charging tenants for electricity usage - PPA

[SolarRoofSols]

A client has a 50kW on their roof, they are vacating the building and are renting out the space. They would like to charge the new tenant for using the generated electricity so need a way of measuring export so they know how much the tenant has used. The tenant will still keep their normal supply for imported power but this bill will reduce as they are using more of the generated power, which will be charged for at a reduced rate.

I have spoken to a british gas rep and someone at the current supply meter company and info is a little slow in coming back.

Has anyone organised this before who can offer assistance on the metering side of things?

 

[Gavin A]

bang in an unofficial export meter, problem solved.

use a GPRS meter if they want to be able to sort this out remotely

 

[SolarRoofSols]

Who supplies those? or am i being a plank. Been out of the PV minefield for a blissful week and it's taking a while for the cogs to start turning again!

 

[TedM]

I assume from what you say that there is no existing export meter fitted (possibly for financial reasons)? Are the supply and PV both 3-phase?

Metering the total consumption for the tenant could be very simple. It depends on how the PV is presently wired in to the supply.

You may be able to just install an extra meter that is wired in between the PV connection to the supply and the main distribution board. No need to get BG involved at all.

If the PV is currently wired straight in to the distribution board then this would be a good opportunity to move it.

Is the customer aware that commercial tenants now have the right to switch to whichever electricity supplier they want?

 

[SolarRoofSols]

There is no export meter as the client uses most of the generated electricity, the new tenant would be the same. it is 3 phase and the PV is connected into the distribution board across the 3 phases.

So we could just put in another 3phase generation meter between the db and the supply?

 

[TedM]

Not if the PV is connected to the db. The separate export meter would be easier as Gavin said.

You will also need that if the owner is going to charge a separate rate for the PV generation used compared to the import rate as they will need to calculate separate consumption as:

A. grid import meter
B. total generation meter
C. export meter

Tenant is charged A kWh x standard import rate, plus B-C kWh at whatever the agreed local generation rate is. Owner still won't get paid the FiT export value for the export as it will not be a registered meter but sounds as if that will be a small amount anyway.

 

[gallorross]

Indeed its great idea to Handel this tenant problem, also you can install prepaid electricity meters to get rid off this problem. The owner of the house or room rental, do not have to worry anymore with the electricity bills are not paid by the occupants of the house rented by the use of electricity has become the responsibility and have been adapted to the needs of tenants. It’s their responsibility to recharge and use it accordingly.

 

[Worcester]

We've done TedM's solution for a number of our clients, works just fine - "Owner" of the PV system obviously need to include for this in his tenancy agreements, the usual arrangement is the rate they the consumer is paying less a percentage (10% - 50%) but never less than the export rate . Tenancy agreement will obviously also include things like tampering, access for maintenance etc etc. If it hasn't got remote monitoring the client will also benefit from that (the sold on leccy will pay for it anyway) Speak to Andy O'Leary at Sibert, he could supply either a DC (Direct Connect) or CT (Current Transformer) based meter - CT means no alteration to the existing wiring / no interruption in power supply, DC meter will be cheaper.

 

[SolarRoofSols]

Thanks Worcester - I have been in contact with Sibert who have been helpful, Andy is away at the moment but the team are trying to get me some answers. I have discovered that the the PV is going into a sub db which is no where near the incoming mains (about 40m away in a separate building). Sibert didn't think it would be a problem and that a L&G 5219B should still be ok sited alongside the main db in the plant room to monitor the export. Does this sound about right?

 

[Worcester]

Sounds about right, just make sure it doesn't exceed the maximum current rating, that meter is only rated at 100A / phase.

Hence the CT option on the Iskra MT174 - what is the incoming supply rated it? If they have been using the max generation possible that would have been 72.5Amps on its own

It needs to be able to cope with how much could be being imported, not exported, so if it has 200A main fuses that is what the meter needs to be rated at (hence CT).