Of 104 transmission and substation construction projects under South Korea's 7th through 10th Basic Plans for Long-Term Electricity Supply and Demand, 68 were either completed after their target dates or remain under construction past those deadlines. Building 345-kilovolt transmission and substation facilities, used mainly for wide-area power transmission, took more than 10 years on average.
Only 19 projects, or 18.3%, were completed on schedule, according to data submitted by Korea Electric Power Corp. to Rep. Eo Gi-gu of the Democratic Party of Korea, a member of the National Assembly's Climate, Energy, Environment and Labor Committee.
Thirty-two projects, or 30.8% of the total, were completed after their target dates. Another 36 sites, or 34.6%, remain under construction despite having passed their deadlines. For 17 projects, or 16.3%, the completion target has not yet arrived.
Excluding projects counted more than once across the plans, 31 projects have passed their completion targets. Of those, 16 are still under construction. Adding up the overruns for each of the 31 projects gives a total of 1,454 months, or 121 years and two months.
Building 345-kV transmission lines and substations, core facilities for wide-area transmission, also required considerable time. Over the past 20 years, erecting the transmission towers needed for 345-kV lines took 10 years and one month on average, KEPCO said. Building a 345-kV substation took 10 years on average. Limited to projects launched since 2023, construction of 345-kV transmission lines has stretched to about 13 years, indicating that timelines have lengthened in recent years.
Of 136 transmission line projects undertaken over the past two decades, 40, or 29.4%, were delayed by complaints from local residents. Permitting problems extended construction in 28 cases, or 20.6%. Among 147 substation projects, the most common cause of delay was slow industrial complex development and difficulty securing customers, accounting for 49 cases, or 36%. Delays in preceding work came next with 28 cases, followed by changes in grid conditions with 27.
"To make the three mega-projects a success, we must adjust permitting and resolve issues such as consultations with residents and funding, so that industrial facilities are never left idle for lack of electricity," Eo said. "The government needs to bring together the capabilities of the relevant ministries and prepare extraordinary measures to clear up the delays in the power grid."