Power grid operator warns of thin supply in summer

Transmission backbone operator National Grid Corp. of the Philippines (NGCP) warns that power supply will be tight during the summer months when demand traditionally peaks as Filipinos use more electricity to beat the scorching heat.

The NGCP stressed, however, that “no occurrence of yellow or red alerts” is expected based on their current projections, which means that there is still enough power supply from generating plants to meet the peak demand and the required grid reserves.

However, “there are weeks between March and April where operating margins are below required levels due to higher demand and planned outages of plants.”

This means that should a large power plant of about 200 megawatts unexpectedly shuts down, there is a greater possibility of rotating blackouts or power interruptions.

Simulations

In the case of Luzon, operating margins or excess power will be thin from April to June “due to the historically high” electricity consumption when air conditioners, for example, operate for a longer time.

Citing simulations conducted by the Department of Energy (DOE), demand in Luzon is seen to reach the peak of 13,125 MW in May 2023, an increase of 8.35 percent from the 2022 peak demand of 12,113 MW recorded on May 12, 2022.

With available capacity then at 15,785 MW, there is still enough margin left over to cover for the required reserves to ensure the reliable and efficient operation of the power grid.

Visayas is estimated to record peak demand of 2,691 MW in September, which can also still be covered by the projected available capacity then of about 2,950 megawatts.

Meanwhile, peak demand in Mindanao is forecast to reach 2,395 MW in June, up by 10.52 percent from 2,167 MW last June 1, 2022. Available capacity was pegged at 3,386 MW.

Reducing demand

To ensure that there will be enough leeway for unforeseen shutdowns or spikes in demand, The NGCP again appealed to policymakers to immediately explore ways to reduce electricity demand.

“As transmission service provider, the NGCP can only give an overview of the current supply and demand situation, and endeavor to dispatch any and all available grid resources. It cannot intervene on matters concerning power generation,” it said.

Yellow, red alerts

The NGCP said it had formulated a grid operating and maintenance program to ensure adequate supply during the coming critical months, but stressed that “there are instances of forced or unplanned outages of plants which may disrupt the normal operations of the grid and warrant the issuance of yellow or red alerts.”

A yellow alert is raised when the operating margin falls below the transmission grid’s regulating and contingency requirement, which is at 668 MW each, although no interruptions are planned. A red alert is declared when power supply is unable to cover both the peak consumer demand and the transmission grid’s required reserves to ensure that the grid is up and running.

Yellow means the grid does not have enough buffer to avoid rolling blackouts or power interruptions if a large power plant shuts down, while red means rotating blackouts are expected during the peak hours of the day.

To help ensure adequate power supply during summer, the DOE has prohibited the conduct of any scheduled maintenance shutdown of power plants.

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