if all those EV owners add solar, then the extra power is distributed and the need for massive high voltage lines running over farmland is less needed.
But that's simplistic, I know. :)
PS we own a Leaf and have solar. We are not net-zero (yet) because when the solar was installed, you could not over produce and get a check. So most home solar arrays were designed to juuuuust be enough to.break even and no more.
We have doubled our electricity use since the Leaf, but that's because we're almost all LED lighting and use gas for water heater, cooking, dryer. And we're even eyeing the dryer as a massive user of electricity. I think we pay around $400 annually for electricity? (One year we paid $120 for the year. Before the Leaf of course. :) )