‘NORMAL, FOR NOW’: Visayas brownouts ease as power plants return online

By Rjay Zuriaga Castor

ILOILO CITY — The Visayas grid returned to normal operating condition on Friday, Sept. 18, a sign that the months-long struggle with tight power supply and rotational brownouts, which escalated in recent weeks, is easing.

The National Grid Corp. of the Philippines (NGCP) said the improvement was partly due to increased generation capacity in Mindanao, where Therma South Inc. Unit 1 and GNPower Kauswagan Unit 2 are back online.

Their return allowed Mindanao to export the full 450 megawatts of available power to the Visayas through the Mindanao-Visayas Interconnection Project.

As of Friday morning, the Visayas grid had an available capacity of 2,672 MW against a peak demand of 2,308 MW, a margin of 364 MW.

Despite the improvement, NGCP cautioned that a major generating plant outage could still trigger a yellow alert in the Visayas.

A yellow alert is issued when the operating margin is insufficient to meet the transmission grid’s contingency requirement.

NGCP last placed the Visayas grid under red alert Sept. 15.

A red alert is issued when power supply is insufficient to meet consumer demand and the transmission grid’s regulating requirements.

The region remained under yellow alert Sept. 17 before NGCP lifted it that evening.

NGCP had attributed the recent alerts to the unavailability of large coal-fired power plants in the Visayas and limited power imports from Mindanao.

As of Sept. 11, the grid operator reported 31 Visayas plants on forced outage and 14 others running on derated capacities, leaving 1,030.1 MW unavailable to the grid.

Major Visayas plant returns

NGCP lead specialist Reagan Alcantara confirmed to the Daily Guardian on Friday that Therma Visayas Inc. (TVI) Unit 2 in Toledo City, Cebu, resumed operations at about 4 p.m. Sept. 15, ahead of its scheduled Sept. 16 return.

The unit has a capacity of 169 MW.

Alcantara said the unit’s return helped ease the supply deficit that had contributed to repeated grid alerts in the region.

He noted that the return of TVI Unit 2 coincided with the absence of manual load dropping over the previous two days.

Manual load dropping is the deliberate cutting of power to selected areas to protect the grid, which consumers experience as rotational brownouts.

“When they were able to get back, yesterday was the first day that there was no red alert. There was only [a] yellow alert, and today, so far, if things are going to continue in the trend, hopefully there will be no more alerts,” Alcantara said.

He added that TVI Unit 1, also rated at 169 MW, was targeted to return Sept. 18.

In an advisory, TVI said Unit 1 was undergoing startup and synchronization activities and estimated that it would synchronize with the grid between 1 and 2 a.m. Sept. 18.

Alcantara said the return of generating units and the additional supply from Mindanao had markedly improved the Visayas grid.

“It is gradually improving. There is a marked improvement from the almost one month of red and yellow alerts and manual load dropping, almost daily,” Alcantara said.

He said the situation was moving toward normalcy but cautioned against considering the power situation fully resolved.

“Hopefully things will continue to be on the path to normalcy,” he said.

He also urged stakeholders to temper their expectations because grid conditions could change quickly.

He cited the last week of August, when the power situation failed to improve as expected because several generating plants encountered forced outages while others extended their maintenance periods.

“We always hope that this will be continuous,” he said.