EVs and the ability to power your house for several days. I think the combination of solar and and EV provide the ability to store power when the sun goes down. This starts to solve one of solar's paradoxes IMO.
For instance, a home battery might have to be more durable (so withstand more charging cycles) but on the flip side can be heavier.
That said there might be synergies by repurposing worn out EV batteries as home or grid storage batteries.