Tesla Wall Charger Gen 3 and Solar/Powerwall?

[barry.perfect]

Just researching Car Chargers ready for when I get Solar/Powerwall installed.

I have read in a few places that the Tesla Wall Charger Gen 3 might play nicely with Solar if you have a Powerwall.

Has anyone seen/tried this and know how it works, assuming it does?

At the moment I have a Ohme charger which is great, but cannot cope with Solar Divert.

I know there is the Zappi, but looking at possible alternatives.

 

[hairysteve]

Maybe an option is the Anderson - The case is clear - Solar, Tesla Powerwall & EV charging solution - Electec Energy

 

[scdoubleu]

I have read in a few places that the Tesla Wall Charger Gen 3 might play nicely with Solar if you have a Powerwall.

It doesn't. It's an often-requested feature; Tesla has all the data they need to make it happen (The GW2 is very chatty to the mothership via the 'net, and the TWC3 is also on the 'net) but so far they have not implemented it.

I also wouldn't buy it in the hope they will implement it soon. It's a bit like FSD...

 

[Dilly]

Zappi just does the job.

 

[Enginerd]

What specifically is the question here? I have a work-around for the main feature I'm looking for. What I would like is for the car to charge with excess solar when the Powerwall is full, without drawing any from the grid (at a fixed current level). When I want to do this, I use the "go off grid" feature, and the system dumps all solar excess into the car (no more, no less). I wish it could do that in normal mode.

 

[barry.perfect]

What specifically is the question here? I have a work-around for the main feature I'm looking for. What I would like is for the car to charge with excess solar when the Powerwall is full, without drawing any from the grid (at a fixed current level). When I want to do this, I use the "go off grid" feature, and the system dumps all solar excess into the car (no more, no less). I wish it could do that in normal mode.

@Enginerd Yes that is pretty much what I want to do. Is that "Go Off Grid" mode on the Powerwall, or the Tesla Wall Charger (2 or 3)?

If it is the Powerwall then I can do this with my existing Ohme Charger if I leave it plugged in and in Dumb Mode?

Edit: Just realised that if this is on the Powerwall, I won't be able to do that if I go on the Tesla Energy Plan as I believe they block these settings. But it would work if I stayed on Octopus Go.

 

[barry.perfect]

Zappi just does the job.

I understand, the Zappi sounds great. But one issue I would have if I go the Zappi route is that it is not compatible with the Tesla Energy Plan I am considering, as it prohibits Solar Divert devices like the Zappi.

I am working on the assumption (possibly wrongly) that if Tesla have a solution then I could use it with the Tesla Energy Plan...

 

[PITA]

Today is a good example how I use Solar to charge the car...

Powerwalls are getting full... and Solar is still running strong.

So I plug my car into the 7kW Zappi charger and within the Tesla App I manually start charging the car. I typically set the charge at about +10%

Then the Zappi starts charging at 7kW... and takes all the Solar (however much that is), and makes up the rest from stored Solar in the Powerwalls. But zero grid import.

Then the Powerwalls run down a little, allowing more Solar later in the day.

If I still have a lot of energy in the Powerwalls by bedtime, I can transfer more to the car later tonight.

Setting the Powerwalls up for a good Solar Day (drain them empty), or a bad Solar Day (keep them full)

 

[PITA]

My setup above isn't a Zappi thing... I'm using it as a dumb charger... just turning it on and off via the Tesla App.

 

[Enginerd]

If efficiency is a goal (it isn't for everyone), pushing and pulling power from the PWs incurs some roundtrip efficiency penalty. I don't know exactly what it is, but I mentally bookkeep 5-10% loss when going from DC solar, to AC wiring for the PW, to DC storage in the PW. Then on the way back out, it's perhaps another 5-10% going from DC in the PW to AC for transmission, back to DC when charging the car. Those efficiencies add up. When trying to maximize, it's best to eliminate those conversions as much as possible. Make hay while the sun shines, as they say.

 

[barry.perfect]

My setup above isn't a Zappi thing... I'm using it as a dumb charger... just turning it on and off via the Tesla App.

I suspect this is likely to be my best option if the Tesla Wall Charger 3 isn’t Solar Friendly. Was hoping for something a bit more automated.

My main goal is to not waste Solar, whether I am on Octopus Go or the Tesla Energy Plan.

One bonus is that I don’t need a new charger.

 

[Mrklaw]

does the TES have a minimum solar requirement or do they only care about the PW?

Assumed it was like net metering (for you) but didn’t realise they block solar diverters - so seems clear they’re factoring in some level of solar generation to help keep the export costs down (which helps with their finance of course)

 

[Dilly]

I looked at TEP but it’s not for me as one of the constraints is that you lose deemed export permanently.

my maths for the whole of 2021 on Octopus Go were thus:
2268kWh cost £210 inc standing charge
deemed export 2903kWh @ 5p - £145
nett cost £65

2021 Under TEP (theoretically)
2268kWh @ 11p inc standing charge - £329.48
actual export 1085kWh @ 11p -£119
net cost £209

Of course, what I can’t factor in is: a) whether my DNO would allow PW’s to export and b) if it was permitted, whether Octopus would draw more from me in export. Given the amount of money involved, it isn’t worth the hassle.

 

[btc1k]

I suspect this is likely to be my best option if the Tesla Wall Charger 3 isn’t Solar Friendly. Was hoping for something a bit more automated.

My main goal is to not waste Solar, whether I am on Octopus Go or the Tesla Energy Plan.

One bonus is that I don’t need a new charger.

But you won't "waste" any solar on TEP, effectively, as you export at the TEP rate and then import back at the TEP rate. You're using the grid as a battery.

Or that's how I see it.

I think we need a new thread just on Powerwall settings - ordered mine now and I have a lot of similar questions!

 

[AaronD12]

Looks like Zappi got zapped. Their account is suspended.