[1dom]

I'm looking at doing similar stuff right now. I already have a house battery.

However, looking at getting an EV - were you able to get bidirectional charging going?

I saw a few places mentioning demos of it over the past 5 years, but I can't find any v2x charger/car configurations I can buy and use in the UK.

Before looking at any of this stuff, I didn't realise how large and cheap the battery in an EV is compared to house batteries. Now I'm struggling to justify getting an EV if I can't do at least V2H bidirectional charging.

[chris222]

You can do bidirectional with most GM vehicles now with the GM energy solution. I don’t have this but I did have a call with them.

Thier max output is only 9.6kW so it can’t do a whole home backup and the car can only run in backup mode when the grid is out.

https://gmenergy.gm.com/

[1dom]

Interesting thanks! It looks like most of the GM vehicles that v2x works with are... uh... not really something a European would consider an option (not even sure if some of them will fit on our roads). Ford UK makes no mention anywhere of anything to do with v2x though.

There's a few places that apparently offered it here, but when I've contacted them, they've all explained it was a tech demo, or trial, or some other PR type thing which means they didn't take it any further and regular humans can't buy it. I think there's some nuance or regulation around the UK power network which is stopping any progress with bidirectional charging here.

Over here though, if you don't have old electric heating, or an electric shower, 9.6kw is very much more than enough for the average household. I have a relatively high usage, and a 6kw inverter can power my house in a powercut, as long as I don't use the electric shower. The various retired people in my life tend to use 2 - 4kwh /day, the peak draw is the kettle which uses 3kw for a minute or so.

[scarby2]

> Thier max output is only 9.6kW so it can’t do a whole home backup and the car can only run in backup mode when the grid is out.

9.6kW should be enough to backup your entire house, that's 87A... Lots of people only have a 100A supply in general. Depending on your setup you may have to limit what you use at one time but even in a large house that will be more than enough for AC, lights and electronic devices.

[quickthrowman]

9.6kW is 40A at 240V, and a 240V 100A single-phase residential service is 24kW.

Still, 9.6kW should be more than enough to run a fridge, lights, receptacles, sump pump, a 2-3 ton A/C unit, and a furnace fan. It would be challenging to impossible to back up a home with electric (resistive) furnace and electric (resistive) water heater with only 9.6kW.

[_w1tm]

That’s peak production, without battery storage the fluctuation during the year will likely be too much to keep the “lights on”. Would be cool to have a smart home that prioritizes the electricity supply to different systems based on how much is available.