The National Grid Corporation of the Philippines (NGCP) may implement rotational brownouts in Metro Manila and other parts of Luzon as its grid will be placed under red alert on Friday afternoon.

The NGCP announced the possible manual load dropping in parts of La Union under La Union Electric Cooperative Inc., Santiago City under Isabela Electric Cooperative I, Ilagan City under Isabela Electric Cooperative II, Cabanatuan City under Cabanatuan Electric Corp., Angeles City under Angeles Electric Corp.,, Batangas under Ibaan Electric & Engineering Corp.,Albay under Albay Electric Cooperative, Metro Manila under Meralco and the entire City of Olongapo under Olongapo Electricity Distribution Co.

It also reported that the Luzon grid will be placed under red alert from 2 pm to 11 pm and yellow alert 1 pm to 2 pm and 11 pm to 12:00 am.

A red alert status is issued when power supply is insufficient to meet consumer demand and the transmission grid’s regulating requirement while a yellow alert is issued when the operating margin is insufficient to meet the transmission grid’s contingency requirement.

The alert status was raised "due to the tripping of GNPower Dinginin Unit 1, resulting in the loss of 668 megawatt and further aggravating the supply deficiency."

The NGCP noted that a total of 17 plants are on forced outage since May 1, while 14 plants are running on derated capacities, for a total of 4,828 megawatt unavailable to the grid.

It noted that the rotational brownout "may be cancelled if system condition improves, such as if actual demand falls below projections."

"NGCP encourages everyone to exercise prudence in using electricity," it added.

In her Facebook post, Energy Secretary Sharon Garin said millions of Filipinos in Luzon were affected due to the disruptions in Ilijan transmission.

Garin said the Department of Energy (DOE) seeks full accountability from NGCP following the Ilijan transmission disruptions.

It has called on the NGCP to provide a full disclosure of the back-to-back tripping of the 500 kilovolt (kV) transmission lines at the Ilijan power complex in Batangas on May 13, 2026, which resulted in the severance of a major generation plants from the Luzon grid and prompted grid emergency alerts across two island grids.

"These transmission failures had real consequences on grid stability and placed millions of consumers at risk. The public deserves full and immediate transparency from NGCP. The DOE will ensure that all operational, reportorial, and regulatory obligations are strictly enforced in protection of consumers," said Garin.

She noted that the NGCP has not yet submitted the required incident report identifying the root cause or causes of the 13 May 2026 tripping events, failing to comply with its obligations under the Philippine Grid Code. Robina Asido/PHS