NEW DELHI: It was a Terrible Tuesday that 684 million Indians are not going to forget in a hurry. In the world’s biggest blackout that affected one-tenth of the global population, 21 states and Union Territories went on the blink after three arterial power lines collapsed at 1 pm.
The northern, eastern and north-eastern regions suffered the outage when their respective grids collapsed in quick succession with devastating effect. The blackout disrupted normal life, rail and air services as well as industrial production across sectors.Even as the country was reeling under the outage, power minister Sushil Kumar Shinde was moved out to the home ministry, and Veerappan Moily given the additional charge of power – a move that hardly indicated seriousness on the government’s part in dealing with the crisis.
Some 300 miners were trapped in coal mines. Two hundred miners were evacuated from mines in Bengal. Efforts were still on till the time of reporting to rescue 65 others stuck in Jharkhand mines.More than 300 trains were affected. Many others are likely to be cancelled. Airports, hospitals and BPOs functioned with their back-up generators. In Delhi, once again commuters had a harrowing time, and a scary one for those who were stuck in the Metro Rail trains that stopped in their tracks several feet above the street or deep inside tunnels. Roads were gridlocked as traffic lights stopped working.
In Kolkata, the metro was not hit by the outage, but West Bengal Chief Minister Mamata Banerjee asked all government offices to shut early and urged the private sector and schools to do the same to protect against commuter chaos in the evening. The Metro was not affected as the city largely remained isolated since power is supplied by a private firm.Tuesday’s grid collapse, like Monday’s, was triggered at Agra, a major interconnect between the northern, western and eastern grids. On Monday, the Agra relay station had tripped to trigger a blackout. This time too, the station kicked off a domino effect after suspected overdrawal by some states in the eastern grid. Within a fraction of a second of the Agra station tripping, the northern, eastern and the north-eastern grids went down.
At the time, the three grids together were carrying some 66,000 MW, 12 times Delhi’s demand. The tripping immediately shut down some 14,000 MW of generation capacity of state-run utility NTPC.Who triggered the collapse? Fingers were pointed at Uttar Pradesh, Haryana and Punjab for overdrawing power. All three states stoutly denied the charge. PowerGrid chairman A M Nayak could not give a reason for Tuesday’s grid collapse. “I am a technical person and it will be unfair on my part to suggest a reason without fully understanding and analysing the sequence of events that led to the problem.”
He said the complex grid network and the increasing interconnectivity increases the vulnerability of the system. “It is difficult to point a finger at something quickly in a complex grid. Things happen in milliseconds. We have the data from some 100 critical sub-stations. Only after a proper analysis and reconstruction will we be able to identify the reason.”Some 5,000 MW in the northern grid was restored by 4pm, or three hours after the outage. The grid was carrying 32,400 MW when it tripped. Similarly, 2,000 MW was restored in the eastern grid (12,000 MW) and 500 MW in the north-eastern grid (1,100 MW).
The northern grid was carrying 22,000 MW, or 80% of its load by 7.30pm. The eastern grid carried a load of 4,400 MW, or 40% of its usual load of 12,000 MW. The northeastern grid was operating at near-full capacity of 1,200 MW.But without naming any state, Nayak indirectly pointed that overdrawal could be causing the collapse. “Some sections (of the grid, an indirect reference to states) are creating problem by overdrawing. The grid system is dynamic and not static. There are several parameters…voltage, frequency etc. These keep changing. Small over or under-drawal will be here and there. I can’t say it will stop.”But Nayak’s words did not cut much ice with UP, Punjab and Haryana – the states that had been blamed for tripping the northern grid by overdrawing power on Monday. All three denied the allegation. – TOI
