Negros Power says brownouts may persist through year-end

By Glazyl M. Jopson

BACOLOD CITY — Power supply in the Visayas has improved this month, but rotational brownouts, or manual load dropping, may continue through the end of the year, Negros Electric and Power Corp. said Monday.

Joe-Mel Zaporteza, Negros Power vice president and chief operating officer, said at a news briefing that the power supply situation has improved compared with August.

“We’re seeing some (power) plants going online. The demand is manageable now because summer peak months are over,” he added.

Zaporteza presented the current power situation in the Visayas and explained how recurring supply constraints have affected Negros Power as a distribution utility.

Since May 13, Negros Power has recorded 44 manual load-dropping incidents, resulting in 3,335,834 kilowatt-hours of unserved energy.

Zaporteza said three coal-fired generating units in the Visayas grid with a combined capacity of 488 megawatts have been on forced outage since May 13.

Another 268 MW of generating capacity has been operating below its rated capacity, he said.

The supply constraints have contributed to red alerts declared by the National Grid Corp. of the Philippines, which can require distribution utilities to implement manual load dropping when available generation cannot sufficiently meet demand and reserve requirements.

Under NGCP terminology, a red alert indicates that contingency reserves have fallen to zero or that a generation deficiency exists, while a yellow alert means reserves are below the required level.

Zaporteza said the company wanted consumers to understand why rotational brownouts have been necessary.

He said forcing a generating plant to provide more electricity than its available capacity could create a bigger problem.

Zaporteza stressed that the situation is not confined to Negros Power because other distribution utilities across the Visayas, and at times Mindanao, have also been affected by tight power supply.

“Malaki ang impact nito sa consumers. Whatever available power supply pinagkakasya natin,” he said.

Amid criticism over manual load dropping, Zaporteza said Negros Power, as a distribution utility, remains dependent on the condition of the transmission grid and the amount of electricity available from generators.

He pointed to generation constraints as a probable cause of the supply shortage but declined to discuss the matter further.

Asked when manual load dropping could end, Zaporteza said Negros Power is exploring additional power sources, including smaller generators.

The Department of Energy said last week that it was targeting to resolve persistent power supply problems in the Visayas and Mindanao before Christmas through measures that include additional battery energy storage systems and diesel power barges.

Negros Power continues to implement prearranged power interruptions separately from grid-induced rotational brownouts as part of its five-year rehabilitation and system upgrade program.

The company’s five-year development plan covers the rehabilitation of electrical equipment and substations, deployment of new technologies, and other upgrades aimed at improving distribution reliability.

Zaporteza said the company is sectionalizing its distribution lines to reduce the number of customers affected and shorten the duration of scheduled interruptions.

“We see to it that least possible customers will be affected,” he added.

Negros Power began full operations as the distribution utility for its franchise area in November 2024 after obtaining a provisional certificate of public convenience and necessity from the Energy Regulatory Commission.