Visayas grid on thin reserves again as power plant outage triggers yellow alert

Local

THE Visayas power grid will operate under a yellow alert for three hours on Monday evening, Aug. 3, after another coal-fired power plant went offline, highlighting the region's increasingly tight power reserves.

In an advisory issued Monday morning, the National Grid Corporation of the Philippines (NGCP) placed the Visayas Grid under yellow alert from 5 p.m. to 9 p.m. It said available capacity is projected at 2,478 megawatts (MW) against an expected peak demand of 2,327 MW.

NGCP attributed the alert to the continued unavailability of major coal-fired generating units—Therma Visayas Inc. (TVI) Units 1 and 2, Kepco SPC Unit 1, and Cebu Energy Development Corp. (CEDC) Unit 1—as well as the emergency shutdown of Toledo Power Corp. (TPC) Coal on Sunday, Aug. 2.

The grid operator also reported that three power plants have been on forced outage since August, three since July, three since June, seven since May, one since March, three since 2025, three since 2024, two since 2023, and one since 2021. In addition, 16 generating units are operating at derated capacities, leaving a total of 1,055.8 MW unavailable to the grid.

A yellow alert is declared when the operating margin is insufficient to meet the transmission grid's contingency reserve requirement, although there is still enough generation to meet demand.

During an online press briefing Monday, Aug. 3, Department of Energy (DOE) Undersecretary Mario Marasigan said the latest outage at Toledo Power Corp. pushed the Visayas grid into a more vulnerable position.

Marasigan said the Toledo plant experienced a tripping over the weekend and is expected to return to service by Aug. 6, subject to the completion of the company's technical assessment.

He clarified that CEDC's planned preventive maintenance outage did not push through after it was abandoned.

The DOE official explained that the prolonged shutdown of Therma Visayas Units 1 and 2 has had a bigger impact on the region's supply.

According to Marasigan, the units were originally scheduled for preventive maintenance but encountered unexpected technical problems after both units developed abnormal thermal conditions affecting their main turbines.

Because of the repairs, the generating units have remained offline since May, leaving the Visayas grid with thinner operating reserves.

"The reason why we are on alert today is because of Toledo Power's outage the other day," Marasigan said.

He noted that while DOE projections do not indicate possible yellow or red alerts in Luzon over the coming weeks, the Visayas remains highly dependent on imported electricity.

Marasigan said the Mindanao-Visayas Interconnection Project can deliver about 400 MW of electricity to the Visayas during the afternoon and as much as 450 MW in the evening. The Luzon-Visayas interconnection can likewise provide around 250 MW.

"Without the transfers from Mindanao and Luzon, the Visayas would always be under red alert," he said.

However, Marasigan noted earlier in the briefing that growing electricity demand in Mindanao has also tightened that grid's reserves, limiting the amount of power that can be exported whenever local demand rises.

To improve grid reliability, the DOE has instructed the NGCP, in its capacity as system operator, to immediately negotiate and contract additional auxiliary services for the Visayas under emergency arrangements.

Marasigan said around 270 MW of battery energy storage system (BESS) projects have already been identified for deployment in the region, with approximately 50 MW already undergoing testing and commissioning.

The DOE is likewise evaluating additional emergency generating capacity, including a 50-MW power barge that could be deployed to Cebu.

Marasigan said the proponent has already begun preparations for the transfer, including securing the necessary permits, with the facility targeted to be relocated, tested and commissioned before the end of the year.

He added that the DOE continues to receive proposals for additional emergency generation projects and is evaluating all available options to ensure sufficient capacity for the Visayas in the coming months.

Despite the current supply constraints, Marasigan said the government continues to expand the country's generation portfolio under Task Force 200.

He said 45 completed power projects—consisting of renewable energy, conventional power plants and battery energy storage systems—have already added more than 1,900 MW of capacity to the grid. Another 31 projects, equivalent to about 1,800 MW, are expected to come online before year-end to further strengthen the country's power supply.(MyTVCebu)