So if you had a choice, £ not much in it, would you choose single phase or triple phase?

[CalvinHobbes]

New build, sliding door moment, had an electric car, cheesed off at slow charging....dunno what to do.

[FuerteStu]

Car charging is a short term problem. 

 

Unless you're running a commercial kitchen, or a 12 bedroom with outbuildings, there is no need for the risk 400v in a domestic environment. 

 

[joth]

Are you asking about the DNO supply or what you route around the building?

The for the supply, if there's no extra cost it's a no brainer, get 3 phase to the meter head. You can alway start with a single phase meter on it, and "upgrade" to 3ph in future if it's ever needed at minimal cost. Whereas upgrading the supply line to building at a later date will cost thousands.

 

Aside EV charging (which I personally believe is a growing requirement here with us to stay, for at least our lifetimes), the 12kW allowance for solar before needing G99 paperwork is a big bonus.

 

 

 

Edited September 7, 2023 by joth

[IanR]

Even at a reasonable premium, I'd go 3 phase for 22kW home charging and future proofing for V2H + the larger PV allowance.

 

EV's are here to stay for at least the medium term and batteries will be increasing in capacity over the next 10 years.

[CalvinHobbes]

1 hour ago, joth said:

Are you asking about the DNO supply or what you route around the building?

The for the supply, if there's no extra cost it's a no brainer, get 3 phase to the meter head. You can alway start with a single phase meter on it, and "upgrade" to 3ph in future if it's ever needed at minimal cost. Whereas upgrading the supply line to building at a later date will cost thousands.

 

Aside EV charging (which I personally believe is a growing requirement here with us to stay, for at least our lifetimes), the 12kW allowance for solar before needing G99 paperwork is a big bonus.

 

 

 

Been informed the unit price is the same regardless also I could get an economy 7 style 3 phase meter. 

[Dave Jones]

isnt a choice for us western power will only fit 3 phase for new builds.

[joth]

8 hours ago, CalvinHobbes said:

Been informed the unit price is the same regardless also I could get an economy 7 style 3 phase meter. 

 

Personally I'd keep with a (3ph) smart meter, as it enables many more variable rate tariffs than an old school economy 7 meter, and having a large contactor yank out power from appliances outside the cheap rate is very brutal. If you want to control when your EV charges or ASHP runs it's better for the device and probably more user friendly to use the built in control panel on it to set a schedule or whatever.

 

3ph Smart meters are also required by design to do "net metering" across phases, which is important if you're having PV at all. Old school meters it's pot luck how the installer configures it (at least, that's what I was told by one supplier)

[Mr Blobby]

I'm surprised you got fed up with slow EV charging.  You must do hundreds of miles or have short range.

I've been cgarging overnight on a 3-pin plug at 2kW for the last 3 years and never had a problem.  But then I rarely do > 150 miles in a day.

 

Even so, we're getting 3-phase into our new build for 11kW EV charging.  And we will be getting am E7 3P meter.  (Smart meters are not a thing in Northern Ireland yet)

With our DNO 3 x 100 amp phases is easy to get.  Above 100 amp then the DNO insists on CT metering and that costs loads more, so 100A is the sweet spot here.

 

Don't forget that few cars support 11kW and even fewer can charge at 22kW.   A freind of mine just spent thousands upgrading to a 3-P supply only to discover his brand new EV (nissan ariya) doesn't do 3-p charging.  So he wasted his money.

 

If you can get 3P for the same price as 1P then go for it.  I know a lot on here suggest splitting a single hase off into the house.  I think we'll be going full-monty and 3-phasing the CU just for kicks. 😬

 

[IanR]

30 minutes ago, Mr Blobby said:

Don't forget that few cars support 11kW and even fewer can charge at 22kW.   

 

It's an area of development over the next few years, 22kW will become a standard offering. I'd also wait as long as possible before installing the 3P charger to benefit from the new Tech coming in, but easier to put the infrastructure in at the start.

[JohnMo]

1 hour ago, joth said:

Old school meters

Does anyone install them now, we are getting E7 it will be through a programmed smart meter, even though our smart meter, will be dumb, as we cannot connect to the radio link due to very poor signal.

[Mr Blobby]

23 minutes ago, IanR said:

 

It's an area of development over the next few years, 22kW will become a standard offering. I'd also wait as long as possible before installing the 3P charger to benefit from the new Tech coming in, but easier to put the infrastructure in at the start.

 

Tesla (our curent EV) used to support 22kW (32A) but have downsized to 11kW (16A).  I think its the extra weight and cost of the in-car charger that is difficult to justify.

Saying that, we are going to install two 3P 32A chargers to cover all bases.

[freshy]

13 hours ago, CalvinHobbes said:

New build, sliding door moment, had an electric car, cheesed off at slow charging....dunno what to do.

I was in the same situation and went with 3 phase it was about £100 extra for the bigger 3P cable, which made sense to me at the time.

 

If you are getting PV Panels the next question will be 3 phase or 1 phase inverter?

[Alan Ambrose]

>>> I think we'll be going full-monty and 3-phasing the CU just for kicks. 😬

 

I think for general house stuff, single phase is good. Remember, we're trying to use less energy, and all our appliances are slowly getting more efficient.

 

Sure 3P for potential car chargers, heat pumps etc.

 

It slightly bothers me that there's potentially (see what I did there!) 400V between any two line conductors in the house, and I do have 3P in a domestic situation.

[JohnMo]

34 minutes ago, Alan Ambrose said:

heat pumps

Need a big leaky house for that size heat pump - (3P). If you need that big a heat pump, is a heat pump the correct technology for your situation?

[TonyT]

3 phase for solar PV too, more phases to get more panels!!

[SteamyTea]

2 hours ago, Alan Ambrose said:

think for general house stuff, single phase is good. Remember, we're trying to use less energy, and all our appliances are slowly getting more efficient.

Most of the inefficiency is not in the home these day, especially all electric homes.

With generation changing to RE, inefficiency is, environmentally, a thing of the past as they don't pollute like combustion plants.

This does not mean we need to go back to 100W incandescent lightbulbs and 32inch CRT TVs,  just that overall, electrification is a much better system than combustion.

[Big Jimbo]

So i currently have a 3 Phase supply. Only 1 phase is in use, and i get a cheaper rate electricty during the night. I am planning on having this moved to the new garage, and mounted on an external wall. I think i will need a larger in wall meter box ? I have to fit an electric car charger as a condition. Would you fit a larger 22kw charger, or a slow One ? Would a fast charger be a good selling point ? I expect i will sell when completed, as i have no need for a large house anymore. Thanks for your help.

[PNAmble]

1 hour ago, Big Jimbo said:

Would you fit a larger 22kw charger, or a slow One

With octopus intelligent I can get my car from 20% to 80% minimum using by 7.5kw pod point on cheap rate over night I wouldn’t expect any one really to see a faster charger at home being a selling point - especially as many cars don’t support it.  Two chargers (or the ability to add a second) might be a better investment IMO. 

Edited September 27, 2023 by PNAmble

[SteamyTea]

7 minutes ago, PNAmble said:

can get my car from 20% to 80% minimum using by 7.5kw pod point on cheap rate over night

How small is the car battery though.

 

In my opinion, it is best to design your electrical needs to be as low as possible, both in power and energy.

Only if that proves to be impossible, then consider 3phase.

The use of local storage can mitigate the maximum power problem a bit as you can draw from the battery for an hour or so.

[PNAmble]

4 minutes ago, SteamyTea said:

How small is the car battery though

It's a Q4 82Kwh size battery, so larger than many.

[SteamyTea]

1 hour ago, PNAmble said:

82Kwh size battery

So 7 hours to charge 50 kWh then 

[IanR]

3 hours ago, Big Jimbo said:

Would you fit a larger 22kw charger, or a slow One ? Would a fast charger be a good selling point ?

 

If you are selling, then I'd stick with a 7kW charger, as a 22kW charger is not "yet" likely to be valued by a purchaser.

 

 

2 hours ago, PNAmble said:

With octopus intelligent I can get my car from 20% to 80% minimum using by 7.5kw pod point on cheap rate over night I wouldn’t expect any one really to see a faster charger at home being a selling point - especially as many cars don’t support it.  Two chargers (or the ability to add a second) might be a better investment IMO. 

 

Battery sizes are increasing and will settle in the 100kWh - 150kWh range for passenger cars. For typical small vans (Vito/Transit Custom/Transporter), as the BEV versions come out they will be in this range already and needing to increase to the 200kWh level to achieve similar performance to the current ICE variants. Families will also have multiple EVs on the driveway. Then there's the wish to monetise the battery in the EV with V2H technologies.

Edited September 27, 2023 by IanR

[PNAmble]

5 minutes ago, SteamyTea said:

So 7 hours to charge 50 kWh then 

Yep, plug it in when I get home, define in Octopus app what charge I want by when and octopus does the rest.  There is no limit to EV charging hours with Intelligent Octopus Tariff.   (Smart charge your car with unlimited super-cheap green electrons plus six hours for your whole home between 11:30pm and 5:30am.).   

 

works for me as I very rarely would do over 150 miles in a day.  All I'm saying is given most cars don't support 22Kw charging, and most people who have jumped to EV cars don't do huge daily commutes, they are more likely to want to plug in two cars overnight then fast charge at home.  only my opinion.