MANILA, Philippines — The Luzon grid was placed under tight supply conditions for most of the day yesterday following forced outages of several power plants.
In an advisory, the National Grid Corp. of the Philippines (NGCP) raised the yellow alert status on the Luzon grid from 10 a.m. to 5 p.m., and from 6 p.m. to 9 p.m.
A red alert status was also initially raised from 5 p.m. to 6 p.m., but it was lifted by around 11:30 a.m.
The NGCP kept the Luzon grid under yellow alert from 3 p.m. to 4 p.m. and from 5 p.m. to 7 p.m.
A yellow alert means power reserves are not enough to cover the largest running generating unit at the time, but does not necessarily lead to outages.
A red alert is placed over the grid when the supply-to-demand balance further worsens, which can lead to rotating power interruptions.
The placing of the Luzon grid on yellow and red alerts yesterday was due to the forced outages of six power plants, on top of three others that were running on derated capacities.
The alerts caused a total of 2,648 megawatts (MW) becoming unavailable to the grid.
The Department of Energy (DOE) said that among the power plants placed on forced outages were the Calaca 2, GNPower Mariveles 1, Sual 1, Sta. Rita Module 20, Masinloc 3 and San Buenaventura.
Those running on derated capacities were the Masinloc 1 and 2 as well as the Magat power plant.
The agency said the Sual 1 and Masinloc 3 went back online at 10:19 a.m. and 11:19 a.m., respectively, reducing the unavailable capacity to 1,600 MW.
In a statement, Energy Secretary Raphael Lotilla assured the public that there was no fuel supply constraints after the power plants went on forced outages.
Lotilla said the DOE informed the Manila Electric Co. (Meralco) to advise its Interruptible Load Program (ILP) participants to prepare their manual load dropping as a precautionary measure.
In such cases, he said the ILP participants might run their facilities to allow more grid capacity to serve other customers.
Meralco said it had 346.40 MW of committed de-loading capacity under the ILP by 11:30 a.m. yesterday.