THE Energy Department on Wednesday ordered the power producers and other stakeholders to explain the cause of the tripping of eight power plants that caused the brownouts Tuesday night.
“There was an outage [Tuesday night]. The plants simultaneously went off and that caused disturbance on the grid. We lost around 2,400 megawatts,” Energy Secretary Alfonso Cusi told reporters.
He said parts of the franchise area of Manila Electric Co., the country’s biggest power distributor, were affected by the power cutoff that was also restored immediately.
“I have written Meralco, NGCP [National Grid Corporation of the Philippines] and the concerned gencos [generation companies] for an explanation and what happened, Including ERC (Energy Regulatory Commission),” Cusi said.
He also ordered the Philippine Electricity Market Corp., the operator of the Wholesale Electricity Spot Market, to explain.
Cusi said he expected their replies by 5 p.m. Wednesday.
“There was a tripping. What caused the tripping we still don’t know. That’s why i have to wait for report,” Cusi said.
The Energy Department said it was continuing to monitor the power situation in Luzon and the Visayas following the tripping.
“I am asking for a comprehensive report and will tap experts to come up with a fair analysis on what transpired,” Cusi said.
“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.”
The power supply in Luzon stood at 9,925 MW Wednesday noon with a demand of 8,183 MW and a reserve level of 1,742 MW.
Initial findings showed that the three units of Sta. Rita (600 MW) and two units of San Lorenzo (526 MW) tripped and caused the automatic load drop in the Luzon area. The frequency of the system dropped to 58.68 hertz.
The department said there was also a tripping of “motor sensitive loads in the area resulting in the frequency to bounce back to 61.08 hertz.”
The department said a second set of plants totaling 861 MW tripped including San Roque (81 MW), Quezon Power Philippines (452 MW), Bacman (136 MW), Trans Asia (27 MW) and GN Power (151 MW).
First Gen Corp., which owns the Sta. Rita and San Lorenzo power plants, said tripping occurs at the same time and within seconds when there is a fault in the system.
“Let me clarify. It was a grid/line event fault that resulted in the triggering of our plants’ protection system to prevent damage,” First Gen president Francis Giles Puno said.
“The protection system of these power plants are triggered to prevent them from getting damaged. It is not only the gas plants that was first to go down. Other plants, including some coal and oil plants, tripped simultaneously,” he said.
He said the gas plants had the flexibility to restart quickly and be synchronized to the grid at a shorter time than the coal plants.
