Electricity was cut at 10:57 a.m., affecting around 40 million people and inflicting significant damage to commercial life in Metro Manila and surrounding areas. The Philippine Stock Exchange was forced to halt trading at 11:30 a.m.
As of 8 last night, power had been restored to about 75 percent of the country’s main island.
National Power Corp. (Napocor) officials said a series of transmission line failures had knocked off three baseload power plants at 10:57 a.m.
Napocor senior power specialist Ronnie Santiago said the transmission line tripping was caused by a power line carrier failure at the Manila Electric Co. (Meralco)-owned Sta. Rosa sub-station in Laguna. A PLC is a communication system that signals breakers to open when there is a problem in the line.
Santiago said the transmission line breakdown was caused by a "spurious signal" sent to the so-called power line carrier which is connected directly to the transmission line of Napocor.
Napocor OIC-president Roland Quilala said they have yet to determine the source of the signal, which apparently caused the tripping in the transmission line.
Yesterday’s power outage was the fourth blackout in 13 months, and came as President Arroyo was on a visit to Japan pleading for more investments.
In November last year, a five-hour blackout that affected millions of people on Luzon hit only hours after the President left for a trip for Brunei to attend an ASEAN Leaders’ summit.
Power was restored to "more than 50 percent" of Napocor service areas by mid-afternoon yesterday, but large parts of Manila were still without electricity, Napocor spokesman Dennis Gana said.
Energy Secretary Vincent Perez said they hope to fully restore power by 6 p.m.
Meanwhile, Vice President Teofisto Guingona said the blackout was not connected with the restoration of the collection of the controversial purchased power adjustment (PPA).
Metro Manila remained calm amid the massive blackout, but tempers flared in the domestic and international airports as hundreds of departing and arriving passengers sweated it out following failure of the air-conditioning systems in the facilities.
The power outage came on the heels of a National Transmission Co. (Transco) promise to make blackouts "a thing of the past" by solving transmission line problems, including pilferage of high tension wires.
In a recent memorandum to Perez, Transco president Asisclo Gonzaga said their upgrading of a number of transmission lines has made them "confident of a robust, more stable and reliable Luzon grid."
Luzon is home to the country’s main industries and contributes an estimated 66 percent of the total GNP.
At the Calabarzon industrial estate, private export processing zones switched to their own emergency power to limit the damage and keep assembly lines running.
People in Metro Manila switched on their noisy back-up power generators while people in buildings without amenities such as generators went outdoors to try and beat the summer heat.
National police chief Leandro Mendoza said Napocor officials had assured him that the problem was "technical" in nature, as opposed to possible sabotage.
The blackout was perceived by observers as bad publicity for the President’s campaign to lure investors back to the Philippines.
In his own tele-conference from Tokyo at the Malacañang RTVM office yesterday, acting Press Secretary Silvestre Afable said Mrs. Arroyo immediately received reports of the blackout.
"The President just made a comment that this stresses very much the need for the privatization of the transmission facilities because she has always been confident once privatized, we can avoid such incidents," Afable said.
He refused to say if the latest Luzon-wide blackout would prompt the President to carry out her warning to Napocor officials that "heads will roll" if ever there would be a recurrence of massive power outage due to negligence.
Mrs. Arroyo had issued an ultimatum earlier this year against Napocor officials following an incident involving a back hoe that rammed and cut transmission lines in Luzon.
"I’m sure there will be investigations on this and I’m sure this will be reported to the President. So let’s just wait for her actions until she receives the full details of this incident," Afable said.
"I think it (Luzon-wide blackout) was just really a coincidence and these are really accidents only," Afable said.
"I mean to say there would be very clear signs if there is really sabotage. I think it was just a trip of transmission lines just like what happened the last time," he said.
Business in the city slowed down, badly affecting restaurants along the university belt and Taft Ave. Most closed early, while those which remained open made do with candle light.
The light railway transit system resumed operations at about 4 p.m. after stranding some half a million commuters.
Airports authorities switched on their alternative power supply, but capacity load was enough only to provide lighting inside the terminals, and to provide power to computer and equipment used by airlines and immigration authorities at the arrival and departure counters.
Many passengers took off their shirts, while other fanned themselves profusely as the heat became unbearable.
Compounding the heat problem was the delay caused by the non-functioning of the airport carousels where baggage are picked up.
"What kind of airport do they have here in Manila?" one arriving foreigner asked reporters.
Airport general manager Edgardo Manda said that "there is a problem in the airport’s centralized air-conditioning system. There is not enough power to run them whenever there is a blackout."
Power outages that hit Metro Manila have alarmed a foreign consortium involved in building a state-of-the-art $500-million new Terminal 3 facility. Consortium officials have said that the frequent power outages may destroy sophisticated equipment to be installed in the new airport.
"No (connection to PPA restoration). As far as they (Department of Energy) reported, there is no malintention," he said.
Energy Secretary Perez said the blackout was not related to the PPA issue confronting Napocor and Meralco. "There is no connection. It is purely incidental."
Perez also ruled out sabotage as a probable cause of the blackout.
Sen. Edgardo Angara has asked Napocor and Meralco to forgo "an overload of technical jargon and complex financial assumptions to give urgent relief to millions of power consumers through a drastic cut in their respective PPA."
In a statement, Rep. Miguel Zubiri said the Napocor would have a lot of explaining to do. "Last week, Napocor said they have already upgraded their transmission line. Apparently, Napocor lied to the public because the source of the brownout is transmission breakdown."
Meanwhile, Commission on Elections (Comelec) Commissioner Resurreccion Borra said that some of the youth who were intending to register may have lost interest in going to barangay centers where the two-day special registration was held.
Borra said that if there was a low turnout, neither the Comelec nor the SK Federation can be blamed because they have done all they could to encourage registration. — With reports from Marichu Villanueva, Mike Frialde, Non Alquitran, Jose Aravilla, Cecille Suerte Felipe, Christina Mendez, Rey Arquiza, Felix de los Santos, Pia Lee-Brago, Cesar Ramirez, Ding Cervantes, Sandy Araneta