Sub metering

notbeatenyet

Hello,
My question is about sub metering. Where my partner lives are two garage blocks of 4 garages all sharing one meter. One of the owners has a plug-in hybrid and asks how much it would cost to install a sub meter in his garage so he can charge his car independently of the other owners.
Regards
Phil

Robin9

He needs to contact his DNO (but think £100's) not forgetting he may need to upgrade the wiring from meter to where he wants the EV.

 It would probably be cheaper to take the supply solely in his name and give the other 7 free electric. This arrangement may work for the first but what happens when a second comes along ?   I guess all 8 might be well beyond the capacity of the incoming supply cable.

Ectophile

If it's a sub-meter, then the DNO don't need to be involved, nor the electricity supplier.  Buy a standard (non-smart) meter from an online retailer, and get a local electrician to fit it.

Then the person with the car charger can pay the right amount for what they have used, and the rest of the bill can be split between the other garage owners.

Robin9

@notbeatenyet   What are the present arrangements for paying the bill ? - 

FreeBear

Ectophile said:

If it's a sub-meter, then the DNO don't need to be involved, nor the electricity supplier.  Buy a standard (non-smart) meter from an online retailer, and get a local electrician to fit it.

Then the person with the car charger can pay the right amount for what they have used, and the rest of the bill can be split between the other garage owners.

If an EV charging point is being installed, he doesn't need a sub meter. Most (all ?) EV charging points will record how many kWh has gone into the battery.

gm0

Ooh an app.   I am sure all involved will be delighted to take their word for it on what part of the total they used based on their 100% reliable, never upgraded app.  And fundamental honesty.
And do the same for ALL future owners whoever they are.

Somebody somewhere is paying the bill standing charge and usage for an MPAN with load on it.  And they may not like a high trust open ended solution as the bill rises.  How it is recovered now will influence.

If this is a 100A supply then you will start rate limiting everyone a lot as you go up garage by garage towards 8. 
8 7.6kw is 253A.  >100 - Sub 40% speed.  If it can be safely configured at all to current sense in that configuration on a simple single phase supply.  8 lower wattage chargers (so some hard to police rules on what goes in) would be easier but less useful.  Or a supply upgrade when you get about halfway through.  First come first served. Or equal shares to pay for that.  Or rate limiting. At some point - money changes hands for common infrastructure.  Committing to that as an unknown is a barrier to getting 8 people to agree - anything.

You definitely can fit a meter of your own as described upthread. And make whatever arrangement you like with other owners.  But basically this is between the owner paying the bill. And the one now wanting to use more energy and meter it.

Putting this on a "legal" basis will likely cost money to execute a binding agreement that doesn't irk lawyers later at conveyancing.  But not putting it on a legal basis - may also cause trouble later with subsequent changes of ownership and dispute over bills.   My app says x/2.  The bill is for Y.  The difference isn't that Dave left his garage light on.

Informal has its charms too

Personally I would not entertain it as the bill payer for a second - without a meter on the sub-wiring to the new heavy load.  Accessible for me to view without "at the time" consent from the new high use consumer but connected to the only wiring to that load.  And with a legal agreement binding on sucessors in title to share costs of energy used, costs to maintain etc. as measured on the relevant sub-meters to new wiring to each garage for chargers. 

It could be a point agreement with the adopter and the supply owner of the billing MPAN for the address on national DB.  Or it could be the "everybody joins in" one - if the will can be summoned to get all owners to focus on the future and agree a solution which will last until all have a charger one day.

Attempting making this the electricity billing companies problem to sort out  - i.e. billing master/sub, master/deduct etc. master/add etc is something of a fools errand in the modern era.  Competition seems to have more or less knackered what was once possible to get right at least some of the time for meter relationships and odd wiring. Avoid. 

And if you go for more than one independent supply at DNO level.  New MPANs. Switch how you like. And you get your own i.e. more than one standing charge.  So there is that.

Energy Suppliers won't have an MPAN for a "meter" you just stick on garage wiring.
So strictly unoffical. And a great source of confusion if someone later trys to switch it.  And can't. 
Label carefully what it is.  And who to contact about it.

HampshireH

What would the plan be if another (or several) owner wants to do the same thing?  

Once you agree to one how would you refuse another? Could the supply safely support multiple vehicles being charged?