Grid Failures Spark Emergency Power Interruptions Across Luzon And Visayas
- May 15, 2026
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Rotating power interruptions affected hundreds of thousands of consumers in parts of Luzon and the Visayas this week after a series of power plant outages and transmission line failures prompted the National Grid Corporation of the Philippines (NGCP) to place both grids under red alert status.
The NGCP on Thursday declared a red alert over the Luzon and Visayas grids from 3 p.m. to 10 p.m., triggering manual load-dropping measures that led to rotating brownouts across several provinces and Metro Manila. The situation eased early Friday after the yellow alert over the Luzon Grid was lifted shortly before 1 a.m.
Transmission Failures
In an advisory issued Thursday afternoon, the NGCP said available capacity in the Luzon Grid fell to 12,464 megawatts (MW) against a peak demand of 12,877 MW. In the Visayas, available capacity reached 2,377 MW while demand climbed to 2,552 MW.
The Department of Energy (DOE) earlier said the disruptions stemmed from transmission-related problems after the 500-kilovolt Tayabas-Ilijan and Dasmariñas-Ilijan transmission lines tripped at around 6:30 a.m. Wednesday.
The supply deficiency forced the grid operator to raise red alerts, the highest warning level issued when available electricity can no longer meet consumer demand and reserve requirements needed to stabilize the power system.
Yellow alerts were also imposed in Luzon from 2 p.m. to 3 p.m. and again from 10 p.m. to midnight, while the Visayas Grid remained under yellow alert from 10 p.m. to 11 p.m.
Under a yellow alert, power supply remains sufficient but operating reserves fall below required levels, leaving the grid vulnerable to additional outages. A red alert, however, signals an actual shortage in supply and usually results in manual load dropping or rotating brownouts to prevent a wider system collapse.
Rotational Brownouts
Manila Electric Co. (Meralco) implemented emergency manual load dropping across portions of Metro Manila, Batangas, Bulacan, Cavite, Laguna, and Rizal on Wednesday and Thursday as the grid struggled to stabilize.
In its latest advisory Thursday evening, Meralco said more than 320,000 customers had been affected by rotational power interruptions in parts of Bulacan, Cavite, Laguna, Metro Manila, Pampanga, Quezon, and Rizal.
The utility said the outages in affected areas lasted up to two hours, although earlier interruptions averaged around three hours in some locations.
Meralco also said participants under its Interruptible Load Program (ILP) helped reduce strain on the grid by voluntarily shifting to their own generator sets.
“Our big-load customers enrolled under the Interruptible Load Program have been helping lessen the demand with a collective de-loading capacity of around 270 MW,” the company said. The utility added that it was continuing to monitor grid conditions and would provide updates as needed.
Yellow Alert Lifted
The situation improved early Friday after the NGCP lifted the yellow alert over the Luzon Grid at around 12:56 a.m.
At the time the alert was removed, available capacity in Luzon had climbed to 12,276 MW while demand dropped to 11,528 MW, restoring a more stable operating margin.
The NGCP said yellow alerts are issued when the operating margin becomes insufficient to meet contingency requirements needed to maintain grid reliability.
Power demand in the country typically peaks three times daily — around 11 a.m., 2 p.m. and 7 p.m. — when residential and commercial electricity consumption simultaneously rises.
The latest grid disturbances renewed concerns over the vulnerability of the country’s power system during periods of high demand and unexpected transmission or generation outages, particularly amid rising temperatures and increased electricity consumption during the dry season.
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