"Charging an EV from the roof skips the grid entirely" As long as you have enough sunshine hours in your region. Southern Spain is fine year-round, but you wo

"Charging an EV from the roof skips the grid entirely" As long as you have enough sunshine hours in your region. Southern Spain is fine year-round, but you won't get any meaningful output out of a solar panel in Finnish winter. The rest of Europe lies between those two extremes. Northern winter will be made more challenging by addition of EVs to the grid, because a lot of electricity is being used for heating as well.