Cable for home charging

insular1

Hi all,

We're currently starting the building of our future family home. We have decided that when we replace the car (in 2-3 years depending how much the build costs!) our next one will be full electric.

We want to set up a charge point out of the garage that would be capable of charging 2 EV's as eventually plan to replace both cars once longer range vehicles drop to our price point.

Is there a particular type of cable or any details I should be looking at installing during the build to facilitate the addition of this charge point once we get an EV? Also what available options are there for at home charging? Is fast charge possible?

All advice appreciated!

zilog_jones

You're probably stuck with single phase AC if you want something remotely affordable, so fast charging at home is not really a possibility. For two cars you'd want to go for 32A at the very least - currently most home installations are only 16A as that's (IIRC) all the SEAI grant will pay for, and 32A may require upgrades elsewhere with existing domestic installations (main fuse? I forget specifics). I don't know if installing two 32A chargers is a possibility.

I'm sure there are people around here who know more about this stuff than me...

KCross

insular1 wrote: »

Hi all,

We're currently starting the building of our future family home. We have decided that when we replace the car (in 2-3 years depending how much the build costs!) our next one will be full electric.

We want to set up a charge point out of the garage that would be capable of charging 2 EV's as eventually plan to replace both cars once longer range vehicles drop to our price point.

Is there a particular type of cable or any details I should be looking at installing during the build to facilitate the addition of this charge point once we get an EV? Also what available options are there for at home charging? Is fast charge possible?

All advice appreciated!

Presumably the garage will have its own consumer unit so you need to tell your electrician that two cars will draw 32A and if its a long run to the garage I believe they prefer 10sqmm cable (usually 6sqmm cable will do).

Most cars draw 16A but some can draw upto 32A. With a "normal" domestic connection it would not be possible to draw 2x32A unless you pay ESB for an upgraded supply. That will cost a few grand.

You will likely have to have two 16A chargers, hence the 32A cable. Unless you are considering getting a 3 phase supply? The answer is very different then.

n97 mini

Need more information. How far is the garage from the house? What is your central heating powered by? Have you any public charge points nearby?

cros13

zilog_jones wrote: »

You're probably stuck with single phase AC if you want something remotely affordable, so fast charging at home is not really a possibility. For two cars you'd want to go for 32A at the very least - currently most home installations are only 16A as that's (IIRC) all the SEAI grant will pay for, and 32A may require upgrades elsewhere with existing domestic installations (main fuse? I forget specifics). I don't know if installing two 32A chargers is a possibility.

Two 11kW (48A) Tesla Wall Connectors would do the job. You need two runs of 10sqmm cable from the main panel to the locations for the chargepoints in the garage and single pair bell wire between the two chargepoints (max. distance 15 meters) for communication. 50A C-Curve MCBs at the main panel. The Telsa wall connectors load balance between them so they won't exceed what you set as the available power and as one car's battery fills they will re-allocate power to the other.

The Tesla wall connector will charge any vehicle using the standard Type 2 connector (with the exception of the Zoe which doesn't comply properly with the standards).

You can get a single phase 22kW CCS rapid charger for home use but your grid connection would need upgrading to 28kVA to support just one and they cost €5k each.

KCross

cros13 wrote: »

Two 11kW (48A) Tesla Wall Connectors would do the job. You need two runs of 10sqmm cable from the main panel to the locations for the chargepoints in the garage and single pair bell wire between the two chargepoints (max. distance 15 meters) for communication. 50A C-Curve MCBs at the main panel. The Telsa wall connectors load balance between them so they won't exceed what you set as the available power and as one car's battery fills they will re-allocate power to the other.

The Tesla wall connector will charge any vehicle using the standard Type 2 connector (with the exception of the Zoe which doesn't comply properly with the standards).

You can get a single phase 22kW CCS rapid charger for home use but your grid connection would need upgrading to 28kVA to support just one and they cost €5k each.

Do you think two of those Tesla Wall Connectors would work on a standard domestic supply? How do you stop them blowing the fuse allowing for background load in the house as well?
Assuming that all charging is at night isnt a good assumption. There is also the possibility the OP is going to have a Heat Pump in operation since its a new house.

I think your suggestion would be risky without getting an increased supply from ESB.

Maybe the best option is just to ensure that there is an accessible duct from the main consumer unit to the garage consumer unit and then they can pull whatever cables they want/need in 3yrs time when they actually have an EV and they know what they want.

Water John

The question of 2 EVs will need addressing soon.
The other big pullers are the HP and electric shower.

Will we deal with it? No, we'll drag our arse, as usual.

Storage may become important at household level esp with significant solar coming on stream. Electricity, with smart metering may actually be fairly cheap in the middle of the day.

I'd go as suggested with the ducting, with a rope fitted.

cros13

KCross wrote: »

Do you think two of those Tesla Wall Connectors would work on a standard domestic supply? How do you stop them blowing the fuse allowing for background load in the house as well?

No problem. You dial in a maximum current draw you want to allow at installation in the wall connector you want to make master (from 10A to 48A). Set the second to slave and the master controls dynamically what power is drawn by both. They'll even take three-phase. No issue at all, they are designed to fail safe, if the slave loses connection to the master for example it will just stop working.



For example position 8 will set the total power draw of the master wall connector AND all slaved units COMBINED to 40A. Position 9 is 48A, 7 is 32A etc. etc. Position F is the slave setting.
The D+ and D- in/out are for the daisy chained inter-connector communications over the bell wire.

A two connector install looks like this (note: I advise a separate run to the main panel for each, and you can embed all the cabling in the wall):

KCross

cros13 wrote: »

No problem. You dial in a maximum current draw you want to allow at installation in the wall connector you want to make master (from 10A to 48A). Set the second to slave and the master controls dynamically what power is drawn by both. They'll even take three-phase. No issue at all, they are designed to fail safe, if the slave loses connection to the master for example it will just stop working.


For example position 8 will set the total power draw of the master wall connector AND all slaved units COMBINED to 40A. Position 9 is 48A, 7 is 32A etc. etc. Position F is the slave setting.
The D+ and D- in/out are for the daisy chained inter-connector communications over the bell wire.

A two connector install looks like this (note: I advise a separate run to the main panel for each, and you can embed all the cabling in the wall):

Well, thats one for the EVSE sticky then!

Whats the cost of a powerwall in this country?

cros13

KCross wrote: »

Whats the cost of a powerwall in this country?

€6.3-6.5k

The Tesla power connectors are around €400.

You can see they thought carefully about where all of this is going and ease of installation for multiple vehicles.

insular1

Wow! Thanks for all the great info all. Have some serious googling to do before I understand half of the technical stuff 😂.

To answer some of the earlier questions it's a site in the middle of the country so no immediate access to public charging. The garage will be 2m away from the house. Will be installing Air2water heat pump and underfloor heating.

I think running a duct to allow future cable installation once I know more is a great idea! Thanks for that!

Also this might be a stupid question but as it seems from the above it would be pretty expensive to upgrade my ESB supply for fast charging is it possible to fast charge from a stored energy source? For example in my (distant) future fantasy world where my Tesla powerwall and solar/wind farm allow me to live off the grid would it be possible have your powerwall charging all day from solar/wind/ESB then to fast charge directly from the powerwall if needed and so avoid the issue with upgrading the ESB.

Honestly I can't think of too many situations where this would be a necessity but it could come in handy.

KCross

insular1 wrote: »

Will be installing Air2water heat pump and underfloor heating.

Also this might be a stupid question but as it seems from the above it would be pretty expensive to upgrade my ESB supply for fast charging is it possible to fast charge from a stored energy source? For example in my (distant) future fantasy world where my Tesla powerwall and solar/wind farm allow me to live off the grid would it be possible have your powerwall charging all day from solar/wind/ESB then to fast charge directly from the powerwall if needed and so avoid the issue with upgrading the ESB.

Since you are planning on having a Heat Pump you will probably need to request the enhanced supply anyway (16kVA vs standard 12kVA). Your heat pump installer should be able to advise you here.

Personally, since you have a heat pump and are looking to the future with 2 EV's I think you should request the 16kVA supply.... its €700 extra when its a new build. The next step up is 20kVA and that could be a few grand alright. Ask ESB Networks when it comes time to sign the application form for a new connection.

Jakey Rolling

Was considering our options here too, rural house. I could easily install 2 x 16A charge points off the garage, house supply is 12kW, but what if we have visitors for the weekend (frequent enough). In 5 years when I have persuaded them all to get EVs then we will be in a right pickle when it comes to overnight charging. We'll need some kind of complicated load balancing like the Tesla setup, or possibly set timers on each car - otherwise it's get up in the middle of the night to change over plugs. Some serious infrastructure changes needed surely when everyone goes electric. 3 phase to the house would be ideal - any idea of installation cost and standing charges for 3-phase?

KCross

Jakey Rolling wrote: »

Was considering our options here too, rural house. I could easily install 2 x 16A charge points off the garage, house supply is 12kW, but what if we have visitors for the weekend (frequent enough). In 5 years when I have persuaded them all to get EVs then we will be in a right pickle when it comes to overnight charging. We'll need some kind of complicated load balancing like the Tesla setup, or possibly set timers on each car - otherwise it's get up in the middle of the night to change over plugs. Some serious infrastructure changes needed surely when everyone goes electric. 3 phase to the house would be ideal - any idea of installation cost and standing charges for 3-phase?

2 chargers should be enough for the vast majority. Even if you have visitors they can charge by day or vice versa. Would you really need more than 2 charging at the same time?

There isnt a set price for 3 phase. They quote it as "€2,541plus MV network charges" for a 20kVA 3 phase connection. The "MV Network" charges require a site visit and could be anything really depending on how far the 3 phase network is from your house.

An enhanced 16kVA single phase connection is a flat €2,664 regardless of where you are.

I dont know about the standing charge for 3 phase.

cros13

KCross wrote: »

I think you should request the 16kVA supply.... its €700 extra when its a new build. The next step up is 20kVA and that could be a few grand alright. Ask ESB Networks when it comes time to sign the application form for a new connection.

Agreed, certainly with a new build that should be your default. 16kVA supply does not attract any additional standing charges or ongoing fees over the 12kVA, it's just the €700 on to your

insular1 wrote: »

Also this might be a stupid question but as it seems from the above it would be pretty expensive to upgrade my ESB supply for fast charging is it possible to fast charge from a stored energy source? For example in my (distant) future fantasy world where my Tesla powerwall and solar/wind farm allow me to live off the grid would it be possible have your powerwall charging all day from solar/wind/ESB then to fast charge directly from the powerwall if needed and so avoid the issue with upgrading the ESB.

Tesla might be making an announcement on that soon. I know it's something they are working on, possibly might see an announcement around the time they talk about the new inverter they are launching (which might be the end of the month/beginning of next). Let's just say if you are thinking about ordering powerwall 2s I'd go for the DC option, not the AC powerwall 2 with the built-in inverter.

However, I would point out that fast charging at home is a luxury not a necessity. As I pointed out in another thread, over the 9 nightsaver hours, you could draw 132.5kWh from a 16kVA grid connection (while maintaining the 0.8 power factor you are required to). That's enough power for two cars to do Dublin to Limerick and back every day. I wouldn't see the average car in a family taking more than 10-15kWh/day as an average.

And for future use beyond the 132.5kWh/night... well you could either extend your charging time, upgrade your grid connection or use public charging along the way.

stesaurus

insular1 wrote: »

Wow! Thanks for all the great info all. Have some serious googling to do before I understand half of the technical stuff 😂.

To answer some of the earlier questions it's a site in the middle of the country so no immediate access to public charging. The garage will be 2m away from the house. Will be installing Air2water heat pump and underfloor heating.

I think running a duct to allow future cable installation once I know more is a great idea! Thanks for that!

Also this might be a stupid question but as it seems from the above it would be pretty expensive to upgrade my ESB supply for fast charging is it possible to fast charge from a stored energy source? For example in my (distant) future fantasy world where my Tesla powerwall and solar/wind farm allow me to live off the grid would it be possible have your powerwall charging all day from solar/wind/ESB then to fast charge directly from the powerwall if needed and so avoid the issue with upgrading the ESB.

Honestly I can't think of too many situations where this would be a necessity but it could come in handy.

I think you may be getting hung up on Fast Charging. FCPs are by and large going to be located at services stations or close to main motorways. You won't be installing one at home unless you're setting up a commercial enterprise
You probably just mean 7kw as opposed to the standard default ESB free option of 3.3kw.
Future proofing to allow for potentially 2 cars charging at 7kW at the same time is a good idea. On current gen EVs your looking at typically 24-30kWh of battery. Future, probably double that. So you'd have no problems charging fully from low to 100% in the next morning, in 8 hours say.
Powerwalls sound like they would suit you perfectly if you're planning on heat pump and EVs offset by solar, wind etc. I had no idea they would be around €6k I would have thought double that.

cros13

s.welstead wrote: »

I had no idea they would be around €6k I would have thought double that.

https://www.tesla.com/de_DE/powerwall?redirect=no

€6,200 in Germany (£5,400 in the UK) incl. VAT for the raw unit alone excl. cabling and installation.

And the AC version has an inbuilt inverter so if you bought one outright and had a sparks to hook it up, it's just a matter of mounting it to the wall, hooking the power and meter (separate unit to measure power export and import at your meter) hooking both to ethernet and an internet connection and go...

The price per kWh they've managed to hit has exceeded my most optimistic expectations.

n97 mini

s.welstead wrote: »

Future proofing to allow for potentially 2 cars charging at 7kW at the same time is a good idea.

14kw is 61 amps and is close to the limit of a standard supply. Add in electric heating and even an enhanced supply will be beyond its maximum import capacity.

Problem with ground or air source heat pump central heating systems is they are massive consumers of electricity by themselves. They can cost more than plain old natural gas to run for heating a house. And like EVs their consumption is usually at night.

OP, do the maths, but I suspect you'll need 3-phase, or you'll need to scale back on some of your planned consumption.

insular1

I should have mentioned at the start I have ordered the 16kva from the ESB because of the heat pump.

Few great points above thanks again. I guess for now I'll make do with standard supply as a 3phase connection would likely run into the thousands I'm guessing?

And what cros13 mentioned above made me realise that even if I did have to charge 2 completely drained EVs overnight (rarely likely to happen I'd say) I'd likely get more than enough into them for the next day and could just top up then.

Thanks again!

KCross

n97 mini wrote: »

Problem with ground or air source heat pump central heating systems is they are massive consumers of electricity by themselves. They can cost more than plain old natural gas to run for heating a house. And like EVs their consumption is usually at night.

I'll have to disagree with most of the above.

If a HP costs more to run than gas the installer has made a mess of the install.

HP's run via weather compensating controls so they come on/off as required based on changes of outside temp and not mainly at night.

There are plenty scare stories of high electricity bills from HP's but they are from cowboy installs during the boom.

Calahonda52

n97 mini wrote: »

Problem with ground or air source heat pump central heating systems is they are massive consumers of electricity by themselves. They can cost more than plain old natural gas to run for heating a house. And like EVs their consumption is usually at night.
.

I concur with KC where he refutes this "alternative set of facts"

A properly [designed, installed, commissioned, maintained and used] HP will not do as you say.

An improperly [designed, installed, commissioned, maintained and used] HP will pretty much do as you say.

It think heat pumps were also installed in unsuitable homes, not being properly efficient that and probably poor installation.

n97 mini

KCross wrote: »

I'll have to disagree with most of the above.

If a HP costs more to run than gas the installer has made a mess of the install.

HP's run via weather compensating controls so they come on/off as required based on changes of outside temp and not mainly at night.

There are plenty scare stories of high electricity bills from HP's but they are from cowboy installs during the boom.

I was careful with the words I used, as two variables which are beyond the control of even the best system and installer are the cost of gas and the cost of electricity. My understanding is that in Germany (for example) the difference is so large (cheap gas, expensive electricity) that HP cannot compete. Add in the capital costs, combine with running costs and, well have a look at the Space Heating section in this report -- even in Ireland over the first 15 years GS HP with UFH is considerably more expensive.

The only practical example I have is actual costs of heating my (old) house with gas and rads vs a friend's (new) house which has GS HP and UFH. Per sq ft his bills exceed mine by between 10% and 40%. He attributes that to his system being "topped up" by an immersion heater in certain conditions, which are not factored into initial estimates. Additionally there is such a lag with UFH that if he wants to use the spare room he has to turn on the heat 1-2 days before the room will be in use to give it time to heat up. Apply that second principle across the board and compare to a dynamic fast reacting system. His is so laggy that if he goes away for a weekend the house is still warm when he gets back. That heat costs money. (As an aside it irks me that I have to heat a couple of hundred litres of water to heat air, when all I want is just the warm air... he has to heat tens of tonnes of concrete to heat air).

It's off topic on this thread, so there's no point in debating it here. But I am satisfied that the costs in that report are reflected in the reality I see.

And back on topic, the point is if you are space and heating using electricity and you want to charge 2 x EVs at the same time you will need to make the right preparations.

KCross

n97 mini wrote: »

I was careful with the words I used, as two variables which are beyond the control of even the best system and installer are the cost of gas and the cost of electricity. My understanding is that in Germany (for example) the difference is so large (cheap gas, expensive electricity) that HP cannot compete. Add in the capital costs, combine with running costs and, well have a look at the Space Heating section in this report -- even in Ireland over the first 15 years GS HP with UFH is considerably more expensive.

Maybe in Germany yes. Their electricity is considerably more expensive than us but hardly relevant to the OP since those figures dont matter here.

The figures in that report dont match my experience either for GSHP + UFH.

n97 mini wrote: »

The only practical example I have is actual costs of heating my (old) house with gas and rads vs a friend's (new) house which has GS HP and UFH. Per sq ft his bills exceed mine by between 10% and 40%. He attributes that to his system being "topped up" by an immersion heater in certain conditions, which are not factored into initial estimates. Additionally there is such a lag with UFH that if he wants to use the spare room he has to turn on the heat 1-2 days before the room will be in use to give it time to heat up. Apply that second principle across the board and compare to a dynamic fast reacting system. His is so laggy that if he goes away for a weekend the house is still warm when he gets back. That heat costs money. (As an aside it irks me that I have to heat a couple of hundred litres of water to heat air, when all I want is just the warm air... he has to heat tens of tonnes of concrete to heat air).

That doesnt tally with my experience. Maybe his system isnt designed right. The other points about UFH lag are true but thats not a HP issue. Thats a design decision to pick UFH or else rads. I picked UFH because I prefer the heat it gives off. Its consistent everywhere, unlike rads. If you prefer rads then fine.

It doesnt really matter how much concrete you have to heat to get the house to 21C. Its the amount of energy required to do it that matters.... it costs me 700/yr to heat a 350sqm house. If I made the house more airtight I could drop that further again. Adding gas means you have another standing charge to pay as well as the gas you use.

n97 mini wrote: »

It's off topic on this thread, so there's no point in debating it here. But I am satisfied that the costs in that report are reflected in the reality I see.

Usually with reports there is an opposing report that tells a different story!

HP's are not new tech. They are around a long time and are well proven and used in much colder climates than ours. That speaks for itself too.

n97 mini wrote: »

And back on topic, the point is if you are space and heating using electricity and you want to charge 2 x EVs at the same time you will need to make the right preparations.

Agree totally.