9-minute vigil: Power sector pulls off PM Modi's challenge despite fluctuation being higher than estimated

Prime Minister Narendra Modi lit a lamp after turning off all the lights at his residence. (Image: Twitter/@narendramodi)

Eventually, the fluctuation was 31GW, more than twice of the 13GW as estimated by Power System Operation Corporation Ltd (POSOCO) - the public sector company responsible for managing India’s grid operations.

But, to the credit of the company and its men manning generating stations, substations and load dispatch centres, the nine-minute exercise of solidarity went off without a hitch.

In Pics | India turns off lights to switch on solidarity

The nation switched off lights at homes for nine minutes at 9pm on April 5, responding to the solidarity call from Prime Minister Narendra Modi.

"The demand went down from 117300 Megawatts at 2049 hrs to 85300 Megawatts till 2109 hrs; that is a reduction of 32000 Megawatts. Then it started increasing. Frequency was maintained within a band of 49.7 to 50. 26 Hz, which means the voltage was kept stable," tweeted RK Singh, Minister of State for Power & Renewable Energy.

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"The national grid operator POSOCO and the national, regional and state load despatch centres did a great job with support from all generators; NHPC, NEEPCO, THDC, SJVNL, BBMB, NTPC, all state gencos and IPPs, Transcos and Distribution companies and their officers and staff," he added in another tweet.

A senior executive from the industry told Moneycontrol that the fall in power demand was higher than expected as people had switched off not just lights, but fans and appliances also.

POSOCO arranged resources almost at a war footing to pull off the event.

It entailed a co-ordination that was unprecedented in the country's power sector. All power generators - thermal, hydel, gas and wind - had to work in tandem with the power distribution companies, or DISCOMS, and local dispatch centres.

By 20.45 hours on April 5,hydro generation was maximised,  and was consequently reduced in the next 25 minutes, till 21.10, to match the demand reduction as everyone switched off lights.

In these 25 minutes, generation from thermal and gas plants was also brought down.

POSOCO and its units had in advance switched off transmission lines, and other steps to manage the voltage within permissible limits.

"The event was managed smoothly without untoward incident while power system parameters were maintained within limits," POSOCO said, in a report after the exercise.

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