[Edaily Marketin KIM SUNG-SOO Reporter] As large-scale electricity demand—including that from semiconductors and artificial intelligence (AI) data centers—concentrates in the Honam region, the importance of expanding the power grid and ensuring its stable operation is growing.

Korea Electric Power Corporation (KEPCO) is expanding its capacity to accommodate renewable energy through flexibility measures that involve both constructing new transmission lines and increasing the utilization of the existing power grid. It is also pursuing a plan to proactively build substations near large-scale power consumers.

Honam Semiconductor Project Power Demand: 6.2 GW

Kwak Eun-seop, Head of the Power System Planning Division at Korea Electric Power Corporation (KEPCO), identified semiconductors, physical artificial intelligence (AI), and AI data centers as the three major projects that will drive large-scale power demand during the “Honam Region Semiconductor Mega-Projects and Future Power Infrastructure Forum” held on the 5th at the Kim Dae-jung Convention Center in Gwangju-Jeonnam Integrated Special City as part of “BIXPO 2026,” an event hosted by KEPCO.

He explained that the power supply plans related to semiconductor industrial complexes submitted to KEPCO total approximately 15 GW. Of this, the power demand from semiconductor projects in the Honam region alone amounts to about 6.2 GW.

Director Kwak said, “In the past, it was uncommon for power demand to be measured in gigawatts (GW), but these days, whether it’s semiconductors or artificial intelligence, demand on the scale of 5 GW or 10 GW arises easily,” adding, “We are now in the ‘era of large loads,’ where we must respond to massive power demand.”

Demand for AI data centers is also growing rapidly. Director Kwak noted, “AI data centers are often proposed in units of 1 GW,” adding, “In addition to the currently planned capacity, future demand is expected to be substantial.”

As large-scale power demand shifts to non-metropolitan areas, addressing regional disparities in power infrastructure has also been identified as a key challenge.

Director Kwak explained, “Data centers exceeding 1 GW generally require a 345 kV connection, but there are relatively few 345 kV substations in non-metropolitan areas,” adding, “This is because demand is concentrated in the Seoul metropolitan area, so existing infrastructure is also more heavily concentrated there.”

In response, KEPCO is promoting a “demand-driven substation” project to preemptively build substations in regions where large-scale demand has been confirmed. Director Kwak said, “A plan has been devised for the government to proactively construct 345 kV-class substations in non-capital regions even before definite demand arises,” adding, “We plan to proceed with this initiative through the joint participation of local governments, high-tech companies, and data center operators, backed by government support.”

He emphasized, “From the perspective of AI data center operators, the presence of a 345 kV substation nearby is extremely important,” adding, “If a substation is 60 km away, it takes a considerable amount of time to construct new transmission lines. Whether there is a substation close to the facility can determine its competitive edge in terms of location.”

The Honam region was assessed as having sufficient power supply capacity. Director Kwak said, “Power generation in the Honam region is about 1.3 times greater than regional demand, and in South Jeolla Province alone, generation exceeds demand by more than two times,” adding, “South Jeolla Province has one of the highest energy self-sufficiency rates in the country.”

The region’s power supply capacity is expected to grow further as additional renewable energy and gas-fired combined-cycle power plants are built. However, he noted that public acceptance could pose a hurdle during the process of expanding the transmission grid needed to send locally generated power to other regions, such as the Seoul Metropolitan Area.

Director Kwak said, “Approximately 70 GW of renewable energy capacity is scheduled to be installed in the Honam region in the future, and transmitting that electricity to other regions will require a corresponding expansion of the transmission grid,” adding, “We anticipate significant difficulties, such as residents banding together to oppose the construction of transmission lines.”

KEPCO to Build Substations in Areas with Confirmed Large-Scale Demand The company

is also pursuing a plan to maximize the use of existing facilities rather than relying solely on new transmission grid construction. The plan involves utilizing battery energy storage systems (ESS)—included in the government’s power grid innovation measures—to distribute power flows that are concentrated during specific time periods and increase the utilization rate of existing transmission lines.

Director Kwak explained, “We cannot just sit idly by until the transmission grid is completed,” adding, “The flexibility measures are the result of our deliberations on how to utilize the existing transmission grid to connect additional renewable energy sources.” He continued, “By using battery energy storage systems (ESS) to charge during peak demand periods and discharge during off-peak periods, we can use existing transmission lines more efficiently.”

He explained that through these measures, “the goal is to accommodate more than 50 GW of additional renewable energy through the existing transmission grid.”

He also emphasized the need for structural changes to the power grid. Director Kwak noted that South Korea’s power system has evolved in tandem with economic growth over the past 70 years, explaining, “Over the past 70 years, power generation capacity has increased 426-fold, while electricity demand has risen 314-fold.” Although the increase in the length of transmission lines was relatively modest, the grid’s transmission capacity has been expanded by increasing transmission capacity and voltage.

However, he assessed that as the share of renewable energy increases, changes are also needed in how the stability of the existing power system is maintained. Conventional synchronous generators, such as those in nuclear and coal-fired power plants, have historically absorbed sudden changes in the power system through the inertia of the rotating generators. In contrast, he explained that as inverter-based power sources—such as solar and wind—increase, this inertial function could weaken.

Director Kwak stated, “In the existing system centered on synchronous generators, rotational inertia absorbed the shock even when problems arose with generators or the transmission grid,” adding, “If the system shifts toward renewable energy, that capacity may become insufficient.”

He particularly emphasized the importance of technical measures to prevent situations where minor failures in the power grid spread in a chain reaction. “The power system behaves like dominoes—if one component fails, the failure spreads to the next,” he explained. “While the first failure can occur at any time, the key is to prevent the chain reaction from progressing to the second stage.”

To this end, he predicted that the role of grid stabilization equipment—such as synchronous condensers, batteries, and grid-forming inverters—would grow. Director Kwak explained, “In the future, synchronous condensers, batteries, and grid-forming technologies must take on the role of ensuring grid stability,” adding, “The fundamental challenge is securing grid inertia, which goes beyond simply ensuring power quality.”

He also called for preparations against overvoltage and overfrequency. This is because if a failure occurs in renewable energy generation equipment and an inverter disconnects from the grid, the balance between power demand and supply can shift rapidly, causing voltage and frequency to rise.

Director Kwak said, “While Korea is relatively accustomed to preparing for low-voltage and low-frequency situations, we have relatively little experience with overvoltage and overfrequency issues,” adding, “As renewable energy expands, we must prepare very carefully for overvoltage and overfrequency as well.”

He emphasized, “Going forward, establishing a system to reliably connect and operate the power grid is just as important as securing power supply capacity,” adding, “To respond to large-scale power demand and the expansion of renewable energy, we must simultaneously pursue the expansion of the transmission grid, the utilization of existing facilities, and measures to stabilize the grid.”