Electrical cables crisscross one another as electric meters hang on posts in Barangay Old Capitol, Quezon City on July 11, 2023. Maria Tan, ABS-CBN News

MANILA (UPDATE 3) - The country's power grid operator put the Luzon grid on yellow alert and the Visayas grid on red alert on Wednesday due to the shutdown of several power plants. 

The National Grid Corporation of the Philippines placed the Luzon grid on yellow alert from 1 p.m. to 11 p.m. as 19 power plants in Luzon were not operating.

Meanwhile, the NGCP raised the Visayas grid's alert status from yellow to red after two more plants experienced outage, adding to the 13 power plants that were already not operating. 

The Visayas grid is on red alert from 5 p.m. to 9 p.m. and on yellow alert from 9 p.m. to 10 p.m.

"Manual load dropping or rotational power interruptions may be implemented to protect the integrity of the power system," the NGCP said.

A red alert status is issued when power supply is insufficient to meet consumer demand and the transmission grid’s regulating requirement, the company added.

The Philippine Independent Power Producers Association (PIPPA) meanwhile said most of the 19 Luzon power plants on outage are hydropower plants, which are unable to operate when water levels are low.

The Department of Energy said the red alert on Tuesday was triggered by the sudden tripping of Pagbilao Plant which aggravated the situation where a number of power plants are on scheduled and unscheduled plant shutdown.

DOE Assistant Secretary Mario Marasigan said it will investigate the unplanned shutdown of some plants as well as the prolonged shutdown of other facilities.

Earlier the DOE said there would be no power problem during the dry months as there was more than enough power supply available.

MERALCO STILL ON ALERT

Meralco Spokesman Joe Zaldarriaga said participants of the interruptible load program (ILP) have been alerted for a possible red alert today.

Yesterday, the ILP saved Meralco consumers from power interruptions as it deloaded around 300 MW of power from the utility.

Luzon grid on red alert on Tuesday afternoon