3-phase to new build shed or annexe first?

[steve.gmarsh]

We have recently got planning permission for an Annexe and a steel framed shed. They are about 25m apart. The shed will be put up this autumn n and the annexe next spring. We can't put PVs on the annexe due to overshading, so they will be put on the shed with the inverter and batteries. The annexe will be all electric with ASHP. To futureproof the development, I am thinking 3-phase which will also allow a larger solar array without having to ask permission and reasonably fast EV charging when we get our first EV.

Is there any reason why I can't put the meters in the shed and get National Grid to take the 3-plase power directly to the shed this autumn? This way the shed can be connected this autumn and I won't need to install a temporary supply.
The annexe will then be attached via an underground conduit which will be installed as part of the build process for the annexe.

What size supply should I ask National Grid for? (PS the shed will never have a huge demand as power only required for lighting and occasional 3kw for tools.)

Will National Grid want to charge me more as it is not initially domestic ?

Any other thoughts would be appreciated.

Thanks in advance

 

[ProDave]

No reason at all why not. My supply is still in a meter box on the boundary of my plot. I saw no reason to pay to have it moved.

If this is self build in any way, take a look at the buildhub forum.

 

[binky]

question is do you really want 3 phase in the annexe?

 

[UNG]

To futureproof the development, I am thinking 3-phase which will also allow a larger solar array without having to ask permission and reasonably fast EV charging when we get our first EV.

I'm not sure why you think having a 3 phase supply will also allow for a larger solar array without "asking for permission" I presume for the export of any excess electricity
The DNO has to be informed of the installation of grid connected solar, EV chargepoints and other large load connections and may limit what you can connect

 

[ProDave]

I'm not sure why you think having a 3 phase supply will also allow for a larger solar array without "asking for permission" I presume for the export of any excess electricity
The DNO has to be informed of the installation of grid connected solar, EV chargepoints and other large load connections and may limit what you can connect

You are allowed 16A per phase without seeking permission so that's 3.6kW for single phase or 10.8kW for 3 phase.

Fine if you are SURE your 3 phase meter does net metering so PV export on different phases to where the house is consuming power does not matter.

 

[binky]

I'm not sure why you think having a 3 phase supply will also allow for a larger solar array without "asking for permission" I presume for the export of any excess electricity
The DNO has to be informed of the installation of grid connected solar, EV chargepoints and other large load connections and may limit what you can connect

in the days of the FiT where you got paid for what you generated, I did have customers who installed multiple phases so they could have multiple arrays.

 

[steve.gmarsh]

Fine if you are SURE your 3 phase meter does net metering so PV export on different phases to where the house is consuming power does not matter.

How can we be sure that any 3 phase meter installed does net metering? as imbalances between the phases are inevitable whether or not we have the house single or 3 phase.