A fundamental problem here is that V2H during an outage requires a disconnection device (in the NEC this is a “microgrid interconnect device”), and the manufacturers of such things have made no effort whatsoever to standardize the control protocol. This means that you cannot build an islanded-V2H-ready house and just plug in a car. So the whole concept is kind of dead in the water.
At least Tesla is vertically integrated enough to pull it off within their own product portfolio, but this has approximately no value if you want to use a non-Tesla car.
At least Tesla is vertically integrated enough to pull it off within their own product portfolio, but this has approximately no value if you want to use a non-Tesla car.