The Department of Energy (DOE) on Wednesday, May 13, ordered the National Grid Corporation of the Philippines (NGCP) to immediately address transmission constraints that disrupted the dispatch of several large power plants and triggered yellow and red alerts in the Luzon grid.

Energy Secretary Sharon S. Garin issued the directive after the 500 kV Tayabas-Ilijan and Dasmariñas-Ilijan Transmission Lines tripped at 6:30 AM disconnecting the 1,200-megawatt (MW) Ilijan 1 and 2 plants and the 1,262.1-MW EERI Units 1, 2, and 3 from the grid.

Masinloc Unit 3, with a 325-MW capacity, also went on forced outage at 6:34 a.m.

Garin ordered NGCP to submit details on the incidents and the transmission outages. She also directed San Miguel Power Group Corporation to immediately restore Masinloc Unit 3 after its turbine tripped.

The Visayas grid, meanwhile, was placed under red alert from 3:00 PM to 8:00 PM and yellow alert from 8:01 PM to 9:00 PM on the same day.

Garin instructed Therma Visayas Inc. Units 1 and 2 and Panay Energy Development Corporation Unit 3 to expedite the restoration of their generating units.

The DOE Visayas Field Office was also directed to conduct on-site inspections of the three affected plants and to coordinate with the generation companies to ensure the units return online safely.

"The DOE is managing both situations in real time," Garin said. "On both the transmission side and the generation side, our directive is the same: restore normal conditions as quickly as possible and protect Filipino consumers from prolonged supply disruptions."

The DOE has coordinated with distribution utilities in both grids, which are on standby to activate the Interruptible Load Program (ILP) if needed.

The Manila Electric Company (MERALCO) said load dropping in its franchise area can be avoided once the ILP is deployed in Luzon.

The DOE said it will continue to monitor both grids and provide updates as the situation develops.