The Visayas grid was placed on yellow alert on Wednesday afternoon after three power facilities became unavailable, leaving the system with a slim supply-demand margin.
In an advisory, grid operator National Grid Corp. of the Philippines (NGCP) said the alert would be in effect from 3 p.m. to 9 p.m. A yellow alert indicates that while supply can still meet demand, the reserve margin is thin enough that any additional plant outage could trigger rotating brownouts.
NGCP reported that the Visayas grid's available capacity stood at 2,550 megawatts (MW) against peak demand of 2,478 MW, leaving a reserve of just 72 MW.