Today as well Himachal along with 21 other states plunges to darkness as 3 electric grid collapsed and the region faced the one of the worst power shutdowns in the past decade. It took more than 10 hours for at least nine northern states to get their grids restarted and restore electricity supply to essential services.
In the preliminary investigation it learned that the power on Gwalior-Agra circuit tripped first due to over-drawing. The systems in place are such that when one line trips, the load is shifted to the next. Last night, all the lines tripped one after another as the power load was too much. Following the cascading effect, the entire northern grid collapsed.
The northern grid collapse affected power supply to Punjab, Haryana, Rajasthan, Uttar Pradesh, Delhi, Himachal Pradesh, Chandigarh (Union Territory) and Jammu and Kashmir. The electricity was restored around 5 p.m. but there was frequent tripping and power failures. It took than one hour to be normalised in the Himachal Pradesh.