South Korea posts fifth-highest power demand on record

South Korea’s market electricity demand reached 95.3 GW at 3 p.m. (GMT+9) on Aug. 7, the highest level recorded this summer and the fifth-highest on record, the country’s Ministry of Climate, Energy and Environment (MCEE) said in a new analysis report published this week. Record heat drove the peak despite reduced industrial output during the summer vacation period.

The four higher peaks were 97.1 GW on Aug. 20, 2024, 96.0 GW on Aug. 25, 2025, 95.7 GW on July 8, 2025, and 95.6 GW on Aug. 19, 2024. Market demand would have surpassed 100 GW had industrial facilities not reduced operations for the holiday period, the ministry said. Total grid demand would have reached 106.8 GW.

The Korea Meteorological Administration (KMA) said the city of Yangsan reached 42.5 C on Aug. 2, the highest temperature recorded since national observations began in 1904. The national average temperature for the first 10 days of August reached a record 29.1 C, according to KMA data cited by the ministry.

Market demand refers to electricity supplied by generators participating directly in South Korea’s wholesale power market, distinct from total demand, which also includes power-purchase agreements with state utility Korea Electric Power Corp. (Kepco) and behind-the-meter generation not traded on the market. The MCEE said solar power across both categories met approximately 25% of total demand during peak daytime hours.

On Aug. 3, total demand reached 97.1 GW at 3 p.m., with 17.4 GW supplied by non-market solar sources and a further 7.2 GW from solar participating directly in the electricity market, said the ministry.

Moon Yang-taek, director general for power industry policy at the MCEE, said the government will closely monitor weather conditions and power supply through the remainder of the summer as generators begin scheduled maintenance ahead of winter peak demand.

South Korea has selected nine operators to install 128 MW/640 MWh of energy storage systems across 32 distribution lines in the Honam and Jeju regions, where saturated substation and distribution-line capacity has left new solar projects waiting in interconnection queues. The ministry is targeting roughly 700 MW of distribution-line ESS by 2030, which it says would enable an additional 1 GW of renewable interconnection capacity.

The government has also introduced a non-wires-alternatives compensation scheme that pays ESS operators an amount equivalent to avoided grid construction costs when storage substitutes for new transmission infrastructure, starting with a pilot project in Jeju before expanding to mainland projects. The MCEE secured KRW 558.6 billion ($411.5 million) in national budget funds over five years for the broader distributed-grid initiative.