The Visayas power grid will be placed under a six-hour yellow alert on Thursday, June 11, according to the National Grid Corporation of the Philippines (NGCP).
In an advisory, NGCP said the yellow alert will take effect from 3:00 p.m. to 9:00 p.m. due to tight operating reserves in the grid.
The grid’s available capacity is projected at 2,675 megawatts (MW), while peak demand is expected to reach 2,564 MW.
Despite this narrow margin, a total of 863.1 MW is reported unavailable to the system due to multiple plant outages and derated capacities.
According to NGCP, nine generating plants are on forced outage in June 2026, eight have been offline since May 2026, one since March 2026, three since 2025, two since 2024, two since 2023, and one since 2021. In addition, 10 plants are currently operating at derated capacities, further limiting supply.
The grid operator cited several factors that contributed to the yellow alert declaration, including the unavailability of major Visayas coal plants—TVI Unit 1, TVI Unit 2, and PEDC Unit 3.
It also noted "reduced power imports from Mindanao due to earlier plant trippings caused by a recent earthquake," as well as higher-than-expected demand forecasts, which further added pressure to the grid.
"A yellow alert is issued when the operating margin is insufficient to meet the transmission grid’s contingency requirement," it said.
