As candles are ready to be lit at 9 pm, power utilities asking people to switch off only lights
BENGALURU: The Power System Operation Corporation (Posoco) which operates the national load dispatch centre expects the load to fall by 12,879 MW across the five regions during the nine-minute light switch-off event this evening, according to its advisory to state load dispatch centres. The Posoco has advised load managers to go for a graded reduction in generation to prepare the grid for the nine-minute event which will begin at 9 pm.
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. Sharp fall in frequency used to be a general occurrence in the summer months in the 1990s with one state or the other within a region overdrawing from the grid causing the frequency to fall to precarious levels. It is another matter that such rogue states had to pay a fine. The trend, however, became a thing of the past after the power sector moved to merit-order dispatch or availability based tariff. In other words, tariffs payable by utilities is linked to the frequency.
