Just read the interesting poll V2grid (Vehicle to Grid) and Tesla about if V2G was available, would you install it? It polled pretty unfavourably at only 32% yes. Between not wanting to wear out your car's battery pack, already having Powerwalls or living in a state without "Time of Usage", it's easy to understand why it would be unpopular. But. if it were restricted to only emergency back up in case of a power outage, with the nice side effect of any installed solar panels running in said outgate. It could have an anti-islanding grid disconnect and a decent quality inverter back feeding your house. I'm imagining if it is designed to run only occasionally it could be less expensive than a continuous V2G unit, needing fewer lifetime hours. If you voted "it depends", on what?