"I don't think one can have a blame game between the state and the center," said Veerappa Moily, the new power minister.
More than half of India's population lost electricity on Tuesday after a cascading series of problems in three of the nation's power grids shut down power from Imphal in the east to Jaisalmer in the west, and from Leh in the north to Bhubaneswar in the middle of the country.
The blackout affected an area encompassing about 670 million people, or roughly 10 per cent of the world's population. It trapped coal miners, stranded train passengers and caused huge traffic jams in the nation's capital.
Federal officials initially blamed the northern states of Haryana, Punjab and Uttar Pradesh for taking from the grid far more than their electricity allotments. Part of the reason may be that low rainfall totals have restricted the amount of power delivered by hydroelectric dams, which India relies on for much of its power needs. Another cause may be that drought-stricken farmers are using more power than expected to run water pumps to irrigate their crops.
But Ajit Sharan, the power secretary for Haryana, said that the central government is supposed to warn states if they are drawing excessive power from the system, and that did not happen on Tuesday or Monday, when another blackout affected a quarter of the nation's population.
"This hype that states are overdrawing is the reason for the collapse is not right," said Ajit Sharan, the power secretary for Haryana state. It is too early to say what exactly happened, he said.
When the grid collapsed, the frequency was 50.2 hertz, he said, which is normal. Had states been overdrawing, the frequency would have dropped well below that level, he added.
Whatever the cause, the scale of the blackout - the largest in human history - caused India acute embarrassment on the international stage. Indians track world opinion of them closely, not only for reasons of national pride but because foreign investments and remittances are crucial parts of the economy.
"The image of it looks very bad," said Naresh Chandra, a former ambassador to the United States and former electricity regulator in New Delhi.
But Mr. Chandra said the problems were fixable and that international investors should not lose heart. "India is on a learning curve and hasn't managed its technology as it should. But it will," he said.
Power experts in the United States speculated that inattention by those manning crucial circuit breakers on India's electrical grid may have led to the blackout.
India's basic power problem is that the country's rapid development has led demand to far outstrip supply. That means power officials must manage the grid by shutting down power to small sections of the country on a rotating basis. But doing so requires quick action from government officials who are often loathe to shut off power to important constituencies.
Mr Moily promised that he would ensure that the nation's power grid had round-the-clock monitoring.
Some 300 million people in India have no access to power at all, and 300 million more have only sporadic access. Another of the nation's basic problems is that supplies of coal, which is largely controlled by the government, have not been enough to meet demand even among power plants that have the capacity to generate more electricity.
Shailendra Tshwant, an environmental activist and energy consultant, said that relying on more coal and further centralizing the nation's energy infrastructure would be a mistake.
"Decentralized renewable energy sources like wind, solar and micro-hydropower plants are the answers here," Mr Tshwant said.
Many of India's major corporations and industrial groups generate their own power and thus were spared much of the disruption from the blackouts on Monday and Tuesday. Many apartment and office buildings in India's major cities have their own generators as well. And as India's power grid becomes ever more unreliable, private power alternatives will further proliferate, despite their relative inefficiency.
Tuesday's blackout affected a broad swath of India. Three of the country's interconnected northern power grids collapsed for several hours, as blackouts extended almost 2,000 miles, from India's eastern border with Myanmar to its western border with Pakistan.
For a country considered a rising economic power, Blackout Tuesday - which came only a day after another major power failure - was an embarrassing reminder of the intractable problems still plaguing India: inadequate infrastructure, a crippling power shortage and, many critics say, a yawning absence of governmental action and leadership.
India's coalition government, battered for its stewardship of a wobbling economy, again found itself on the defensive, as top ministers could not definitively explain what had caused the grid failure or why it had happened on consecutive days.
Theories for the extraordinarily extensive blackout across much of northern India included excessive demands placed on the grid from certain regions, due in part to low monsoon rains that forced farmers to pump more water to their fields, and the less plausible possibility that large solar flares had set off a failure.
"This is a huge failure," said Prakash Javadekar, a spokesman for the opposition Bharatiya Janata Party. "It is a management failure as well as a failure of policy. It is policy paralysis in the power sector."
For millions of ordinary people, Tuesday brought frustration and anger; for some, there was fear. As nighttime arrived, Kirti Shrivastava, 49, a housewife in the eastern city of Patna, said power had not been restored in her neighbourhood. "There is no water, no idea when electricity will return," she said. "We are really tense. Even the shops have now closed. Now we hope it is not an invitation to the criminals!"
Tuesday also brought havoc to India's railroad network, one of the busiest in the world. Across the country, hundreds of trains were stalled for hours before service resumed. At the bustling New Delhi Railway Station, Jaswant Kaur, 62, found herself stranded after a miserable day. Her initial train was stopped by the power failure. By the time she reached New Delhi, her connecting train was already gone.
"Now my pocket is empty," she said. "I am hungry. I am tired. The government is responsible."
Sushil Kumar Shinde, the power minister, who spoke to reporters in the afternoon, did not specify what had caused the grid breakdown but blamed several northern states for consuming too much power from the national system.
"I have asked my officers to penalize those states which are drawing more power than their quota," said Mr Shinde, whose promotion was announced a few hours later.
Surendra Rao, formerly India's top electricity regulator, said the national grid had a sophisticated system of circuit breakers that should have prevented such a blackout. But he attributed this week's problems to the bureaucrats who control the system, saying that civil servants are beholden to elected state leaders who demand that more power be diverted to their regions - even if doing so threatens the stability of the national grid.
"The dispatchers at both the state and the regional level should have cut off the customers who were overdrawing, and they didn't," Mr Rao said. "That has to be investigated."
India's power sector has long been considered a potentially crippling hindrance to the country's economic prospects. Part of the problem is access; more than 300 million people in India still have no electricity.
But India's power generation capacity also has not kept pace with growth. Demand outpaced supply by 10.2 per cent in March, government statistics show.
In recent years, India's government has set ambitious goals for expanding power generation capacity, and while new plants have come online, many more have faced delays, whether because of bureaucratic entanglements, environmental concerns or other problems. India depends on coal for more than half of its power generation, but production has barely increased, with some power plants idled for lack of coal.
Many analysts have long predicted that India's populist politics were creating an untenable situation in the power sector because the government is selling electricity at prices lower than the cost of generating it. India's public distribution utilities are now in deep debt, which makes it harder to encourage investment in the power sector. Tuesday's blackout struck some analysts as evidence of a system in distress.
"It's like a day of reckoning coming nearer," said Rajiv Kumar, secretary general of the Federation of Indian Chambers of Commerce and Industry.
India's major business centers of Mumbai, Bangalore and Hyderabad were not affected by the blackout, since they are in the southern and central parts of the country that proved to be immune from the failure.
Phillip F Schewe, a specialist in electricity and author of the book "The Grid: A Journey Through the Heart of Our Electrified World," said the demand pressures on India's system could set off the sort of breakdown that occurred on Tuesday.
In cases when demand outstrips the power supply, the system of circuit breakers must be activated, often manually, to reduce some of the load in what are known as rolling blackouts. But if workers cannot trip those breakers fast enough, Mr Schewe said, a failure could cascade into a much larger blackout.
Some experts attributed excessive demand in part to the lower levels of monsoon rains falling on India this year, which have reduced the capacity of hydroelectric power and forced many farmers to turn to electric pumps to draw water from underground.
Meanwhile, about 200 coal miners in the state of West Bengal were stranded for several hours in underground mines when the electricity to the elevators was shut off, according to reports in the Indian news media.
"We are waiting for the restoration of power to bring them up through the lifts, but there is no threat to their lives or any reason to panic," said Nildari Roy, an official at Eastern Coalfields Ltd., the mine's operator. Most of the miners had been rescued by late evening, news agencies said.
Ramachandra Guha, an Indian historian, said the blackout was only the latest evidence of government dysfunction. On Monday, he noted, 32 people died in a train fire in Tamil Nadu State - a reminder that the nation's railway system, like the electrical system, is underfinanced and in dire need of upgrading.
"India needs to stop strutting on the world stage like it's a great power," Mr Guha said, "and focus on its deep problems within."