Rotating blackouts expose risks of PH’s centralized power grid

By Joseph Bernard A. Marzan

QUEZON CITY — This week’s rotating blackouts across Luzon and the Visayas reveal the hidden vulnerabilities of the Philippines’ centralized energy infrastructure, a climate and energy policy group said Wednesday, May 14.

The Institute for Climate and Sustainable Cities (ICSC) said the cascading alerts and forced outages show why the country needs a decentralized, diversified, and flexible power system rather than continued reliance on a small number of large facilities.

The grid stress began Tuesday afternoon, May 12, when the National Grid Corporation of the Philippines (NGCP) placed the Visayas grid on Yellow Alert from 5 p.m. to 10 p.m. A Yellow Alert is issued when the operating margin is insufficient to meet the transmission grid’s contingency requirements.

A second Yellow Alert followed Wednesday and escalated into a Red Alert around 3 p.m., with available capacity at 2,510 MW against peak demand of 2,413 megawatts (MW). The Luzon grid was also placed on Red Alert the same day. A Red Alert is declared when supply is insufficient to meet both consumer demand and the grid’s regulating requirements.

NGCP continued issuing Red and Yellow alerts for both island groups on Thursday, May 13, and announced Manual Load Dropping (MLD) from 3 p.m. to 10 p.m. on Thursday, May 14, to preserve system integrity.

Affected Western Visayas distribution utilities include MORE Power, Iloilo Electric Cooperatives I, II, and III, Aklan Electric Cooperative, Antique Electric Cooperative, and Guimaras Electric Cooperative.

NGCP reported that 12 power plants have been on forced outage since March — four since 2025, two each since 2023 and 2024, and one since 2021 — while 15 others are running on derated capacities, removing a combined 862.3 MW from the grid.

ICSC pointed to the April 16 forced shutdowns of the Ilijan 1 and 2 and EERI Units 1, 2, and 3 power plants, all of which were knocked offline by issues at a single liquefied natural gas (LNG) terminal that supplied them.

“These recent events show that the available electricity supply can drop significantly when more than one major power plant or key facility goes offline at the same time. This raises an important consideration: as the power system continues to rely on large centralized infrastructure—such as LNG facilities—the level of reserves or backup needed to maintain reliability may need to increase, with possible implications on electricity costs,” the ICSC said.

ICSC Chief Data Scientist Engr. Jephraim Manansala said current planning standards may be outdated.

“Reserves today are sized based on the largest power plant connected to the grid. But if a single shared facility, such as an LNG terminal or critical transmission corridor, can affect multiple plants at once, then that shared infrastructure should arguably become the benchmark for reserve requirements,” Manansala said.

The group argued that distributing generation across more sites would lessen the impact of any single failure.

“A more decentralized and diversified approach enables communities to depend less on a handful of large plants, strengthening local reliability and self-sufficiency while reducing the risk of supply disruptions caused by outages, disasters, or other physical shocks,” ICSC said.

It also flagged the limits of baseload-heavy planning, noting that grid alerts cluster in narrow demand windows.

“Flexible – given that grid alerts persist only during specific hours of the day, this indicates that additional power capacity is needed only during those particular periods. Inflexible baseload power plants will not resolve the issues we are encountering today, as they are not designed to ramp up and down quickly during these windows,” the group added.

The Big Picture

The Philippines has faced recurring grid stress through 2025 and into 2026, with the Department of Energy repeatedly warning that thin reserve margins and aging plants leave Luzon and the Visayas vulnerable during summer peak demand. ICSC’s argument lands in the middle of an ongoing policy fight over the country’s energy mix: whether to lean further into imported LNG and large centralized plants, or accelerate renewables, distributed generation, and battery storage. This week’s outages give decentralization advocates fresh evidence that single points of failure — a terminal, a corridor, a fuel supply chain — can cascade across regions, with Western Visayas consumers among the first to feel it.