You ARE wrong - EVs do not require massive new sources of power. In fact they are a storage resource making existing power - notably making renewables far more efficient because they store additional power and let grids load level.
Ummm hundreds of millions of vehicles is an overstatement - it will work within the existing replacement cycle.
There is a tipping point where it makes no sense to continue to drive an ICE vehicle.
Copenhagen hurries that along with a 180% tax on new ICE vehicles. Other jurisdictions will move it along for various reasons.
In the US you are sheltered by very low fuel costs so the economics are not as compelling ....places like Norway the uptake on EV far outstripped gov expectations.
Tipping point comes around 25% of new car sales ....in Norway the program got EVs to 20% of new car sales in a heartbeat.
Each jurisdiction will be different and you can bet California will lead.
Hybrids will lead for a good while and distances on plug in hybrids on EV only are getting into the 40 mile range which is within most commuters range. So no range anxiety but little hydrocarbon fuel use.
One side effect is fuel providers need to react and add charging to their product mix but I suspect shopping areas will outdo them - using charging as a draw.
There will still be a long tail off for fossil vehicle fuels but for the heavy commuting regions that need clean vehicles ...they will force the issue
The Ford Bolt and the Tesla 3 both sell for average price of a similar ICE car and of course fuel costs are minimal, performance amazing.
We shall have to learn to be wary of EVs ...they shal eat us for lunch