The Visayas and Mindanao power grids will be placed under red and yellow alerts on Friday as several power plants remain unavailable, according to the National Grid Corporation of the Philippines (NGCP).

As of 8 a.m., the NGCP said the Visayas grid would be under red alert from 3 p.m. to 10 p.m., while yellow alerts would be in effect from 1 p.m. to 3 p.m. and from 10 p.m. to 11 p.m.

The grid has an available capacity of 2,233 megawatts (MW) against a projected peak demand of 2,504 MW.

A total of 815.8 MW is unavailable due to forced outages and derated power plants. The situation was also attributed to the unavailability of the large coal plants TVI 1 and PEDC 3, as well as limited or unavailable power imports from Mindanao.

In Mindanao, a red alert will be in effect from 1 p.m. to 9 p.m., with yellow alerts from 10 a.m. to 1 p.m. and 9 p.m. to 10 p.m.

The grid has an available capacity of 2,549 MW, compared with a projected peak demand of 2,592 MW. About 784.5 MW remains unavailable due to forced outages and derated generating units.

The NGCP cited the unavailability of the large coal plants GNPK 1 and 2 and TSI 2 as a contributing factor to the alerts.

A red alert means available power is insufficient to meet demand and the transmission grid’s regulating requirement. A yellow alert means the operating margin is insufficient to meet the grid’s contingency requirement.