Environment ministry launches seasonal power grid pilot in Jinan and Geumsan

The environment ministry said Friday it will launch a one-year pilot project starting Sept. 19 to test seasonal allowable rating systems for power transmission lines in Jinan, North Jeolla Province, and Geumsan, South Chungcheong Province.

The initiative aims to improve grid efficiency by adjusting transmission capacity according to seasonal temperature changes, which alters the thermal capacity of power lines. By increasing line capacity during cooler seasons, the ministry expects to reduce output curtailment for renewable energy sources and facilitate more flexible maintenance schedules.

Under the current static line rating system, domestic power grids set transmission limits based on worst-case scenarios involving temperatures of 40 degrees Celsius and wind speeds of 0.5 meters per second.

Seasonal allowable rating leverages the fact that power lines can carry more electricity when ambient temperatures are lower. During the pilot, transmission lines in the selected regions will operate with capacities adjusted against seasonal maximum temperature benchmarks rather than fixed worst-case assumptions.

Similar dynamic rating methods are already applied in 27 European countries such as Germany as well as in the United States.

Following verification of the pilot project's effectiveness, the ministry plans to consider additional trials for ambient adjusted rating systems.

"Through this pilot project, we will be able to utilize the power grid more efficiently and reduce output curtailment," Lee Jae-sik, the ministry's power grid policy director, said. "We will continue to pursue various measures to secure power grid conditions for the expansion of 100 gigawatts of renewable energy."