The National Grid Corporation of the Philippines (NGCP) raised alert status over the Visayas grid Wednesday night.

In an advisory issued on Wednesday, the NGCP noted that red alert was raised in the Visayas grid from 5pm to 9pm and yellow alerts from 9pm to 10 pm.

The NGCP said the "red alert status is raised in the Visayas grid due to the reduced output of MVIP brought about by the tripping of GNPK 2 (138MW) & SMCPC U2 (135MW)."

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

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

In the Bagong Pilipinas Ngayon interview, Assistant Energy Secretary Mario Marasigan explained that there is a possibility of rotational brownout in areas under red alert.

"When we say red alert, the reserve is thin. We do not have enough reserve and there is a possibility for a rotational brownout," he said.

Earlier, the NGCP raised yellow alerts in the Luzon grid from 1 pm to 11 pm and in Visayas grid from 1pm to 10 pm.

The alert was advised as 18 power plants in Luzon and 13 others in Visayas are on forced outage.

The NGCP noted that "a yellow alert is issued when the operating margin is insufficient to meet the transmission grid’s contingency requirement."

For Luzon grid there are three other power plants that are "running on derated capacities, for a total of 1,969.3MW unavailable to the grid" while for the Visayas grid there were five other power plants that are also "running on derated capacities, for a total of 698MW unavailable to the grid."

It noted that the Luzon grid has an available capacity of 13,607MW and peak demand of 12,874MW while the Visayas grid has available capacity of 2,713MW and 2,523MW.

Marasigan said the power plant that experienced problems on Tuesday may be fixed on April 20 while the other power plants are expected to be restored by the end of the month. Robina Asido/DMS