NGCP completes major transmission line project

By Rjay Zuriaga Castor

The National Grid Corporation of the Philippines (NGCP) has announced the completion of stage 3 of the Cebu-Negros-Panay (CNP) project, a top official of the transmission service provider said on Friday, April 5.

Redi Allan Remoroza, NGCP’s Transmission Development Plan (TDP) head, confirmed the completion of CNP Phase 3 during the Philippine Electric Power Industry Forum in Iloilo City.

“We are all excited that finally our CNP has been completed. The Negros and Panay Islands are already benefiting from these new links,” he said.

The timely completion of CNP this year follows pressure from energy regulating bodies after two massive power blackouts that hit Panay Island in April 2023 and early January this year.

The backbone project faced delays at least seven times from the original completion date of December 2020.

Remoroza said the project involves 442 circuit kilometers (km) of new transmission lines, 98 circuit km of submarine cables, and the development of six new 230 kV substations with an overall capacity of 3800 mVA, allowing accommodation of generation additions and load growth.

With its completion and the gradual ramp-up process, Remoroza said that as of April 5, NGCP recorded a peak power flow of 275 megawatts (MW) on the 230 kV links between Cebu and Negros, and a peak power flow of 215 from Negros to Panay.

The NGCP official further emphasized that the establishment of the 230 kV loop configuration will ensure resiliency and operational flexibility in power transmission on the islands of Visayas.

CNP phase 3 involves the construction of 230 kV transmission line facilities from the Barotac Viejo Substation in Iloilo province to the Cebu Substation.

NGCP, in its TDP 2016-2040, said the development of new power plants, particularly in Panay and Negros Islands, will increase power exchange between Panay, Negros, and Cebu.

However, the existing Negros-Panay interconnection system has limited capacity to handle the excess power generation from Panay towards Negros, potentially leading to power curtailment.

Based on NGCP’s data from March 2024, the Visayas region maintains a capacity margin of 11 percent, with an available generating capacity of 2,295 MW out of a system peak demand of 2,221 MW.

Negros Island exhibits a 9 percent operating margin, with a system peak demand of 387 MW and a generating capacity of 424 MW.

In contrast, Panay Island’s operating margin is lower at 4 percent, with a system peak demand of 416 MW and a generating capacity of 433 MW.

With a low operating margin in Panay, the excess capacity of Negros Island is stranded due to transmission limitations.

To ensure effective transmission of excess power generation from Panay to Negros, the backbone project will accommodate the transmission of excess power equivalent to the output of two 400-MW plants from Panay and Negros to Cebu.

Stage 1 of the CNP was aimed at increasing the transfer capacity of the existing corridor.

Meanwhile, the second phase of the project is an additional submarine cable for N-1 contingency which will enable the transmission grid to withstand a major system disturbance with minimal disruption to the system between Negros and Panay islands.

BIG STEP FORWARD

The Department of Energy and DUs in Panay believe the completion will address persistent power issues plaguing Panay Island.

Roel Castro, president of MORE Electric and Power Corporation (MORE Power), the electric distribution utility (DU) of Iloilo City, described the completion of the full backbone as “a big relief” for Panay Island.

He emphasized this citing the Panay sub-grid’s reliance on a single transmission door or one only baseload plant while the country is in its dry season and the demand for all DUs in Panay Island is at its peak.

“Though that does not yet guarantee the highest level of reliability, it is definitely a big step towards better reliability for us in Panay Island,” Castro added.

But what’s next after CNP’s completion?

Remoroza said NGCP has several projects provided in its TDP, including the construction of an extension or substations of the 230 kV transmission line backbone.

The substations are expected to provide a high-capacity transmission corridor for the expected large generation entry in Panay.

“We will have continuing development in this part of the grid. The next stage would be another 230 kV highway corridor which passes through Guimaras island to Bacolod,” he said.

“There will also be a project that will further extend the 230 kV from Barotac Viejo to Unidos and will have a link to Mindoro island,” he added.

The construction of the substations will be implemented in stages, according to Remoroza.