Manila, July 14 -- Continued unavailability of several major coal-fired power plants prompted the raising of another yellow alert status for the Visayas grid on Tuesday, from 5 p.m. to 8 p.m.

A yellow grid is issued when the grid's operating margin is inadequate to meet contingent demand.

The National Grid Corporation of the Philippines (NGCP), in an advisory, said the available capacity on the grid is around 2,590 megawatt (MW) while peak demand is expected to hit 2,394MW.

This, as generating units 1 and 2 of the Therma Visayas Inc. and the Palm Concepcion Power Corporation remain out.

NGCP said a total of eight power plants are on forced outage just this month.

NGCP said 13 other power plants are running on derated capacities, bri...