NOT A STANDALONE FIX NGCP: Mindoro-Panay power link needs new plants to work

PASIG CITY — The proposed Mindoro-Panay transmission line alone will not solve the power supply problems in the Visayas unless new generation facilities are also built along its route, the National Grid Corporation of the Philippines (NGCP) said.

NGCP lead specialist Reagan Alcantara said a large transmission backbone would have limited impact if power generation is insufficient at various points along the system.

“The solution is not just a transmission line. Transmission lines and generation have to go together. One cannot leave without the others. Even if you have a very long transmission line already with this western backbone but if the generation is absent in different points of that route, we would still be in a tight spot,” he told the Daily Guardian on Sept. 18.

Alcantara compared electricity to water being delivered to a high-rise building.

Even if a building has access to a large water source at ground level, the water cannot reach the upper floors through gravity alone and requires booster pumps to push it upward.

The same principle applies to electricity, Alcantara said.

He explained that voltage naturally degrades when a large amount of power is pushed from Luzon to the Visayas over a long transmission path.

If the receiving end, in this case the Visayas, depends too much on distant power with little local generation or voltage support, voltage at the region’s end can fall too low under heavy load, he added.

The system can also become more sensitive to disturbances such as line trips and generator outages.

Existing local generators may also be forced to operate under stressed conditions to hold voltage and frequency.

“Even if you have a very big excess capacity of power from Luzon, if it would be only Luzon who is going to push it to Visayas, the voltage will naturally degrade along the transmission line because of the long distance involved. That is a basic law of physics,” he said.

“Transmitting electricity over such a great distance without ‘booster pumps,’ in the sense of additional power plants along the route, will cause voltage to drop and could potentially threaten the stability of the healthy power plants in the Visayas grid,” he added.

Alcantara made the remarks after Energy Secretary Sharon Garin called for expediting the construction of the Mindoro-Panay Interconnection Project to give Panay Island a “power loop.”

Garin said the loop will strengthen the power grid and improve the energy security of the Visayas grid, which has experienced recurring rotational brownouts due to thin power supply over the past weeks.

NGCP is the private concessionaire that operates, maintains, and expands the country’s power transmission network.

The Visayas grid is currently linked to Luzon through the Leyte-Luzon interconnection and to Mindanao through the Mindanao-Visayas Interconnection Project, which went into full operation in 2024.

Panay’s vulnerability drew national attention in January 2024, when multiple power plant trippings caused an island-wide blackout that lasted for days.

The proposed Mindoro-Panay link is scheduled for implementation during the 2041-2050 period, based on NGCP’s Transmission Development Plan (TDP) 2024-2050.

The plan identifies it as a 230-kilovolt (kV) inter-island transmission link that will connect the Luzon grid, through Mindoro, with the Visayas grid via Panay.

‘A massive project’

Alcantara said NGCP recognizes the call to accelerate the project but noted that the timeline reflects the scale and complexity of the undertaking.

“While that call is there and we recognize that, we also need the proper generation investments or boost that power going to Visayas,” he said.

He described the project as “very, very massive,” involving long transmission distances, submarine cables, overhead transmission lines, substations, and extensive right-of-way and permitting requirements.

“It involves a very long distance and will cross two bodies of water. From Batangas, it will cross to Mindoro, which is already quite a significant sea crossing. That section will involve a submarine cable with two cable terminal stations to receive the power. Then, you have to run an overhead transmission line across Mindoro,” he said.

The Batangas-Mindoro Interconnection Project Stage 1 involves a 28.5-kilometer submarine cable linking Lobo, Batangas, and Calapan City, Oriental Mindoro, as well as 31.5 kilometers of overhead transmission lines and a 230/69-kV substation in Calapan.

The facilities are designed for 500 kV but will initially operate at 230 kV.

Stage 2 will upgrade the corridor to 500 kV and include a 133.1-kilometer Calapan-Magsaysay 500-kV transmission line and a Magsaysay substation in southern Occidental Mindoro.

NGCP said the Magsaysay substation will also serve as a connection point for future interconnections, including Panay.

Alcantara said the Mindoro-Panay project would not be implemented as a single undertaking.

“It will be done in stages. It will not be done in a one-time big-time because it is really massive. It will be done in stages or in phases,” Alcantara said.

Once the transmission system reaches Panay, the line would still extend through the island, connecting areas from Aklan through Capiz and Iloilo.