This is a question for those who are familiar with the electrical innards of Teslas. How much of a change would it be for Teslas to support Vehicle To Grid (V2G) or Vehicle to Home (V2H). Is it a matter of "just change a couple of things on board XQ9 and modify the software" or is it "rip out half the wires and replace all high voltage hardware". With increasing attention being paid to V2H (F150 Lighting) and V2G (California) I was just wondering how difficult it would be for Tesla to join the parade.
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Making Teslas do V2H and/or V2G
- Thread starter OldEVDude
- Start date
I am not technical enough to say for sure, but this topic always tends to pop up in the tesla energy subforum with the same refrain "now that company X is doing this, when will tesla?"
First, most people may not be aware that ford will require a specific install at someones home to get this done. They have a specific charging station, with switching in it, etc, and its not "a few hundred dollars". People think they are going to roll up with their ford lightning and simply plug in during a storm, without spending a bunch of money prior to that (X,XXX) getting the specific switching hardware installed, are in for a very rude awakening.
Its going to be the same for any other company, they will have to install specific switching hardware.
Tesla has no incentive to play along with this for anyone that does not already have powerwalls (and gateway / switching hardware that comes along with a powerwall install). other companies have incentive to do this because they are not the leading "residential home battery" manufacturer. Tesla is, though, and thus has no incentive to do something that cuts into their own selling of powerwalls.
I still believe that, at some point, people with tesla powerwalls and the hardware that goes with those will end up with some integrated solution, while those that dont, wont (from tesla).
Anyway, to answer your question with the information I think (but dont know) is correct, I believe the only real change Tesla would have to make would be to include bi directional chargers in the cars, then also allow the cars to be seen as a battery source by the Tesla Energy Gateway (that gets installed when you have powerwalls).
The charge port would need to be bi directional, as well as support whatever amount of energy they decide to allow to flow through it in that manner. Definitely doable with planning on tesla's part.
First, most people may not be aware that ford will require a specific install at someones home to get this done. They have a specific charging station, with switching in it, etc, and its not "a few hundred dollars". People think they are going to roll up with their ford lightning and simply plug in during a storm, without spending a bunch of money prior to that (X,XXX) getting the specific switching hardware installed, are in for a very rude awakening.
Its going to be the same for any other company, they will have to install specific switching hardware.
Tesla has no incentive to play along with this for anyone that does not already have powerwalls (and gateway / switching hardware that comes along with a powerwall install). other companies have incentive to do this because they are not the leading "residential home battery" manufacturer. Tesla is, though, and thus has no incentive to do something that cuts into their own selling of powerwalls.
I still believe that, at some point, people with tesla powerwalls and the hardware that goes with those will end up with some integrated solution, while those that dont, wont (from tesla).
Anyway, to answer your question with the information I think (but dont know) is correct, I believe the only real change Tesla would have to make would be to include bi directional chargers in the cars, then also allow the cars to be seen as a battery source by the Tesla Energy Gateway (that gets installed when you have powerwalls).
The charge port would need to be bi directional, as well as support whatever amount of energy they decide to allow to flow through it in that manner. Definitely doable with planning on tesla's part.
The Ford Charging Station Pro clocks in at $1,310. Then there's the cost of having an electrician require the house so it can automatically switch between the grid and the Ford (probably a couple thousand). V2H is no doubt going to be expensive, but possibly cheaper than a generator.
V2G is more interesting. It may well be that the cost of installation is carried by the utility because it reduces their need to build generating capacity. The gap between peak (4pm to 9pm) and non peak energy consumption is quite large. A utility could charge 40 cents per kWh for electricity during that time, but pay 30 cents per kWh for anyone who allows their vehicle to pump juice back into the grid during peak. If the utility then charges 15 cents per kWh for off peak (say, midnight to 6am), a person plugged in to V2G could make money just leaving their vehicle in the garage.
(Obviously there's the whole topic of wear and tear on the battery, and that becomes another item in the equation).
I'm just wondering how difficult (i.e., expensive) would it be for Tesla to add that capability (and possible provide retrofit ability).
V2G is more interesting. It may well be that the cost of installation is carried by the utility because it reduces their need to build generating capacity. The gap between peak (4pm to 9pm) and non peak energy consumption is quite large. A utility could charge 40 cents per kWh for electricity during that time, but pay 30 cents per kWh for anyone who allows their vehicle to pump juice back into the grid during peak. If the utility then charges 15 cents per kWh for off peak (say, midnight to 6am), a person plugged in to V2G could make money just leaving their vehicle in the garage.
(Obviously there's the whole topic of wear and tear on the battery, and that becomes another item in the equation).
I'm just wondering how difficult (i.e., expensive) would it be for Tesla to add that capability (and possible provide retrofit ability).
I'd wager that to get battery voltage(~400V) out at the chargeport is easy, only software. The real key is to have the appropriate(probably Tesla supplied) hardware and software OUTSIDE the car, to properly(aka safely) draw power.
I gotta assume there's a maximum current, maybe 30kw(75 amps at 400V), that can reasonably be taken continuously from the car(yes, I know supercharging might give 250kw, aka ~1000 amps, but that ramps down quite quickly). The car would clearly want to monitor and disable discharge if it sees too much being drawn or the battery getting too low, and it would be a requirement that the shore-side inverter ramped down its usage before the connectors were disconnected(relays that are switched off while carrying lots of current tend to fail very quickly). The car would also be monitoring to activate battery cooling as needed.
I gotta assume there's a maximum current, maybe 30kw(75 amps at 400V), that can reasonably be taken continuously from the car(yes, I know supercharging might give 250kw, aka ~1000 amps, but that ramps down quite quickly). The car would clearly want to monitor and disable discharge if it sees too much being drawn or the battery getting too low, and it would be a requirement that the shore-side inverter ramped down its usage before the connectors were disconnected(relays that are switched off while carrying lots of current tend to fail very quickly). The car would also be monitoring to activate battery cooling as needed.
RTPEV
Active Member
I don't have specific details, but in my area, not only is the utility cooperating, but they are the one leading the effort, offering financial incentives in the form of lease payment reductions for people that want to participate in a pilot project (based on the F150 platform). I think they (correctly) see it as a big opportunity for them to tap into what is probably a lot of energy just sitting in driveways and garages.
There are all sorts of "demand response" things springing up, some driven by the utilities, for people who have the ability to not only shift power usage, or backfeed to the grid. I dont participate in any, but they exist.
Whether they will continue to exist if something like this takes off, is another story. I personally think this will be a very (very) niche thing, even if available from multiple vehicle manufacturers, unless or until the vast majority of cars sold are EVs.
The only way (and that would require high voltage relay switch) is to disconnect power to the electric motor and at that point insert relay controlled transfer switch, such that upon energizing the switch, power to motor would be shut off and diverted to a plugin (installed in the trunk) allowing you to run a teck cable similar to wall charging controller and end up in an inverter to feed ac voltage to a sub-panel. The sub-panel would feed essential loads of home. Like others before me, I think this to be a bridge too far…lot simpler and safer, just go and get a Powerwall already…or any other backup battery and charge it via a timer, during low tariff times. Where I am, we have Mon-Fri 7pm-7am and 24-hours on Sat and Sun. A good 10kWh battery can do your normal size house for 24-hours…any longer than that, make sure your BBQ has propane or hooked to Nat Gas, so you can make yourself a cuppa, boil pasta and grill squirrel, coon or possum.
Tesla has said the Cybertruck will do V2L, so they obviously can do a two-way rectifier/inverter.
Arguably even the 12V ports/ and mobile charging on the existing cars is a lesser form of V2L
From V2L at 120/230V to V2H/V2H there isn't a massive difference other than standards (which reflect safety).
The key issue being islanding - which is if you have a power outage and start relying on V2H or even solar - you want to make damm sure you aren't transmitting back to the grid while someone is trying to fix the power supply/ lines.
There's also a big price difference in the wall units as to where the DC-AC conversion takes place.
As I understand the existing CHAdeMO standard is DC only, but the recently approved CCS (both American CCS1 and European/ other CCS2) can back feed via AC or DC.
You also possibly need to do some work on house circuits, to ensure you aren't overloading a lesse supply (eg. Say the cars V2H was limited to 20A)
Arguably even the 12V ports/ and mobile charging on the existing cars is a lesser form of V2L
From V2L at 120/230V to V2H/V2H there isn't a massive difference other than standards (which reflect safety).
The key issue being islanding - which is if you have a power outage and start relying on V2H or even solar - you want to make damm sure you aren't transmitting back to the grid while someone is trying to fix the power supply/ lines.
There's also a big price difference in the wall units as to where the DC-AC conversion takes place.
As I understand the existing CHAdeMO standard is DC only, but the recently approved CCS (both American CCS1 and European/ other CCS2) can back feed via AC or DC.
You also possibly need to do some work on house circuits, to ensure you aren't overloading a lesse supply (eg. Say the cars V2H was limited to 20A)
Also worth noting that stuff like VPP is often arranged at the distribution level, rather than the utility level. Utilities might drag their feet on 2-way metering, but if you have it, they can't necessarily get in the way.
But longer-term, cheap batteries would be likely to see economies of scale push a lot of this management to larger grid-scale batteries or larger commercial installations, with smart-charging also doing a lot of heavy lifting.
A lot could hinge on what happens with residential solar. Once people have solar feeding to the grid, V2H and V2G would be a better financial proposition.
tmoz
S85D, Y LR, ex Prius PiP
I'm sadden to say that my recent experience getting solar panels up on the roof and a time-shifting/backup battery was a big nightmare due to poor training of work crews, poor work ethic, and poor management support (such as telling the installer, who must come out to fix all the stuff the previous crew screwed up). I wish I could have V2G instead of the 9.7 kWh battery I bought, but to install this enmasse is just not going to happen in the near future due to a lack of trained installation crews. I didn't pick Tesla, because I heard horror stories, so I stepped in a pile of dog doo thinking this company could pull it off. After 3 months, they finally hired a 3rd party battery guy who was able to finish the installation. I wanted the battery mainly for load shifting as I don't want to sell excess production back to the utility at 2.8 cents per kWh.
So it appears that I'll update my 2015 model S with either a Y or a cybertruck, hopefully with much faster charging than I have now (starts near 100 kW but quickly goes down to 70s. When it hits 50 kW, it's time to stop supercharging and continue the trip.) I'm really tempted with the Y, but I really like the S, so hard choice. 4680 cells was high on my list of must have items so that charging could go faster. V2H is something that wont come any time soon, I think.
So it appears that I'll update my 2015 model S with either a Y or a cybertruck, hopefully with much faster charging than I have now (starts near 100 kW but quickly goes down to 70s. When it hits 50 kW, it's time to stop supercharging and continue the trip.) I'm really tempted with the Y, but I really like the S, so hard choice. 4680 cells was high on my list of must have items so that charging could go faster. V2H is something that wont come any time soon, I think.
tmoz
S85D, Y LR, ex Prius PiP
Update - the system went live on 12/29, but the backup battery is still not working. Solar Edge is trying to figure out what is wrong. They think they need a firmware update. Really?
I used a 2,000W inverter hooked to the 12v battery and double male extension cords to power each leg of my breaker box.
Switched main breaker off and selected various breakers to manage load.
Not elegant but effective.
MDR
Switched main breaker off and selected various breakers to manage load.
Not elegant but effective.
MDR
The frustrating thing is that people who already have a powerwall already and a 240v charging circuit already have everything they need for v2h if Tesla would put bidirectional capabilities in their car. The powerwall gateway can island and modify the frequency to ramp up and down solar or car "production" to meet the load needs of the house, right?
On V2G, V2L etc..... What Would Elon Do. WWDO Tesla developing bi-directional charging feature 'many people' won't use. He has spoken and as always, he makes sense out of nonsense. Here are his words. "
“I mean, if you have a Powerwall that can take the house load, then you can use your car as a supplementary energy source to the Powerwall. And then, you’re not going to drive anyone crazy by unplugging your car and having the house go off.
“So I think there’s some value there as a supplemental energy source down the road. Where if you have a Powerwall, you’ve not diminished the convenience of the people in the house.”
Any car can make AC to run a toaster, but all these V2G ideas being passed about have EV power fed directly to the house or the grid, as AC power. The key to a sustainable future is and always will be DC storage. Thats the secret thats missed with V2G.
To become independent of the big power companies you need big home storage and solar. The more the better. Tesla can make Edisons dream of DC powerhouses literally come true. The EV acts as a buffer, a supplemental power to the Powerwall. The bilateral charge could be DC, not just AC, so less conversion losses. Every watt counts!
The car, tops off the powerwall which runs the house, not the car. Car leaves, house has a fully charged battery, from solar plus the EV battery, when needed.
No feedback problems or expensive hardware to prevent killing line workers restoring power to the grid, no extention cords or expensive add- ons, like the Ford solution. The current output is not limited by the cars electronics, its only limitation is the size of the storage and the sizing of the storages DC/AC inverter. Big battery banks with big inverters can output 10, 20kw etc....handling massive temporary surges, if needed. Output current is not dependent on the EVs AC output abilities. The EV can act like a trickle charger actually, with setpoints. 1kw, 2 kw, 3 kW, 5 kw. Keeping the lights, AC, refrigerator etc... running at 3 am when and if the stored solar in the Powerwall gives out. The real technology not being discussed, is V2B---- Vehicle to battery.
Selling your solar power back to the grid is foolish, as Californians just discovered, the power company can pay you peanuts if they want to, instead of 1 to 1 payouts. Keep the power to yourself. Use it. Go off grid....with Tesla car as a backup to your Powerwall, you'll be much better off and more likely to serve the whole via serving the self.
Get a Tesla, a Powerwall or 2 or 3, load up on cheap solar panels and cut the cord. Come on Elon. Do it! Its the only real sustainable future that you have control over. Selling EV power to the grid--- bad idea--- in Vegas, the house (Big power) always wins.
“I mean, if you have a Powerwall that can take the house load, then you can use your car as a supplementary energy source to the Powerwall. And then, you’re not going to drive anyone crazy by unplugging your car and having the house go off.
“So I think there’s some value there as a supplemental energy source down the road. Where if you have a Powerwall, you’ve not diminished the convenience of the people in the house.”
Any car can make AC to run a toaster, but all these V2G ideas being passed about have EV power fed directly to the house or the grid, as AC power. The key to a sustainable future is and always will be DC storage. Thats the secret thats missed with V2G.
To become independent of the big power companies you need big home storage and solar. The more the better. Tesla can make Edisons dream of DC powerhouses literally come true. The EV acts as a buffer, a supplemental power to the Powerwall. The bilateral charge could be DC, not just AC, so less conversion losses. Every watt counts!
The car, tops off the powerwall which runs the house, not the car. Car leaves, house has a fully charged battery, from solar plus the EV battery, when needed.
No feedback problems or expensive hardware to prevent killing line workers restoring power to the grid, no extention cords or expensive add- ons, like the Ford solution. The current output is not limited by the cars electronics, its only limitation is the size of the storage and the sizing of the storages DC/AC inverter. Big battery banks with big inverters can output 10, 20kw etc....handling massive temporary surges, if needed. Output current is not dependent on the EVs AC output abilities. The EV can act like a trickle charger actually, with setpoints. 1kw, 2 kw, 3 kW, 5 kw. Keeping the lights, AC, refrigerator etc... running at 3 am when and if the stored solar in the Powerwall gives out. The real technology not being discussed, is V2B---- Vehicle to battery.
Selling your solar power back to the grid is foolish, as Californians just discovered, the power company can pay you peanuts if they want to, instead of 1 to 1 payouts. Keep the power to yourself. Use it. Go off grid....with Tesla car as a backup to your Powerwall, you'll be much better off and more likely to serve the whole via serving the self.
Get a Tesla, a Powerwall or 2 or 3, load up on cheap solar panels and cut the cord. Come on Elon. Do it! Its the only real sustainable future that you have control over. Selling EV power to the grid--- bad idea--- in Vegas, the house (Big power) always wins.
tmoz
S85D, Y LR, ex Prius PiP
It only makes sense to sell power to the grid when they are willing to pay you a fair price, as in when peak power happens.
I have a 10.6 kW system on the rooftop and a 9.7 kWh solaredge battery. I'm able to avoid all peak hours. The cost of my off peak and super off peak consumption is easily covered by my excess solar which I export to the grid for peanuts (2.81 cents per kWh) and now my only bill is about $30 for the monthly fee. To go off grid, I think I'd need another 20 kWh of storage - some of that to help me along for the cloudy days, which in Phoenix do not happen often, but they do happen.
Bottom line - I'd like to have both the battery storage for the Solar panels, plus V2G to help the power company stabilize the grid if they are willing to pay me, as well as V2H to help with cloudy days.
Ok. But with V2B there's no need to buy another 20kWh battery. 1 stationary home battery will do. Use your EV to "supplement", as Musk says, your stationary solaredge battery. 20kWh for nighttime, including peak energy, borrowed from a 100 kWh EV, has little if any degradation effect on your EV battery. No need to buy another expensive 20kWh battery. With V2B, from a car you already have, you could easily just cut the cord, completely. Why "help" the carbon burning power company stabilize the grid. Are they "helping" you, or merely profiting from, i.e. using you? What are they doing for you, except using your cars battery resources. You're now subsidizing the power company. By "helping" yourself by going off grid completely you're actually helping more ordinary people, i.e. your world neighbors, by eliminating big powers reliance on fuel. In the future, if everyone had solar on their roofs and an EV or 2 in the garage, say goodbye to big carbon burning power plants. They'd become obsolete.
beatle
Active Member
You're referring to "suicide cords" that backfeed power through an existing breaker. With a proper transfer switch or lockout, there is no risk to line workers - that's what they're there for.
The Ford system is expensive because it includes a home inverter. If you have a powerwall, you already have an inverter (also expensive). When I had a Lightning, I planned to use the onboard inverter and a 240v transfer switch to power most of my house with the truck. Not as seamless as the whole house inverter, but not all that expensive either.
These are nice thoughts about V2B, but they bank on people already having a robust solar setup which is not feasible in all locations. I looked into it but solar at my house would only cover about 20% of my energy usage, and that's with a gas furnace in the winter and only one EV.
tmoz
S85D, Y LR, ex Prius PiP
Right, but at the moment, it would help them not build more natural gas peaker plants.
tmoz
S85D, Y LR, ex Prius PiP
Agreed. The availability of knowledgeable installers is low. These are not overly complex, but they are also not simple systems either.
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