3 Phase Fast Charging on EV Tariffs

[PITA]

Are you charging on 3 phase, with a cheap EV Tariff like Octopus Go?

I'm currently on a Single Phase meter, but with a 3 phase cabling supply (two tails blanked off)

I'm considering upgrading the meter to 3 Phase (I'm on Octopus Go) and hope they'll exchange the meter for me.

Then upgrade my Car Chargers to 3 phase charging, but leave our house wiring on Single Phase.

Does this sound possible?

 

[Morhydro]

Perfectly possible. I have Good Energy EV tariff (7p/kWh Midnight to 7am) and charge on 3 phase 11kW.

Except it did take a long time to get a 3 phase smart meter installed........

 

[PITA]

Perfectly possible. I have Good Energy EV tariff (7p/kWh Midnight to 7am) and charge on 3 phase 11kW.

Except it did take a long time to get a 3 phase smart meter installed........

Ok great, I'll contact Octopus Energy once I have my cabling quote in...

 

[scdoubleu]

I’d hang fire a bit. This is something I’ve been researching over the last few weeks (3-phase conversion) and there are issues with Powerwall integration. I’ll post more details tomorrow when I’m back at my desk.

 

[PITA]

I’d hang fire a bit. This is something I’ve been researching over the last few weeks (3-phase conversion) and there are issues with Powerwall integration. I’ll post more details tomorrow when I’m back at my desk.

Sure... in early stages at moment...

But if it can be done my way, the Powerwalls, solar inverter, would all still be on Single Phase. Just to power the house and 7kW seperate EV Charger.

Only the Extra 22kW Car Charger would be on 3 phase. That's all I want it for.

 

[NewbieT]

Sure... in early stages at moment...

But if it can be done my way, the Powerwalls, solar inverter, would all still be on Single Phase. Just to power the house and 7kW seperate EV Charger.

Only the Extra 22kW Car Charger would be on 3 phase. That's all I want it for.

Do you really ‘need’ a 22kW charger at home? Or is it just because you can? M3 will only charge at 11kW anyway. If you’ve got or might have two EV’s in future, have you considered loading balance with the house on one phase and a 7kW on each of the other two phases?

 

[PITA]

Do you really ‘need’ a 22kW charger at home? Or is it just because you can? M3 will only charge at 11kW anyway. If you’ve got or might have two EV’s in future, have you considered loading balance with the house on one phase and a 7kW on each of the other two phases?

Don't need a 22kW charger no.

But Yes, I do want one. Sooner I can get our house set up for future loading the better. My Tesla can charge at 11kW potentially, and my Powerwalls charge at 10kW... so trying to charge another EV at the same time will be an issue... so may as well dive in with an upgrade now.

Once the DNO has agreed to it all, it's set up then. Like planning permission I guess.

Won't have to mess about with this in the future when car charging gets more demanding.

I've learned already, doing stuff early before demand increases can mean an easier ride.

I haven't considered any options yet, because I'm not an electrician and have no idea what my options are... that's why I'm waiting to hear back from them.

What I do have, is 3 phase cabling already laid up to the house. So it's only the meter and whatever else I need to sort out.

 

[PITA]

The other consideration... is in the past two years since the Pandemic, things take MONTHS to sort out.

Our cabling upgrade took months, my Smart Meters took 6 months, my SEG application took 4 months...

Everything takes months... and that's before theres a proper rush on resources. So best get it done.

 

[scdoubleu]

Ok, residential 3-phase and Tesla Gateway 2 (GW2) + Powerwall(s) (PW2) kinda sorta works, but in a somewhat hackish way.

If you enabled the other two incoming phases (L2/L3) with the GW2 and PW2s still on L1, with only the EV charger connected to all 3 phases, then the PW2s (and solar) would cover the energy requirements for L1 but not L2/L3. You'd be metered and charged for what you use on L2/L3 for EV charging. This may or may not be ok with you.

To fix this, you need to add a CT to each of L2 and L3, connected to the GW2. L1 already has the GW2's internal CT. There may be some config changes to the GW2 to accommodate this. The setup exploits a feature of current UK residential 3-phase meters whereby the sum of the three phases is used to measure imported/exported energy.

So if you're drawing 0 kW on L1, 2 kW on L2, and 1 kW on L3, then the GW2 will export 3 kW on L1 from the PW2 so that the net import remains 0 kWh. You're still importing from the grid on two phases, but exporting enough through L1 so that the meter sums to zero.

Obviously this is how UK residential 3-phase is metered at the moment. Some of our European friends, who have enjoyed residential 3-phase supplies for far longer than us, are moving away from this net metering arrangement. I don't expect it'll be too long before we also close this loophole.

You could put a PW2 on each phase if you're feeling particularly flush. This works just fine, until the grid goes down. In this situation, the GW2/PW2 will only back up one of the phases.

Eventually, battery ESS with native 3-phase support will be more widely available. I suspect Tesla will be late to this party, because their primary market is split phase.

Hope this helps!

Steve

 

[PITA]

Ok, residential 3-phase and Tesla Gateway 2 (GW2) + Powerwall(s) (PW2) kinda sorta works, but in a somewhat hackish way.

If you enabled the other two incoming phases (L2/L3) with the GW2 and PW2s still on L1, with only the EV charger connected to all 3 phases, then the PW2s (and solar) would cover the energy requirements for L1 but not L2/L3. You'd be metered and charged for what you use on L2/L3 for EV charging. This may or may not be ok with you.

To fix this, you need to add a CT to each of L2 and L3, connected to the GW2. L1 already has the GW2's internal CT. There may be some config changes to the GW2 to accommodate this. The setup exploits a feature of current UK residential 3-phase meters whereby the sum of the three phases is used to measure imported/exported energy.

So if you're drawing 0 kW on L1, 2 kW on L2, and 1 kW on L3, then the GW2 will export 3 kW on L1 from the PW2 so that the net import remains 0 kWh. You're still importing from the grid on two phases, but exporting enough through L1 so that the meter sums to zero.

Obviously this is how UK residential 3-phase is metered at the moment. Some of our European friends, who have enjoyed residential 3-phase supplies for far longer than us, are moving away from this net metering arrangement. I don't expect it'll be too long before we also close this loophole.

You could put a PW2 on each phase if you're feeling particularly flush. This works just fine, until the grid goes down. In this situation, the GW2/PW2 will only back up one of the phases.

Eventually, battery ESS with native 3-phase support will be more widely available. I suspect Tesla will be late to this party, because their primary market is split phase.

Hope this helps!

Steve

Ok, I've had my quote in for this work.

£3,955 +VAT

This is to install a 3 Phase Distribution Board, all Cabling and routing, a 22kW Zappy Charger and all paperwork, commissioning & certification.

This'll mean I can run the house and Powerwalls on Single Phase... and continue to use a Single Phase 7kW Zappy Charger.

Plus have a new 22kW 3 phase powered fast charger on the other side of our Driveway.

The new Distribution board will be big enough for adding more stuff in the future like a railgun or additional Heat Pump.

What do you think?

 

[Garry TheBiz]

When you move to a 3-phase supply, so you still only play a single standing charge from your electricity provider, rather than 3 standing charges?

 

[PITA]

When you move to a 3-phase supply, so you still only play a single standing charge from your electricity provider, rather than 3 standing charges?

I don't know... I'm about to find out all this shortly... but I would expect a single standing charge like everyone else

 

[Avendit]

Worth adding that as I was installing all our domestic appliances a number of them could take 3 phase for a boost in peak power. The HP can take 3 phase (although not sure why, I don't think it changes anything), and the hob and oven both get a boost in heat up time and peak sustainable output.

Might be worth running 3 phase to specific appliances in addition to the charger?

 

[PITA]

Worth adding that as I was installing all our domestic appliances a number of them could take 3 phase for a boost in peak power. The HP can take 3 phase (although not sure why, I don't think it changes anything), and the hob and oven both get a boost in heat up time and peak sustainable output.

Might be worth running 3 phase to specific appliances in addition to the charger?

Yes indeed... that's what they're suggesting.

The 3 Phase Distribution board has a lot of future options added to it.

So he's going a bit 'over the top' for the immediate requirement, but he's future proofing the install.

Who knows what extra power demands we'll be presented with in the future.

 

[ACarneiro]

As a house with 2 high mileage EVs, 2 PWs, electric hob and a heat pump I would absolutely be on a 3 phase supply if I had the tails already.
As it is, it would cost me about £10k to dig roads and bury a new cable (plus costs from the electrician) so it’s currently hard to justify and I’m just managing the loads. It gets very tight at night in the winter.
I am hoping there will be financial incentives in the future to retrofit 3phase supplies as the country electrifies more and more (but I accept this is highly unlikely).

 

[pdk42]

Ok, I've had my quote in for this work.

£3,955 +VAT

This is to install a 3 Phase Distribution Board, all Cabling and routing, a 22kW Zappy Charger and all paperwork, commissioning & certification.

This'll mean I can run the house and Powerwalls on Single Phase... and continue to use a Single Phase 7kW Zappy Charger.

Plus have a new 22kW 3 phase powered fast charger on the other side of our Driveway.

The new Distribution board will be big enough for adding more stuff in the future like a railgun or additional Heat Pump.

What do you think?

That sounds pretty steep to me. The Zappi is probably £1k and the CU bits can’t be more than £500, so where’s the rest of the cost? Also, £3995 sounds like a bit of a price point to me rather than a proper quote. With VAT you’ll be pushing £4k.

 

[PITA]

That sounds pretty steep to me. The Zappi is probably £1k and the CU bits can’t be more than £500, so where’s the rest of the cost? Also, £3995 sounds like a bit of a price point to me rather than a proper quote. With VAT you’ll be pushing £4k.

Thanks for this feedback... I thought it was steep as well, but didn't want to steer anybody's opinion on here.

Think he might be taking the mickey, so I'll look at another quote option I think.

Having said that, this will be a Specialist piece of work, and I don't want to be kept offline for any length of time. He said he'd have 3 staff onsite...

 

[MrBadger]

When you move to a 3-phase supply, so you still only play a single standing charge from your electricity provider, rather than 3 standing charges?

That use to be the case, or at least, was a case at a site that I was involved in - basically a large old residential property now used for business purposes. I thought that it was normal that 3 phase was 3 x standing charges, but it appears not always to be the case, at least, not for now... Who knows how companies are going to be charging for electricity in the future. I think in some countries, they also charge based upon an connection size/power capabilities. It wouldn't surprise me if the 'standing charge' ultimately becomes based upon similar capacity rules, ie size of fuse(s) etc.

 

[ACarneiro]

When you move to a 3-phase supply, so you still only play a single standing charge from your electricity provider, rather than 3 standing charges?

One standing charge.
It is one supply that happens to be three phase, not three one-phase supplies.

 

[Morhydro]

Yes. Onl

When you move to a 3-phase supply, so you still only play a single standing charge from your electricity provider, rather than 3 standing charges?

Yes - only one standing charge.