The National Grid Corporation of the Philippines (NGCP) placed the Visayas grid under yellow alert on Thursday afternoon as power reserves tightened following a rise in regional electricity demand.
In its advisory, NGCP said the alert would be in effect from 5 p.m. to 9 p.m.
The Visayas grid was projected to have around 2,578 megawatts (MW) of available capacity against an estimated peak demand of 2,535 MW, leaving a slim operating margin.
A yellow alert is declared when a grid’s operating reserve is insufficient to meet contingency requirements.
Before the alert was issued, 10 power plants in the Visayas were already on forced outage, including one that has remained offline since 2021.
Sixteen other plant units were running on derated capacity, reducing the grid’s available supply by about 482.41 MW.
NGCP said Thursday morning demand climbed by 36 MW, further straining the system.
Additional pressure came from the unavailability of the 103-MW Unit 2 of KEPCO SPC Power Corporation’s coal-fired power plant in Cebu and a 49-MW increase in Mindanao’s electricity consumption.
The higher demand in Mindanao reduced power transferred to Visayas through the Mindanao–Visayas Interconnection Project by 207 MW.
NGCP also noted that the Agus 6 Hydroelectric Power Plant was delivering only 66.5 MW, down from 101 MW the previous day. No reason was provided for the reduced output.
Despite the tight conditions in the Visayas, NGCP said both the Luzon and Mindanao grids remained normal.
