Energy department officials still in the dark about cause of power outage
Energy department officials remain in the dark on Wednesday about the cause of a massive power outage that affected at least 1.6 million customers of Manila Electric Company (Meralco) Tuesday night.
In a press conference, Energy Secretary Alfonso Cusi and Undersecretary Wimpy Fuentebella directed concerned agencies "to explain in writing within the day what occurred" after eight power plants with a total capacity of 2,407 megawatts (MW) tripped. This represents about 15 percent of the total load in the Luzon grid.
Fuentebella said this would help in preventing the same incident from happening.
"We are trying to analyze what happened and to investigate this further," he said.
Ordered to submit reports were generation companies, the Philippine Electricity Market Corporation, the National Grid Corporation of the Philippines and distribution utilities, including Meralco.
Meralco said 1.6 million out of its 6 million customers lost power from 7:30pm to 8:50pm or 1 hour and 20 minutes.
Fuentebella said at 7:30pm, three units of Sta. Rita power plant with the capacity of 600 MW tripped and two units of San Lorenzo with the capacity of 526 MW followed.
Due to huge drop in the power supply, "it brought up the spike in the frequency, so the transmission became unstable," he said.
After five minutes, Fuentebella said a second batch of power plants with total capacity of 1,371 MW tripped. These include the San Roque (95 MW), San Gabriel (420MW), Quezon Power Philippines Ltd. (452 MW), BacMan (136 MW), Trans Asia (27 MW), and GN Power (151 MW).
Fuentebella said at least two dispatchable plants with a total capacity of 290 MW were activated and manual load dropping was implemented.
After that, those power plants tripped started to get reconnected to the grid, he said, citing that the first one to return was San Roque at 7:58pm on Tuesday and the last one was the GN Power at 5:08am on Wednesday.
Asked of the cause of the tripping, Fuentebella said, "we are looking at the entire system."
According to the energy department, as of 1pm Wednesday, Luzon grid had the power supply capacity of 9,985 MW with a demand of 8,341 MW and a reserve level of 1,644 MW. Celerina Monte/DMS