Electricity demand surged to a record high of 76.6 million kilowatts on Wednesday morning due to the frigid temperatures, officials said.

During the morning peak between 10 a.m. and 11 a.m., it was 75.9 million kilowatts on average. Soaring demand amid the cold spell took electricity reserves to below 4 million kilowatts at 10:44 a.m., leading the power control agency to issue an “attention” warning.

It was the sixth time the attention light has lit up in December. The attention warning goes off when the nation’s power reserves linger between 3 million and 4 million kilowatts.

The Korea Electric Power Corp,, the nation’s sole electricity transmission and distribution operator, ran the varied electricity demand control program, while expanding power supply capacity to prevent a possible blackout.

In the afternoon, four big buildings in Gangnam, southern Seoul, including Kyobo Tower, suffered from a sudden power outage for about one hour. But KEPCO officials said the power cut was caused by a problem with power cable lines, not by a surge in power consumption.

As the imbalance between power demand and supply is expected to deteriorate next month, the coldest month of the wintert in Korea, the Ministry of Knowledge Economy will introduce a “selective extra-charging system” targeting big energy spenders from Jan. 1 next year.

The system will charge applicants extra when they use power during peak hours, while offering a discount for power use outside peak periods.

By Seo Jee-yeon  (jyseo@heraldcorp.com)