Brownouts hit parts of Metro Manila and surrounding provinces Thursday as the 1,000-megawatt Sta. Rita and 500-MW San Lorenzo natural gas power plants of the Lopez-led First Gen Corp. tripped.
Cynthia Alabanza, spokesperson for transmission operator National Grid Corp. of the Philippines, explained in a phone interview that the facilities went off grid and stopped supplying power at 1:55 p.m.
This led to an automatic “load shedding” or the cutting off of electric supply to certain areas for a few hours as the grid lost a hefty 1,258 MW during those hours, Alabanza said, citing initial reports.
It was not until 3:26 p.m. that First Gen power plants started to gradually resume operations, she added.
In a separate text message, First Gen explained that “five units of the Sta. Rita and San Lorenzo gas plants tripped due to the activation of gas turbine protection.”
“The cause of activation of gas turbine protection is still being investigated. As of 5 p.m., four out of five units are back on line,” it said.
In another phone interview, Joe Zaldarriaga, spokesperson of power distributor Manila Electric Co., said that the tripping of the two gas-fed plants caused brownouts in parts of Sta. Mesa, Sampaloc and Malate in Manila; Kamuning, Balintawak and La Loma in Quezon City; Pasay; San Juan and Mandaluyong.
The Sta. Rita and San Lorenzo gas facilities which are both located in Batangas use natural gas from the Malampaya gas field off northwest Palawan to produce the electricity it provides to Meralco.
The problem in the power supply also led to the suspension of Light Rail Transit (LRT) Line 2 operations for several hours.
LRT Authority spokesperson Hernando Cabrera said that the Recto to Santolan operations were paralyzed at around 2 p.m.
According to Cabrera, the agency was eyeing a huge electricity spike near the LRT Pureza Station as the cause.
“Our UPS (uninterrupted power supply) units were damaged by the spike in power,” said Cabrera, who also sits as the agency’s corporate secretary. UPS units are used to insulate the train line’s main power systems from spikes in electric supply.
The train line’s full operations were restored at 4:51 p.m.
Cabrera said the lack of power supply also caused some problems at LRT Line 1. “We had to reboot the computers for our passenger gates so for a few minutes, people could not get into the trains,” he added.