Manila, Oct. 1 -- A yellow alert status has been raised over the Visayas grid from 1 p.m. up to 12 midnight on Wednesday after 27 power plants became unavailable following the magnitude 6.9 earthquake that hit Cebu Tuesday night.

A yellow alert is raised when the available power supply has a limited margin vis-a-vis the demand.

In an advisory, the National Grid Corporation of the Philippines (NGCP) said around 1,444.1 megawatts (MW) was lost after the tripping of the power plants due to the tremor.

It said the available capacity in the Visayas is around 1,888 MW, while peak demand is around 1,839 MW.

The NGCP explained that even before the earthquake hit, 16 power plants were already unavailable, and another one is on derated capacity...