MANILA, Philippines — When the major power plants on Panay Island switched off, the transmission system remained normal and stable during the first two-hours of the power outage on January 2.
This situation prevented the National Grid Corporation of the Philippines (NGCP) to take “manual corrective actions” in accordance with the rules, its official said during the hearing of the Senate committee on energy.
“After the tripping of PEDC (Panay Energy Development Corporation), the system remains stable. Normal po yung system, stable sya,” Clark Agustin, head of NGCP’s national system operations, said.
“Voltage and frequency are within normal limits…Wala tayong transmission line na overloaded…” he went on.
This baffled Senator Raffy Tulfo, chairman of the committee.
“Pano mo masabing normal at stable e nag trip na nga?” Tulfo asked, “Kung nag trip so ibig sabihin, hindi stable.”
(How can you say it’s normal and stable when the power plants already tripped? If they tripped, it means it’s not stable.)
Agustin explained that the stability of the grid refers to its “ability to recover after an event or disturbance.”
Still, Tulfo said, NGCP could have done something during a two-hour window period — from the time PEDC 1 went off at 12:06 pm on January 2 before six more power plants switched off at 2:10pm on the same day.
“Between 12:06 p.m. to 2:19 p.m, may two hours window yun. You could have done something to address the problem but you did not. Bakit?” the senator asked.
Agustin reiterated that during the two-hour period, the system was stable as voltage and frequency remained within “normal limits.”
“And on top of that po, si PGC (Philippine Grid Code) does not allow us to impose manual corrective actions in anticipation of a secondary contingency,” he said.
“The Philippine Grid Code says that we should not impose manual corrective actions in anticipation of a secondary contingency during normal conditions,” he added.
Senator Francis “Chiz” Escudero later clarified in the hearing that the PGC is not a law but the rules set by the Energy Regulatory Commission.
Also at the start of the hearing, Escudero reiterated that NGCP was not solely to blame for the recent power outage.
“Madaling ituro at ibaling ang sisi sa pinakamalaki sa kwarto, ika nga at yan ay ang NGCP Subalit kung wala naman silang kuryente na ihahatid, wala namang made-deliver sa distribution utility din,” Escudero pointed out.
(It’s easy to point fingers at the biggest one in the room, as they say, and that’s the NGCP. However, if they don’t have electricity to deliver, nothing will be delivered to the distribution utility either.)
The senator likewise believes that the system operator is not allowed to make any interventions if the factors provided under the PGC such as voltage and frequency remain within range.
“The same is true for the power plant,” he said, “Hindi pwedeng mag-manual shutdown and unscheduled shutdown ang planta, ng decision lang nya. Dapat pinagbibigay alam at sumusunod pa rin sa National Grid Code…”
(The plants cannot undergo a manual shutdown or unscheduled shutdown just based on their own decision. It should be communicated and still in accordance with the National Grid Code…)