Spain's blackout could serve as a warning for Korea's energy vulnerability

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Spain's blackout could serve as a warning for Korea's energy vulnerability

Published: 19 May. 2025, 11:29 Updated: 19 May. 2025, 15:26

Audio report: written by reporters, read by AI

A family eats a snack by candlelight during a blackout in Barcelona, Spain, on April 28. [AP/YONHAP]

More than 20 days after a massive blackout swept across Spain, the exact cause behind it still remains unknown. The alarm has also rung in South Korea due to the vulnerability of its own power grid, with the country located in geographical isolation and having a growing reliance on so-called "inflexible" energy sources like nuclear and renewables.

When it comes to energy and resources, South Korea is a virtual "energy island" — surrounded by the sea on three sides and bordered by enemy state North Korea — making it difficult to respond quickly if a blackout like Spain’s was to occur. Analysts suggest that Korea should utilize liquefied natural gas (LNG) power generation and resolve the “transmission bottleneck” phenomenon.

On April 28, the power outage cut off around 60 percent of Spain’s electricity supply, affecting not only the entire country but also parts of neighboring Portugal and France.

It halted essential urban infrastructure — phones, traffic lights, payment systems and elevators — for over 10 hours. Tragically, one person died after a ventilator stopped functioning. It marked one of Europe’s largest-ever blackout incidents.

Potential causes include Spain’s high proportion of renewable energy — solar accounts for 53 percent and wind for 11 percent — sudden climate fluctuations and suspected cyberattacks on the transmission network. An investigation is still ongoing.

Major European countries, including Spain, France and Germany, send excess power to neighboring countries in real time through the international power trading network, or import power when there is a shortage. South Korea’s power grid is more vulnerable than Spain’s.

The Shin-Hanul nuclear power plant is seen in Uljin, North Gyeongsang, on Nov. 7, 2022. [NUCLEAR SAFETY AND SECURITY COMMISSION]

“Korea cannot send or receive power from outside, so the flexibility of energy supply and self-responsibility determine its survival,” said Yoo Seung-hoon, professor of energy policy at Seoul National University of Science and Technology.

A comparable incident occurred in Jeju Island in 2006, when a ship’s anchor damaged an undersea cable, plunging the entire island into a two-and-a-half-hour blackout.

As Korea is geographically isolated, a flexible power supply is important to prevent power outages. However, the trend is to increase the proportion of “rigid power sources” that require long-term constant output, such as nuclear power, or that are difficult to controldepending on the weather, such as renewable energy.

Last year, nuclear power accounted for 31.7 percent and renewables 10.5 percent of total generation, according to the Ministry of Trade, Industry and Energy. By 2038, these are expected to increase to 35.2 percent and 29.2 percent, respectively, according to the 11th Basic Plan for Electricity Supply and Demand.

Power lines connecting pylons of high-tension electricity are seen during sunset at an electricity substation on the outskirts of Ronda, during a blackout in the city in Spain on April 28. [REUTERS/YONHAP]

Meanwhile, the share of LNG — a flexible source that can be adjusted quickly — is projected to fall from 28.1 percent to 10.6 percent.

“Spain had to urgently activate LNG plants to recover from the blackout,” said Kim Jae-kyung, a senior researcher at the Korea Energy Economics Institute. “We need to adjust the speed of reducing the proportion of LNG power generation and use it as a ‘bridge power generation’ during the transition period of increasing renewable energy.”

The “transmission bottleneck” phenomenon, where the generated electricity cannot be sufficiently delivered to demanders, is also a problem.

For example, the Shin-Hanul nuclear power plant on South Korea’s east coast has completed construction, but its output is restricted due to delays in building high-voltage lines to Seoul.

Passengers wait at Humberto Delgado airport after most of the boarding controls resumed operations following a major blackout, in Lisbon, Portugal, on April 19. [EPA/YONHAP]

Similarly, renewable-rich regions in South Jeolla and the southwest sea are at capacity and can’t accommodate new facilities until 2031.

“Inflexible transmission systems can destabilize the grid, even when there’s ample power supply,” said Sonn Yang-hoon, a professor of economics at Incheon National University. “We need to expand our transmission infrastructure to balance supply and demand.”

“We shouldn’t view the Spanish blackout as a distant problem,” said Jerng Dong-wook, a professor of energy systems engineering at Chung-Ang University. “Rather than getting stuck in a debate over nuclear versus renewables, we need constructive discussions on how to ensure grid stability as we expand renewable energy — which is the inevitable path forward.”

Translated from the JoongAng Ilbo using generative AI and edited by Korea JoongAng Daily staff.
BY KIM KI-HWAN [[email protected]]