Using Model 3 Battery to Power Home in the Evening

Using Model 3 Battery to Power Home in the Evening

I recently got solar panels installed. I've been considering installing a battery system (e.g. Powerwall) to allow me to store the electricity generated by my panels and use it in the evening.

I remember reading a post on the Model S forum a few years ago about using the batteries in an EV for this purpose. Is this currently possible, or do you think Tesla might consider building this capability into the Model 3 as yet another unique selling point?

It would further reduce the total cost of ownership. Tesla could include electricity savings in their calculator.

JayInJapan | 8 aprile 2016


richard | 8 aprile 2016

Why would you want to do that? I mean, if you have solar panels you should probably be using a TOU plan that gives you lowest possible rate at night.

If I install a battery I would rather be charging it up at night and use the power (or sell it back) during peak hours when rates are 2-3 times higher.

yongliangzhu68 | 8 aprile 2016

Why not get a Powerwall?

Supraman | 8 aprile 2016

I'm in the UK and I don't think the Powerwall is available here yet. I also have no idea how much they will cost in GBP. How much are they in the US?

Anyway, I've been quoted £6,000 for a similar product from LG.

So, I guess my thinking is "why pay for expensive batteries twice" if the batteries in the car can serve both purposes.

I realise that other people's home and car usage may not make my idea viable, but I think it might work for me. I intend to give this a bit more thought and post an answer to richard's post later today.

steveg1701 | 8 aprile 2016

I believe I saw something in the owners manual about doing this will void your warranty

jordanrichard | 8 aprile 2016

Supraman, just because you read it on here, doesn't mean it happened. What you read was someone posing the idea, like you are now, of using their MS has a back up generator if they lose house power. By the way your worded it, you make it out to be a fact that it could be done, when it can't.

Supraman | 8 aprile 2016

jordanrichard - I admit that the phrase "I remember reading a post on the Model S forum a few years ago about using the batteries in an EV for this purpose" is slightly ambiguous as to whether somebody actually did it, but that wasn't what I meant.

However, I hope the fact that I immediately followed that statement with the question "is this currently possible?" shows that I am categorically not making it out to be a fact.

jordanrichard | 8 aprile 2016

My apologies. I have been on this forum for 2 1/2 years and like everything on line, it is a global "telephone game" where things rumored or speculated quickly become fact, just by the simply change of a phrase or word. So my remarks were probably a vain attempt to squelch that.

The reason I don't think you will ever see this happen is because what would stop someone from going to their local supercharger, fill up for free, drive back home and connect the car to the house and supplement their home electric bill?

Supraman | 8 aprile 2016

jordanrichard - No worries. Thanks for the clarification.

You make a very good point about using a supercharger to power your home. I hadn't thought of that. However, there's no reason why Tesla couldn't use some sort of geofencing to ensure that only charge that was developed at your home address (by solar panels) could be used to power your home in the evening.

yongliangzhu68 | 8 aprile 2016

Also if you used your battery daly from a full charge to a full discharge it would not last because it would run out of cycles. Tesla would have to replace it under warranty.

FelixMendeldog | 8 aprile 2016

As others have stated, it would cycle the car battery array without putting miles on the car. It's really best to have a separate system for the house than to use the battery on which the car depends. Stay on grid; sell your sunshine surplus; buy power at the lower nighttime rate; get a Powerwall to flatten the dips.

Tropopause | 8 aprile 2016

From the North American Owner's Manual, Warranty (MS):

This New Vehicle Limited Warranty does not cover any vehicle damage or malfunction directly or
indirectly caused by...

• Using the vehicle as a stationary power source

SUN 2 DRV | 8 aprile 2016

Having leather seats (and lots of other high cost items) attached to your energy storage system makes no economic sense.

And do you really want all of the power to go out on your family when you take your M3 out at night?

inconel | 8 aprile 2016

If supercharging for Model 3 is not free then the argument of abusing superchargers to power our homes for free is no longer valid. Other manufacturers can use this capability as a selling point for their upcoming EVs as well. It can be extra peace of mind in case of power failure.

damien666 | 8 aprile 2016

personally I think it would be great if we could use our car as energy buffer

I see no reason why tm couldn't do that, as negative points for tm could monitored by software and defined in a contract.

1. the 8 year warranty could be changed to none or some formula that respect something like KW.
2. energy taken from superchargers cannot be used for external use (can be calculated/monitored by software)
3. maybe some electric converter have to built in (not an electronics affine perseon)

I think using your electric car as buffer combined with smart grid could help the idea of decentralized power storage / usage and using renewable energy in a better way, like wind energy in the night