As candles are ready to be lit at 9 pm, power utilities asking people to switch off only lights

Indian grid system is designed to operate at a frequency of 50 Hz (or cycles per second). A sharp drop below this level or a sharp rise above this level will hamper the grid stability. If the fall or rise is too sharp, it can set off a series of tripping of transmission lines resulting in outage of generating stations.

from Energy-Industry-Economic Times https://ift.tt/2V2BNeT