The Visayas power grid was placed under a yellow alert on Monday, June 29, due to the unavailability of large coal-fired power plants, according to the National Grid Corporation of the Philippines (NGCP).

In an advisory, NGCP said the yellow alert was in effect for one hour, from 6:00 p.m. to 7:00 p.m.

Among the affected facilities are the Visayas’ large coal-fired power plants TVI 1, TVI 2, and PEDC 3, which contributed significantly to the reduction in available supply.

As of 8:30 a.m., the grid’s available capacity was 2,571 megawatts (MW), while peak demand was 2,288 MW.

However, multiple generation units remained offline or operating below normal capacity, reducing the effective supply available to the grid.

"13 plants are on forced outage on June 2026, 8 plants are on forced outage since May 2026, 1 plant since March 2026, 3 plants since 2025, 2 plants since 2024, 2 plants since 2023, and 1 plant since 2021," NGCP reported.

Meanwhile, 16 plants are operating on derated capacities, bringing total unavailable capacity to 963.4 MW.

A yellow alert is issued when the operating margin is insufficient to meet the grid’s contingency requirements, signaling a thin reserve buffer in case of unexpected plant outages or demand spikes.

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 power facilities.

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