probably the op is referring to ev out during day when sun is shining and so excess power from solar has to go to grid , and then have to charge car up at night with grid power as unless have battery to store solar that is likely the only alternative .
Maybe the answer is to have solar at the work place (rather than at home) where it can directly charge the employees cars during the day ?
still can also use solar though to heat water during day and use the hot water heater as a quasi battery if well insulated -need to think outside the square solar panel .
