A yellow alert was raised over the Luzon Grid Tuesday after modules of the San Lorenzo natural gas power plant with a total capacity of 534 megawatts (MW) tripped.
The temporary loss of the San Lorenzo modules thinned the available power on the grid although this did not mean imminent loss of power altogether.
According to the National Grid Corporation of the Philippines (NGCP), the alert was raised from 1 p.m. to 4 p.m. Tuesday as available capacity totaled only 12,705 MW versus peak demand of 12,222 MW.
The Department of Energy (DOE) said interruptions were reported to have occurred at NGCP and Manila Electric Co. (Meralco) feeders following the trip at San Lorenzo although power was immediately restored at 11:06 a.m. for Meralco customers and at 11:04 a.m. for NGCP customers.
Meralco said the service interruption affected approximately 500,000 customers in portions of Metro Manila, Bulacan, Cavite, Laguna, Rizal and Quezon which was restored fully after eight minutes.
The DOE is still coordinating with the operator of the San Lorenzo power plant and other stakeholders for the cause of the anomaly.
Meralco said it also quickly activated its interruptible load program (ILP) Tuesday but did not detail the capacity secured by it.
Under the ILP, customers with large electricity consumption are encouraged to run their own generator sets whenever the supply of electricity in the grid is short in exchange for monetary incentives.
The fuel that they use in running their own power source are then paid by consumers.
