South Korea to overhaul time-of-use electricity tariffs; daytime rates fall, night rates rise.

South Korea plans to overhaul its seasonal time-of-use electricity pricing to reflect changing power supplies, with daytime rates expected to fall while nighttime charges rise. The Ministry of Climate, Energy and Environment and state-run KEPCO announced the plan after a screening by the Electricity Tariff Committee. The reforms target industrial customers with at least 300 kW of load and would run from April 16 through the end of 2030, a five-year window, with an option for companies to apply for a deferral until September.

The changes are driven by a shift in the power mix, as daytime solar output has grown and altered the overall supply-demand balance. The current scheme, which already prices daytime demand higher to curb usage and offers lower rates at off-peak hours, will be adjusted further as solar provides more daytime energy and nighttime supply tightens. Under the new plan, the high daytime rate could drop by up to 16.9 won per kWh, while the lowest pre-dawn rate could rise by 5.1 won per kWh. The tariff uses three load levels—maximum, mid, and low—with the plan lowering the maximum-load charge on average by 15.4 won and increasing the cheapest low-load rate by 5.1 won.

In addition, the government will impose further shifts: the 11–12, and 13–15 hour blocks now categorized as mid-load would be reclassified, and the 18–21 hour block would move to the maximum-load category, amplifying the daytime savings while increasing some nighttime charges. The policy also includes a 50% discount for 11:00–14:00 rates on weekends and holidays during the spring (March–May) and fall (September–October) seasons. This discount also applies to electric vehicle charging tariffs.

Beyond the industrial sector, the plan is slated to apply from June to other tariff categories, including secondary industrial and household electricity tariffs (such as 일반용 갑Ⅱ, 산업용 갑Ⅱ, 일반용 을, 교육용 을). Officials say the broader rollout will gradually extend the reform's impact across the market.

Government analysis suggests the reforms would ease Korea’s industrial electricity burden overall. About 97% of roughly 38,000 companies currently billed under the 을 tariff are expected to see lower bills, with an average reduction of 1.7 won per kWh—roughly 1% of the current average price of about 170 won per kWh. Smaller enterprises that operate mainly during daytime could benefit more, with a projected drop of about 2.7 won per kWh, compared with about 1.1 won for large corporations. For facilities operating around the clock, a reduction near 1 won per kWh is anticipated.

Separately, the Electricity Tariff Committee introduced a dedicated electricity tariff for heat pumps, designed to support broader adoption of this heating technology without imposing higher costs on households. Homeowners with heat pumps may either keep the residential progressive rate, have only heat pump usage billed under the general-use rate, or choose from three residential seasonal-time-of-use options introduced in Jeju. While three options may suit most homes, those with rooftop solar will often benefit more from the current progressive tariff.

For U.S. readers, the significance lies in how Korea’s energy pricing strategy shapes manufacturing costs, technology adoption, and climate goals. South Korea remains a key supplier in electronics, semiconductors, and automotive components; electricity costs influence the competitiveness of its exporters. The new tariffs also reflect Korea’s push to accelerate building electrification and the integration of solar and other renewables, with potential implications for supply chains, energy markets, and cross-border collaboration on clean energy technologies.