I think the only vehicle to grid (V2G) or vehicle to home (V2H) system available now outside a few niche trials is the Chademo based Nissan Leaf, and even here relatively few UK electricity distributors seem to be offering this. And the two-way DC home charging equipment is still pricy (low volumes), on a par with a small home battery.
I'd suggest you look again in a year or two as things should improve.
I'd suggest you look again in a year or two as things should improve.