Yeah, there are efficiency losses along the way, but two points: - More and more net metering tariffs are homeowner-buys-at-retail-pricing-grid-purchases-back-at-wholesale-pricing... the homeowner value of solar's excess energy is getting less - In a lot of cheaper EV purchases, the car company still owns the battery packs. This is for two reasons: 1) They sell you on a new battery pack when your range starts to decline after a few years, and 2) They're going to use the degraded batteries as second-life storage products... maybe not good enough to power your car, but more than plenty to provide a cheap powerwall alternative.
The points you bring up about mass charging is true, but once pricing starts to reflect that, that's going to make home storage far more economical (it already makes economic sense in some markets).
Gasoline has about 33kWh per gallon. A typical gas pump is limited to 10 gal/min flow rate (lets say 8gpm just to be conservative).
That means your gas pump takes about a minute to dispense 250 kWh or 23 seconds to dispense 100kWh. That generates effectively no heat. To charge one electric vehicle at the equivalent rate (assuming it could tolerate it) would take a 15 megawatt power source per 'pump'.
Here is the size of a one megawatt AC to DC power substation:
"The complete ABB megawatt station weighs only 20 tons. At 50 m3, the container’s volume is some 15 percent smaller than equivalent solutions."
https://library.e.abb.com/public/52d148c3c4b02ded85257e4c004...
I own an EV (hybrid really, Volt, but I'm 85% electric). I support electric vehicles enormously. But this is a huge huge problem with scaling that no one talks about. My volt can charge, slowly, at 8 amps (~1kW) while I'm at home, a rate my home power can easily take. Most vehicles in the US are static for at least 8 hours once, if not twice, during the day. Using that time to charge slower is a stopgap but I really doubt that the US grid has the excess capacity for this.