FOR the third straight day, areas in Luzon faced rotational brownouts on Friday after the system operator warned that power reserves had been wiped out and the system was running on a buffer that is only about a fraction of peak consumer demand.

Just before the start of work hours on Friday, privately owned National Grid Corporation of the Philippines (NGCP) issued a “red alert” notice for 13 hours or between 9:00 a.m and 10:00 p.m., with the outlying hours of 8-9 a.m. and 10-11 p.m. experiencing the milder “yellow alert.”

Peak demand was placed at 10,334 megawatts (MW), exceeding the available capacity at 10,220 MW.

“NGCP may implement manual load dropping (MLD) to maintain the integrity of the power system,” it said, referring to a process where the limited electricity supply is distributed to different areas, resulting in rotational brownouts.

The thinning reserves “due to major generation inadequacy” came after another power plant was added to the four others that went on an unscheduled shutdown. The warning was issued after the system’s dispatchable and contingency reserves — equivalent to the capacity of Luzon’s two biggest power plant units at 647 MW each — were fully spent.

The Department of Energy (DoE) said on Friday that it had called for an emergency meeting the night before with NGCP and that it would conduct a follow-up meeting the day after with the grid operator, Energy Regulatory Commission (ERC), Independent Electricity Market Operator of the Philippines, Inc. (IEMOP) and Manila Electric Co. (Meralco) “to coordinate efforts and address the situation.”

The DoE said the alert warnings were issued because of the unplanned outage of five plants, with the 150-MW unit 2 of SMC Consolidated Power Corp. in Limay, Bataan as the latest addition when it went out at 4:28 p.m. on Thursday.

The four other plants on unscheduled outage are the 647-MW unit 1 of TeaM Sual Corp. in Sual, Pangasinan; 150-MW unit 2 of Southwest Luzon Power Generation Corp. (SLPGC) in Calaca, Batangas; 420-MW unit 3 of Pagbilao Energy Corp. in Pagbilao, Quezon; and 135-MW unit 1 of South Luzon Thermal Energy Corp. in Calaca, Batangas.

SEM-Calaca Power Corp.’s 300-MW unit 2 plant in Calaca, Batangas was de-rated by 100 MW. In all, 1,602 MW was out of the system, apart from the 827 MW from previously approved outages due to scheduled maintenance.

“However, we see an improvement of the system for Saturday and Sunday due to low demand on weekends,” it said in a statement.

It expects more system improvements between Saturday and Tuesday with the re-entry of two plants that shut down, namely: the Sual plant’s unit 1, and the Calaca plant’s unit 1.

On Tuesday, the Limay plant’s unit 2 is set to be back along with the Pagbilao plant’s unit 3.

“The energy family is expected to have a better determination of the week’s outlook by Sunday,” it said. — Victor V. Saulon