There is a line in bold in the annual report of India?s national power transmission company, Power Grid Corporation of India Ltd (PGCIL). ?Indian Power Grids have not experienced any major grid disturbance during more than last eight years. Even minor grid disturbances in regional grids have come down significantly.? The printers will have to be told to reset that line in the forthcoming report.
On Monday and Tuesday, as power generating companies literally sat on a million units of electricity with no power line to wheel them, that level of under investment was slammed home to all of us.
Grids and their maintenance have basically been afterthoughts in the Indian power sector. Until the 1980s, what passed for the national grid was maintained by NTPC and NHPC engineers. Sadly for them, they were spun off into a separate company?PGCIL?as realisation dawned that there was a need for a dedicated utility to manage the show.
The most telling evidence of the low priority is that the race for the post of the chairman of the national grid chief of PGCIL is never as hotly contested as that for the generation companies. The race is so intense in the latter ones that the government has had to split the monopoly of its premier hydel power generation company to create three corporations to satisfy more people.
To its credit, since 1989, when it was set up, PGCIL has repaired and redone 50% of the national network. This has meant upgrading all 220 KV lines to 440 KV or more. But this means another half of the grid is with the state electricity boards down the road. While PGCIL lines are now one of the best globally, with the company moving towards even robot and helicopter led maintenance platforms for its network, the state electricity board lines are in bad shape. These boards are short of money even to buy the power from the central utilities and have nothing to offer for revamping the transmission and distribution networks. While some have offloaded some of the load from the distribution centres by privatising them, transmission has remained a government utility and so has been under-invested. Raising electricity tariffs from the public to make distribution companies finance transmission better is something no political party has been keen to try out.
This also means it is going to take time to piece together the jumble of evidence from the blackout on Monday and Tuesday. It took the US literally months to understand how a similar grid collapse happened in 2003. Here, with the boards keen to protect themselves from the backlash and the national grid data going only that far, it will take even more time. In fact, the outgoing power minister Sushilkumar Shinde has jumped the gun in setting a time limit of 15 days to complete the probe by the three-man committee.
The overall contours of what happened are clear. UP had its Ramzan festivities to light up, Haryana and Punjab had their irrigation needs and the rest simply needed some electricity to run the ACs in a sweltering, scanty monsoon season. As demand mounted, PGCIL had the relays to cut off supplies as frequency dropped, but those kick in only when the frequency dips below 49.5Hz, which didn?t happen on both days. There is a possibility then that some of the relays, thanks to the continuous overdraw by the states, actually shut down the power lines or transformers, to protect the system. And if they cut off too much load, frequency could have bounced back at too high a level, leading to a cascading disturbance, which propagated through the system. Since it is an interconnected grid that connects northern regions with the east and the north-east, the spread was instantaneous. The power stations went on tripping merrily as the transmission lines blanked out.
Cutting out those conjectures, however, the extent of overdraw is clear from the second petition filed by the Northern Regional Load Despatch Centre (NRLDC) with the Central Electricity Regulatory Authority on July 26. The first one was filed on July 7.
The details show that it is basically a free-for-all at the state level, which the Centre too connives at. In just the 30 days of June, NRLDC issued 371 caution messages to UP, i.e. one every two hours. Haryana got warning notices every three hours. Delhi, by the way, got two in the entire month. These are system-generated ones but show how appalling the discipline in the system has become. There is supporting corrosive evidence too. In July, UP again has bought power to the tune of R7 crore per day as per its records.
In a seven-day span in July, there was an overdraw by one or the other of the seven states in the northern region (Delhi and Chandigarh excluded) every day on an average of about 8% of the time. It is just happenstance that the states were not on the ?wrong side of the law? this week.
The level of stress that had been induced was, however, good enough to bring the entire grid down in such mammoth proportion. Incidentally, just a few months ago, some of the utilities had suggested to the regulator to increase the tolerance of the frequency. The implications would have been even more.
So, even as the country has set up a state-of-the-art 82,355 circuit kilometres of transmission lines and in the last five years added about 70,000 MW of power with about 20,000 MW of this coming on to the grid in just one year, we have had the largest-ever blackout in history. The load despatch centres have told the courts that other than messages they are helpless in taking any punitive measures to curb overdrawal from the grid. There is only one way the blackouts will not recur; but then we need a power minister to start it off.
subhomoy.bhattacharjee@expressindia.com
