To put that into perspective: A single bolt of lightning is about 5 billion joules, which translates to 1.2 million calories worth of food someone would have to scarf for their body to generate that much energy. Storm would have to be downing 2,131 Big Macs per thunderous kill shot -- which means her particular mutation must allow her body to instantaneously materialize power from either the electromagnetic energy around her or fucking nowhere ... and either option would be a world-changing miracle.
20th Century Fox
"You ... didn't ... supersize me, motherfucker!"
The wattage in a single bolt of lightning could power a home for a month -- meaning that with the right conductor and tapering, she could be spending her mutant off-days occasionally taking the time to run entire cities. Her body can produce endless amounts of sustainable juice on such a large scale that she could piledrive the energy crisis like a robotic Al Gore, but instead she wastes all her time teaching children and saving civilians like a selfish asshole.