The National Grid Corp. of the Philippines (NGCP) placed the Visayas grid under a yellow alert for several hours on Tuesday, May 26, due to tight power supply conditions driven by plant outages and rising demand.

In an advisory issued as of 10 a.m. on May 26, NGCP said the yellow alert would be in effect from 3 p.m. to 9 p.m., when electricity demand is expected to peak.

Available capacity for the grid was projected at 2,647 megawatts, while peak demand was forecast at 2,493 megawatts, leaving a thin operating margin.

A total of 37 power plants were either offline or operating at reduced capacity. Of these, 14 plants have been on forced outage since May 2026, one since March 2026, three since 2025, two since 2024, two since 2023, and one since 2021. In addition, 14 plants were running on derated capacities.

These outages and limitations have resulted in 892.25 megawatts of unavailable capacity for the Visayas grid.

NGCP cited the unavailability of major coal-fired power plants—TVI Units 1 and 2, and PEDC Unit 3—as a key factor behind the alert status, along with increased forecasted system demand.

A yellow alert is issued when the power supply operating margin is insufficient to meet the grid’s contingency requirements, indicating a higher risk of power interruptions if additional generation units suddenly go offline.