Can the Tesla battery power my house?

[callmesam]

If you build in a factor to account for battery degradation that occurs with cycling, V2G in a Model S is a very expensive proposition. While it might be justified for emergency uses (i.e., you're going to lose a 'frig full of food), in most cases it's a poor choice.

Specifically brought this topic up the JB Straubel at the battery swap event last June. This is a no-go. He mentioned the pack they are building for solar city. I hope, over time, that this policy changes.

 

[rolosrevenge]

I have talked with Tesla people about various aspects of V2G and they're not looking to do anything on it any time soon. If you plug an inverter into the DC socket, you can void your warranty. The harmonics from the inverter can fry the power electronics in your car. So, can you use a Tesla to power your house? The best solution that I've heard, which is rather clever, is to put a dyno in your garage that's hooked to a generator. Then set the cruise control. However even this would only give you a constant power output and you'd need some sort of feedback loop to generate exactly the amount of power you'd need. You could use it to charge a battery and then discharge that, but then you really wouldn't need the Tesla.

I imagine that some aftermarket V2G upgrades will start to become available in 6 years, as the batteries go out of warranty. Until then, don't expect much.

 

[mitch672]

Specifically brought this topic up the JB Straubel at the battery swap event last June. This is a no-go. He mentioned the pack they are building for solar city. I hope, over time, that this policy changes.

Right. Also, Tesla is providing the warranty for 8 years on these packs, you can see why they wouldn't want extra cycles on them.
Now, after 8 years, when your $40K battery pack is out of warranty, I'm sure they wouldn't mind (as much), they'd probably prefer you still don't mess with it, but if they are off the hook financially for the warranty, you will only be hurting your own packs health, not Teslas responsibility for the warranty at that point.

 

[djp]

The best solution that I've heard, which is rather clever, is to put a dyno in your garage that's hooked to a generator. Then set the cruise control. However even this would only give you a constant power output and you'd need some sort of feedback loop to generate exactly the amount of power you'd need.

Thanks! :smile:

I don't think you'd need a feedback loop, the cruise control does that for you. A four pole generator needs a constant speed of 1,800 rpm to produce 60Hz power. Changes in power drawn will be seen by the car as changes in torque, much like going up or down a hill, which the cruise control will even out by maintaining a constant speed (and constant rpm).

Power utilities use a similar back-to-back motor and generator to convert between 50Hz and 60Hz power, so in theory it's possible. Not too practical for a garage though.