Is this really a good thing for the environment? Grid power is still mostly fossil. Even if we posit that fossil -> power station -> grid -> battery -> motors is, say, twice as efficient as fossil -> fueling station -> combustion engine, it's a lot more than twice as cheap. So wouldn't we expect the shift to EVs to cause energy consumption to rise, and hence also emissions?

I understand the argument that it's easier to upgrade centralized power generation to green technologies than the entire fleet of vehicles, but the timing is critical if that is to be a net win for emissions, a nuance which seems to be swept under the rug as everyone's keen to avoid fuel taxes by switching to EVs.

Of course, if everyone switches to EV electricity demand will spike and prices will rise, and governments will be eager to reclaim lost fuel tax revenue with other automobile focused taxes. It might not stay cheaper.