Grid woes, power plant works affect electricity supply

One of the two circuits of NGCP’s 138kV high voltage submarine cable was damaged last June 15, 2021 due to dredging and re-channeling activities of the DPWH, resulting in limited transmission capacity in Negros and Cebu and an oil spill in the area. (NGCP photo)

By Francis Allan L. Angelo

Power supply stability in Panay and Guimaras Islands is on shaky ground due to a busted submarine cable and scheduled preventive maintenance works on a power plant in Northern Iloilo.

In a press statement, the National Grid Corporation of the Philippines (NGCP) said it is repairing one of its 138kV high voltage submarine cable which was damaged during dredging and re-channeling activities undertaken by the Department of Public Works and Highways (DPWH) along Bio-os River, Brgy. Jagna, Amlan, Negros Oriental last June 15, 2021.

The cable, which interconnects Negros and Cebu, has two circuits of 138kV submarine cable with 90-megawatt (MW) capacity each or a total capacity of 180MW.

Michelle Visera, NGCP corporate communications officer, said in a radio interview that the damaged submarine cable did not affect power supply in Visayas in June, particularly in Panay, because all power plants were running.

But the situation became precarious after Palm Concepcion Power Corp. (PCPC) began its scheduled maintenance works on its coal-fired power plant in Concepcion, Iloilo on July 8.

Visera said PCPC might return to normal operations in August 2021, thus they are monitoring the power supply situation and may implement manual load dropping (MLD) if demand for electricity surges, especially during the peak hours of 6 pm to 8 pm when electricity use is heavy in residential areas.

On July 8 and 9, NGCP issued warnings of possible power supply interruptions between 7 pm and 9 pm because of the uncertain situation of the grid.

The MLD was most likely to affect the franchise of MORE Power in Iloilo City, ILECO I, ILECO II, and ILECO III in Iloilo province; GUIMELCO in Guimaras, CAPELCO in Capiz, ANTECO in Antique, and AKELCO in Aklan.

 

LIMITED SUPPLY

Because of the damage to one of the two submarine cable circuits, the transmission capacity of NGCP is currently limited to 90MW between Cebu and Negros.

NGCP’s System Integrity Protection Scheme (SIPS) was automatically activated after the incident to isolate the affected circuit and prevent overloading of the remaining cable.

Initial reports received by NGCP indicate that a contributing factor to the incident was the deviation on the agreed work site by DPWH.

NGCP has requested the local government of Amlan and the DPWH to temporarily stop their operations, and immediately implemented measures to contain the oil spill.

“It is unfortunate that this happened at such a crucial time when electricity is critical to COVID-19 response efforts. NGCP assures its stakeholders that all hands are on deck to restore the affected facility and mitigate the impacts of the oil spill and scattered cable debris,” NGCP said.

The extent of the damage was fully assessed on 23-24 June. Coordination is ongoing with partner foreign technical experts for the commencement of actual repair activities.

Visera said they will regularly issue updates and warnings so that power consumers can prepare even as she assured that they will try to maintain stable supply to distribution utilities and electric cooperatives.