It all started when Hon’ble Prime Minister of India, Narendra Modi shared a short video message with the country on Friday, 3rd April at 9 AM and urged citizens to switch off all lights in the house on 5th April at 9 PM for 9 minutes and light a Diya or candle as a mark of every Indian’s fight against COVID-19. Since his broadcast, there has been a lot of discussions about the electric grid security during the event as people believe that suddenly switching electric loads ON and OFF may pose risk to the electric grid and result in a blackout throughout the country/region or part of it. I have been discussing it on Whatsapp throughout the day and thought to replicate the same here on my blog.
Being an Electrical Engineer and that too with a Masters in Electrical Power System, I find myself suitable to talk on this topic. This blog post is for those who claim that there are high chances that the electric grid will fail on 5th April 9 PM if all citizens simultaneously and suddenly switch their lights On/OFF.
It is true that electrical energy cannot be stored. It has to be (transmitted, distributed and) consumed at the moment it is generated. The electric grid is used to transmit and distribute electrical energy to each consumer as and when for his consumption. Electric gird is nothing but an interconnected network of transmission and distribution lines (wires) equipped with appropriate equipments like transformers, circuit breakers, and related switchgears. India’s electric grid comprises of 5 regions (namely Northern, Eastern, North-eastern, Western and Southern). These regions are interconnected to each other to make a national level electric grid. India has the world’s largest operational synchronous grid!
Management of Indian Electricity Grid
The operation of this grid is managed by National Load Dispatch Centre (POSOCO-Power System Operation Company) and 5 regional load dispatch centers. In addition to this, every state also has its state load dispatch center for state-level management. These load dispatch center’s (LDC’s) manage the supply-demand of electricity online for 24×7, 7-days a week, throughout the year! They continuously forecast (predict) long term, medium-term and short term load demand in the future and act accordingly. All LDC’s are connected to their concerned generating stations and major substations via a hotline to control active and reactive power generated from each generating station for every moment. They also direct major substations to change transformer taps if its voltage level goes beyond tolerance limits.
Effect of Chinese Corona Virus on Load Demand
Some social media posts are claiming that it is not good to switch off lights as load demand is already reduced by 70-80% because of the nationwide lockdown. I would like to clarify that load demand is not reduced by that much margin. According to POSOCO’s official demand comparison report as on 29th March 2020, the all India load demand is reduced just by 20%. The western region recorded a maximum reduction of around 29% out of all regions as can be seen in the following table showing region-wise load demand comparison between 15 March 2020 and 29 March 2020.
The figure above shows the graphical representation of load demand comparison between 15 March 2020 and 29 March 2020 by POSOCO. The primary reason behind such a small reduction might be increased residential consumption, the effect of seasonal variation, etc. A detailed data analysis will help understand the numbers.
The Sunday Night Event
It should be noted that switching lights off/on at 9 PM on 5th April is a planned outage for power system engineers and planners. It has been seen that various office orders and circulars have been given by authorities to manage the event. Similar things happen when we celebrate earth hour every year. I believe that the effect on 5th April will not be as high as compared to the earth hour as all hospitals, street lights and other important loads will function normally as only residential consumers are asked to switch off (only) ‘lighting’ loads.
While I advocate in the favor of Sunday night event, let me clarify that there are always chances of a system collapse as no system is 100% error-free. However, the chances are as same as they are at this moment or every moment that we are living in!
To conclude, I would reiterate that our electric grid can easily ride through during such conditions and there is no need to worry because of Sunday night blackout. In other words, you can fearlessly switch your lights on and off on this Sunday night and light a Diya or candle as a mark of your fight against Chinese Corona Virus.
Link to POSOCO report: 29 March 2020 Demand Comparison