TOUGH JOB Linemen from Manila Electric Co., or Meralco, repair an electric post in a neighborhood in Valenzuela City. . —GRIG C. MONTEGRANDE
Electricity supply in Luzon and the Visayas hit critically low levels on Thursday as many power plants were unavailable to meet the spike in demand amid the hot weather.
The National Grid Corp. of the Philippines (NGCP), the operator of the country’s electricity superhighway, placed the two major island groups under “red” and “yellow” alerts that lasted for several hours.
The Luzon grid was on red alert from 1 p.m. to 4 p.m. and again from 6 p.m. to 10 p.m. A yellow alert was raised from 12 noon to 1 p.m., 4 p.m. to 6 p.m., and 10 p.m. to midnight.
In the Visayas grid, a red alert was hoisted from 1 p.m. to 9 p.m., then tempered to a yellow alert from 9 p.m. to 11 p.m. Before that, a yellow alert had been issued from noon to 1 p.m.
A red alert means the power supply is insufficient to meet consumer demand and the regulatory requirements of the transmission grid.
Under a yellow alert, the operating margin is not enough to meet the contingency requirement of the transmission grid.
The NGCP said that in the case of Luzon, the operating margin should be 668 megawatts, equivalent to the capacity of the largest power plant in the populous island group, to avoid red or yellow alerts.
The alert levels were raised as Luzon and the Visayas, respectively, lost 2,525.5 MW and 553.1 MW of power supply.
Plant outages
In the Luzon grid, three power plants have been on forced outage since 2023, while four other facilities went offline between January and March this year. Between April and May, a total of 11 power plants went offline, while three others reduced their output.
Available capacity in Luzon is estimated at 13,441 MW, leaving just a narrow margin from a projected peak demand of 13,438 MW.
In the Visayas grid, one power plant has been unavailable since 2022 and two others have gone offline since 2023. Two power plants shut down between January and March this year and 16 facilities went offline between April and May. Three others reduced capacity.
Peak demand in the Visayas is pegged at 2,657 MW, inching closer to the available capacity of 2,717 MW.
Rotating outages
Power distributor Manila Electric Co. (Meralco) plans to implement rotating power interruptions or manual load dropping to manage limited supply in its franchise area.
“We have secured commitments from big-load customers under Interruptible Load Program (ILP) participants to de-load more than 300 MW to help ease demand,” Meralco head of corporate communications Joe Zaldarriaga said in a statement.
ILP is a voluntary, demand-side management program of the Energy Regulatory Commission wherein big customers are requested to use their own generator sets instead of drawing electricity from the grid. Participants are compensated for any price difference.
Since January this year, NGCP has issued red alerts 15 times: seven times in Luzon and eight in the Visayas.
It has also hoisted yellow alerts 44 times nationwide during the same period: 20 times in Luzon, 22 in the Visayas and 2 in Mindanao.