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Using Tesla Car batteries to buffer energy

Using Tesla Car batteries to buffer energy

Maybe my question has been put up here before. If so, please direct me there. I couldn't find it, as a newly...

I plan to buy a Model3 asap. However to diminish my grit dependency, it would be great if it's possible to use the car's batteries also as buffer for the energy generated by my own solar PV-panels during the day. And to use (part of) that energie during the night. Like the Power Wall.
At the nearest Tesla store (Duiven, The Netherlands) they told me that isn't possible.

Can anyone confirm? If not possible, is Tesla Motors working on that possibility? Because that could greatly diminish our dependency on the grit, and so diminish the CO2 output by conventional electricity plants.
I'm not asking after legal or financial possibilities, or the lack of those. They will differ from country to country and electricity provider.
I'm solely asking about the technical possibility.

Thanks!

yongliangzhu68 | 28/05/2016

If you do it will void your warrantee.

MichelT3 | 28/05/2016

As I said, I'm asking about the technical possibility...
For Tesla it would be a great addition to their product and de publicized goal of CO2 reduction. If they make it possible and allow it within te warrantee.

yongliangzhu68 | 28/05/2016

advies: Tesla is not going to cover batteries under warranty that are cycled and worn out because of doing double duty as a home power supply.

MichelT3 | 28/05/2016

wj: third time: that's not what I'm asking. Please...

yongliangzhu68 | 28/05/2016

If you have the expertise and technical knowledge (or enough cash to hire) of course it IS possible. :)

It would be much less expensive and far more practical (can't drive a car in the morning with a dead (flat) battery anyway & it will void your warranty) to buy/install a PowerWall.Tthat is why Tesla makes them.

Dramsey | 28/05/2016

What wj is trying to say is "No, it's not possible without extensive physical modifications to the car that will be difficult to impossible to accomplish and void your warranty in the process."

Tesla has said many times that they never plan to make the Mod S usable in this fashion.

rlwrw | 28/05/2016

Tesla also has a complete separate battery division for home use.
Even though they use essentially the same cells as the cars, it's more like apples and oranges for interfacing.

tesla | 28/05/2016

The idea of using electric vehicles' batteries as power storage is especially being thought about by some power suppliers. In southern Germany we have plenty of renewable energy from solar and wind power, but it's not constant enough, so nuclear and coal power plants are still running, and many wind generators are standing still even on windy days because the electricity can't be transported nor used.

I don't drive long distance trips every day, so there will be plenty of time when my future M3 will stand in the garage, connected to the power grid. Not only could it store an amount of energy which is way more than an average household can consume in a day. It can smooth out peaks on the power grid by up to +/- 100 kW within fractions of a second. Keeping a minimum charge of maybe 40 %, the car should still be able to take shorter trips and reach the nearest SC for longer distances. Planning a longer trip a few days in advance could have the car pull power when it's most abundant (and cheapest or even free).

On a technical level it doesn't need to be available now, but it might be an option in the future, especially when M3 will be available in higher quantities. Like already mentioned, for the DC/AC conversion the hardware of a stationary Powerwall could be used.

MichelT3 | 29/05/2016

Thank you.
f-klein has expanded very clearly on the reasons behind my question.
In more general terms: Harvesting renewable energie is not the main problem of the current energy transition. Buffering that energy is. Cars (and especially Tesla's) have huge capacity batteries. That's why people buy them. But people use very seldom (the full capacity) of their battery to commute. Since I work from home, I myself use my car seldom in the early morning, but often later during the day, or in the evening. But certainly not every day. Electric cars are widely seen as one of the solutions to buffering. And there already are some experiments running.
I know of one city neighborhood in my country in which such an experiment is running, in which also a Model S is used, as well as Leaf's, Renault ZoE, Smart Full Electric's, etc.. The main problem is not the cars, but the public charging points.

@ rlwrw: A double system of a Powerwall in your house and a electric car in front of it, using almost the same technology, seems a waste of resources, energy and money to me.

@ Dramsey thanks for explaining that the current Tesla's need to be physically modified. That was my prime question. Of course I would never do that on my future Model 3, without the cooperation of Tesla.

The refusal to let the cars be adapted in this way seems to me to be in contradiction to the public Tesla-goal of diminishing CO2 output. Hopefully this will change in the future, maybe with the higher numbers of Model 3.

The warranty-issue still seems strange to me. Because people already differ a lot in the way they use the car. Number of trips, length of trips, number of times they charge, etc. Putting different strains on car batteries, but all included in the warranty... (as far as I know).
I stay convinced that using car batteries as backup power source would be a huge improvement of the usability of Tesla cars. If possible and allowed.

MichelT3 | 29/05/2016

Thank you.
f-klein has expanded very clearly on the reasons behind my question.
In more general terms: Harvesting renewable energie is not the main problem of the current energy transition. Buffering that energy is. Cars (and especially Tesla's) have huge capacity batteries. That's why people buy them. But people use very seldom (the full capacity) of their battery to commute. Since I work from home, I myself use my car seldom in the early morning, but often later during the day, or in the evening. But certainly not every day. Electric cars are widely seen as one of the solutions to buffering. And there already are some experiments running.
I know of one city neighborhood in my country in which such an experiment is running, in which also a Model S is used, as well as Leaf's, Renault ZoE, Smart Full Electric's, etc.. The main problem is not the cars, but the public charging points.

@ rlwrw: A double system of a Powerwall in your house and a electric car in front of it, using almost the same technology, seems a waste of resources, energy and money to me.

@ Dramsey thanks for explaining that the current Tesla's need to be physically modified. That was my prime question. Of course I would never do that on my future Model 3, without the cooperation of Tesla.

The refusal to let the cars be adapted in this way seems to me to be in contradiction to the public Tesla-goal of diminishing CO2 output. Hopefully this will change in the future, maybe with the higher numbers of Model 3.

The warranty-issue still seems strange to me. Because people already differ a lot in the way they use the car. Number of trips, length of trips, number of times they charge, etc. Putting different strains on car batteries, but all included in the warranty... (as far as I know).
I stay convinced that using car batteries as backup power source would be a huge improvement of the usability of Tesla cars. If possible and allowed.

yongliangzhu68 | 29/05/2016

advise: Lit-ion batteries are good for about 1000 cycles and then they start to lose precipitously the amount of charge they will hold. Tesla offers an 8 year warranty on the battery pack. During an average day you may drive about 50 miles which is well under ¼ of a cycle (closer to ⅛ of a cycle since partial discharges & recharges are less stressful) . However using as a home power supply would add nearly a full cycle a day to the battery pack. This would shorten the average life of a battery pack by well over 75%. There is NO way Tesla could cover the costs of replace battery packs under this scenario.

yongliangzhu68 | 29/05/2016

advise should be Michel3

MichelT3 | 29/05/2016

I tried to change to more appropriate name, but failed. Now it miraculously worked. LOL

My average day would never be just 50 miles. More like 120 to 200 miles, 3 to 4 times a week. Other 3 or 4 days I drive 0 miles. But I would be allowed to drive 120 - 200 miles each day, wouldn't I?
At the local store they told me about a client driving 75.000 miles a year with his Model S. Under warranty. Every 2,5 - 3 years getting a new Model S. The cars were NOT given a new battery pack, just got a checkup and were then resold.

From this site: "New Tesla vehicles are protected by a 4 year, 50,000 miles (whichever comes first) new vehicle limited warranty and 8 year, unlimited mile battery and drive unit warranty."
Unlimited mile battery warranty => no matter how many charges and discharges!

regards, Michel

yongliangzhu68 | 29/05/2016

According to you stated figures your average is about 80 miles a day. :)

Also your post about milage is exactly the problem. You would NEVER get 75,00 miles out of your car's battery if you used it for your home too. Who would want to but a used Tesla that had 50,000 on the odometer but actually had the equivalent of 150,000 miles on the battery pack. :)

brando | 29/05/2016

Buffering is probably only part of the solution, the production side of electricity.
Demand or consumption is the other side. Lowering AC/Heating, Refrigerators, Water Heaters, lighting during peaks demands.

Both approaches will no doubt be used. The book "Reinventing Fire" covers these topics and below is just one of the YouTube talks. Search on " google talks Amory Lovins " will also give you a couple of 20 min. talks to watch.

https://youtu DOT be/2tPvqFeHRmo

MichelT3 | 29/05/2016

Daily =NOT= average
Reading is difficult, isn't it?

Yes @brando: diminishing use is necessary too, but in reality use is increasing, certainly worldwide.
I'm active in the ecological building business, so I know a bit about possibilities to diminish consumption. They are certainly there for the forefront of society, but the large majority of the population isn't achieving much.

TeslaTap.com | 29/05/2016

Looking at the car's design, it would require a trivial software change and no hardware changes to the car to offer V2H. You would need a DC to AC converter external to the car, and this would not be cheap to make. A retail cost might be in the $3K range to handle 20 kW or so. There is no value to adding the weight/cost/complexity inside the car for something only used at a fixed location. Limits could be designed to ensure the car has some range and doesn't exhaust the battery.

As others have pointed out, it is a warranty concern for Tesla, as it could use the battery far more than designed. There is a second issue in that you could go to a nearby Supercharger, charge up and then return to your house and power your house on Tesla's dime. This could be quite expensive for Tesla.

Both of these issues are solvable. Tesla could state the battery warranty when used for V2H is only 3 years or limited to some number of cycles. The Supercharger issue could also be addressed with some kinds of limits or back-charges to customers who use a Supercharger and then drain the battery in a V2H configuration.

Since few customers are asking for V2H, and they have an alternative solution with the Powerwall, I don't expect Tesla to offer V2H with the current cars anytime soon.

yongliangzhu68 | 29/05/2016

120 to 200 mean is 160 and 3 to 4 is 3.5 mean

(160 x 3.5) + (0 x 3.5) / 2 = 80 miles is your daily mean

No need for you to be mean :) , It is just simple math.

MichelT3 | 29/05/2016

My name on this forum seems to changing erratically. Sorry. Advies = Michel3.

@TeslaTap: thanks for your remarks. I understand. I see the problems too. Nice that you (also) think they're solvable.
However, I think demand could increase a lot, when a large number of Model 3 owners come into play. Those have less money to spend and therefore seem to buy more out of energy-viewpoint. For those people an expensive Powerwall doesn't seem to be a financially viable option. Furthermore those hundreds of thousands of M3 batteries could be put to a better use, also financially.
This all could increase the demand, inspiring Tesla to make an offer like you suggest.
Would a 20 kW AC-DC converter really be that expensive? Simple electrical technics it seems to me.

@ wj: You don't seem to understand. I wasn't being mean, just exasperated that you fail to understand.
I either drive 200-350 km (120-200 miles) on one day, or I don't drive at all.
On the days that I don't drive, the batteries are 100 % free for backup power for my home (in theory).
Therefor your mathematical average over all days leads to nonsensical information, because in my case that would never happen on any one day.
My question is not about me though, as f-klein.info confirmed, it's a question that lives among many people who are concerned with renewable energy, diminishing energy use and less CO2 output.

Can we get back on subject now?
About the technical and energy-wise rationale on using (Tesla) car batteries also as a buffer for renewable energy and lessening our CO2 output.

Tesla-David | 29/05/2016

@advies

JB Straubel, Tesla cofounder discusses among other things, the potential use of Tesla battery for home PV systems, and readily discounts it in the link below. https://evannex.com/blogs/news/117920965-tesla-co-founder-jb-straubel-hi...

Tesla-David | 29/05/2016

From the video link above @~23 minutes they discuss the battery use regarding use with home PV systems.

yongliangzhu68 | 29/05/2016

advies/Michel3 I was starting to believe you were correct or at least I can't recall very well. I keep asking myself why I called you advise more than once when it said Michel3 but now it is back to advise again. :confused:

I also understand that you won't drive your M3 for 3 to 4 days a week and would like to use if for V2H. However to the battery pack the wear and tear will be the same as if you are driving the M3 for 200+ miles a day while the M3 is setting still. If effect this is analogous to running back the odometer on an ICE to make it look less used than it is.

So the questions is: Would you fell ethically comfortable selling your car to a 3ed party with 50,000 miles on the odometer while knowing that the battery pack was used to equal about 200,000 miles?

Also as you can see if Tesla allowed this they could be held financially liable by the person who bought your car under false pretenses. This is another strong reason Tesla will not allow it.

This could possibly be intrepid as fraud in the US (uncharted territory but I would not won't to be a test case) and that would FAR outweigh any lessening of energy use or CO2 output.

MichelT3 | 29/05/2016

Thanks Tesla-David. I'll look into it.

dyefrog | 29/05/2016

OP, I have a Leaf and when it's no longer viable, my plan is to do what you're describing. Nissan either offers already in Japan or at least it exists, the "Leaf-to-Home" thingamajig intended to take over when the grid goes down. It's an interface that allows you to backfeed your panel from the car. At 24 KW, it's not going to last more than a few days on critical loads only. You could drive to the nearest EVSE that still has power though and fill it back up as needed.

brando | 29/05/2016

@advies I think you'd find interesting
The book "Reinventing Fire" and/or YouTube talks. Search on " google talks Amory Lovins " will also give you a couple of 20 min. talks to watch.

Also http://www.rmi.org/ Rocky Mountain Institute
http://www.rmi.org/Knowledge-Center/ReinventingFire

As you seem to be a seriously thinking about energy use/storage and creation/demand of electricity you will find Reinventing Fire very interesting and useful.

TeslaTap.com | 30/05/2016

@advies - On the cost, the electronics are very similar to the Tesla 10kW internal car charger, but perform the reverse operation (DC to AC). Tesla charges $2500 for the 10kW charger module. I doubled it for 20 kW as there isn't a lot of cost savings when doubling it. It will also need some cabling and extra safety measures (more cost) similar to Solar inverters. Cooling may be a problem, as the charger mounted in the car is connected into the fluid cooling loop. If dynamic cooling is required, the cost would go up further.

Now with huge volumes the cost may come down, but how much and at what volume, I'd need a lot more details and effort!

bb0tin | 30/05/2016

JB Straubel talks about it in this video from a few days ago.
Telsa have considered the possibility but have discounted it.
Google: youtube lgcozueYXMU

dansplans | 20/06/2016

@advies - The biggest problem with your idea is that the Tesla batteries used in both cars and PowerWall are in a single word - junk. They were chosen based on cost rather than quality or superior technology. Tesla may very well have huge warranty claims for replacements down the road for regular auto usage. Any deep discharge usage will drastically reduce the life cycle from what is at best a poor life cycle profile to begin with.

Before haters and fanboys jump all over me for stating the truth. I do believe that Tesla fully intends to move forward to higher quality, next generation batteries soon. As a matter of fact, if Tesla does not introduce technologically advanced batteries very soon, they will be eating the dust of the true innovators of battery technology as early as 2017.

TeslaTap.com | 20/06/2016

@dansplans - Well I'll jump on you... I've never heard about your made up story about the batteries. The packs have been exceptionally reliable and far exceed anything in consumer products (phones or laptops). They work from well in temperature extremes and under high vibration. Panasonic makes the batteries in Japan, so they are not some cheap fake chinese battery either. The stories in the forums of complete pack failures requiring replacements are also quite rare (I can think of 2-3 in the last 4 years) for about 100,000 packs in use. I do agree deep discharge will shorten lithium-ion battery life, but Tesla doesn't let the battery go to deep discharge. Even at 0% range, Tesla maintains a reserve so that battery life is not affected. Obviously you know very little about Tesla's design and the batteries.

dansplans | 20/06/2016

@TeslaTap - You misunderstand me. Tesla has taken the best available mass market lithium battery, due to their need for immediate production car usage. Had they waited for mass market quantities of next generation batteries, they would never have gotten an EV on the road.

It is what it is, namely 5 year old technology with low power density and a poor life cycle. The Panasonic 18650 battery is a stop gap measure until Tesla is able to begin production of next generation cells.

None of this is a knock on Tesla.

I have no idea what made up stories you refer to. I haven't been telling any stories.

The facts are that the 18650 cells do not tolerate deep discharge nor fast discharge well. Either scenario will dramatically reduce expected lifespan. The potential for massive warranty claims exists. I do not claim knowledge of massive failure rates to date. I am simply stating that the pragmatic choice of these cells in Tesla cars could lead to a big financial headache for Tesla as these batteries enter their final days under warranty.

Back to the OP - these batteries may or may not prove to be adequate over their lifespan, for Tesla vehicles. They absolutely would not be adequate doing double duty for power grid support as well.