Both the Luzon and Visayas grids were placed under alert status on Tuesday after 39 power plant units were on forced outage or alternatively de-rated with a total capacity of 2,793.8 megawatts (MW).
De-rating forces grids to operate below rated capacity for safety, thermal and reliability reasons.
A red alert was raised in the Luzon grid from 4 p.m. to 11 p.m. as 19 power plant units with a total capacity of 1,811.3 MW were on forced outage and three more with generating capacity of 306 MW were de-rated.
The yellow alert was raised in the Visayas grid also from 4 p.m. to 11 p.m. as 12 power plant units with a total capacity of 414.9 MW were on forced outage and five more with generating capacity of 261.6 MW were similarly de-rated.
Yellow alerts are issued when power reserve in the grid is low. Red alerts are declared when actual power supply against demand is insufficient and power interruptions are imminent.
According to the National Grid Corporation of the Philippines (NGCP), the available capacity in the Luzon grid was only 13,537 MW versus peak demand of 13,024 MW. Available capacity in the Visayas Ggrid was only 2,742 MW against peak demand of 2,440 MW.
As a consequence, manual load dropping (MLD) was implemented in parts of Baguio City, Benguet, Ilocos Sur, Nueva Ecija and Aurora province.
The Manila Electric Co. or Meralco as of 4 p.m. Tuesday said it neither resorted to MLD nor rotating power interruptions in part because of de-loading around 300 MW under the interruptible load program (ILP).
Under the ILP, customers with large electricity consumption run their own generator sets as supply of electricity in the grid runs short in exchange for monetary incentives. The fuel they use in running their own power source are then paid by consumers.
The Department of Energy (DOE) is closely coordinating with power stakeholders to ensure appropriate measures are taken to minimize the impact of the power reserves shortage.
“While we continue to monitor and ask our power plant operators to work on restoring full operations, we can maximize our energy efficiency efforts as we go through this period of extreme heat. Flexible work arrangements and other conservation measures would also be helpful. The extremely high temperatures have been affecting the operations of power plants in the grid,” said Energy Secretary Raphael Lotilla.
