NGCP continues repair of damaged Negros submarine cable

The National Grid Corporation of the Philippines (NGCP) said it continues to repair of one of its 138kV high voltage submarine cable in Amlan, Negros Oriental.

The cable was damaged last June 15, 2021 during the dredging and re-channeling activities undertaken by the Department of Public Works and Highways (DPWH) along Bio-os River.

The two circuits of the 138kV submarine cable have a total capacity of 180MW.

With the loss of one circuit due to the damage caused by the incident, the transmission capacity of the submarine cable between Negros and Cebu was halved to only 90MW.

The incident caused congestion in the Negros-Cebu transmission corridor, affecting the Negros and Panay sub-grids.

The congestion resulted in power distributors and electric cooperatives to pay high line rentals and other fees.

In a statement, NGCP said it has coordinated with concerned local government units in Amlan, the Department of Environment and Natural Resources (DENR), and the Department of Public Works and Highways (DPWH) regarding the incident, as well as the Department of Energy (DOE) to request their support in relation to its repair.

The unique underwater nature of the facility needed pre-inspection of the nature and extent of the damage prior to actual repair.

The cable’s manufacturer and service provider is currently conducting a “cut and inspection” of the submarine cable to determine this.

Subject to the manufacturer’s findings, the completion of repairs is estimated in February 2022 if the water ingress does not exceed 400 meters, and only 500 meters of the cable using available spares need replacement.

Should water penetration exceed 400 meters, there is a need to replace a longer length of the cable or manufacture a new set; further extending the timeline of repair. The penetration of the water to the submarine cable is the main factor considered in determining the best course of action.

The incident caused a steep increase in electricity prices in the Negros and Panay islands, as reported by the Independent Electricity Market Operator of the Philippines (IEMOP).

However, the Energy Regulatory Commission (ERC), in its letter to the Philippine Electricity Spot Market Corporation (PEMC) dated 20 September 2021, has instructed the latter to halt the collection of congestion charges and other applicable fees, and refund those which were collected in previous billing months until the affected line is completely restored and back to normal operations.

“Fixing damaged submarine cables is a little more complex than restoring ordinary transmission lines. We need enough time to determine the exact extent of the damage before proceeding with the actual repair. This entails diving, crane lifting, and testing activities to be performed by experts with specialized equipment. We are well aware of the difficulties this incident has caused, and we are doing all we can to expedite the process,” the company said.

NGCP is a Filipino-led, privately owned company in charge of operating, maintaining, and developing the country’s electricity transmission grid, led by majority shareholders Vice Chairman of the Board Henry Sy, Jr. and Co-Vice Chairman Robert Coyiuto, Jr.