The National Grid Corporation of the Philippines (NGCP) placed the Visayas power grid under yellow alert Tuesday evening as multiple plant outages and high demand squeezed electricity reserves.

The alert was in effect from 5 p.m. to 8 p.m. According to an NGCP advisory issued at 3:45 p.m., the region’s available capacity stood at 2,684 megawatts, barely exceeding the forecast peak demand of 2,512 megawatts.

A yellow alert is issued when the operating margin is too thin to meet the grid’s contingency requirements, though it does not typically result in rotational brownouts.

The Department of Energy (DoE) said the shortage was triggered by the forced outage of several major facilities, including Therma Visayas Inc. Units 1 and 2, which provide 169 megawatts each, and Panay Energy Development Corp. Unit 3, which provides 150 megawatts.

The grid is currently missing a total of 833 megawatts due to 11 plants being on forced outage and another nine operating at reduced capacity. Some of these facilities have been offline for years, with one plant out of service since 2021.

Energy Secretary Sharon S. Garin directed the affected generators and stakeholders to expedite restoration efforts.

“Secretary Garin has directed TVI Units 1 and 2, and PEDC Unit 3, and all concerned stakeholders to immediately undertake the restoration of the affected power plants,” the DoE said in a statement.

The agency’s Visayas Field Office will inspect the facilities to coordinate a safe and prompt return to service. The DoE added it is working with the system operator and generation companies to stabilize the supply and prevent prolonged impacts on consumers.

While the Visayas faced tight supply, the NGCP reported that the Luzon and Mindanao grids remained under normal operating conditions.