Power home with car inverter

Power home with car inverter

If an EV's poly phase(3) Motor(s) are disconnected from it's inverter('s}, the inverter output is set to 60Hz, an acceptable voltage is maintained, and an acceptable(sinusoidal) wave form is achieved, the EV to a greater, or lesser extent, can power a home. Big dumb motors would run like topsy, resistance loads wouldn't notice, but pickier loads might act up, for instance power supplies that already have a high ripple voltage, or looking at it another way smallish capacitors across the output of their rectifiers.
If DC power is placed on the DC buss of the inverter, or the battery buss the car can "power" a home indefinitely, serving as storage solution, and inverter. This means that with a photovoltaic array, configured to the correct voltage, or using DC-DC converter/MPPT units similar to what SolarEdge manufactures, can supplement, or charge the EV batteries.
An EV that could do these things would form 2/3 of an "off the grid", or "back up" function better than anything else in terms of power. It would only lack a "prime mover". It could run your conventional heat pump, your well pump, your water heater, your air compressor, and in fact, it could run your neighbor's houses too.
Wikipedia lists the model 3 rear motor as 192 kW. In order to get 192 kW out of an induction motor, yes that's what it is, your inverter would need to supply around 213 kVA, assuming a power factor above 0.9.

SUN 2 DRV | 17. Januar 2018

A Powerwall does those things better and won't leave the house dark and cold when the car goes off to get groceries.

reed_lewis | 17. Januar 2018

Tesla will never modify the car to allow it to be a power source. As @SUN 2 DRV points out, the power wall is a much better solution. The power wall is designed for this very use.

Furthermore, a car could not power a home indefinitely at all. There is a limit to the amount of power stored in the battery, and then you would need to charge it somehow.

wiboater4 | 18. Januar 2018

It would definitely be nice if somewhere down the line Tesla would do that. I am retired and won't be driing my car all that often so the battery will be charged and just sitting there a lot of the time. As far as recharging the battery I have solar panels so that would not be any problem at all. Since the power companies are moving to increase the fixed Facilities charges to make up for what they are losing to energy efficient appliances and green energy going off grid is starting to look more attractive. The Tesla power wall is still pretty expensive especially if your older an may not make up the cost over time. I know the batteries will come down in price though eventually By then the power companies will probably have a way to penalize you for having one.

reed_lewis | 18. Januar 2018

A car is a method to drive and get from place to place. To make it also a power source is not a good use of the car.

A powerwall is a device used to store and get power for a house.

Just because a car has a battery does not make it a good idea. That would be like saying that using your car to power your house during power outages is a good idea. It is not. | 18. Januar 2018

Actually, I think the car battery to power a house is a good idea - in some situations. For example, we get 1-2 power failures a year for less than 2 hours each. Rather than our 3 UPSs or buying a Powerwall, that would be barely used, using the car power for these brief outages would be cool.

Now the costs are not trivial, as you need a DC to AC inverter, at a significant power level. You also need AC power switching to disconnect the outside power lines when you're supplying power from the battery. This could easily cost a few thousand dollars.

Now from Tesla's perspective, if you used the vehicle battery every day to power your home (i.e. like some parts of India that has 8+ hour power outages every day), the vehicle battery will degrade far quicker than it's design life and may require replacement within the 8 year warranty period. There could be some complex warranty adjustment, perhaps 10 hours of house power usage a year is included, but beyond that, it reduces the warranty period.

I can see it becoming a complex mess, that I presume Tesla just doesn't have the time to deal with right now, especially since they have a good solution with the Powerwall.

martaegalt | 18. Januar 2018

The people who have commented don't seem to consider the additional cost of a powerwall, and the inverter not included with a powerwall. They also don't seem to understand that every bit of utility you can build into a product results in more sales. I believe Nissan sells an option to use the leaf to power homes in Japan, though they use a seperate inverter.
Using the car as an emergency backup would be a great useage. Combined with a prime mover, it could power a home. I have driven my pickup today, but not my car(not a EV), so it could have served as storage, and inverter all day long if it was an EV.

martaegalt | 18. Januar 2018

Once all those model 3s are out of warranty, you will see many hobbyists doing exactly what I propose.

reed_lewis | 18. Januar 2018

The power wall 2 has an inverter in it. It takes 240 in and puts 240 AC out. All it needs is the switch.

But as TeslaTap points out, the car is a car and is not designed to be a home power source.

Hey if you are thinking that way, why not allow the power wall to power a car? That is just as bad an idea.

reed_lewis | 19. Januar 2018

@martaegalt - I seriously doubt that more than 1 or 2% of the Model 3s out there will be used to power a house or anything like that. There is a small hacker movement, but the vast majority of people buy a car to transport themselves and others from point A to point B. They do not think of a car as a power source.

And the price of the power wall is something that will be added to the value of your home. It is like putting a new heating system in. Once you install it, it is done.

Very few people want to 'hack' their house's power system. It is a very small group. Most people want to just use their power and have it work.

Manjushr | 19. Januar 2018

hmmmm... V2H does have value here in NEngland.. .where time of use we pay $0.23 /kWh in the day and $.08/ kWh at night. PV array sends to the grid in the day, getting the net meter credits, on occasion the car sends to the house at $0.08 /kWh or... dare I say, $0.00 /kWh (thanks superchargers ;-)

reed_lewis | 19. Januar 2018

@ Manjushr - That is another reason why it will never happen. Why should Tesla power your house?

And the power wall gives you the Time of Use shifting functionality.

Uncle Paul | 19. Januar 2018

As current Tesla's batteries degrade, using them to time shift and backup power to a house would be a good use.

While maybe running at only 80% or original capacity might not be optimum for powering a car, those slightly depleted batteries might be repurposed as home backups.

SUN 2 DRV | 19. Januar 2018

martaegalt: Having a battery back up system makes sense, using a car for that doesn't. Yes once an EV battery is retired from its transportation duty it would be a very useful component of a battery back up system

And there's significant design and installation costs to have ANY kind of battery backup system attached to your house. The house must have equipment added to isolate it from the grid. To prolong the backup duration you may want to rewire your panel so only the highest priority circuits and devices are powered by your backup system.

So even if your car could do that there's still a lot of cost and other issues involved. And the result still wouldn't be very satisfactory as a back up system since the car might be anywhere but home when the power goes out. A powerwall is a much lower cost approach because it doesn't have the extra costs associated with fancy seats, tires and a nice audio system. And a powerwall will be right where you need it when the power goes out.

amarinder19 | 25. August 2018

Got to say this is an added advantage of the inverter. Home would still keep going if car is off to grocery store.good going

amarinder19 | 05. September 2018

Always funny to see some people go out of the way to use an appliance for some think unrelated. Why would people use can inverter to power houses and if they find fault then then would blame tesla. has recommended inverter for the purpose they are to be used.

jamespompi | 05. September 2018

+1 Limited use for outages (i.e. Tesla only enabling it during a state of emergencies) would be the way to add more use to your car without cannibalizing powerwall sales. It would take 5.5 powerwall 2's to match the 75 kwh capacity on my m3. With the few times we have power outages (Florida) and not having a solar array, getting power packs for emergency situations is not practical. Rather, we resort to gas/ diesel generators which is super lame.

kcheng | 05. September 2018

I can see it being useful only as an emergency, but preparing your car to be the inverter for your house in an emergency is probably an expensive solution. Best to get a cheap gas generator.

tesla | 11. September 2018

Hello folks,
I read all this about tha ta car is a car, and that a battery is a battery.
And I -Kind of agree -

I wan't my cart to be part of the solution for the infrastrucure problem.
Today it is reported that the huge amount of electrical car is a problem for the infrastructure.
If we could (as home owner) use our car as 'battery' then the electrical consumption is high, and then avoid that an cole powerplant is started up, then we are part of the future solution.
That why I would like to have teh ability to use my car 'wisely' and as part of a solution.
Tesla powerwall is the next step.
But why should I not use my battery tha tI already have.
Why shoud I have 2 batteries when batteries also are 'challanged' as vironmental hostile.

So in this perspective,
I agree that an powerwal is the best opotion, but right now I (only) have an car.

TimeHorse | 18. Januar 2019

I think the OP and posters are missing an important use case the Powerwall can't solve. Namely a tailgate party with your Tesla and any electric appliances you need to run without hauling around a generator and burning Hydrocarbons.

On the Drive Electric Week Mailing List, folks are bragging how they can use the Accessory Battery Charger DC-DC output to generate AC for their events using a 1kW COTS Inverter. I really wish this was possible on a Tesla.

Misterbee6 | 18. Januar 2019

Speaking as a newbie, I love my M3. And I would love nothing more than be able to plug in an inverter and power 120V AC appliances from it. Since Tesla's advanced battery technology seems to be key to their success, I tend to view Tesla as as much a battery company as a car company. That's why things like the Powerwall and solar make sense. I hope it is just a matter of time before owners are able to use the power that is in the car for more that driving.