Power minister Sushil kumar Shinde said Indian power supply system was quite efficient as we have been able to restore power supply within a very short span of time.
Shinde further said that it took four days to restore power in US after a major failure in 2003.
He also said that a three-member panel will look into the failure of the Northern grid, which led to power outages throughout the region today, and submit its report in 15 days.
The grid would be completely restored in the next two hours, he said. "We have set up a three-member committee to look into the collapse of the Northern power grid. The panel will submit its report in the next 15 days," Shinde told reporters.
Central Electricity Authority chairperson AS Bakshi, Power Grid Corporation chairman and managing director AM Nayak and Power System Operation Corporation chief executive officer SK Soonee will make up the panel.
On the possible reasons for the collapse, the minister said they would be known once the panel submits the report. Responding to a query on whether over-drawal by states led to the grid's failure, Shinde said, "It cannot be said whether over drawing by states is one of the reasons or there is any other reason. The panel will find out.
"Right now, we are getting additional 8,000 MW hydro power, including from Bhutan, to meet our demand." The Northern region is getting power from the Eastern and Western grids, he added.
A major collapse of the Northern grid had happened in 2001-02, he said. There was a failure due to fog moisture in January 2010. The Northern grid, which caters to about 28% of the country's population, covers nine regions -- Punjab, Haryana, Rajasthan, Delhi, Uttar Pradesh, Uttarakhand, Himachal Pradesh, J&K and Chandigarh.
The normal frequency at which electricity is transmitted through the Northern grid ranges from 48.5 to 50.2 Hz. At the time of the collapse around 2.35 AM, the grid frequency was 50.46 Hz, a few notches above normal.
This could have tripped the supply, Shinde said.
(With PTI inputs)