Metro Manila (CNN Philippines, January 3) — Residents in Western Visayas still have limited electricity supply on Wednesday as some power plants on Panay Island have not been fully restored yet after multiple trippings on Jan. 2, the National Grid Corporation of the Philippines (NGCP) reported.
In its 8 p.m. advisory, the NGCP said 9 out of 13 Panay power plants were operational, supplying around 203 megawatts (MW) and augmented by nearly 50 MW from other sources in the Visayas.
It explained that the Visayas grid needs about 300 MW to stabilize.
According to the Energy Regulatory Commission, customers of Guimaras Electric Cooperative, Inc. (GUIMELCO), Iloilo I Electric Cooperative, Inc. (ILECO I), Iloilo II Electric Cooperative, Inc. (ILECO II), Iloilo III Electric Cooperative, Inc. (ILECO III), and MORE Electric and Power Corporation (MORE POWER) were experiencing power interruptions.
Iloilo City Mayor Jerry Treñas also ordered classes suspended at all levels in public and private schools “pending the return of power” in the city.
“Given the developments and expected risks involved in the return of students to their respective schools, per the [advice] of our City Health Office, I hereby order the suspension of classes in all levels, both public and private, pending the return of power in Iloilo City,” the mayor said.
Based on NGCP’s advisory, power plant Units 1 and 2 of Panay Energy Development Corp. (PEDC) were serving at least 69 MW or around 84% of their capacities. The 150-megawatt PEDC Unit 3 is under planned maintenance, the NGCP previously said.
“We’re still waiting for the largest remaining plant on scheduled maintenance…to indicate to us when they’re coming back,” NGCP spokesperson Cynthia Alabanza told CNN Philippines’ News Night.
“We’re hoping that they can come back tomorrow, and when they do, we’re hoping that this is a stable reconnection to the grid,” she added.
The NGCP also said it is waiting for the Palm Concepcion Power Corporation (PCPC) — a power plant located in Concepcion, Iloilo that could serve 135 MW — to synchronize back to the Visayas grid.
“We reiterate that load restoration will be done conservatively, by matching loads to restored generation, to prevent repeated voltage failure,” the corporation said. “NGCP is ready to transmit power once it is available.”
In a statement, the Department of Energy (DOE) said the target synchronization of the PCPC power plant is between 10 p.m. Wednesday and 12 a.m. Thursday.
The DOE added it is coordinating with the NGCP and affected power plants and distribution utilities about the status of the plants and the estimated timeline for the power supply restoration.
The agency said PEDC Unit 1 tripped on Tuesday afternoon due to a boiler feed pump issue, and then PCPC Unit 1 and PEDC Unit 2 simultaneously tripped because of a grid voltage imbalance. The Panay grid disturbances affected other power plants within the Visayas grid.
“NGCP is still analyzing the data to determine the cause and order of tripping of the six power plants,” the DOE said.
Various electric cooperatives in Iloilo, Guimaras, Capiz, Negros, Antique, and Aklan earlier issued advisories on the sudden power interruption on Tuesday afternoon.
The NGCP lifted the yellow alert on the Visayas grid at 9:01 p.m. on Tuesday.
The corporation previously said multiple plants on the island tripped due to unknown reasons.
On Wednesday, it said that “the unscheduled maintenance shutdowns of the largest power plants in Panay island was the primary cause of the power interruption.”
Iloilo City mayor calls for probe
Treñas is calling for an investigation from both the House of Representatives and the Senate into the matter.
“NGCP holds a franchise from Congress and therefore is accountable to it,” the Iloilo City mayor said.
The DOE reminded the NGCP to “adhere to its responsibilities as system operator.” Energy Undersecretary Rowena Cristina Guevarra added the corporation “is in a position to anticipate system disturbance.”
Guevarra explained that “the system disturbance that happened in April last year in Panay and Negros Sub-grids was already a lesson for all the stakeholders involved, emphasizing that what happened yesterday could have been resolved differently.”
The DOE noted that the NGCP already implemented some of the recommendations.
For its part, the NGCP said it is calling for a whole-of-industry approach, including better energy resource planning.
“Given the configuration of the Panay sub-grid and its dependency on variable energy sources in Negros when it loses internally generated power, NGCP also noted the need to provide sufficient non-variable sources to stabilize the system,” the grid operator said. “The company also included its Cebu-Negros-Panay Stage 3 project (CNP3) as a contributing solution.”
“NGCP strongly recommends the review of the Philippine Grid Code to cater to renewable energy sources, particularly the effective use of emerging technologies such as energy storage systems, among others,” it added.
