Luzon grid on alert amid low reserves

MANILA, Philippines — The Luzon grid was placed on yellow alert yesterday due to thin power supply after at least seven power plants tripped and several generating plants ran on limited capacity.

In a text advisory, the National Grid Corp. of the Philippines (NGCP) said it raised the yellow alert from 11 a.m. till noon and from 2 p.m. to 4 p.m.

The NGCP said available capacity was estimated at 9,971 megawatts, with peak demand projected to reach 9,018 MW.

A yellow alert means there are not enough reserves to cover the largest running generating unit at the time, but it does not necessarily lead to power outages.

The Department of Energy said the grid lost 1,655 MW from the unplanned outages.

Among the power plants that went on forced outage were the 382-MW Pagbilao Unit 2 due to a derailed submersible flight conveyor, 316-MW GNPower Unit 1 due to conveyor trouble, 55-MW Makban Unit 5 due to high-turbine vibration and 121-MW Southwest Luzon Power Generation Corp. due to a boiler air preheater tube leak.

The 150-MW Malaya went offline due to a turbine vacuum problem, 50-MW Makban Unit 8 tripped at 20 MW-load and 265-MW San Lorenzo Module 50 after fuel change.

The 316-MW Unit 2 of GNPower will be on maintenance outage until March 25.

The DOE said the 50-MW Unit 3 of the Angat hydropower plant, 300 MW Calaca Unit 2, 315-MW Masinloc Unit 2, 460-MW Quezon Power Philippines Ltd. Co. and South Luzon Thermal Energy Corp. are on planned outage for annual maintenance works.

Ronnie Aperocho, Manila Electric Co. first vice president and head of networks, said it was the first time the  grid was placed on yellow alert this year, with a net reserve of around 250 MW.

“Yellow alerts will not persist, but with aging plants within the Luzon grid, it’s not a remote possibility,”  Aperocho said.