The Department of Energy has called on power and generation companies involved to determine the root cause of the power outage on that occurred in some parts of Metro Manila and nearby provinces on Tuesday night.

“I have written Meralco (Manila Electric Co.), NGCP and the concerned generating companies for an explanation and what happened,” DOE Secretary Alfonso Cusi told reporters yesterday.

The power outage affected several localities in the Luzon grid that lasted about 1 hour and 20 minutes, the National Grid Cooperation of the Philippines (NGCP) reported. The Luzon grid was placed on red alert status.

Initial data from the DOE showed that three units of the 600 megawatt (MW) Sta. Rita and two units of the 526 MW San Lorenzo Natural Gas Power Plant in Batangas tripped, causing a frequency imbalance in the system.

The San Roque (95 MW), San Gabriel (420 MW), QPPL (452 MW), Bacman (136 MW), Trans Asia (27 MW) and GN Power (151 MW) have also tripped.

The power trip lost a total of 2, 407 MW of power from the eight plants.

“I am asking for a comprehensive report and will tap experts to come up with a fair analysis on what transpired. We will look into the entire system and the specific roles and responsibilities of the stakeholders. This is to assure the public that there will be enough power supply during the holiday season,” Cusi said.

First Gen Corp., which operates the Sta. Rita, San Lorenzo and San Gabriel power plants, said a grid or line fault caused the tripping of their plants.

“This is because the protection system of these power plants are triggered to prevent them from getting damaged. It is not only the gas plants that was the first to go down. Other plants, including some coal and oil plants, tripped simultaneously,” First Gen president and COO Giles Puno said.