There's some opportunity for this, and I've seen discussions of it. The capability is real and is being seriously considered, though with existing EV fleets the effects are too small to consider.
Given the variability of renewables supply, this is a good way to allow for surplus daytime supply (of solar) and possibly overnight supply of wind (though in many areas winds tend to peak during the afternoon/evening due to land heating effects).
The challenge though is that you're still ultimately limited by battery materials. Known lithium reserves would be exhausted within a century even with recycling (about 90% efficient) providing only a fraction of the world's population with a Tesla-sized battery. Other electrolytes, improved recycling, or sourcing lithium from much poorer sources (potentially seawater) might work around this, but it's still a constrained resource.
Given the variability of renewables supply, this is a good way to allow for surplus daytime supply (of solar) and possibly overnight supply of wind (though in many areas winds tend to peak during the afternoon/evening due to land heating effects).
The challenge though is that you're still ultimately limited by battery materials. Known lithium reserves would be exhausted within a century even with recycling (about 90% efficient) providing only a fraction of the world's population with a Tesla-sized battery. Other electrolytes, improved recycling, or sourcing lithium from much poorer sources (potentially seawater) might work around this, but it's still a constrained resource.