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Explained: Grid challenges to the Sunday night blackout plan

What is the 5 April lights out about?

In his address to the nation on Friday morning, Prime Minister Narendra Modi asked citizens to turn the lights off in their homes for 9 minutes on Sunday (5 April) starting at 9pm. Instead, “stand at your doors or in you balconies, and light candles or diyas, (or shine) torches or mobile flashlights for 9 minutes" as a show of unity in the nation’s fight against covid-19 pandemic. While this is simple gesture for households to follow, the national electricity grid - which meets India’s power needs - has a lot of work to do maintain reliable power supply during and after this period.

Why is this complicated to manage?

India has a baseload power demand of roughly 160 gigawatts (GW), that is 160,000 megawatts (MW). Power System Operation Corporation Ltd (POSOCO), which is the national load despatch centre and operates the national electricity grid, predicts daily demand of power and regulates supply from power generators based on these predictions. In order to maintain the grid’s stability within a certain frequency (48.5- 51.5 hertz) and because we don’t have adequate electricity storage mechanisms, the accuracy of these predictions are very important so that power demand can be matched with supply. During this 9-minute lights out initiative, about 10,000-12,000 MW of power demand is expected to vanish, according to estimates by power industry experts. So POSOCO needs to ramp down electricity supply accordingly during this time block and ramp up again once this 9-minute period is over and the baseload demand returns in full strength. Any missteps in handling this could possibly lead to a high voltage surge, tripping the lines, causing damage to the national grid and an extended power outage.

Does India have experience in handling such planned power shutdowns?

A recent example of major shifts in power demand over a short timeframe was on Janta Curfew of 22 March, when national power demand fell to 135GW, down 26GW from the 161GW demand on the previous day (21 March). That’s a difference of 26,000 MW handled successfully over a 24-hour period, a senior official in Ministry of Power, who did not wish to be named, told Mint.

During Sunday’s scheduled lights out, only lights will be turned off while other household appliances can stay on. So the scale of the change in demand is expected to be smaller but concentrated over a 10-15 minute time block, and there is little historical experience of this to made accurate predictions.

What steps is the power industry taking to handle the lights out?

All through Friday, senior officials at POSOCO and Power Grid Corporation have been in video conference meetings with their state and regional load depatch centres, power distribution companies and state government officials to strategise handling the blackout. For instance, Uttar Pradesh’s load despatch centre is predicting that there will be a 3000MW sharp load reduction in the state starting 9pm on Sunday. The state has suggested starting load shedding operations in a staggered manner at 8pm on Sunday and keeping generation at a technical minimum. This will be ramped back up after the scheduled blackout which ends at 9.09 pm. POSOCO and state load despatch centres are expected to issue similar orders to generators, transmission operators and distribution companies by Saturday evening to safely handle the scheduled blackout on Sunday.