor Kim Jin-soo of Hanyang University at the 7th public forum for the 12th Basic Plan for Long-Term Electricity Supply and Demand, held by the Ministry of Climate, Energy and Environment at KEPCO's South Seoul Headquarters on September 18.

Coal accounted for 28.7% of South Korea's total power generation in 2025. The 21 units with a design life extending beyond 2040 represent 19.1 GW.

First, 27 units that will reach their 30-year design life by 2036, totaling 13.6 GW, are to be replaced by LNG during the same period. Four units whose replacement sites are undecided will be relocated based on large-scale industrial demand.

Replacement LNG generation for Yeongheung Units 1 and 2 would go to the Seoul metropolitan area, while that for Dangjin Units 5 and 6 would go to the Honam region.

For the 12 units slated for closure between 2037 and 2038, about 6.8 GW, the plan proposes using 7.5 GW from 13 pumped-storage hydroelectricity projects now underway. The remaining 21 units would be retired in stages between 2037 and 2039 rather than all at once by 2040.

To ease the burden on operators, preferential treatment would be given in bidding for new projects such as battery energy storage systems (BESS), and conversion to small modular reactors (SMR) would be considered if the local community accepts it. Some private generators could also be converted to LNG combined heat and power generation after 2030 to meet heat demand.

A key feature is the designation of up to 10 of the 21 units as "security power sources" based on plant performance and grid contribution. These would not take part in the electricity market under normal conditions but would serve as reserve resources during emergencies such as peak demand, declines in renewable generation, LNG supply instability, and surging oil prices.

The targets and scale would be confirmed in the next Basic Plan for Long-Term Electricity Supply and Demand after reviewing renewable energy distribution and regional grid conditions.

Overseas cases show that coal plants have been kept as reserve power rather than dismantled immediately. Dr. Park Myung-duk of the Korea Energy Economics Institute noted that Germany, while phasing out coal by 2038, reduced hard coal generation through reverse auctions and used some successful bidders as grid and capacity reserves for transmission bottlenecks or supply shortages. Its lignite closure schedule was set through government-operator negotiations, considering mining and local employment.

Taiwan, which like South Korea is not connected to neighboring grids and has a large semiconductor industry, also chose to convert aging coal plants to gas while keeping some as emergency reserves. The Taichung Power Plant is replacing 10 coal units with six gas units, ending commercial coal generation by 2034, but may maintain up to six units as reserve facilities.

The conclusion drawn from these cases is that supply stability is a prerequisite for phasing out coal. Rather than closing plants uniformly, countries should combine competitive bidding, government negotiation, environmental regulation, alternative power sources, and reserve power according to their own electricity market and grid conditions.