[Exclusive] Technical Standards for West Coast Energy Expressway to Be Set by Foreign Company

KEPCO Signs Service Contract With Sweden-Based Hitachi Energy
Consulting to Define Technical Specifications for 2-GW Saemangeum?Seohwaseong Voltage-Source HVDC
Four Korean Heavy Electric Equipment Makers Aim for Localization by 2027

A 200-megawatt high-voltage direct current (HVDC) system supplied by Hyosung Heavy Industries to the Yangju Substation of Korea Electric Power Corporation. Hyosung Heavy Industries.

Korea Electric Power Corporation (KEPCO) has signed a consulting contract with Sweden-based Hitachi Energy (formerly ABB's Power Grids business) to establish technical specifications for a 2-gigawatt ultra-high-voltage direct current (HVDC) system, also known as the "West Coast Energy Expressway."

Although this is considered an unavoidable choice because the technological level of Korean companies lags behind that of overseas firms, concerns are being raised that technical standards and the industrial ecosystem could become dependent on foreign companies. Four domestic power equipment companies plan to commercialize the relevant technology by 2027.

According to the power industry on February 11, Korea Electric Power Corporation recently signed a contract titled "Service for Establishing HVDC Technical Specifications" with Sweden's Hitachi Energy through an international tender.

According to the request for proposal (RFP) disclosed by KEPCO, Hitachi Energy must provide services from February for six months to establish technical specifications for a "2GW, 525 kV-class bi-pole voltage-source HVDC system." KEPCO explained the purpose of the service, saying, "Through a preliminary specification planning study, we aim to identify the key performance requirements of the HVDC system and the detailed technical specifications of the 2GW Saemangeum-Seohwaseong VSC (voltage-source) projects."

The 2GW Saemangeum-Seohwaseong voltage-source HVDC project refers to the first project under the government's West Coast Energy Expressway initiative. As one of the new administration's national agenda items, the core plan is to connect the HVDC network via subsea cables to transmit renewable energy produced in the Honam region to industrial complexes in the Seoul metropolitan area. The total length of the power grid will reach 220 kilometers.

The project was originally scheduled for completion by 2031, but the Ministry of Climate, Energy and Environment and KEPCO have decided to move the target date up by one year to 2030. The total project size is estimated to reach around 11 trillion won, drawing intense interest from power grid equipment companies. The budget for just the first phase alone is expected to reach 2.8 trillion won.

KEPCO stated, "The Saemangeum-Seohwaseong project is the first attempt in Korea to build a 2GW large-capacity voltage-source HVDC power grid, and we are conducting consulting work to standardize the technical specifications with a view to future localization of the technology."

Although the West Coast Energy Expressway project plans to adopt a 2GW voltage-source HVDC technology scheme, no company in Korea has yet commercialized such a system. Therefore, the plan is to define the specifications needed for construction based on consulting with a company that already possesses this technology.

KEPCO effectively restricted domestic participation by setting a bidding requirement that the bidder must have "at least one research track record within the past 10 years on a ±500 kV, 2GW bi-pole voltage-source HVDC system or a system of equivalent or higher level."

According to the power industry, Korea's HVDC technology is assessed to be at about 80% to 90% of the level of global leaders. In particular, voltage-source HVDC, a next-generation technology, is still at an early stage. The global HVDC market is effectively dominated by three companies: Hitachi Energy, GE Vernova, and Siemens Energy.

Model of a voltage-source high-voltage direct current (HVDC) system exhibited by Hitachi Energy at the Elex Korea 2026 exhibition on Feb. 4, 2026. Photo by Kang Heejong

In Korea, Hyosung Heavy Industries supplied a 200-megawatt voltage-source HVDC converter to the Yangju Substation in 2024. To apply this to the West Coast Energy Expressway, the capacity would need to be increased tenfold. A converter is equipment that converts alternating current (AC) into direct current (DC).

To build a 2GW-class voltage-source HVDC system, a dedicated converter transformer is required in addition to the converter. A converter transformer is a facility that provides appropriate voltage so that AC-DC conversion equipment can operate properly. Because of its high technical complexity, it has not yet been commercialized in Korea.

Since the second half of last year, the government has been carrying out a national R&D project with four major domestic heavy electrical equipment manufacturers-Hyosung Heavy Industries, HD Hyundai Electric, LS Electric, and Iljin Electric-to develop converter transformers for HVDC.

The government plans to secure design technology for converter transformers by the end of this year, build manufacturing capability by the end of 2027, and deploy them in the field in 2028. If this schedule is not met, Korea may fail to complete the West Coast Energy Expressway by 2030 or be forced to rely on imported products.

Some observers are concerned that, because a foreign company is providing the 2GW voltage-source HVDC design services, participation by domestic firms may be restricted in the future. In response, Cho Kisun, Power System Program Director (PD) at the Korea Institute of Energy Technology Evaluation and Planning, said, "The specifications applied to the first-phase project in 2028 will reflect not only the results of KEPCO's consulting work but also the design technologies developed domestically," adding, "The role of KEPCO, as the project owner, is crucial."

A Korea Electric Power Corporation official said, "Establishing technical standards is intended to create opportunities for domestic companies in the future, and the domestic power industry ecosystem will not become dependent on foreign firms."

Separately from the national R&D project, domestic heavy electrical equipment manufacturers are also focusing on technology development to participate in the West Coast Energy Expressway project. LS Electric signed a memorandum of understanding (MOU) with GE Vernova in July last year to localize converter facilities for HVDC.

In October last year, HD Hyundai Electric signed a "Strategic Cooperation and MOU on HVDC Technology" with Hitachi Energy and began developing technologies for the entire transmission grid system, including converter facilities, transformers, and control systems. Hyosung Heavy Industries plans to independently develop converters, transformers, and controllers.

<Terminology>

Voltage-source HVDC: Ultra-high-voltage direct current transmission technology is classified into current-source (thyristor-based) and voltage-source (IGBT-based) systems depending on the type of semiconductor used. Voltage-source HVDC is considered more suitable for transmitting renewable energy such as offshore wind power because it enables bidirectional power transmission and can flexibly respond to output fluctuations.

Bi-pole: A power grid designed so that even if a fault occurs on one circuit, 50% of the power can still be supplied through the other circuit.