The government is broadening its approach to the power grid, a bottleneck in renewable energy expansion, from "building more" to "using more of what exists." The strategy allows grid connections during peak demand hours on the condition that power generation is reduced, with surplus electricity stored in energy storage systems (ESS).
While continuing to push ahead with transmission and distribution network construction, the government aims to accelerate renewable energy expansion by raising the utilization rate of existing grids, given that grid expansion takes time.
On September 29, the Ministry of Climate, Energy and Environment (MCEE) announced a "power grid innovation plan" that will lift the designation of grid management substations in the Honam region starting October 1, and raise the capacity of existing power grids through flexible access, autonomous access, energy storage systems (ESS), and access rights restructuring. Through this plan, the government aims to increase the renewable energy capacity of transmission grids from the current 119 gigawatts (GW) to 171 GW by 2030, an increase of approximately 43.7 percent.
From 119 GW to 171 GW: Operations, not just capacity
The core of this plan is to increase access capacity by considering not only the maximum capacity of power generation facilities connected to the grid, but also how much electricity actually flows through it.
Flexible access is a prime example. When the power grid temporarily exceeds what it can handle, new connections are permitted on the condition that power plant output is reduced. Using this method, the government will raise the solar power connection limit on distribution lines from the existing 14 megawatts (MW) to 16 MW, and at substations from 50 MW to 60 MW. Without building separate grids, Honam can accommodate an additional 2.6 GW of solar power.
Autonomous access will also be introduced. Developers install capacity larger than the permitted connection capacity, but manage the actual power supplied to the grid within the permitted range using output limiters or ESS. Solar power equipment capacity connected to distribution lines can be increased from the existing level to 2 to 3 times, up to a maximum of 6 times. Even as equipment increases, the power supplied to the grid at once is limited.
ESS bridges the gap between the time electricity is produced and when the grid has spare capacity. Solar power generated during the day is stored and then released when the grid has spare capacity, raising the utilisation of existing distribution networks and substations.
By 2030, the government plans to connect an additional 3 GW of solar power through distribution grid ESS, and install ESS of approximately 40 MW per substation at 41 saturated substations in Honam, securing a total capacity of around 1.6 GW. The government will also install 2.6 GW of reinforcement ESS in areas such as Sinokcheon and Cheongyang where transmission grid flexibility is insufficient.
The role of ESS is also expanding. Rather than just supporting renewable energy generation, ESS will be used as equipment to substitute for some grid expansion needs.
Lee Jae-sik, energy policy official at the MCEE, said "renewable energy distribution grid ESS and substation ESS will be 5 GW or more by 2030," and "the total capacity of ESS will be finalized in the 12th Basic Plan for Long-term Electricity Supply and Demand."
Honam grid constraints resolved in one year: changing the structure of rejection due to lack of grid
Regionally, Honam shows the biggest change. The government has decided to lift restrictions on Honam, which it designated as a grid management substation starting September 2025, restricting new renewable energy connections. Of the 189 grid management substations designated in May 2024, all 164 in Honam were restricted. The government had blocked developers' connections due to insufficient grid capacity for renewable energy, and is now moving to ease this.
The government has recovered approximately 9 GW of access rights through verification of inactive projects. Going forward, the government will proactively adjust access rights for projects delayed over the long term to align connections with actual project implementation timelines.
Honam offshore wind is a prime example. It has secured 15.8 GW of access rights by 2030, but the actual expected volume entering the grid is only about 3 GW. The government expects to recover more than 10 GW of access rights by 2030 by adjusting the connection timing of delayed projects such as offshore wind in Honam.
Kim Jin-soo, professor of resource and environmental engineering at Hanyang University, evaluated the plan as "timely, given that expanding the power grid requires considerable time and cost, focusing on using existing grids more effectively in addition to building more," and "tools to increase grid capacity at relatively low cost in a short period have been appropriately deployed."
However, he pointed out that to ensure the plan's effectiveness, transparency in capacity calculation and verification procedures must be established, and financing possibilities must be secured considering output control conditions. Professor Kim said "smooth financing will be possible only when control priority, annual control limits, and compensation principles for exceeding limits are established," and "a roadmap on when and how much to reduce inflexible power sources and secure flexible resources must also be implemented."
Original Korean article: Edaily
English brief by Korea Wind Intelligence, koreawindintel.com
