Despite last Saturday’s Yellow Aler

t in Luzon, Energy Sec. Alfonso Cusi said there was “still enough capacity in the system as it did not result [in] any power interruption.”

The National Grid Corporation of the Philippines (NGCP) particularly declared the Yellow Alert after several power plants either shut down or derated their operating capacities. A total of 2,834 megawatts  (MW) was shaved off the country’s largest grid.

“Last Saturday [evening], the largest plant in the grid also went offline resulting [in] a Yellow Alert,” said Cusi, who was referring to the 668MW Unit 1 of Aboitiz Power Corporation’s GNPower Dinginin coal-fired power plant in Mariveles, Bataan.

“As summer approaches, low water levels also result in derating or the unavailability of hydro plants. These have been considered in the scheduling of the maintenance activities of the power

plants,” he added, referring to CBK Power’s 720MW Kalayaan hydroelectric power plant in Laguna.

Three other coal plants in Calaca, Batangas owned by ACEN and Semirara Mining and Power Corporation with a total capacity of 623MW also went offline.

“Some power plants deliberately dera

te their units on weekends for them to conduct minor maintenance works without the need to shut down the plant,” Cusi added.

Four generators, also in Batangas, derated their capacities by a total of 823MW.

Incidentally, the Philippines was participating in the annual Earth Hour during the Luzon Yellow Alert. The Department of Energy (DOE) said that the country saved a total of 65.32MW during the one-hour switch-off of non-essential lights, 35.26MW or 54% of which came from Luzon. Visayas and Mindanao, m

eanwhile, saved 14.7MW and 15.3 MW, respectively. 

The Yellow Alert was lifted at 11 PM on Saturday due to “receding system demand.” 

“Most of the derated plants are already back to normal and the largest plant on outage has also already returned to service. We expect to have sufficient capacity in the system moving forward,” Cusi said. 

Earlier, the DOE said that if power generation companies would follow the approved scheduled maintenance programs under the 2022 Grid Operating and Maintenance Program (GOMP), and if there would be no forced outages, no alerts would be declared throughout the year.

However, NGCP had warned of thin power supplies in the Luzon Grid this summer as the GOMP “is not always followed.”