[aerohead]

AeroStealth's experience has been that, electricity isn't necessarily any cheaper than gasoline, on a per-gallon basis, but because the BSFC-e of a BEV is so superior to that of an ICE, that, overall, one is ahead.
Mercedes-Benz new EQXX concept illustrates the point.
At an EPA equivalent of 33.705 kWh/gallon, the Mercedes has an approximately 2.9669-gallon 'tank.'
At M-B's claimed 620-mile range, that's an average 208.9-mpg Combined.