V2G support in Backup Gateway/Switch

[craigcabrey]

According to a reddit post (

https://www.reddit.com/r/electricvehicles/comments/udd78w

), the standard for V2G has finally been published.

Most people don't realize that a bunch of hardware will need to be installed house side to use V2G. But we do!

In theory, Tesla could add support for V2G protocols to the Backup Gateway and PW+ (since that's the controller when Backup Switch is used). That would minimize the amount of hardware needed for those of us with PW installations already.

The only other piece of hardware needed is a wall connector that can do the DC -> AC conversion.

Would be great to supplement PW capacity with V2G in extended outages!

 

[jjrandorin]

Tesla vehicles do not have bi directional chargers, so they can not push anything out of their charge ports (current tesla vehicles).

 

[craigcabrey]

Tesla vehicles do not have bi directional chargers, so they can not push anything out of their charge ports (current tesla vehicles).

I'm not asking for a discussion around Tesla vehicles. I'm talking about Tesla Energy products supporting an industry standard to allow V2G.

V2G requires grid isolation, which the Backup Gateway & Switch are capable of providing.

 

[jjrandorin]

I dont understand the comment "Vehicle to grid requires grid isolation". What does that mean?

 

[holeydonut]

I dont understand the comment "Vehicle to grid requires grid isolation". What does that mean?

The Ford implementation requires the house to be disconnected from the grid before the EV can export energy.

 

[jjrandorin]

The Ford implementation requires the house to be disconnected from the grid before the EV can export energy.

That would be "V2H" (vehicle to Home, or powering your home from your car). The post here is about V2G (vehicle to grid) which by definition would mean you are sending energy from your vehicle, to the grid (not your home) so I dont understand what "vehicle to grid requires grid isolation" might mean.

If the OP is talking about V2H, thats not what the post is saying in the first post about a standard.

I believe any V2H implementation would require the grid be disconnected (like fords implementation does) and requires additional hardware and a specific wall connector with bi directional power, none of which tesla has currently.

With that being said, I have always thought that at some point, the most likely tesla customers to get V2H capability would be those who already have powerwalls and tesla a tesla gateway. Not sure how this would help, though, since its not powering our homes, but sending the power to the grid.

 

[craigcabrey]

Sorry, I tend to think of V2G & V2H as the same. But you're right, they are distinct.

I'm more interested in V2H, not V2G.

 

[LoudMusic]

Tesla vehicles do not have bi directional chargers, so they can not push anything out of their charge ports (current tesla vehicles).

I haven't read the ISO standard for V2G/V2H, but seems to me it would be easiest to not use the onboard chargers and have the home charging system be DC. That way the stationary equipment at the home could access the high voltage battery directly.

It would also potentially be far less lossy than a bunch of AC/DC transitions.

 

[slcasner]

I dont understand the comment "Vehicle to grid requires grid isolation". What does that mean?

A V2G implementation would require the ability to switch off (isolate) if the grid goes down.

 

[LoudMusic]

A V2G implementation would require the ability to switch off (isolate) if the grid goes down.

Unless I have different definitions of the terms, "switch off" and "isolate" are two different things. It can continue operating in order to supply power to the house so long as it is not supplying power to the public grid. After all, why would you want the ability to draw power from your vehicle to power your house if you couldn't do that during a power outage?

 

[slcasner]

Unless I have different definitions of the terms, "switch off" and "isolate" are two different things. It can continue operating in order to supply power to the house so long as it is not supplying power to the public grid. After all, why would you want the ability to draw power from your vehicle to power your house if you couldn't do that during a power outage?

I agree. I was just making the point that a V2G implementation would at least need to guarantee that it would stop sending power to the grid if the grid goes down. To the extent that the system is serving as V2H as well, then indeed what you want is to continue operating in isolation from the grid.

 

[holeydonut]

A V2G implementation would require the ability to switch off (isolate) if the grid goes down.

At the simplest form, I would assume the same UL standards that can turn off a solar inverter (without the homeowner having to go open a disconnect) can be applied to a V2G inverter. While the Tesla Energy Gateway solves this problem with a relay, it makes sense that V2G (when the G goes offline) could be managed without the relay just like a solar-only installation.

@jjrandorin could also re-name this thread to V2H so we focus on the micro-grid aspect only as OP intended heh.

 

[jjrandorin]

At the simplest form, I would assume the same UL standards that can turn off a solar inverter (without the homeowner having to go open a disconnect) can be applied to a V2G inverter. While the Tesla Energy Gateway solves this problem with a relay, it makes sense that V2G (when the G goes offline) could be managed without the relay just like a solar-only installation.

@jjrandorin could also re-name this thread to V2H so we focus on the micro-grid aspect only as OP intended heh.

I thought about it, but the information the OP posted was specifically information about a specification for Vehicle to Grid, and there is no current (or what we can see, planned) implementation on V2H or V2G using teslas products.

 

[holeydonut]

I thought about it, but the information the OP posted was specifically information about a specification for Vehicle to Grid, and there is no current (or what we can see, planned) implementation on V2H or V2G using teslas products.

Out of left field question… what is the main difference between what a Tesla vehicle has today and what it would need to export energy back into the house/grid?

Basically… why hasn’t wwhitney tried to put a 2 way inverter from a Powerwall into a Model 3 yet? Haha.

 

[jjrandorin]

Out of left field question… what is the main difference between what a Tesla vehicle has today and what it would need to export energy back into the house/grid?

Basically… why hasn’t wwhitney tried to put a 2 way inverter from a Powerwall into a Model 3 yet? Haha.

I havent looked into this closely at all, but I saw a video somewhere that when a teardown was done of the charge ports in the model 3 / Y, first someone reported that the compnents there were capable of bi directional charging, then someone else came back and said "no thats not correct, and heres why".

Its my understanding that bi directional charging ports are not installed in the car, which would be the first step in doing something like this. The charge port / chargers are also linked by all the software running the car, so its not like you could easily hack in another charge port or something. That would only work if tesla offered this in some cars but not others.

Thats as far as I got looking into it as I was wondering if I would be able to use my car to supplement my powerwalls, and the answer was "not likely in its current configuration".

I still figure at "some point" tesla will use this as a selling feature for those of us that have powerwalls and gateway, but this discussion doesnt normally go there. It normally goes to people expecting to be able to use it like in the ford lightning commercial, and railing against tesla as to why they cant.

 

[h2ofun]

I havent looked into this closely at all, but I saw a video somewhere that when a teardown was done of the charge ports in the model 3 / Y, first someone reported that the compnents there were capable of bi directional charging, then someone else came back and said "no thats not correct, and heres why".

Its my understanding that bi directional charging ports are not installed in the car, which would be the first step in doing something like this. The charge port / chargers are also linked by all the software running the car, so its not like you could easily hack in another charge port or something. That would only work if tesla offered this in some cars but not others.

Thats as far as I got looking into it as I was wondering if I would be able to use my car to supplement my powerwalls, and the answer was "not likely in its current configuration".

I still figure at "some point" tesla will use this as a selling feature for those of us that have powerwalls and gateway, but this discussion doesnt normally go there. It normally goes to people expecting to be able to use it like in the ford lightning commercial, and railing against tesla as to why they cant.

But Elon said the first Tesla roadster could?

 

[jjrandorin]

But Elon said the first Tesla roadster could?

I believe it could, but I personally dont believe much with the 1st roadster is applicable to anything tesla these days.

 

[h2ofun]

I believe it could, but I personally dont believe much with the 1st roadster is applicable to anything tesla these days.

He said nobody used it which was a reason
to not continue the feature?

 

[jjrandorin]

He said nobody used it which was a reason
to not continue the feature?

Yeah, but thats what people say when they dont want to do something. Just like they are saying now " our data shows that most people dont use the mobile connector" which completely contradicts what the feedback here is.

Its also not relevant what people who bought what was likely a "3rd weekend car in 2008 to 2012" did in relation to "V2H / V2G" vs what people who might buy a daily driver model 3 or Y would do.

TL ; DR - It doesnt matter that roadster people didnt use it, Tesla doesnt want to provide that functionality currently and will use any excuse they can come up with to justify it.

 

[cwied]

This conversation prompted me to look up this DIY V2H thread from the past that others might also find interesting: Powerwall 2.0 Backup Runtime Extender