The Visayas grid was placed under yellow alert from 4 p.m. to 8 p.m. on Thursday, May 21, according to the National Grid Corporation of the Philippines (NGCP).

The latest warning marks the fourth straight day that a yellow alert has been raised over the Visayas grid this week.

In an advisory issued Thursday, the NGCP said the yellow alert was declared due to high power demand and the unavailability of several large coal-fired power plants in the Visayas.

A yellow alert is raised when the operating margin is insufficient to meet the transmission grid’s contingency requirement, indicating a thin power supply buffer.

During the alert period, the Visayas grid recorded an available capacity of 2,670 megawatts (MW) against a peak demand forecast of 2,479 MW.

Data from the NCGP showed that 10 power plants have been on forced outage since May 2026, one plant since March 2026, three plants since 2025, two plants since 2024, two plants since 2023, and one plant since 2021. In addition, 14 plants are operating on derated capacities, leaving a total of 867 MW unavailable to the grid.

Among the major factors cited for the yellow alert declaration were the unavailability of large coal plants TVI 1, TVI 2, and PEDC 3, as well as high projected system demand.

Meanwhile, the Department of Energy (DOE) said it is actively coordinating with the Independent Electricity Market Operator of the Philippines (IEMOP), NGCP, the Energy Regulatory Commission (ERC), generation companies, and other industry stakeholders to expedite the safe restoration of affected facilities and implement measures to stabilize the grid and protect consumers.

The DOE added that it continues to closely monitor the situation in both grids and will provide updates to the public as developments unfold.