Underwater electricity highway to be built from Honam to Seoul

A high-voltage direct current (HVDC) transmission network is set to be constructed in the West Sea of Korea, aiming to transmit surplus electricity from the Honam region to the Seoul metropolitan area. The underwater "electricity highway" is designed to prevent blackouts resulting from excess power supply and address the power supply imbalance between the two regions. However, there are concerns about Korea Electric Power Corporation (KEPCO)'s ability to cover the substantial costs of building the power grid, especially after recording its worst operating deficit last year.

On Monday, KEPCO announced that the '10th Long-Term Transmission and Transformation Facility Construction Plan' has been finalized following a review by the Electricity Committee under the Ministry of Industry, Trade, and Energy. The plan, spanning from 2022 to 2036, focuses on constructing a power grid that distributes electricity evenly across the country, to solve problem of regional concentration of electricity power. The kep part of the plan is to establish a power grid connecting the Honam region and the Seoul metropolitan area. With a high concentration of solar power facilities, the Honam region experiences an excess supply of electricity. KEPCO states that approximately 63% of the 65.7 GW (gigawatt) solar power generation target for 2036 is located in the Honam region. The concern is that blackouts may occur not only when the power supply fails to meet demand but also during periods of low demand with excessive power supply.

To prevent such a risk, KEPCO has resolved to build a high-voltage transmission network to transfer the surplus electricity from the Honam region to the Seoul metropolitan area. The underwater HVDC cable system minimizes power loss during transmission, enabling more power to be sent over greater distances compared to existing transmission networks.

The challenges faced include the costs of constructing the power grid and opposition from local residents. The 10th Transmission and Transformation Facility Plan's costs amount to 56.5 trillion won. Considering KEPCO's operating deficit of around 32 trillion won last year, covering the required expenses will not be an easy task.


kalssam35@donga.com