South Korea, a country in East Asia, is known for its technological advancements, vibrant economy and strategic role in global trade and innovation. The country has unveiled an ambitious plan to transform its energy sectors, aiming to generate 70 per cent of its electricity from carbon-free sources by 2038. South Korea aims to have 30 nuclear plants by 2038 and to more than triple its solar and wind power output to 72 GW by 2030. The government also plans to replace ageing coal power plants with more sustainable options like pumped storage hydroelectricity and hydrogen power plants.
The energy transition comes at a crucial time as South Korea is heavily investing in its semiconductor industry. Semiconductors are South Korea’s largest export item, and the global demand for memory chips – driven by new information technology (IT) devices and innovative services like artificial intelligence (AI) and cloud computing – is expected to fuel continued growth in the sector. To diversify beyond chips, the country is implementing government-led development plans to enhance its capabilities in microprocessors, sensors and other semiconductor products. South Korea is set to launch a KRW10 trillion programme to fortify its crucial semiconductor industry. As the world’s leading memory chip producer, the country will invest KRW622 trillion in a semiconductor mega cluster in Gyeonggi Province, which the government plans to support with tax incentives and other measures to attract investments.
The synergy between the energy and semiconductor sectors is evident. The energy transition plan anticipates a surge in electricity consumption due to the expansion of data centers and large chip-production bases necessary to meet the growing demand for AI and other advanced technologies.
The shift towards renewable energy sources (RES) and the expansion of the semiconductor sector are expected to create millions of jobs and drive economic growth. However, the transition is not without challenges. South Korea’s heavy reliance on fossil fuels has historically led to high electricity costs, as seen during the global energy crisis in 2022. South Korea aims to mitigate these issues by diversifying its energy sources and enhancing energy efficiency across industries. One major aspect of the country’s future plans is promoting the offshore wind industry (OSW). South Korea aims to achieve 14.3 GW of OSW capacity by 2030, contributing to its broader net-zero emissions goal by 2050. Overall, grid integration is crucial to facilitate the country’s energy transition. South Korea’s sole transmission and distribution grid operator, Korea Electric Power Corporation (KEPCO), is expanding its network across the country, particularly along the western coast, to accommodate the increasing demand.
Current infrastructure
As of early 2024, South Korea had an installed generation capacity of 144 GW, of which the majority (or 58 per cent) was based on thermal sources such as coal, oil and natural gas. Of the remaining, 23 per cent was based on RES including hydro, solar and wind, and 17 per cent was based on nuclear. KEPCO, through its six generating subsidiaries, owns around 70 per cent of the generation capacity, while the remaining capacity is accounted for by independent power producers and community energy systems.
Figure 1: South Korea’s installed generation capacity, as of early 2024 (%)
Total installed capacity = 144.4 GW
Note: Thermal includes coal (bituminous and anthracite), oil and natural gas; hydro also includes pumped storage; others include fuel cell, integrated gasification combined cycle (IGCC), marine energy, bioenergy, etc.
Sources: Korea Electric Power Corporation; Electric Power Statistics Information System, South Korea; Global Transmission Report
As the country’s sole electricity grid company, KEPCO owned and operated about 16,302 km of transmission lines at voltage levels of 154 kV to 765 kV, as of 2023. Of this, the majority of the lines (or 67 per cent) were at 154 kV alternating current (AC), followed by 29 per cent at 345 kV AC, 3 per cent at 765 kV AC and 1 per cent at 180 kV high voltage direct current (HVDC). Of the total line length, 13,753 km were overhead lines, 2,451 km underground cables (UGC) and 98 km were undersea cables (USC).
Figure 2: South Korea’s transmission line infrastructure as of 2023 (%)
Total line length = 16,302 km
Over the past five years, the transmission line length remained stable, with a marginal compound annual growth rate of about 0.34 per cent.
Figure 3: Growth in South Korea’s installed transmission line length (km)
Note: Data for 2023 is the same as 2022 since no major projects were commissioned that year.
Sources: Korea Electric Power Corporation; Electric Power Statistics Information System, South Korea; Global Transmission Report
Recently, in May 2024, KEPCO successfully completed the 500 kV Bukdangjin–Godeok HVDC Phase II project, enhancing the transmission capacity from the west coast to the Seoul Metropolitan Area by 3 GW. The KRW1.15 trillion project, which includes 34.2 km of the HVDC network (29 km UGC and 5.2 km USC), is the country’s first 500 kV underground HVDC system, the first phase of which (1.5 GW capacity) was completed in December 2020. The new infrastructure alleviates grid constraints, allowing approximately 900 MW of previously limited power generation from the Taean thermal power plant to better serve high-tech industrial complexes, particularly semiconductor facilities in Pyeongtaek and Godeok.
Future plans
Consumption and generation
South Korea’s Ministry of Trade, Industry and Energy’s (MOTIE) 10th Basic Energy Plan for Electricity Supply and Demand (released in January 2023) has projected electricity consumption to reach 597.4 TWh by 2036 from around 533 TWh in 2021. This is driven by increased demand from data centers and increased electrification. However, through demand management efforts and technological advancements, electricity consumption is expected to be reduced by 105.7 TWh. To meet the increased demand, South Korea plans a significant increase in power generation capacity to 667 GW. This expansion involves the continued operation and construction of nuclear power plants, substantial investment in RES capacity, integration of more advanced grid technologies and energy storage solutions to ensure a stable and flexible energy supply system, along with the phasing out of old coal facilities.
Figure 4: South Korea’s planned generation mix by 2036 (per cent)
Total installed capacity = 667 GW
Note: Thermal includes coal and natural gas; the share of RES reflects the percentage after solar and wind power curtailment. Without curtailment, the proportion would be 33 per cent.
Source: 10th Basic Energy Plan for Electricity Supply and Demand
Offshore wind
South Korea’s OSW development is set to play a pivotal role in the country’s pursuit of a carbon-neutral society by 2050. Efforts are underway to enhance the grid infrastructure necessary to support the 2030 OSW targets. In addition, the country is augmenting existing ports and constructing new ones specifically tailored for OSW operations. For instance, Incheon and Gunsan ports are being developed to serve as major hubs for OSW installation and maintenance, particularly for OSW farms along the western and southern coasts of South Korea. To attract technology providers and investors to the OSW segment, the government is offering incentives such as tax breaks and free economic zones. Regions like North Jeolla and Incheon are poised to become industrial clusters for OSW, leveraging their existing manufacturing bases and infrastructure. As part of efforts to address the technical, regulatory and environmental challenges related to OSW integration, the South Korean government, in collaboration with industry stakeholders, is developing standardised guidelines for community engagement and environmental assessments.
Transmission infrastructure
KEPCO’s 10th Long-Term Transmission and Substation Facility Plan of 2023 outlines a comprehensive strategy for the expansion and reinforcement of transmission and substation facilities from 2022 to 2036. This plan is aligned with MOTIE’s latest supply and demand plan, and aims to address increasing electricity demand, integrate nuclear and RES, and ensure a stable and flexible power grid. By subdividing the country into six regions and 42 subregions, KEPCO has planned and allocated resources to meet specific regional electricity needs. The plan emphasises securing system capacity for the national energy mix, implementing innovative measures for timely construction, and reinforcing the power distribution network between regions.
The plan details long-term transmission line and substation projects along with several ongoing projects across various categories. It includes 345 kV and 154 kV substations and transmission lines, HVDC transmission lines, static synchronous compensators (STATCOM), static var compensators (SVC), and synchronous condensers.
Table 1: Projects under KEPCO’s 10th Long-Term Transmission and Substation Facility Plan
Note: The new and ongoing projects are as of 2023; HVDC includes both lines and substation projects.
Source: 10th Long-Term Transmission and Substation Facility Plan, KEPCO
One of KEPCO’s major ongoing transmission projects is the 500 kV East Coast–Singapyeong line, designed to enhance power evacuation from major thermal power plants including Samcheok, Gangneung Anin and Shin Hanul. Spanning 230 km and supported by 440 transmission towers, the line is divided into 11 sections, with the eastern segment covering 140 km and the western segment 90 km. Initially confirmed in the 4th Power Supply and Demand Plan in 2008, the project faced delays due to land acquisition and environmental impact assessment issues. Notwithstanding the delay of over five years, KEPCO has advanced the project, which is expected to commence operation in 2026, addressing power supply challenges in the Seoul Metropolitan Area.
Technological innovations are integral to South Korea’s future transmission plan. These include expanding alternative technologies for power grid construction, such as non-wire alternatives (NWAs) and flexible AC transmission systems (FACTS). Electro Magnetic Transient (EMT) Analysis technology is introduced to improve the precision of system analysis by including dynamic characteristics. In addition, the plan involves establishing databases for power system analysis by various time slots, contributing to better grid management and optimisation.
International collaboration and MoUs
KEPCO has been actively entering into global partnerships to enhance its technological capabilities and expand its business footprint in the energy sector. In 2024, KEPCO signed several MoUs with state-owned utilities and corporations in various countries.
In March 2024, KEPCO and Denmark’s Energinet signed an MoU to collaborate on stable grid operation technologies, including OSW power and HVDC systems, with KEPCO contributing its expertise in substation digitalisation. KEPCO and Samsung Electronics signed an MoU to exchange technology on power system operation, focusing on preventive diagnosis for transformers and circuit breakers, and supporting the semiconductor industry’s growth through advanced power infrastructure.
To share its technological and technical expertise with other foreign utilities, KEPCO signed MoUs with Electricity Vietnam, Indonesia’s PLN and Siemens, Mozambique’s Electricidade de Mozambique, and Kyrgyzstan’s Ministry of Energy to collaborate on new energy technologies such as HVDC transmission and advanced metering infrastructure.
Conclusion
South Korea’s strategic plan to increase renewable electricity generation underscores its commitment to sustainable growth and advancement. By diversifying energy sources through nuclear and RES expansion and strengthening the semiconductor sector, the country aims to drive economic growth, create job opportunities and maintain its competitive edge in global markets. However, the transition presents challenges, including high electricity costs and the need for advanced grid management systems. Addressing these issues through innovative solutions and international collaborations will be crucial to achieving South Korea’s ambitious goals.
