The National Grid Corporation of the Philippines (NGCP) placed the Luzon grid under yellow and red alert status on Monday.

In an advisory, the NGCP said the Luzon grid was placed under yellow alert from 10 a.m. to 5 p.m. and 6 p.m. to 9 p.m. The grid will be under red alert from 5 p.m. to 6 p.m.

A yellow alert is issued when the excess power is insufficient to meet the regulating and contingency requirements. It is raised to red alert if the supply-demand balance worsens to the extent of requiring rotating brownouts.

The NGCP said the available capacity was estimated at 10,708 megawatts, while the peak demand was seen at 10,246 megawatts.

It added that 2,648 megawatts were lost because six power plants were on forced outage while three others were running on derated capacities.