Following a "brownout weekend" that affected millions of consumers, Luzon grid tumbled into new round of "red alert" on Monday, Sept. 12, that extended until 8 pm due to confluence of factors ignited by transmission line tripping, forced outages of power plants and de-rating of electricity generation of some facilities.
On Monday, system operator National Grid Corporation of the Philippines (NGCP) declared "red alert" in the biggest power grid of Luzon originally from 1:00 to 4:00 pm, but extended it until 8:00pm, indicating that some consumers in the grid may suffer rotational blackouts within that period.
The "red alert" was declared after NGCP placed the grid on "yellow alert" status due to insufficient power reserves from 9:00am to 1:00pm.
As a result, power utility giant Manila Electric Company (Meralco) said it already advised its interruptible load program (ILP) participants to switch on their generating units to ease strained capacity in the main grid.
As of 2:00pm Monday, there are anticipations that the Sual plant may return to operation, hence, that could spare various areas in Luzon from suffering unwanted rotational blackouts, especially those in Ilocos Norte, Baguio City, Cagayan, Angeles City, Laguna, Quezon, Camarines Sur, Albay and Metro Manila.
The precarious power supply situation that already resulted in brownouts last Sunday, Sept. 11, was a stark contrast to the pronouncement of Energy Secretary Raphael P.M. Lotilla last week that Luzon grid will have sufficient power supply until the end of the year.
NGCP reported that at least seven electric generating plants had been on simultaneous forced outages leading to a loss of more than 3,400 megawatts in the power system.
The generating facilities on unscheduled downtimes include Unit 1 of GNPower Dinginin plant of the Ayala-Aboitiz joint venture; Calaca-2 plant of the Consunji group; Masinloc 2 and 3 as well as Sual 1 and 2 plants of the San Miguel group; and the Quezon Power plant.
The sudden outages of the power plants had been aggravated by the de-rated (reduced) capacity of the other power plants, that in turn resulted in additional capacity loss of 226MW in the Luzon grid.
The plants with de-rated capacities, NCGCP said, include Unit 2 of the GNPower Mariveles plant which is also a joint venture of the Ayala-Aboitiz group; unit 1 of the Masinloc plant of the San Miguel group; and Unit 2 of the South Luzon Thermal Energy Corporation (SLTEC) facility of the Ayala group.
On Sunday, several parts of Metro as well as provincial areas had been tormented with brownouts because of the tripping of the 500-kilovolt Nagsaag-Bolo lines 1 and 2 of NGCP, hence, that subsequently caused the non-availability of the Sual and Masinloc plants into the power system.
Industry players have sounded off concern on the reliability of the power system as the tripping of the transmission line happened at a time of low consumption weekend; and weather temperatures were even at a low scale.
According to Meralco, more than 600,000 of its customers had been afflicted with brownout predicaments on Sunday – causing an inconvenience to the public while they are on their usual weekend break from work.
The affected customers are those in various parts of Metro Manila such as Caloocan, Makati, Manila, Muntinlupa, Paranaque, Pasay, Pasig, Pateros, Quezon City, Taguig as well as the provinces of Bulacan, Cavite, Laguna, Rizal and Quezon.