
On January 6, 2025, Japan experienced grid curtailment for the first time, METI’s Next-Generation Power Grid Working Group reported at its meeting held on January 23, 2025. The working group also released its economic curtailment forecast for FY2025 in which it expects the Tokyo TSO area to be affected for the first time.
According to the report, approximately 150MWh of generation in the Boso substation, Chiba Prefecture, portion of the TEPCO Power Grid’s grid was curtailed during three 30-minute time periods (12:00 to 12:30 p.m., 1:30 to 2 p.m., and 2 to 2:30 p.m.). While this was the first case of grid curtailment nationwide, METI expects more such cases as capacity under non-firm connection contracts, which allow assets to be curtailed in cases of grid congestion, increases.
In its economic curtailment forecast for the next fiscal year, which starts on April 1, 2025, the working group expects 2TWh to be curtailed nationwide with approximately half of the volume being in the Kyushu TSO area. While Tokyo has been the only of the 10 TSO areas in the country to avoid economic curtailment to date, the working group forecasts that will change in FY2025, albeit on a limited basis with a 0.009% curtailment rate accounting to 3GWh.
The overall forecasted curtailment volume is slightly lower than the revised FY2024 forecast of 2.12TWh.
The February 2025 issue of The Japan Power Industry Executive report will cover this topic in greater detail, alongside other key regulatory, policy, and market developments.