The National Grid Corporation of the Philippines placed the Luzon power grid under yellow alert from 5 PM to 7 PM, Wednesday due to higher-than-expected demand and multiple power plant outages.

The transmission operator reported an available capacity of 12,488 megawatts (MW), while peak demand reached 11,829 MW, surpassing the initial morning forecast of 11,325 MW by the Independent Electricity Market Operator of the Philippines (IEMOP).

Twelve power plants were on forced outage, including eight that had been offline since February and four since 2024.

Sixteen others were derated, resulting in 3,362.3 MW of unavailable supply.

A yellow alert signals an insufficient operating margin to meet contingency requirements, but no rotational power interruptions were announced.

The Visayas and Mindanao grids, on the other hand, remained under normal conditions.

With rising temperatures driving up electricity consumption, the Department of Energy said earlier this week that peak demand this summer would likely exceed last year’s levels.

Luzon’s peak could reach 14,769 MW, up from 14,016 MW recorded in April 2024. In the Visayas, demand is projected to rise to 3,111 MW from 2,641 MW in May, while Mindanao could hit 2,789 MW from 2,577 MW in May .

To help stabilize supply, new power projects under testing and commissioning are expected to add 1,890 MW in Luzon and 193 MW in the Visayas.

The Luzon-Visayas and Visayas-Mindanao high-voltage direct current interconnections will also allow capacity sharing of 250 MW and 450 MW, respectively.

The expected onset of La Niña may also help moderate temperatures, while continued water releases from the Pantabangan and Magat dams could support power generation in Luzon.