Power interruptions hit several parts of Luzon and Visayas after thinning electricity reserves forced grid operators to implement manual load dropping, affecting households and businesses.

The outages lasted from one to two hours in several areas on Wednesday, catching some residents off guard and disrupting daily activities.

Isabel Rosario, who runs a canteen in Dagupan City, said she was tending to her business when electricity suddenly went out without prior notice.

“Mahirap kasi siyempre kawawa kami mga ice cream baka matunaw, nagulat kami na walang kuryente,” Rosario said.

Local utility officials said the outage stemmed from manual load dropping ordered by the grid operator after several power plants went offline, reducing available electricity supply.

“‘Yung manual load dropping ginagawa ‘yan ng operator na NGCP kasi masyadong manipis ang suplay ng kuryente, may mga kumalas kasing planta sa grid,” Atty. Randy Castilan, chief operating officer of DECORP, said.

The National Grid Corporation of the Philippines (NGCP) placed the Luzon grid under Yellow and Red Alert status for several hours on Wednesday after supply reserves tightened.

According to NGCP, the Luzon grid faced a shortage of 4,681.6 megawatts (MW) after two transmission lines tripped, several power plants disconnected and the Masinloc Unit 3 facility suffered a forced outage.

NGCP again raised a Red Alert on Thursday from 3 p.m. to 10 p.m., warning that power supply was insufficient to meet demand and reserve requirements. The grid was also placed under Yellow Alert before and after the Red Alert period.

Meanwhile, a Red Alert was also hoisted over the Visayas grid from 3 p.m. to 10 p.m. to be followed by a yellow alert from 10 p.m. to 11 p.m.

The Visayas grid is operating at an available capacity of 2,377 MW against a peak demand of 2,552 MW as 12 plants are on forced outage since May 2026, one since March 2026, four since 2025, two since 2024, two since 2023, one since 2021, while 13 are running on derated capacities, for a total of 902.7 MW unavailable to the grid.

Officials said a Yellow Alert means reserves are low and power supply could become insufficient if additional emergencies occur, while a Red Alert indicates a severe shortage in available supply.

Castilan said power interruptions remain possible whenever generating plants unexpectedly break down.

“‘Yung possibility palaging nariyan ‘yan kasi siyempre kunyari sasabihin nila na ganitong ang available na capacity tapos biglang may plantang masisira,” he said.

Authorities advised consumers to prepare for possible outages as power supply conditions continue to be monitored.