Energy Output Conflict Grows with Rising Solar, Nuclear Power

As the proliferation of solar power continues, the share of renewable energy is growing, leading to concerns about the management of power that is produced in excess of demand. Critics are urging the government to swiftly establish measures to address this issue.

According to sources in the electricity industry on June 11, between 12 p.m. and 1 p.m. on April 9, a Sunday, average solar power output reached 21,778.7 megawatts (MW), making up 39.2% of the 55,577 MW of total power consumption in South Korea at that time. That is, solar power accounted for approximately 40% of total electricity consumption. This figure includes the amount of power traded on the electricity market (power exchange) and the power produced outside of the market, such as that generated by the Korea Electric Power Corporation.

Solar power generation increases during spring due to the increased amount of sunlight. Notably, the power capacity produced by solar power facilities increased almost fourfold over about five years from 7.5 gigawatts (GW) in 2018 to 26.4 GW as of March 21 this year, making the share of solar power in the total electricity consumption reach the 30% range.

The problem lies in the difficulty of controlling the supply of excess power as renewable energy generation facilities are expanding and nuclear power generation is also increasing. Renewable energies such as solar power have fluctuating electrical output based on weather conditions, making power production prediction and control difficult. Similarly, adjusting the output of nuclear power plants can cause safety issues, and it takes one to three days to restart a reactor once it has been shut down.

The administration of President Yoon Suk-yeol faces difficulties in harmonizing power system operations as the two challenging power sources continue to increase, making power supply control increasingly difficult. The government is pushing forward with a nuclear expansion policy, which includes extending the lifespan of 12 existing nuclear power plants and resuming construction of Shin Hanul units 3 and 4. Yu Seung-hoon, the dean of the Seoul National University of Science and Technology, emphasized, “The problem will become more serious in the fall, next spring, and the year after if both the operation of Shin Hanul unit 2 starts this fall and solar power continues to increase.”

The Ministry of Trade, Industry and Energy currently matches power supply by limiting the output of nuclear power and renewable energy. Limiting power supply prevents blackouts from overwhelming transmission and distribution networks.

Experts point out that considerations must be made for enhancing transmission networks, expanding energy storage systems (ESS), and other midterm solutions, as well as managing each power source's weaknesses to maintain a stable power system.