Seven out of 10 new solar and wind power projects that cleared South Korea's Electricity Regulatory Commission this year came with conditions requiring grid upgrades or limits on output. The government is accelerating the buildout of renewable generation capacity, but transmission construction is not keeping pace, raising concerns that power grid bottlenecks will worsen.
A review by The Seoul Economic Daily of all decisions from the commission's 319th through 328th sessions this year found that 31 of 43 new or conditional approvals for solar and wind projects, or 72.1%, carried grid-related conditions, according to results released on the 17th. Thirty were conditioned on "connection after grid reinforcement," and one on "priority output curtailment." The count excludes amended permits, deadline extensions, deferred reviews, rejections and projects licensed separately by local governments.
A grid reinforcement condition means the plant has been approved but the transmission lines and substations that would take its electricity lack spare capacity. Until the grid is upgraded, operators cannot ship as much power as they want from a new plant over transmission lines to other regions or sell it. Adding generation to a grid with no headroom can cause overloads or voltage instability. Even when flexible connection is permitted before reinforcement, operators must accept output curtailment when the grid is congested.
That goes directly to project viability. Generators can recover their investment only once they begin commercial operation and start selling power. For projects whose grid upgrades are scheduled for 2033 or 2034, the timing of commercial operation also depends on transmission expansion, making expected cash flows harder to model and adding strain to project financing.
"The longer the connection delay, the more project economics can deteriorate — not just through financing but through site costs and rising equipment and construction expenses," said Yoo Seung-hoon, a professor of future energy convergence at Seoul National University of Science and Technology.
The bottleneck was most pronounced in Jeollanam-do, where solar and wind projects are concentrated. Of the 43 new projects, 29 were in the province, and 27 of those, or 93.1%, carried conditions requiring connection only after grid reinforcement. Twenty-four were premised on upgrades in 2034, and the remaining three on December 2033. Grid reinforcement for the Goheung Nuri No. 1 to No. 3 solar projects is set for April 2034, and for the Shinan No. 1 and No. 2 offshore wind projects for December of the same year.
The problem is not confined to new projects. Three floating solar projects led by local governments in the Saemangeum area — in Gunsan, Gimje and Buan — whose amended permits were reviewed at the commission's 322nd session, also carry conditions requiring connection after grid reinforcement in December 2034. Projects already licensed and under way are likewise affected by transmission expansion schedules.
Under the government's plans, renewable capacity must be added far faster than it is now. In the first basic plan for renewable energy, released in May, the government set out to expand renewable capacity from 37.1 gigawatts in 2025 to 100 GW by 2030. That requires adding an average of 12.6 GW a year between 2026 and 2030, or 3.6 times the 3.5 GW annual average of the past five years.
The difficulty is that transmission lines take much longer to build. According to the Ministry of Climate, Energy and Environment, a long-distance 345-kilovolt overhead transmission line takes about nine years from site selection to completion. Actual construction runs about four years, but pre-construction steps alone — site selection, permitting and design — take about five years.
The biggest obstacle is local acceptance. "For a power plant, you only need to win over residents in that one area, but a transmission line runs much farther, so you have to win acceptance across many more communities," said Chung Dong-wook, a professor of energy systems engineering at Chung-Ang University.
Reflecting such concerns, the ministry recently released a set of measures to improve public acceptance of transmission construction. It plans to consolidate existing and new lines to cut the number of newly built towers by up to 40% and to expand underground cabling in densely populated areas. While waiting for transmission lines, some large power consumers are turning to liquefied natural gas generation, producing the electricity they need at the point of demand. The catch is that LNG prices have surged in the wake of the Middle East conflict this year, driving up costs.
Experts suggest reordering grid connection queues for projects that have been licensed but have made little progress over a long period, aligning them with actual project status, while expanding energy storage systems and pumped hydro generation and allowing flexible connection to make better use of the existing grid. "Using energy storage systems, you can raise grid utilization by charging and discharging at particular hours," said Park Jong-bae, a professor of electrical and electronic engineering at Konkuk University.
