New House Construction - Ideal EV Set Up

Gumbo

Ok Guys,

So i am in the construction business and am in the lucky position to have talked a large developer into offering EV Charging facilities onto his new homes which will be open for in a month or two as show houses.

The developer will offer a charging point as an optional extra, but wants to know whats the ideal set up that will future proof the charge point?

Thanks.

cros13

kceire wrote: »

Ok Guys,

So i am in the construction business and am in the lucky position to have talked a large developer into offering EV Charging facilities onto his new homes which will be open for in a month or two as show houses.

The developer will offer a charging point as an optional extra, but wants to know whats the ideal set up that will future proof the charge point?

Thanks.

A 32 amp socketed Type 2 charger like this one:

http://nuworldenergy.co.uk/shop/ev-charge-points.html/home-charge-points.html/wallpod-ev:-homecharge-32amp-type-2-universal-socket

Everyone has a cable for it as it's the european standard and it's what the public chargers use.

Minimum cable from the distribution board to the charger is 3x6 AWG and minimum breaker is 63A. Make sure the sparks knows that there could be a draw of 34 amps for a solid ten hours, that kind of load is not what they are used to in domestic settings.
Ground connection also needs to be good as the ground connection is tested before charging and the car will refuse to charge if the ground doesn't check out.

For additional futureproofing, the cable from the distribution board to the charger should be 3x8 AWG and a 120A breaker should be used. That would allow you to fit a 22kW sometime in the future without replacing the cable.

When the ESB supply is ordered it would be best to get 16kVa rather than the standard 12kVa. There should be no additional cost for doing this, it's just a box on the form.

I think builders/ Electricians etc need to look at the future which is without doubt the electrification of transport.

If you have 2 EV's in a house both on 32 amps that's 64 amps or roughly 15,400 Watts and beyond the capabilities of , afaik, all modern domestic supplies ?

However that being said, there will be a gradual reduction in the current drawn as the batteries charge up but still the load needs to be capable of significant currents for long periods of time.

At this point wouldn't it be better to have 3 phase in new homes today rather than the hassle of doing it after ? surely it's better to up the voltage rather than the current ?

If we can move or build in the next few years I'll be getting 3 phase or at least have it 3 phase ready.

One way or another I do feel builders, electricians and especially the ESB need to seriously reconsider the supply to modern homes. I can only imagine the headache in the years to come when houses run out of power !

cros13

Deleted User wrote: »

If you have 2 EV's in a house both on 32 amps that's 64 amps or roughly 15,400 Watts and beyond the capabilities of , afaik, all modern domestic supplies ?

You can have single phase domestic supplies up to 29 kW from ESB. However above 16KW you pay more in standing charges and more for connection.

Domestic usage has been declining in recent years due to higher efficiancy appliances and LED lighting.

Deleted User wrote: »

At this point wouldn't it be better to have 3 phase in new homes today rather than the hassle of doing it after ? surely it's better to up the voltage rather than the current ?

If 22kW home charging becomes commonplace, then sure. For 1-3 EVs charging at 7KW single phase is sufficient. I'm being a bit of a hypocrite here because I already have a domestic three phase supply, but I had that for a workshop before the EVs came.

However we're just getting started here... EV sales have just hit 1% of new car sales in the last few months. While many families who move one car to EV quickly follow by replacing the other car, it's not a widespread problem yet.
And we already have the model to deal with it, when you get that 3rd EV you just have factor in the money to upgrade your supply.

cros13

cros13 wrote: »

You can have single phase domestic supplies up to 29 kW from ESB. However above 16KW you pay more in standing charges and more for connection.

Domestic usage has been declining in recent years due to higher efficiancy appliances and LED lighting.

I'm a fan of more voltage than big ass cables to carry more current. It's more efficient to have higher voltage especially for charging electric cars.

There's a good reason EV's use high voltage, that is current, the current to drive a leaf at say 100 volts would be far higher needing much heavier cables costing a lot more in the process. It's also more efficient, more current also creates stresses on electrics and cables and it also creates more heat.

cros13 wrote: »

If 22kW home charging becomes commonplace, then sure. For 1-3 EVs charging at 7KW single phase is sufficient. I'm being a bit of a hypocrite here because I already have a domestic three phase supply, but I had that for a workshop before the EVs came.

If you have a model S then 22 Kw home charging would actually be needed, though maybe not, most people don;t drive more than 50 odd miles per day and so the model S with the 85 Kwh battery could trickle charge over a few days at home and be ready for the long trip a few times a year.

One reason I'm more of a fan of faster charging smaller batteries than carrying around big ass batteries for those who don't really need 300 miles range every day.

cros13 wrote: »

However we're just getting started here... EV sales have just hit 1% of new car sales in the last few months. While many families who move one car to EV quickly follow by replacing the other car, it's not a widespread problem yet.
And we already have the model to deal with it, when you get that 3rd EV you just have factor in the money to upgrade your supply.

This is where if building or renovating it's important to get it right in the beginning. There needs to be at least 30 Kw supply (capable) so it's easy to upgrade if required. I still think 3 phase is better.

I still think people will be more than happy with faster charging and 200 miles max range. But if people really want 400-500 miles range then they better be prepared to be able to charge them. I think this will cause havoc in the years to come though maybe at that stage cars can charge in 5-10 mins and maybe more and more garages will install fast chargers easing the burden on house supplies.

3.5 Kw is plenty for 70 odd miles range over the course of a charge within the off peak period above this you need 32 amps or 6.5 kw.

If the 2nd EV is doing 70 miles per day or less then it will be fine on 16 amps.

So this would be about 10 Kw and within the abilities of most current domestic Supplies but it would be very close to the limit and sure most electric cars will charge at the cheaper off peak.

reboot

kceire wrote: »

Ok Guys,

So i am in the construction business and am in the lucky position to have talked a large developer into offering EV Charging facilities onto his new homes which will be open for in a month or two as show houses.

The developer will offer a charging point as an optional extra, but wants to know whats the ideal set up that will future proof the charge point?

Thanks.

The developer could also offer to a future EV owner the deal I got which was a free 32 Amp CP with the Car.
I know the offer does not extend to the ROI at present, but worth investigating first?