Here's the thing: it's totally impossible to know. With the way our scientific advances are made based on adaping to our environment it could go two totally different ways.
On one hand the people of our planet could preemptively find ways to generate and harness power in non-traditional ways. This would allow them to plan for the inevitable and innovate, possibly findingmore eco friendly ways to generate energy.
On the other, everyone could panic, and as a result do nothing. They could rely on their governments to find a solution and rely on the people around them to do the scientific work that they aren't individually qualified for, and in the end a solution not be found. At this time wed just be sitting ducks waiting for the shift and hoping it doesn't destroy the power grids currently in place.
Either way, we wouldn't truly know If new sources of energy could sustain that kind of shift until it happens, especially since they wouldn't have the opportunity to go through much endurance and environmental testing by the time the shift came to pass. So it's sort of like we're damned if we do and damned if we don't.
P.s. sorry if there are typos, my phone keeps freezing. I think I got them all -.-"