The Visayas grid will be placed under red alert from 5 p.m. to 10 p.m. on Saturday, August 8, amid insufficient power supply to meet demand, the National Grid Corp. of the Philippines (NGCP) said.

Yellow alerts were also declared for 5 a.m. to 6 a.m., 2 p.m. to 5 p.m., and 10 p.m. to 12 midnight, indicating thin operating margins.

NGCP data showed available capacity at 2,103 megawatts against a peak demand of 2,327 megawatts.

The grid operator said outages and reduced output from multiple plants led to 1,306.5 megawatts of unavailable capacity.

As of August, 10 plants are on forced outage, while several others have been offline for months or operating at reduced capacity.

Among the main causes were the unavailability of major coal plants, limited power imports from Mindanao due to outages, and the tripping of several Panay-based generating units.

A red alert is declared when supply cannot meet demand and grid requirements, while a yellow alert signals insufficient reserves to cover contingencies.