kingdragonfly:

davidcole:

 

How likely, far aware is vehicle to grid.....or more specifically vehicle to house, ie the ability to use the car battery for emergency (primarily) electricity for a household

 

One of the expenses is you need "anti-islanding" certification. It prevents the line workers from being killed, when they are working on a line that suppose to have no power.

There's also a secondary optional expense where some will want a second electrical service panel box. This is so important things like refrigerators and heating get emergency power, while less important circuits, like hot water, do not.

In regard to prioritising what appliances to feed by way of a separate distribution board another option is to apportion feeds between phases if you're on a three phase supply. We do this for what our PV supply feeds to categorise daytime/nighttime requiring supply (as our PV feeds only one phase for our own particular reasons).