Again, snake triggered Panay blackout on February 20

By Jennifer P. Rendon

Blame the snake.

The National Grid Corporation of the Philippines (NGCP) cited “snake intrusion” as the reason behind the prolonged power blackout in the Panay Sub-Grid, including Iloilo City, on Feb 20, 2023.

In a letter to Iloilo City Mayor Jerry Treñas dated March 10, NGCP president and CEO Anthony Almeda explained that snake intrusion on the side of the Panay Diesel Power Plant 1 (PDPP 1) Transformer no. 1 was determined to be the cause of the interruption, which resulted in a fault on NGCP’s 138kV line.

“The protection system of the plant was unable to isolate the fault which resulted in severe undervoltage and cascading tripping of power plants in Panay such as the Panay Energy Development Corporation (PEDC) Units 1 and 2, Palm Concepcion Power Corporation Unit 1, San Lorenzo Wind, Central Azucarera de Antonio Biomass, and Villasiga Hydro Power Plant,” the letter added

At 11:24 a.m. of Feb 20, NGCP’s Bacolod-Barotac Viejo 138kV Shunt Reactor at Bacolod Substation, which was designed to avert any potential damage due to overvoltage, activated, thus isolating the Panay sub-grid.

Almeda said NGCP’s protection systems activated, as intended, to prevent any further damage to the grid.

Almeda added that they were able to restore power transmission services at 2:24 p.m. of the same day and awaited the synchronization of the affected power plants back to the grid.

But it can be noted that most areas in Iloilo City and even neighboring provinces were energized after more than eight hours.

The NGCP said that rotating power interruptions was forecasted due to the unavailability of generation plants but were not implemented due to supply from variable renewable energy (VRE) and power exported through their submarine cable from Cebu.

He added that the NGCP already requested Panay Diesel Power Plant (PDPP) to test its protection systems and to implement corrective actions in their equipment.

Earlier, Treñas wrote to NGCP asking for “a detailed advisory explaining the root cause” of the February 20 power loss.

In a letter to Robert Coyiuto, Jr., NGCP Chairman of the Board dated February 21, Treñas cited that the unscheduled power interruption experienced in the whole metro, which lasted for more than eight hours “brought inconvenience not only to the Ilonggos in and outside their homes but also affected the transactions in both public and private offices and businesses causing backlogs and missing deadlines on that day.”

It can be noted that one of the longest unannounced power interruptions involving NGCP in recent years happened on Jan. 4, 2019.

In the said instance, the NGCP has also cited “snake intrusion at NGCP’s Dingle substation which affected the Dingle-Barotac Viejo 138kV lines 1 & 2,” as the reason for the Panay-wide blackout.

Power transmission services in the areas of Iloilo, Capiz, Aklan, Antique, and Guimaras were restored after more than eight hours.