Itaipu, the world's largest operational hydroelectric dam,Â which on Tuesday caused a four hour blackout in 18 of Brazil's 27 states and most of Paraguay was back in full production early morning Wednesday but authorities have so far remained silent about the causes of the major turnoff.
The CEO of Eletrobrás, José Antônio Muniz, told reporters that the blackout should never have occurred because the system was supposed to isolate the problem that originated the lack of electrical power. Muniz says that there was failure and it's necessary to investigate what made the security system not to work as expected.
The blackout had just started when the Brazilian opposition leaders in Congress began their phone contacts to devise a strategy to take the biggest advantage of the huge snafu. They want the Lula administration and Lula's hand-picked candidate to succeed him, his chief of staff, Dilma Rousseff to pay a heavy price for the power failure.
The opposition wants to hear directly from Rousseff what caused the blackout. José Serra, governor of São Paulo, an a likely candidate to the presidency himself in the 2010 elections, was one of the most severe critics. He accused the federal government of not investing enough in the energy sector.
At 08:00 GMT Wednesday Itaipu was back in operation with 18 of its 20 generators in production totaling 10.450 MW said an official release from the managing office. The dam is shared by neighboring Brazil and Paraguay and supplies 19.7% of all Brazilian power and 87.3% of Paraguay's.
Itaipu president Jorge Samek denied that the blackout was caused by the plant pointing out power continued to be generated but could not be connected to the grid for still unknown reasons.
It was the first time in Itaipu's history that all generators were shut down. The blackout officially started at 22:13 Brazilian time and left most of country in the dark including the main cities, São Paulo, Rio de Janeiro, Belo Horizonte and even part of the capital Brasília. International airports were closed down until Wednesday morning.
Mining and Energy minister Edison Lobão said the problem could have been caused by "atmospheric problems" or "very intense storms" which affected the grids.
"The meteorological problem could have disconnected Itaipu from the transmission systems and this had a domino effect on the whole national power integrated system," said Lobão.
The complete blackout extended to the states of São Paulo, Rio de Janeiro, Minas Gerais, Espírito Santo, Goiás, Pernambuco, Paraná, Mato Grosso and Mato Grosso do Sul plus areas of the Brasília Federal District.
Other states that were exposed include Santa Catarina, Rio Grande do Sul, Bahia, Rondônia, Alagoas and Acre.
It is estimated 50 millionÂ Brazilians suffered the consequences of the mega blackout.
However in spite of the chaos, lack of transport, traffic accidents and some emergency and panic situations no major incidents were reported. Federal and state governments recommended people to remain at home and reinforced street patrolling.