Is it possible to fit an EV charger in my garage if it's away from the house?

Looks like this topic was missed, @EverythingNeedsAUserName when it was posted 7 months ago!  I can see it wasn’t a ‘Question’ topic type, so other Mods didn’t have this on their ‘to answer’ list. I’ll make it a Question topic now, as I know other potential EV owners will have this same question! 

I’m reaching out to the OVO Smart Home team (previously Kaluza Support) now to get some technical advice to you. 

I’m hoping some V2G trialists will be able to advice in the meantime. I know @IbrahimEV and @Jequinlan had lots of visits from OVO and DNO engineers, so might be able to advise today….

Hi. I had my v2g installed on my garage which was separate to my property and they just ran a cable tacked above ground to the v2g from the main unit. I am guessing distance and maths will mean situations vary especially length of run.

@EverythingNeedsAUserName if you have a route to trace around you may be in luck,  but boy my cable is thick! (And, you will need 2 per charger!) I also had a space issue do got the charger mounted on outside garage wall and the cable can go in...

It doesn’t seem as though I am going to be getting an EV. The concrete (shown in blue) is pretty thick and there is very little space for anything inside the garage. If the cars (arrow facing forward) are not parked tightly, there is hardly room to squeeze between them to get out or in!

The garage wall to either side of the door is only about 18 inches. There are fences all along the sides of the drive - at the top of the image is my neighbours garden, at the bottom ours with mature shrubs, and the gate to the garden, next to the house. Our garage wall is their garden edge.

The Leaf is only 7cm shorter than my Golf Estate, and the same width! So I cannot see how I could get at its charging socket.

Length    4490mm
Width    2030mm

Length    4562mm
Width    2027mm

I never thought we’d be stymied because of the mistakes that Persimmon made while building the estate in the mid eighties!  Supposedly they allowed too much space when setting out the earlier houses, and by the time they got to us, everything had to be squeezed in to get the rest of the houses on the land!

@EverythingNeedsAUserName mine is also outside and the cable just runs inside the garage. Ev chargers need to be durable to weather so it should be fine

Erm… I don’t see a problem here.

You just need a SWA (Steel Wire Armoured) cable from your Distribution board to the garage.

If you don’t want to dig a trench between the garage and the house, then run the cable overhead and design yourself a climbing-rose arch to hide it!

Nor do you require two separate cables. You could use a four-core SW cable with the trips at the Distribution Board end. Or you could run a (thicker) 2-core cable and put the trips in a new sub-board within the garage.

Have a look at this helpful explanation and cable-calculator from the website of TLC Direct. Their SWA cables and prices are here.

Ah… progress is being made @EverythingNeedsAUserName 

I have all sorts of ideas about suspending cables beneath rafters. As a self-builder of many years, I’m well used to devising solutions where none seem to exist!

The key point is to obey the rules for heat-dissipation from a cable. Running it in free air is better than using conduits or going underground.

Feel free to post a photo with arrows pointing to where you think the connection board and chargers might be sited within the garage.

@Tim_OVOwrote:

Out of interest, do these cables really get that warm when in use?

You mean the cables from house to garage?

In a word - yes! If you bury an SWA cable in the ground, then you must de-rate its current carrying capacity, or (more likely) increase the size of the conductors..

That’s why I thought I should provide a link to the cable-size calculator on TLC’s website.

To see how much heat it dissipates, enter the figures into the calculator and look at the Voltage-drop it reports. Multiply that by the current, and you’ll have a figure in watts of the losses which will be radiated as heat.

For @EverythingNeedsAUserName to run two 7kW chargers, an overhead SWA 2-core cable to the garage would need to be 10mm² but if he runs it underground, then he requires 16mm². That’s a price increase from £2.60 per metre to £4.64 /m (plus VAT).

And now we begin to see what Kaluza found out when they started installing V2G chargers for the current trial. Once you survey a real house and find a route between the Consumer Unit and the optimal position for a charger, you can quickly gallop through many metres of hefty copper cable!

And if you think we’ve got problems, what headaches do you think the DNOs are facing?

The underground feeds from the local substation to the pavement outside our houses were laid down many years before anyone thought we’d want to be charging Electric Vehicles.

To save money, those Feeds were sized such that they could get hot during the evening peak, and then use the cool hours of the night to radiate that energy back into the surrounding soil. If we now want to charge EVs overnight, that strategy has been blown wide apart .

Since the UK can’t afford to dig up and double the size of all its 440v Feed cables, we need to consider alternative strategies…

That’s why we need someone knowledgeable on this subject from Kaluza to present themselves to our next Forum AMA Topic. The one that comes to my mind is Conor Maher-McWilliams… or possibly Tom Pakenham.

And now perhaps you’ll see why I broached the subject of phase-balancing within the AMA round we’ve just concluded?

It’s not just the substation transformers which get hot; the underground Feeds are equally susceptible to thermal breakdown.

The key to this is to set a levy for customers who insist on using electricity in the evening peak, and ring-fence that to deploy OpenLV monitoring within all 230,000 ground-mounted substations.

The money gets recovered by the DNOs being required to credit back to the electricity accounts of consumers who put their EV chargers at the disposal of the Kaluza Platform. When the substation monitor detects a Feed heading into overload, then it can decouple devices via Kaluza’s smart control system and save the cables from destruction. The credit is due because it’s those customers who have saved the DNO the cost of replacing the Feed cables.

That financial arrangement enables the DNOs to meet their forthcoming RIIO-ED2 revenue-cap targets and everyone’s happy, including their shareholders.

The alternative is dire - a meltdown of our underground Feeds across the entire nation as we all invest in EVs.

Now I realise I’ve gone off-topic from what @EverythingNeedsAUserName wanted to know about putting two EVs in his garage…

… but what he’s facing is a microcosm of the problems we need to resolve nationally.

And I’m just going to tag @D10hul here because he may wish to flag this Topic to others on his V2G FB site.