EIGHT power plants tripped due to a “major system trouble” which caused the brownouts Tuesday night, according to the preliminary report of the Energy Regulatory Commission.
ERC, in its market monitoring report for November 15 showed around 2,700 megawatts of generation loss were shaved off in the Luzon grid on that date due to the simultaneous unscheduled outage of the power plants in southern Luzon.
ERC also noted around 2,100 MW of capacity were on planned, maintenance and forced outages.
The regulator, however, said prices at the Wholesale Electricity Spot Market “remained low and price spikes were prevented due to the SO (system operator) initiated market intervention from 8 p.m. to 11 p.m.
“Based on the CDOR (consolidated daily operations report) of NGCP (National Grid Corp. of the Philippines), the tripping of the identified power plants was due to major system trouble and detailed reasons for the outages have yet to be confirmed,” ERC said.
ERC said “the matter is still being probed into” but the report did not recommend a technical inspection “inasmuch as the cause of the outage is not related to plant operations but appears to be an external grid disturbance.”
Energy Secretary Alfonso Cusi said they have not made any conclusion on the brownouts.
“We got [an] initial report and [are] validating them. Our tech people are studying the matter,” Cusi said.
Cusi earlier directed the power generators and other stakeholders to explain the cause of the tripping of eight power plants which caused the brownouts.
The franchise area of Manila Electric Co. , the country’s biggest power distributor, was affected by the brownouts from 7:30 p.m. to 8:50 p.m. Tuesday but power was also restored immediately.
“There was a tripping. What caused the tripping, we still don’t know. That’s why I have to wait for the report,” the official said.
The department is monitoring 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. 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.
Initial findings show 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 also noted there was also 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).