Standing Charges: difference if 3-phase v single-phase?

welshboy2

I have been told that a potential upgrade to our DNO supply from single phase to three-phase is coming for our group of houses.  However there is one person in the group convinced that our standing charges will increase.  

I have checked with both British Gas (electricity) and Octopus and both have confirmed that this is not the case.   Neither can I find any evidence for this online at all for any other suppliers.

Anyone come across this? or can comment

Many thanks

born_again

Don't know about standing charges, but what other than having a EV that can charge @ 22kWh is the benefit of 3 phase in the household.
Interested to know, but previously looking @ this was not cheap & savings very small.

Zoe, BYD & Tesla. So not many EV's as it is. More will take 11kWh, though.

Netexporter

Most streets have a 3-phase main cable but the single phases are split of, alternately, to each house. So effectively each house is single phase but they aren't all on nthe same phase. It helps to balance the load and increases effective cable capacity. I imagine you are currently at the ens of a single phase spur, which is being upgraded to three-phase, to increase capacity for EV charging and heat pumps, You individual house will still be single phase but you may have your total capacity upgraded. 

You would pay more for a dedicated three-phase supply but not for single phase split from a three-phase cable.

Keep_pedalling

born_again said:

Don't know about standing charges, but what other than having a EV that can charge @ 22kWh is the benefit of 3 phase in the household.
Interested to know, but previously looking @ this was not cheap & savings very small.

Zoe, BYD & Tesla. So not many EV's as it is. More will take 11kWh, though.

A heat pump is the other thing that could benefit. 

welshboy2

All great comments, thank you.
It's a large abandoned property that we're renovating into a home along with two holiday lets.  It has extensive fields, so we have the opportunity for a large PV array:  

  - PV export to the grid
  - fast EV charging for us and holiday lets

  - ground source heat pump

born_again

welshboy2 said:

All great comments, thank you.
It's a large abandoned property that we're renovating into a home along with two holiday lets.  It has extensive fields, so we have the opportunity for a large PV array:  

  - PV export to the grid
  - fast EV charging for us and holiday lets

  - ground source heat pump

Nice.
3 phase would help with the EV charging, as it gives scope for several charge points.

I know someone that did this in Norfolk, with 4 lets. Great place, & they are installing EV points now. Luckily they were on 3 phase supply already as used to be working farm.

Good luck.

I guess on standing charge, best to ask supplier & enquire about install costs if not already there.

doodling

Hi,

welshboy2 said:

I have been told that a potential upgrade to our DNO supply from single phase to three-phase is coming for our group of houses.  However there is one person in the group convinced that our standing charges will increase.  

I have checked with both British Gas (electricity) and Octopus and both have confirmed that this is not the case.   Neither can I find any evidence for this online at all for any other suppliers.

Anyone come across this? or can comment

Many thanks

I believe that the cost from the DNO to your supplier is slightly higher for a three phase supply.  I also understand that most suppliers don't pass that higher cost on to individual customers.

Ectophile

3 phase is also good if you want to install a lot of solar, as it splits the exported current three ways.  A DNO can say "no" to a solar install if they think it will overload their network.

gm0

3 phase is growing in domestic because of heat pumps and solar input and car chargers. 

But until recently the range of supplier and tariff options aimed at it was nowhere near as wide ranging as for single phase.  Less choice. So some deals not available because of being 3 phase as suppliers didn't want to bill it yet.
Or offer a good deal aimed at it.  Getting better slowly as it grows.  See also dual fuel.

Getting categorised as non-domestic outside the price cap during the recent energy spike - was not good.  Recent domestic 3ph should be exactly that - domestic.  But not all legacy installations are as straightforward in how they got to here.  Some were and are caught out paying pass thru nondomestic uncapped rates e.g. converted use buildings not moved from commercial and some park homes as examples

That is about the only downside of it.  If you can get it fitted cheaply or free in reviewing your use and upgrading (green energy stuff, ev etc.) which some have.  Lots of capacity for solar input, for an EV charger and heatpump. 

Others are trapped on old infrastructure a long way from a good 3phase end point and will be tapped up for 20k to fit it if they ask to have it fitted - trenches, transformer upgrades etc. So availability varies a lot.

Your electrician will take care of the detail but the only other thing to be aware of is that there is a good reason why powerful industrial machinery used 3phase motors.  And *similarly* a good reason why only one phase was typically brought into a domestic setting and splashed around the building on ring mains and various spur wiring.  One L an N and an E 

The voltage between the different 3ph Live phases - L1,L2,L3 - is of the order of 480V - it should be obvious why for low current applications mixing phases and jumbling up multiple phase wiring fitted by UK builders in a single house was a non-preferred solution. 

The americans have their toy electricity 110v.  We have the moderately spicy 240v generally and quite good protection arrangements in current part P all told. Nice safe if large plugs too.   But 3 phase lives are best not held in each hand.  Twice the punch again. 

So wiring it all everywhere just in case is a bad solution. Put it where it is needed. Direct to a big 3ph heat pump perhaps. Then a phase to a garage CU and EV charger - dedicated.  And only one phase (outside mansions) to the house wiring CUs  Safer that way when other stuff goes on in the house.  My view anyway.

Mister_G

I thought that three phase was 380v in the UK.

doodling

Hi,

Mister_G said:

I thought that three phase was 380v in the UK.

No.

It was 415V with a 240V supply and is now, with a 230V, supply generally referred to as 400V from an engineering perspective.

Most electricians probably continue to call it 415V as it still is in most places, just as the mains is still 240V in most places.