Korea needs power fast. The answer may lie beneath its roads.

Keeping Korea’s semiconductor industry competitive requires faster access to power. Building transmission lines alongside new roads offers a shortcut — but Korea has been slow to take it.

Building a power transmission line alongside a new road cut construction costs by 93.2 billion won ($66 million) and shortened the project by 17 months. That is what happened with the Gunbuk-Gaya transmission line, which will supply electricity to the Haman General Industrial Complex in South Gyeongsang.

Korea Electric Power Corporation (Kepco) is building the 154-kilovolt Gunbuk-Gaya transmission line in tandem with the construction of a section of national route No. 79 between Gunbuk-myeon and Gaya-eup in Haman County. Workers excavate 3 to 4 meters (9.8 to 13.1 feet) beneath the road to build conduits, install pipes 200 millimeters (7.87 inches) in diameter and then run transmission cables through them.

The joint construction has reduced the project cost to 29.8 billion won from an estimated 123 billion won if the road and transmission line were built separately, according to Kepco on Wednesday. That means the combined approach will save more than 90 billion won. The construction period is also expected to shrink from 49 months to 32 months. The savings are the result of putting the road and power grid on a single timetable.

How quickly infrastructure such as electricity and water can be supplied has emerged as a critical factor in the competitiveness of advanced industries, including semiconductors and AI data centers. That is why Samsung Electronics and SK hynix are racing to secure adequate supplies of both power and water.

“Companies say that if the government can quickly provide land, water and electricity, they can begin producing semiconductors within two years, or even much sooner,” Moon Shin-hak, vice minister of the Ministry of Trade, Industry and Resources, said at a parliamentary meeting on Wednesday.

The biggest obstacle to accelerating infrastructure construction is opposition from residents, which has stalled the very transmission lines Korea needs most: those carrying electricity generated in the southern regions of Jeolla, South Chungcheong and Gyeongsang northward to the greater Seoul area, where electricity demand is particularly high.

The roughly 280-kilometer (173-mile) power transmission line carrying electricity from nuclear and coal-fired power plants on the east coast to the capital region illustrates the problem. Resident complaints and permitting delays have held up the project for eight years, pushing its scheduled completion from December 2019 to December 2027.

One of the most effective ways to ease local opposition is to put transmission lines underground. Burying cables instead of erecting transmission towers can reduce disputes over issues such as damage to the landscape and electromagnetic fields.

A transmission network supplying power to the General Industrial Complex at the Yongin Semiconductor Cluster in Gyeonggi will likewise be buried underground in urban areas where opposition from residents is expected. The transmission cables will be installed beneath provincial road No. 318 while the road is being widened.

The catch is the cost. According to industry estimates, building a 345-kilovolt overhead transmission line using towers costs about 3 billion to 4 billion won per kilometer, while underground construction can cost 15 billion to 30 billion won per kilometer. Depending on the section, underground construction can cost nearly 10 times as much.

Joint construction with roads and railways can ease that financial burden. It can reduce duplicated spending on land acquisition, gaining local support and construction.

“Roads, railways and transmission networks are all linear infrastructure that stretches over long distances, so there are significant advantages to building them together,” said Choi Jae-sung, a research fellow at the Korea Research Institute for Human Settlements. “If planned together from the outset, it can make land acquisition easier, reduce local opposition and significantly cut both construction costs and timelines.”

Some countries have institutionalized this approach. In the United States, the state of Wisconsin changed its law in 2003 to require planners of new transmission networks to give priority to routes along existing transmission lines, roads and railways.

Minnesota overhauled its regulations in May 2024 to allow highway corridors to be used for transmission infrastructure. The reasoning is that using existing highway corridors can reduce the time needed to secure new land, accelerate transmission network construction and lower the cost of underground lines.

In Korea, however, joint construction remains largely ad hoc. There is no national system for mapping road, railway and power grid projects together, identifying those with overlapping routes and timelines, and considering whether they could be built jointly.

The Gunbuk-Gaya transmission line came about only after a Kepco official — who was coordinating with Haman County on the construction of a substation — learned of plans for a nearby national highway project. The official then approached the regional land management authority, leading the two sides to sign a memorandum of understanding and pursue joint construction.

Discussions over provincial road No. 318 in Yongin started with a proposal from the Gyeonggi provincial government to install Kepco’s transmission network beneath the road while the road project was underway.

Despite the potential for dramatic savings in both cost and time, such projects are still regarded as pilots because discussions can begin only when officials overseeing one project happen to learn about another agency’s plans.

The high-voltage direct current transmission project linking the east coast to Seoul and the KTX line extending to Gangneung, Gangwon, are often cited as examples of the shortcomings of this siloed approach to infrastructure planning.

While construction of the transmission network has been delayed for years by local opposition and other hurdles, the Gangneung railway line along the same east-west corridor is already complete.

New railways generally face less local resistance because they improve transportation links.

“If the east coast transmission network had been planned together with the Gangneung railway line, it could have significantly reduced both local opposition and costs,” said Cho Hong-chong, a professor of economics at Dankook University. “The two projects share much of the same route, but the lack of coordinated infrastructure planning led to unnecessary social costs.”

Some local governments have moved ahead with institutional changes of their own. In March, Gyeonggi revised its guidelines for managing the total cost of public construction projects. For road and other public works projects worth at least 50 billion won, authorities are now required from the planning stage to consult agencies responsible for underground electricity and water infrastructure, including Kepco and the Korea Water Resources Corporation, on the possibility of joint construction.

The Ministry of Climate, Energy and Environment has also included plans to promote joint construction of power grids with roads and railways in its work report for the second half of this year. Transmission lines needed for the southwestern semiconductor cluster will also be installed underground along provincial road No. 49, as President Lee Jae Myung calls for the project to move ahead at full speed.

Still, bureaucratic silos between ministries could make it difficult for joint construction to spread beyond a limited number of government-led projects, critics say.

“At the moment, roads have their own plans, railways have theirs and power grids have theirs, making it difficult to link them together,” said Kim Chang-yong, a senior research fellow at the Korea Institute of Civil Engineering and Building Technology. “Korea needs a national system, like those in Australia or Britain, that can review infrastructure investment plans together in advance, identify projects whose routes overlap and coordinate them accordingly.”

BY AHN HYO-SEONG [lee.soojung1@joongang.co.kr]