It makes sense that there would be some pretty hefty electrical system upgrades to do bidirectional charging.
You can power the grid with solar panels that sells excess back but that’s not free.
You could put in a generator for backup in a power outage. That’s not free either.
In theory you could put in a battery pack and charge it at night when the rates are cheaper and then power your home in the day. Business are already doing this. It’s just a cost benefit analysis.