Visayas power grid on yellow alert due to earthquake

The Visayas power grid will be placed on yellow alert on Wednesday as several power plants went on forced outage following a magnitude 6.9 earthquake that hit Bogo City, Cebu on Tuesday evening. 

In an advisory, the National Grid Corp. of the Philippines (NGCP) said the yellow alert will be hoisted from 1 p.m. to 12 midnight on October 1, 2025.

A yellow alert is issued when the operating margin is insufficient to meet the transmission grid’s contingency requirement. 

The grid operator said that the Visayas grid has an available capacity of 1,888 megawatts (MW) against a peak demand of 1,839 MW.

“Twenty-seven plants are on forced outage due to the earthquake, 16 others have been unavailable even prior to the incident; while one other is running on derated capacity, for a total of 1654.7MW unavailable to the grid,” the NGCP said.

The NGCP added that the following transmission lines are on outage:

- Daanbantayan-Tabango 230KV L1 & L2 

- Daanbantayan-Compostela 230KV L1 & L2 

- Tabango-Kananga 230KV L1 & L2 

- Kananga-Ormoc 230KV L1 

- Ormoc-Babatngon 138KV L1 & L2 

- Babatngon-Paranas 138KV L1 & L2 

- Paranas-Calbayog 138KV L1 & L2 

- Ormoc-Maasin 138KV L2 

- Isabel-Tongonan 138KV Line 

- Isabel-Pasar 138KV Line 

- Pasar-IASCO 138KV Line

The grid operator meanwhile said the following lines were restored: 

- Ubay-Maasin 138KV Line energized at 04:01 a.m.

- Ormoc-Maasin 138KV L1 energized at 04:18 a.m.

- Ormoc-Isabel 138KV Line energized at 05:11 a.m.

“Restoration of the remaining parts of the Leyte-Samar sub-grid is ongoing,” the NGCP said.

“Power transmission services in the rest of the Visayas grid (Panay, Negros, Cebu, Bohol) are all under normal operations,” it added.

The company said the tripping of the 27 plants resulted in a total of 1,444.1 MW of power supply lost from the Visayas grid

Meanwhile, it said that Luzon and Mindanao grids are under normal condition. —KG, GMA Integrated News