Help please! £3000 to Install home charging point for electric car

kazwookie

Go back to your company and tell them a charger at home is going to cost (£x) amount, and ask them to fund the work. If they refuse ask them for a petrol / diesel car instead.

I would also get  a quote if possible from someone else if you do need a charger at home

pinkshoes

EVdriver said:

user1977 said:

Isn't charging it at lower power rating (so you don't need a supply upgrade) an option?

I have been told that it is more expensive doing it that way and it will take a lot longer but it might be the way to go, thank you.

Energy (kWh) = Power (kW) x time (hours)

The energy bit is the energy required to charge the car battery. It is the stuff you pay 15p per kWh for (approximately). 

If you charge it at a higher power rating it will take less time. If you charge it at a lower power rating it will need more time. Either way you get the same amount of energy for that you pay the same charge for. 

e.g. a 60 kWh battery can be charged with a 7.5 kW supply for 8 hours, or a 22 kW 3 phase supply for 2.7 hours. 

happyc84

Hi, I would suggest the installer checks the figures submitted to the DNO. Distribution Network operator.
From the ENA website.
"Adequacy of the supply" assessment is required prior to any EVCP. This requires a load survey to calculate the new Maximum demand  including the device to be installed.
Any reinforcement costs associated with this installation may be recharged to the customer. 

The industry is regulated so ofgem provide guidelines.

Hope this helps, 

Ectophile

EVdriver said:

Grumpy_chap said:

Unusual that you need to increase the power capacity.
Most home chargers are around 7.5 kW as that is the limit for single phase power supply.
Are you installing a faster charger that requires 3-phase power?

Hello, we have been told that we need 3-phase, I really don't know anything about electrics which makes it difficult!  Thank you for your comment, I will question why we need to change if you say that 7.5kw is doable on single phase.

It may come down to the size of the transformer and the wiring to your house.

People in urban areas are used to there being a big chunky transformer at the end of the street.  They are typically 3-phase, and can deliver 400A per phase.

Rural transformers are often weedy little things, feeding a group of houses through very long, but equally weedy wires.  The moment you ask for an upgrade to your power supply, the electricity company will want you to pay for any upgrade work they need to do.

Sometimes that means paying for a whole new transformer, and an upgrade of all the wiring.  But if they are only asking £1500, that's probably not it.  Instead, they have worked out that they could tap a bit more power from the other two phases on the transformer.

Bluebell1000

Our 7kW charger is single phase...
OP, you can charge the car from a standard outdoor socket at about 2kW. It's not quick but if you don't need a full charge every day, that might be an option if a regular charger really isn't viable.  That's taking about the same as a boiling kettle.  

Grey_Critic

Why are you talking with Network Power or do you mean UK Power Networks? They are not a domestic supplier - There is a Government - **Electric Vehicle Homecharge Scheme** with a grant of 75% Have a look here.

https://www.gov.uk/government/publications/customer-guidance-electric-vehicle-homecharge-scheme/electric-vehicle-homecharge-scheme-guidance-for-customers

Keep_pedalling

The only reason I can think of for needing to upgrade to 3 phase is because your house already has a high demand for electricity. Many rural properties have no mains gas so are dependant on electricity for heating and cooking, so making Sunday lunch, while someone has a shower while the tumble dryer is running and the car is charging and the heating is running full blast could exceed the capacity of your single phase supply.

This can be overcome by installing a smart charger capable of load sharing. The charger will automatically reduce the current to the car if demand to the rest of the house is high.

I would certainly consult an alternative installer for a second opinion.

AdrianC

Ectophile said:

Rural transformers are often weedy little things, feeding a group of houses through very long, but equally weedy wires.  The moment you ask for an upgrade to your power supply, the electricity company will want you to pay for any upgrade work they need to do.

We have a transformer behind our garage, serving our little cluster of eight houses and a small farm.

It was replaced 6-7yrs ago, when the garage was being built, because access was good at the time. They installed the same rating as came out - 300A, fused at 200A. Single phase, even though all three 11kV conductors come to it. Same size as had been installed in the 60s, when AC first came here.

I asked why - the answer was that the upstream network was so finely balanced that they simply weren't upgrading anything unless they absolutely had no choice, just replacing like-for-like.

So even if we wanted 3ph, it wouldn't be as simple as just paying to upgrade the transformer.

Steve182

All houses have a 100 amp 1ph supply by default so far as I'm aware. Of course you can upgrade if you pay. Some houses (manor houses to stately homes) could have 500 amp 3ph

Assuming standard 100 amp 1ph, there is no obvious reason why you cannot have a 7kw 1ph charger, as recommended for a Tesla or other EV.  It draws 32 amps max so 68 amps left over for other uses.

I've 100 amp 1ph at home and I'm putting a new consumer unit in my outbuilding with intention for a 7kw (32A) charger immediately and a second 7kw chargers eventually, drawing up to 64 amps between them.

Only 36 amps remaining for the house? No problem. It's only going to be a short wait until smart meters/smart chargers all communicate and manage power consumption

Ectophile

Steve182 said:

All houses have a 100 amp 1ph supply by default so far as I'm aware. Of course you can upgrade if you pay. Some houses (manor houses to stately homes) could have 500 amp 3ph

Assuming standard 100 amp 1ph, there is no obvious reason why you cannot have a 7kw 1ph charger, as recommended for a Tesla or other EV.  It draws 32 amps max so 68 amps left over for other uses.

I've 100 amp 1ph at home and I'm putting a new consumer unit in my outbuilding with intention for a 7kw (32A) charger immediately and a second 7kw chargers eventually, drawing up to 64 amps between them.

Only 36 amps remaining for the house? No problem. It's only going to be a short wait until smart meters/smart chargers all communicate and manage power consumption

That was true for a while.  Those of us in older houses may only have a 60A supply.  Some could even be lower if it's an ancient system that hasn't been touched for years, but they should be rare now.

Many new houses are only being given 80A, because the 100A cut-outs tend to overheat when run at 100A for extended periods.