[jackinloadup]

Assuming V2G means Vehicle to Ground, this is something I would like to see for the following use-case.

I would like to use my car battery as a temporary home battery in the inevitable case of a grid outage. This opens the option to bring energy home from another location. Reduce or eliminates the need for a battery in a grid-tied house.

Am I crazy?

Edit: Granted that doesn't mean the energy company can use my car's battery at it's whim. I think compensation would be required and would actually make a lot of sense. It isn't like the electric company could build out a battery system for cheaper. It would need to be a higher compensation than to PV though. Batteries are more expensive and should be compensated as such.

[Reason077]

V2G = vehicle to grid. It’s quite possible for this to operate as a backup battery, but like a Powerwall it requires extra “gateway” hardware to ensure that your house is isolated from the grid when the battery is discharging.

V2L (vehicle to load) is a simpler form that lets you power 115/230V appliances directly from the vehicle. Quite a few EVs (Hyundai, Ford, etc) already support V2L.

[elihu]

There's two ways to power your house off your car battery. You could have your car act as a mobile electrical outlet that you can run extension cords off of to plug things into, or you could have it tie in directly with the wiring of the house so all your electrical outlets work.

The former is pretty straightforward. The latter would need a lot of electrical upgrades to the house. (I'd expect you'd need to do about the same thing that people do when they get solar, which is to replace the meter with something that can measure power flows in both directions, and is smart enough to disconnect the solar panels from upstream power when the power goes out, so you don't electrocute people trying to fix the power lines. If you don't have a local battery, that means basically turning the solar system off in a power failure.)

If you aren't planning on selling storage capacity to your local utility, maybe all you really need is an automatic shutoff switch to disconnect your house from the grid when the power goes out.

Either way you'd need some sort of power inverter to convert DC to AC. That could be built into the car, or it could be attached to the house.

[shagie]

> I would like to use my car battery as a temporary home battery in the inevitable case of a grid outage. This opens the option to bring energy home from another location. Reduce or eliminates the need for a battery in a grid-tied house.

Question is "how long?" and "how much?"

Lets take a 100 kWh battery which matches a Tesla Model S battery option and is a nice number for doing conversions from.

https://shrinkthatfootprint.com/average-household-electricit...

> The recent figures, as of 2021, show that the average annual electricity consumption for a U.S. residential utility customer is 10,632 kilowatthours (kWh). If you divide that by 12 months, the average monthly electricity consumption is 886 kWh per month. What about in a single day? That would be 10,715 KWh divided by 365, or 29 kWh. Then the average daily electricity consumption is 29 kWh.

So, hypothetically, 100 kWh would give you 3 and almost 4 days. This can be improved by unplugging things that consume more power. The other part with this is a "once that 100 kWh is drained, you're stuck stuck."

You're going to still need something between the mains power and the circuit breaker box. I'm also going to note I don't know what rate it can discharge.

You might also want to look at a system that is a dedicated whole house battery backup ( https://www.zdnet.com/home-and-office/energy/best-home-batte... )

The zdnet article links to a Lowes worksheet - https://www.lowes.com/pdf/portable_generator_wattage_chart.p...

And from that, look at the "this is what we want" and the question of "generator or battery" becomes interesting.

Then consider also, you can get a 10,000 watt generator (that does a cutover in event of a power outage in 7 seconds) for about $3000 which can provide 10 kW at 40 amps.

[dahfizz]

Anyone expecting regular 4+ day outages is already going to have a generator. What people want is for the car which is already plugged into their house to kick in when the power goes out for an hour or two.

[toast0]

That's not crazy, it's actually a publicized optional feature on the F-150 Lightning, and the F-150 hybrid has an optional 240V 30A output that can be used as a home backup as well (although that'd be a bit more manual).

[coffeebeqn]

How could you plug a whole house into a 30A without immediately blowing the fuse?

[rnk]

these are already available.

[fomine3]

it is called V2H (to Home)