New electrical supply in garage block

[Daverh]

One of the things that I looked for prior to ordering my Model 3 was whether anyone else had experience of having a new electrical supply installed in a remote garage. I didn't find many real-world examples so have gone through the process of requesting a quote from my local DNO, Northern Power Grid.
I was hoping that the supply would be on my side of the street and therefore avoid digging up the road to keep costs down but that's not the case.

Their quote for a new connection crossing 6m of road and 8m of driveway to a meter inside my garage is £3300 including VAT

Assuming 5p/kwh evening rate on an ev tarrif and 50p/kwh from a public charger gives a 45p/kwh difference. This equates to a break-even value of 7300KWh or ~30,000 miles at 4m/kwh or 2 years.

On the other end of the scale, 15p/KWh home and 30p/KWh public costs would increase this to 88,000 miles.

Does anyone have experience of groundworks costs, specifically whether the £1200 for digging my drive could be reduced significantly?

Description of the Works Unit/Measure Charge (£)
Install a single phase service, from a passing main including a
mains service joint, excavate and backfill joint hole £807.00
Additional excavation in typical tarmac footpath 8m £756.00
Additional excavation in typical road 6m £1,007.00
Additional cable 16m £178.00
Price of the Works £2,748.00
VAT At 20% £549.60
Total Cost £3,297.60

Technical Summary:
Connection voltage 230V
Number of phases Single
Frequency 50Hz
Maximum capacity 18kW

 

[ewoodrick]

New service is definitely expensive. Step back and look at your needs. Does you garage have any power? Standard plugs can often fulfill your needs. My wife charges off US 120V 15A and only plugs in once or twice a week.

 

[Talllbloke]

Expensive, but one way to look at it is: every car you own from now on will be electric, so if you’re planning to live in the house for a good time...

 

[IanB]

Why would public charging change?

Are you thinking the garage supply would be on economy 7, with house still on normal? If so have you taken into account daily charge too?

I’m currently on standard tariff at home and thinking should I switch to economy 7, but that would then mean educating the wife not to use washing, dishwasher or dryer during the day, a fight I think I would lose. So having dedicated supply in garage on economy 7 is interesting.

 

[Roy W.]

Why would public charging change?

Are you thinking the garage supply would be on economy 7, with house still on normal? If so have you taken into account daily charge too?

I’m currently on standard tariff at home and thinking should I switch to economy 7, but that would then mean educating the wife not to use washing, dishwasher or dryer during the day, a fight I think I would lose. So having dedicated supply in garage on economy 7 is interesting.

But wouldn’t that involve having two electricity accounts and two standing charges? I’m only guessing here, but I’ve never heard of a domestic property having one supply on a standard tariff and one on E7.

 

[pgkevet]

I guess it'd have to be two accounts. If OP can get away with a 5p/Kwh night rate and only use that then depending on the standing charge it sounds like a bargain. Hire some gear and dig up your own drive? If young and fit enough and leccy board will allow... jst hope you donlt find some old water/gas or sewage stuff under there or, heaven forbid, archeology or bones.

 

[Peteski]

Does anyone have experience of groundworks costs, specifically whether the £1200 for digging my drive could be reduced significantly?

My biggest concern here would be the actual quality of the work. One of my mother's neighbours had a shared private road dug up to install a new supply and they made a complete mess of it. They dug a channel right up one side of the road and then filled it with the softest tarmac you can possibly imagine, which looked hideous and sank badly in just a few weeks time. The whole thing had to be completely redone at the neighbour's expense. I don't know if this work was originally done on the cheap (I suspect it was), but I would imagine if you get the DNO to do it, there should be some reasonable guarantee on the quality of work. If you get anyone else involved in the digging, then you really need to be confident in their ability and guarantees.

 

[MrBadger]

Is the garage in a shared block? Any chance of teaming up with someone else to share some of the cost? Different charge point obvs...

My in laws block management company (ie some of the residents) are investigating getting wiring infrastructure installed to each of their parking bays then sharing the cost. It will then be up to individuals to get their own charge point installed, but at least the mess and cost of getting infrastructure in is done once only - actually twice cos someone went ahead and already done his own - probably without permission and in most unsympathetic of ways as he is like that.

 

[Rooster6655]

Their quote for a new connection crossing 6m of road and 8m of driveway to a meter inside my garage is £3300 including VAT

I don't know if its possible in your situation and the costs would probably be higher but would be interested in seeing the figures, have you looked into solar panels and battery storage on a small scale?

 

[MrBadger]

Solar panels on a small scale? Forget it for charging an EV unless you have a pretty big garage.

Its currently full sun, boiling hot and I've got 4kW of PV (17 Panasonic panels) and as I type, I'm producing 2.8kW of power (just gone over the top of the curve; peaked at just under 3kW which does seem low but it is very hot). No fault, just the nature of the PV beast - they don't like getting hot, even hybrid Panasonic ones like mine that are more tolerant of the heat.

It may be a pretty much perfect insolation curve today, but you should see it other days or late Oct to late Feb when it probably wouldn't get a Tesla a couple of miles with a days charging.

I might get 20kWh today, 12kWh usable to charge if I am at home. If it needed to be stored in battery, thats probably 8-9kWh. Thats a near perfect hot summers day like today. Oct through to Feb, call that 1-2kWh/day, if that.

 

[Daverh]

Thanks for all of the input
I've asked a couple of my neighbours but none are interested in having power in their garages. Given that it's on a separate block with no current power it would mean having a second account with the associated standing charge etc.

If we planned to live in the house for a long time then I wouldn't bat an eyelid at the cost as the convenience (not just for charging) and long-term savings would easily justify it. We plan on moving in the next 3-5 years however making it more a question of whether it adds value to the house and that's harder to answer.

Re: quality of the work - my thoughts are that the DNO need to be involved anyway to make the connection so i figured the reduced complexity of only having one party involved would be best... unless someone could do the work for half that price The entire driveway is mine from the road to my garage so fortunately there are no issues with messing up neighbours' property.

I think the short answer in my case is that it's not worth it at the moment.

 

[Jason71]

Just get a diesel powered generator for the garage

 

[m-i-l]

I bought a garage in a block of garages not far from where I live in 2017 (after reserving my Model 3 in 2016). Cost of getting UK Power Networks to dig a trench etc. and provide a single phase electricity supply to the block was £5,532. That's in London, so it may be cheaper outside London. In my case I was able to split the cost with one other garage owner (who didn't want it for electric car charging incidentally, but for keeping a classic car frost-free in winter), and have an agreement with the freeholder to get proportional refunds from other garage owners if they want to connect in future.

After electricity was provided to the block, and a Garage Consumer Unit fitted, it was a further £642 to take the supply to my garage itself. Still just a 3 pin 13 amp socket at the moment too, so I expect further expense for installing a faster charging option at some point (I see that there are grants for this though).

Not cheap, but if I ever resold the garage I hope I'd have increased its value.

A couple of notes though:
1. Whole process has taken the best part of 2 years so far.
2. I recently found out that my meter in the Garage Consumer Unit is classed as a submeter, so doesn't have it's own Meter Point Admin Number, which means I can't choose my own supplier.

 

[MrBadger]

2. I recently found out that my meter in the Garage Consumer Unit is classed as a submeter, so doesn't have it's own Meter Point Admin Number, which means I can't choose my own supplier.

Just make sure you are not charged much higher prices than the main meter is charged - I believe there is statute that controls how much sub meter charges can be over and above the main meter pricing. I may be wrong, but I believe that the markup must be negligible or nil. I am sure some may think that charging an excess to sub meters is easy profit.

 

[MidhurstNigel]

You should be able to save money by getting a ground works contractor to dig the trench and make good afterwards. Also if you employ them direct you will have more control of the quality of work than if the work is done by sub-contractors of the supply company. I'd also look at the cost of installing 3 phase instead of single phase. I believe all European model 3s have 3 phase chargers built in so if you have a 3 phase supply you will be able to acheive a much faster charge rate than is possible using a single phase supply

 

[Daverh]

Does 3 phase have higher supply costs?
An 18KW installation would charge a 70KW battery in under 5 hours (or 20%-80% in under 2 hours) which is fine as an overnight solution.