The Luzon grid suffered a second round of temporary system “imbalance” Sunday following the sudden outage of a unit of Sual power plant in Pangasinan province.
Power retailer Manila Electric Co. said the grid imbalance resulted in power losses in some areas lasting 10 to 15 minutes, but the power supply was immediately restored at 10:52 a.m.
“We apologize for the inconvenience. The power interruption in your area may have been affected by the temporary system imbalance due to a sudden power plant outage and may last for 10 to 15 minutes,” Meralco said in an advisory.
Grid operator National Grid Corp. of the Philippines said it monitored a capacity loss of 628 megawatts from the Luzon grid because of the tripping of a generation plant at 10:32 a.m.
Sources said unit 2 of the 1,200-MW Sual power plant in Panganisan tripped. The Sual plant was built in 1996 and started delivering power in 1999.
“The generation loss resulted in automatic load dropping throughout the Luzon grid. NGCP has restored transmission services in all areas as of 10:52 a.m.,” NGCP said.
It was the second time in a week, when a major power plant tripped. NGCP monitored a capacity loss of 653 MW in the Luzon grid on April 25, because of the tripping of generation plants.
The generation loss also resulted in load dropping throughout the Luzon grid but transmission services were restored in all areas at 4:09 p.m. on April 25.
NGCP projected a peak demand of 10,164 MW for the Luzon grid Sunday versus available capacity of 11,251 MW, which meant there would be a reserve capacity of 1,087 MW.
NGCP expects demand to peak in May.
NGCP announced in January that peak demand would likely reach 10,561 MW for Luzon, 2,143 MW for Visayas and 2,064 MW in Mindanao.
“We breached the 10,000 MW demand in power for the first time this year. With an average growth rate of around 5 percent from 2014 to 2017, we are expecting Luzon’s peak demand in 2018 to remain in that growth rate, also in May,” it said.