Visayas grid 'exits' daily yellow alerts

THE Visayas power grid has been free of yellow alerts after one of its power plants returned to service, ending a stretch of daily power supply warnings that began in May, according to the National Grid Corp. of the Philippines (NGCP).

The improvement means electricity reserves have recovered for now, reducing the immediate risk of rotating outages. But NGCP said the situation is still far from normal because several major generating units remain offline. Another unexpected plant shutdown could quickly tighten supply again.

The latest development offers some relief to consumers and businesses after nearly two months of repeated supply warnings. But NGCP said the grid remains vulnerable because it still depends on its largest power plants staying online and on electricity imported from Luzon and Mindanao.

Yellow alerts end after major power plant returns

Senior Network Operations supervisor Amado Otarra said during the NGCP Power 101 forum on Thursday, July 2, that the Visayas grid has been free of yellow alerts since 2:40 p.m. on Wednesday, July 1, after Panay Energy Development Corp. (PEDC) Unit 3 in Western Visayas resumed operations.

However, NGCP’s official Facebook page showed that the company announced at 8 a.m. Wednesday that a yellow alert would be in effect from 5 p.m. to 8 p.m. It later posted at 6 p.m. that the yellow alert had been lifted.

As for PEDC Unit 3, Otarra said the plant restored 150 megawatts (MW) of generating capacity after weeks offline. Its return ended the daily yellow alerts that started on May 11, when four of the Visayas’ largest generating units suffered forced outages.

Even with PEDC Unit 3 back online, Therma Visayas Inc. (TVI) Units 1 and 2 and Kepco SPC Unit 1 in Cebu Province remain out of service.

Otarra said the two TVI units, each capable of producing 169 MW, are expected to return in September after maintenance designed to prevent future technical problems.

PEDC unit restores power reserves

A yellow alert is declared when the grid’s contingency reserve falls below the capacity of the largest generating unit operating at that time.

With PEDC Unit 3 back in service, the Visayas has increased its dependable generating capacity, including imported electricity, to 3,173 MW during the day and 2,729 MW during evening peak hours.

Evening capacity is lower because solar power plants, which account for about 800 MW of installed capacity, do not generate electricity after sunset.

PEDC Unit 3 has also become the new reference point for the grid’s contingency reserve, which is standby power immediately available to replace electricity if a large generating unit suddenly trips offline.

Major generating units remain offline

NGCP stressed that the absence of yellow alerts should not be seen as a guarantee that the problem is over.

Cynthia Perez-Alabanza, assistant vice president and public relations head, said future alerts will continue to depend largely on the condition of power plants rather than the transmission network.

“No assurance yet. For as long as there are unforeseen maintenance shutdowns, we don’t expect that there will be no further alerts. If something goes against the schedule, that may complicate things further,” Alabanza said.

The grid is still operating without 338 MW from the two TVI generating units. If another large plant unexpectedly shuts down before those units return, reserves could again fall below required levels.

Forced outages triggered power shortage

Otarra said the recent power supply problem began when TVI Units 1 and 2, PEDC Unit 3 and KSPC Unit 1 all suffered forced outages at nearly the same time. Together, the four generating units removed 591 MW from the Visayas grid.

The supply shortage coincided with higher electricity demand during the second quarter as extreme heat drove up air-conditioning use. Demand eased in June as cooler, rainy weather reduced electricity consumption, helping stabilize the system while repairs continued.

Interconnections bolster Visayas supply

The Visayas is currently relying heavily on electricity imported through the country’s interconnected transmission network.

The present dependable capacity includes up to 450 MW imported from Mindanao through the Mindanao-Visayas Interconnection Project and another 250 MW from Luzon.

Without those interconnections, power available within the Visayas would drop to about 2,473 MW during the day and 2,029 MW at night, illustrating how transmission links between the country’s major island grids help cushion the impact of generation outages.

Transmission projects move forward

While recent alerts were caused by generating plant outages, NGCP said it continues to expand the transmission system to prepare for future demand.

Among its priority projects are the Cebu-Lapu-Lapu 230-kilovolt transmission line and the Lapu-Lapu 230-kV substation, with a combined approved cost of more than P11 billion.

The projects are intended to increase transmission capacity serving Metro Cebu, Mandaue City and Mactan Island, where existing 138-kV facilities are nearing their operating limits because of continued growth in electricity demand.

A new drawdown substation in Lapu-Lapu City will also absorb part of the load now handled by the existing Mactan Gas-Insulated Switchgear, easing congestion on transmission lines linking Cebu, Mandaue and Mactan.

Construction is underway, including the laying of submarine cables between Cebu and Mactan. The project is scheduled for completion by December 2027.

Perez-Alabanza said work began in 2018, but the Covid-19 pandemic and delays in approvals from the Energy Regulatory Commission slowed implementation. Major approvals were released only in 2025.

Cebu-Leyte interconnection expansion

NGCP is also pursuing the more than P44-billion Cebu-Leyte Interconnection Lines 3 and 4 Project to strengthen power transfers between the Visayas and Luzon.

The existing submarine cable system limits electricity imports from Luzon to about 250 MW because higher transfers would overload the current facilities between Cebu and Leyte.

Stage 1 will install two new 230-kV submarine cable circuits between Poblacion and Calatrava, along with new overhead transmission lines in Cebu and Leyte. Once completed, the additional facilities will increase transfer capability by another 240 MW. This refers to transmission capacity rather than new electricity generation.

The project will be completed in three phases through 2035, eventually providing two 600-MW transfer circuits to improve power sharing among Luzon, Visayas and Mindanao.

Permitting and right-of-way delays

NGCP said engineering work is often not the biggest obstacle to transmission projects. Instead, the company continues to face delays caused by right-of-way acquisition, permit processing, requests to reroute transmission lines and regulatory approvals.

Perez-Alabanza said project schedules depend heavily on support from local government units. NGCP is asking local governments to speed up the issuance of building permits, council resolutions, barangay clearances and certificates of no objection needed for major energy projects.

Long-term capacity plans

As of May 2026, the Visayas has more than 4,193 MW of committed power generation projects, including more than 3,880 MW from renewable energy, 312.5 MW from non-renewable sources and nearly 420 MW of battery energy storage projects.

NGCP noted that the region’s last baseload power plant entered service in 2019. The company said maintaining long-term energy security will require continued investment in dependable baseload generation, a balanced energy mix, geographically distributed power plants and further expansion of the transmission network to keep pace with economic growth. / CAV & JINELLE SIMBAJON, UP CEBU INTERN