THE Luzon power grid was placed on red alert on Monday after five power plants declared forced outages, the National Grid Corp. of the Philippines (NGCP) said.
In a statement, NGCP said that a red alert was raised over the Luzon power grid between 1 p.m. and 4 p.m. and 6 p.m. and 8 p.m. A yellow alert was also in force between 4 p.m. and 6 p.m.
The grid operator said three other power plants are running at derated capacity, taking away a combined 1,354 megawatts (MW) from the grid.
The NGCP estimated that the Luzon grid’s available capacity was 12,186 MW, with peak demand at 12,468 MW.
Yellow alerts are declared when supply available to the grid falls below a designated safety threshold. If the supply-demand balance deteriorates further, a red alert is declared, signifying the grid operators intent to ration power via rolling brownouts.
The Department of Energy (DoE), through its Electric Power Industry Management Bureau, said it is monitoring the situation.
According to the DoE, the Bolo-Masinloc 230-kiloVolt Line 2 tripped which resulted in the tripping of Masinloc units 1 and 2.
The Independent Electricity Market Operator of the Philippines said that the other plants that went on forced outage were the Calaca unit 1 coal-fired plant and units 1 and 4 of the Binga hydropower facility.
The plants running at derated capacity were units 1 and 2 of Sual, and unit 2 of Calaca.
The DoE said reduced power generation on Luzon affected exports to the Visayas grid, which declared a red alert between 5 p.m. and 6 p.m.
“As the situation emanated from a transmission line tripping, the DoE has instructed the NGCP to explain within 24 hours the circumstances that caused the outages,” the DoE said.
The DoE also said that NGCP had declared a suspension of the Wholesale Electricity Spot Market for the Luzon Grid.
“The suspension of the WESM will effectively shield the public from volatile prices that may arise from the unavailability of some power plants,” the DoE said.
The DoE had ruled out the possibility of a red alert on the Luzon grid in 2023 and assumed only 15 yellow alerts in its projection for the year.
Manila Electric Co. (Meralco) said 321,705 customers within its franchise area were affected.
Areas affected in Metro Manila were Las Piñas, Makati, Marikina, Muntinlupa, Parañaque, Pasig, Quezon City, and Taguig.
Parts of Rizal also experienced rotational brownouts such as Angono, Antipolo, Binangonan, Cainta, Cardona, Taytay. Affected areas in Cavite were Bacoor, Dasmariñas, and Imus.
“We immediately activated the Interruptible Load Program (ILP) to help manage the situation, and requested our big-load customers to remain on standby until the situation normalizes,” Meralco said.
Meralco also said that as of 3:45 p.m., power was restored to all affected customers.
ILP participants are large power users that have their own generating facilities. These entities stop drawing power from the grid during times of unreliable supply, tapping their own power plants for their needs and reducing the overall load on the grid.
Jephraim C. Manansala, chief data scientist at the Institute for Climate and Sustainable Cities, said the red and yellow alerts highlight the vulnerability of the centralized and baseload-centric grid planning of the current energy system.
“The insufficiency of power supply in Luzon has been a recurring issue for years during summer due to our heavy reliance on a few large centralized (coal-fired) power plants, which are prone to forced outages,” Mr. Manansala said in a Viber message.
Mr. Manansala said the situation points to the urgency of the energy transition to flexible and distributed energy sources.
“We don’t understand why faulty plants are even allowed to hold power supply contracts. Year in and out, power plant shutdowns are the culprit in red and yellow alerts,” Gerry C. Arances, executive director of Center for Energy, Ecology and Development said in a message. — Ashley Erika O. Jose