In Luzon, light bulbs begin to dim—and the ‘summer heat’ may be driving it

As temperature soars across Luzon, it is no surprise that household electricity demand also increases, especially with the school vacation keeping students at home.

With households simultaneously heavy on cooling and electrical appliances, the strain on the power grid also intensifies—leaving light bulbs flickering amid power shortages across Luzon.

THE LANGUAGE OF GRID ALERTS 

According to National Grid Corporation of the Philippines (NGCP), the Luzon grid currently has a very small safety buffer, with only 595 megawatts of operating reserve against a peak demand of 13 558 MW—signalling tight grid conditions  for unexpected outages or demand spikes.

As a response, an alert level was declared among 200 000 residents, leading to widespread power interruptions across affected areas.

Issued by the NGCP, the Philippine Grid Code serves as the criteria for the state of energy transmission in the country, where each power alert level indicates stability of electricity supply based on a safety margin.

Though the Department of Energy ideally benchmarks around 20 to 25 percent reserve margin for power system planning, NGCP relies on real-time operating reserves that monitor demand against available supply.

The color-coded power advisories are as follows: white alert is issued when the grid is in a normal state and electricity generation meets consumers’ demands; yellow alert is issued when the grid is thin or the reserves are low, where supply is enough to meet demand, yet does not meet the required safety margin; red alert is issued when the electricity supply is insufficient to meet demand because its reserves are currently depleted or zero; and blue alert is issued when a high risk of transmission line damage may occur linked to an incoming weather disturbance.

With a yellow power advisory, possibility of rotational power interruptions increases, while a red advisory means manual load dropping and power interruptions are expected to prevent a total grid collapse.

NGCP attributes the unused 3 942.8 MW of capacity to forced outages or malfunctional power plants, and another 738.8 MW due to derated capacities or where power plants operate below their normal maximum output—worsened by high temperatures.

SUMMER HEAT IS THE CULPRIT

Summer heat is often the cause of peak power demand globally. As the temperature peaks, households and other infrastructures push their air conditioning to run longer and harder in an effort to keep cool, which results in higher electricity being pulled from the grid.

This high power demand thins out the energy reserves and forces agencies to implement yellow and red alerts, signalling how close the power grid is operating to its limits.

Data from the NGCP shows a 30% increase in Luzon’s peak power demand in the last decade, from 9 726 MW in 2016 to over 14 000 MW today. These peaks usually occur in the months of April and May, and sometimes June.

Combine the current demand for cooling with how power plants risk overheating equipment and are forced to reduce output in high temperatures, the strain on the power grid reduces available capacity.

As an emergency strategy, power grid operators deliberately cut-off electricity to specific areas on a scheduled basis, resulting in manual load dropping, commonly known as rotational brownout.

Electric power distribution companies, like Manila Electric Company (Meralco) or Visayan Electric Company (VECO), choose to cut power of less critical customers, namely the residential areas, to ensure electric supply for commercial and industrial sectors.

Manual load dropping has been implemented and is ongoing in parts of Ilocos Sur, Isabela, Quirino, Cagayan, Apayao, Bataan, Tarlac, Nueva Ecija, Batangas, Camarines Sur, Metro Manila, Bulacan, Cavite, Laguna, Quezon Province, and Rizal Province.

This rapid growth in power demand is yet to stop and is projected to continue — which means more problems. The swelling population in the country and its rapid urbanization keeps raising the peak energy demand each year. Meanwhile, energy production in the archipelago is left in the dust as many existing power plants are aging and new ones are taking ages to construct.

AS LIGHT DIMS, LIFE PAUSES

These rotational brownouts impact the daily life and the livelihood of residents, students, small businesses, and the operation of large companies, causing more than inconvenience and detrimental effects.

Disruptions of online classes and work, lowered productivity, internet access interruptions, and worse, hospitals being affected by power disruptions with inoperable medical or assistive electrical devices, to name a few.

Not only that, such disturbance can inflict massive economic loss in just a short amount of time.

In a study on the Philippine Institute for Developmental Studies, it is found that a single electricity supply interruption can result in a 10.7 billion peso loss for the local government while stripping around 3.8 billion peso worth of undelivered public services to the local population.

This means that whenever a power interruption occurs, Filipinos are not just being baked alive in the heat, but are also being deprived of economic stability.

As the summer temperature continues to burn day and night, Luzon is left with no choice but to bear the heat made worse by the flickering light bulbs.