The Luzon grid is running low on power reserves for the third consecutive day.
“The Luzon grid is on yellow alert due to insufficient operating reserve,” a notice from the National Grid Corporation of the Philippines (NGCP) stated. The yellow alert took effect from 10 a.m to 11 a.m, and 12 p.m to 4 p.m. on Wednesday.
The shutdown of several coal-fired power plants led to the issuance of the yellow alert warning. These are the 460-megawatt (MW) Quezon Power Phils. Ltd. (QPPL) plant; Southwest Luzon Power Generation Corp.’s units 1, 3 and 4 (200 MW); GNPower Mariveles Energy Center Ltd. Co. (GMEC) units 1 and 2 (632 MW), and 300-MW SEM Calaca Power Corp. (Calaca) unit 2.
The NGCP said the forced outage of these plants, the reduction of Kalayaan hydro plant’s output by 180 MW, and the reduced power drawn from Visayas via the high-voltage direct current (HVDC) transmission link were among the factors that led to the issuance of yellow alert on Wednesday.
Luzon’s operating requirement stood at 11,274 MW as against the grid’s available capacity of 12,008 MW, leaving a net operation margin of only 369 MW.
The grid has been placed on yellow alert for a couple of hours since Monday. Prior to this, the NGCP issued last June 18 a red alert warning due to multiple power plant outages.
It said that a transmission line tripped due to “underbuilt” lines owned by the Peninsula Electric Cooperative Inc. (PENELCO). These underbuilt distribution lines are constructed underneath NGCP’s transmission lines and are within the grid operator’s right-of-way.
The NGCP said the transmission line issue has already been resolved, but there are still power plants on forced shutdown.
A yellow alert is issued when the excess power is insufficient to meet the transmission grid’s regulating and contingency requirement, pegged at the time at about 495 MW and 647 MW, respectively.
A red alert status, meanwhile, could trigger brownouts. This warning is issued when supplies are insufficient to meet consumer demand and the transmission grid’s regulating requirement.
The Department of Energy (DOE) earlier instructed the NGCP to immediately resolve the transmission line issues, submit the list of affected customers that experienced power interruption, and explain the details of the incident. The DOE has also initiated its coordination with the Energy Regulatory Commission (ERC) in addressing the matter.
The ERC, for its part, said it is now looking into the incident. ERC commissioner Atty. Rexie Digal said the agency would evaluate all submissions by the NGCP and DOE.
Sufficient but expensive supply
Meanwhile, a Manila-based climate and energy policy advocacy group reiterated the need for flexible and distributed power generation in the country’s power system.
Institute for Climate and Sustainable Cities (ICSC) chief data scientist Jephraim Manansala, analyzing the spot market data over the weekend, cited the main causes of the red alert status in the Luzon grid.
He said the Luzon power system had sufficient but expensive supply these past few weeks due to the recurring downtime of a number of baseload power plants at overlapping periods. With Jonathan L. Mayuga