The Mindanao grid was placed under red and yellow alerts on Friday, Sept. 4.
The National Grid Corporation of the Philippines said the red alert -- which is issued when power supply is not enough to meet demand and the transmission grid's regulating requirement -- is in effect from 1 p.m. to 9 p.m.
The yellow alert is in effect from 9 p.m. to 10 p.m.
The alert is raised when the operating margin is insufficient to meet the transmission grid's contingency requirement.
The NGCP said the unavailability of Mindanao's large coal plants GNPK 1 and 2 and TSI 2 contributed to the red and yellow alert declarations.
Eight plants are on forced outage in September, 11 have been in that condition since August, four since July, one since June, two since January, one since 2025 and another one since 2024.
Six plants, meanwhile, are running under derated capacities, for a total of 784.5 MW not available to the grid.
Available capacity is at 2539 MW while peak demand is pegged at 2592 MW.
