THE construction of critical transmission projects was completed in recent months. However, the Luzon and Visayas grids experienced rotating power outages early this week due to over 30 power plants either being shut down or operating at limited capacity.
This time, the National Grid Corporation of the Philippines (NGCP) was not part of the “blame game” as it had energized three major transmission projects for the past 12 months. These are the Hermosa-San Jose 500kv transmission line in Luzon, the Mindanao-Visayas Interconnection Project (MVIP), and more recently, the Cebu-Negros-Panay (CNP) Interconnection—all of which are crucial to maintaining the integrity of the grids.
The scorching heat, aggravated by the El Niño phenomenon, has affected the performance of the power plants, mostly hydropower, it was explained. “As previously noted, the extremely high temperatures have been affecting the operations of power plants in the grid,” according to the Department of Energy (DOE).
Therma Visayas Inc. had to shut down its 150MW coal plant in Cebu due to a “bed material leak” inside the boiler. The Pagbilao power facility likewise encountered boiler tube leak.
The Philippine Independent Power Producers Association Inc. (PIPPA) said majority of the power plants in the Luzon grid that were on outage were hydropower plants with low water levels. “Irrigation is a priority before power generation,” it said, adding that “it is the heat and the drought that play a big role.”
Coal and thermal plants, depending on the design, are affected by ambient temperature. “There are several factors that come into play. Remember that electricity has inherent heat,” commented PIPPA President Atty. Anne Escoro Montelibano, when asked how power plants perform during summer months when demand for electricity is at its peak.
Both the Luzon and Visayas grids have reached all-time-high peak demands for the year so far. The peak demand in Luzon was recorded at 13,222 MW on April 17 at 2:48 p.m., while the Visayas grid reached a peak demand of 2,525 MW at 3:34. p.m. In 2023, peak demand in Luzon stood at 12,550MW; 2,458MW in Visayas; and 2,315MW in Mindanao.
This year’s peak demand nearly outpaced available capacity for both grids for the past three days, prompting the NGCP to issue red and yellow alerts.
A red alert status is issued when the power supply is insufficient to meet consumer demand and the transmission grid’s regulating requirement, while a yellow alert is issued when the operating margin is insufficient to meet the transmission grid’s contingency requirement.
As a result, manual load dropping (MLD) or rotational power interruptions happened this week.
“The red alert status in the Luzon grid and the yellow alert in the Visayas grid are unacceptable and alarming. We have repeatedly called on the DOE to implement the necessary contingency plans that would tide us over when one or several of our power plants are incapacitated or unable to operate at full capacity,” said Senator Sherwin Gatchalian.
The DOE constantly reminded power generation firms of their compliance with the Grid Operating and Maintenance Program (GOMP), which states that no baseload plants should undergo any outages, both scheduled and unscheduled, from April to June this year.
But since many of the power plants are aging, unscheduled shutdowns could not be avoided. “No matter how extensive the maintenance activities are being done on the power plants, we cannot totally prevent the ‘wear and tear’ of some parts of the plants,” said DOE Assistant Secretary Mario Marasigan.
ERC investigation
THE Energy Regulatory Commission (ERC) has already begun its probe and has directed power plant operators to submit their estimated timelines for the resumption of their operations.
“We will continue to monitor their timely compliance. We are fully aware of the difficulties brought about by these power disruptions and affirm our commitment to a thorough investigation,” said ERC Chairperson Monalisa Dimalanta.
She stressed that while the primary focus remains on the immediate restoration of capacity, the agency is mandated to also review the performance of stakeholders concerned to ensure compliance with reporting requirements, maintenance and technical standards, as well as observance of allowable outage limitations.
The ERC, in a 2020 resolution, had set the maximum days of planned and unplanned outages per year and per generating plant technology.
This week’s power situation has led many to believe that the three sectors—generation, transmission and distribution—of the energy industry, coupled with a sound framework should be the right formula to solve the country’s power woes.
“As in the past years, the unplanned maintenance shutdowns of power plants have a considerable impact on supply and demand balance. The entry of new generation must always outpace the growth in demand,” NGCP stressed.
The DOE earlier said that growth in demand for this year could rise by nearly 11 percent in Luzon, 17 percent in Visayas, and possibly 11 percent in Mindanao.
NGCP stressed that it has long advocated for a holistic approach to energy planning. “We must focus development on the three sectors of the energy industry—generation, transmission and distribution—and not just on transmission. NGCP only transmits power when it is available. We remain committed to strengthening the transmission network in the country,” the grid operator said, adding that it continues to pursue its mandate of expanding the transmission system to keep pace with the developments.
Montelibano also recognized the need for additional capacity. “The climate contributes, but that’s not everything. We need more peaking plants. We need more baseload, so in the event a lot of plants bog down, we have sufficient back-up,” she said.
While additional capacities are needed, these should be supported by policies conducive and fair to capital-intensive investments. “Towards this end, the current regulatory framework relating to merchant plants, government approvals, price caps, and the reserve market may be enhanced to allow economically feasible operations by investors,” added Montelibano.
ACEN Corp. President Eric Francia said the three red alerts raised over Luzon and Visayas were not unexpected, given the lack of power reserves.
“We hope that the reserve market will resume operations soon, and that the ancillary service contracts that NGCP signed about a year ago will be honored and executed.
“A predictable and functioning reserve market is needed to encourage the building of much needed new capacity. It is also important to keep the viability of existing power plants that are primarily designed to serve the reserve market as opposed to the energy market,” he said.
The reserve market is envisioned to usher in the trade of power reserves in the WESM (Wholesale Electricity Spot Market), providing additional supply that is crucial during power interruptions.
As of this writing, the alerts are still in place to date for certain hours, as issued by the NGCP, due to insufficient supply and/or insufficient reserves in the said grids.
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