Shortly after PM Modi's announcement of the 9-minutes light-out at 9:00 pm on Sunday, reports had started pouring in about the feasibility of this exercise. There were fears that the entire electrical grid of the country could collapse if there is a sudden drop and then a quick surge of power.
The government has now come out with an elaborate plan to manage the dramatic changes in electricity and its impact on the grid. Following is the broad plan of action as stated by the government.
- Electrical appliances such as AC, fans, TVs, refrigerators are not supposed to be switched off and only household lights are to be switched off from 9 pm to 9.09 pm on Sunday.
- Lights in all essential services, including hospitals, police stations and manufacturing facilities as well as street lights are not to be switched off.
Power System Operations Corp Ltd, the government agency tasked with managing the grid, has mapped out all of the country's lighting load and has estimated it be to be around 12-13 gigawatts. The total consumption of electricity in India is 125-126 gigawatts(WB).
During the 9-minutes lights-out the 12-13 GW would decrease for 2-4 minutes as people switch off lights and then would be would increase back again after 9 minutes when lights are turned back on. This sharp reduction in load and recovery is unprecedented, according to the agency.
The sudden drop and following rise will be managed by using hydro and gas generators that require the least amount of time for ramp-up. According to the plan, all regional grid managers have been advised to maintain their interchange with the grid as per schedule.
Electricity distribution companies have been ordered to avoid any feeder switching operations from 8:00 pm to 10:00 pm on Sunday. Control rooms both at the regional and state levels will be monitoring the grid during the entire exercise and would tackle any contingency that spurs up.
State load distribution centres have asked all electricity distribution companies to ensure that the main supply at subs stations, housing society and residential apartments is not switched off at the feeder level.
During 6:10 pm and 8:00 pm on Sunday, hydro generation of electricity would be reduced significantly to conserve it. This conserved electricity would be used for providing flexibility during the 9:00 pm lights-out. Thermal and gas generation will be scheduled in a manner so that they can manage the supply during this time.
After 8:00 pm electricity generation at thermal Inter-State Generating Stations (ISGS) would be gradually reduced to the minimum level of 60 per cent by 8: 55 pm. At the same time, hydro generation would be increased to maintain balance.
Hydro generation and gas generation will be reduced starting from 8:57 pm while keeping a watch on the system frequency. Gas stations electricity generations would also be reduced to the minimum level.
During the 9-minute lights-out, ramping up of thermal machines will be carried out from 9:05 pm onwards. From 9:09 pm hydropower would also be ramped up to meet the sudden increase in load. After the supply is stabilised hydropower units would be withdrawn.
Conserved hydroelectricity units will be brought in pumping mode by 8:45 pm and will be used till 9:09 pm. After that, machines will be removed from the grid. Wind electricity generating plants have been advised to automatically disconnect the power lines before the lights-out. These will be reopened later 9:30 pm in a synchronised fashion. To avoid voltage fluctuation, all India grid frequency will be kept at lower side of IEGC band. All defence mechanisms such as Under Frequency/df/dt relays and automatic demand management systems will be in service. All transmission lines, line reactors and bus reactors will be ready by 8:00 pm to provide stable voltage, reactors would be put in service whenever required.All flu patients in coronavirus hotspots to undergo COVID-19 rapid tests