The National Grid Corp. of the Philippines (NGCP) has issued yellow and red alerts across Luzon and Visayas due to simultaneous forced power plant outages, which will temporarily impact the power supply in these regions.

In an advisory this morning, the transmission operator said the Luzon grid will be placed under red alert from 2:00 p.m. to 4:00 p.m. and from 6:00 p.m to 9:00 p.m.

Meanwhile, between 1:00 p.m. and 2:00 p.m.; 4:00 p.m. and 6:00 p.m.; and 9:00 p.m. and 11:00 p.m., the grid will be on yellow alert.

Based on the latest NGCP data, the Luzon grid only has an available capacity of 13,537 megawatts (MW), while peak demand is expected to reach 13,024 MW.

“Nineteen power plants are on the forced outage, while three others are running on derated capacities, for a total of 2,117.3 MW unavailable to the grid,” the NGCP said.

Meanwhile, a yellow alert will also be raised across the Visayas grid from 2:00 PM to 4:00 PM and from 6:00 PM to 7:00 PM.

As of this morning, the Visayas grid has an available capacity of 2,742 MW and a projected peak demand of 2,440 MW.

Similar to Luzon, 12 power plants in the region are on forced outage, while five others are running on derated capacities, which means that a total of 676.5 MW capacity will be slashed from the grid.

As of posting time, the NGCP has yet to identify which specific plants went on unplanned outages.

A yellow alert is issued when the operating margin is insufficient to meet the transmission grid’s regulating and contingency requirements. When this status is in place, all power plants must run normally; otherwise, a red alert may be raised.

A red alert, on the other hand, is issued when supplies are insufficient to meet consumer demand and the transmission grid’s regulating requirement.