Luzon’s power supply situation could stay critical today (Tuesday) and the risk of possible rotating brownouts remain unless power plants that went on unplanned outage go back online and demand is tempered by lower temperatures, the National Grid Corp. of the Philippines said Monday.
“If power plants on unplanned shutdown on Monday go back online then we won’t need to issue any further grid alerts. Of course, this assumes that no other power plants go on unplanned shutdown,” NGCP spokesman Cynthia Perez-Alabanza said.
Customers of Manila Electric Co. suffered two-hour rotating brownouts on Monday after five power plants went offline and a 230 kilovolt transmission line tripped. Meralco declined to give a supply situation forecast for Tuesday.
Meralco said the manual load dropping affected around 321,705 customers located in Metro Manila (Las Piñas, Makati, Marikina, Muntinlupa, Paranaque, Pasig, Quezon City, Taguig), Rizal (Angono, Antipolo, Binangonan, Cainta, Cardona, Taytay) and Cavite (Bacoor, Dasmarinas, Imus).
Power supply was restored at 3:45 p.m. Monday with the help of Meralco’s large power users who deloaded from the grid and used their gensets to free up the needed capacity.
“We immediately activated the Interruptible Load Program to help manage the situation, and requested our big-load customers to remain on standby until the situation normalizes,” Meralco said.
NGCP placed the Luzon grid on red alert status from 1 p.m. to 4 p.m. due to insufficient power generation capacity.
NGCP has also placed the Luzon grid on yellow alert from 4 p.m. to 6 p.m. amid the forecasted continuing thin power supply.
NGCP lifted the red alert status at 6 p.m. Monday.
A red alert status is issued when power supply is insufficient to meet consumer demand and the transmission grid’s regulating requirement.
A yellow alert is issued when the operating margin is insufficient to meet the transmission grid’s regulating and contingency requirement.
Meanwhile, the Department of Energy , through its Electric Power Industry Management Bureau, said NGCP placed the grid on red alert
following the tripping of the Bolo-Masinloc 230 kV Line 2, which led to the tripping of Masinloc Units 1&2 which is equivalent to 618 MW.
DOE said the reduced generation supply in Luzon affected export supply to the Visayas grid.
“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,” DOE said.