Communal PV system on a Block of Flats

[The Solar King]

I have been approached about the possibility of doing this. The question being asked is can all twelve flats in the block be connected to the PV? Anything is possible in theory. Any ideas on how to do it? I am working on the basis there is a 3 phase supply to the building. There is possibly room for 20kW on the roof

It could become interesting when looking at the management agreement for the block and how ownership is allocated.

Anyone done anything like this?

Any help greatly appreciated.

 

[Worcester]

It all depends upon how the power is already distributed and metered withinthe flats - I'm sure this very discussion has been had before on here.

I guess the management company (that all the flat owners will be members of) would be the owner of the system

 

[Pascaleto]

Maybe if you have only one Electricity meter for all of those flats.
Or better to have 12 systems of 1,5kW per each flat.
Or you should connected on the stairway circuit.

 

[SibertSolar]

Are you looking to determine each flat's consumption of generated energy Peter? Do all 12 flats currently connect to a single DB or are there several sub-DBs?

 

[The Solar King]

Each flat has its own CU. Yes the idea would be to measure use in each flat for some sort of monetary charging system to ensure equity and fairness.
This would mean sub meters on the PV feed to each flat. One thing that crossed my mind was the interconnectivity this could give between flats via the PV feed. Could you end up using someone elses Grid electricity FOC and how would you prevent this?

 

[MCS Renewables]

Why not just install twelve individual 2kW systems , each one will get the higher FIT rate as they will stay under 4kW threshold and each can get the benefit of own generation electricity.
Its only one cable from each supply to the roof, up a service duct or outside.

 

[Earthstore]

I too had thought of this but would you not then need to use 12 2KW inverters rather than one nice big one, but on the plus side you would be able to monitor the system as a whole to see if there were any problems occurring by comparing generation meter readings.

 

[Worcester]

By doing it with 12 x 2kW systems you don't have to worry about the different phases either

There is no way to safely interconnect the systems unless you re-route the whole power supply to each site, and you also need to be careful about the phases. Multiple smal inverters, everyone gets an equal share, and if they don't use it then it is exported. Otherwise if you have one big user, then do you compnesate the other that didn't have the chance to use it - small voltage drops would cause havoc with who get the free/lost cost leccy.

Is each meter a supply meter or the management companies meter (sub meter of landlord supply) that adds another dimension to the whole intercharging situation espcially for exported excess power - each flat if it has an immersion may also want an immersun type device - the financial ramifications are a minefield for a management company.

 

[MCS Renewables]

If you used Enphase Micro inverters you could "up sell" the project because of the 20 year warranty and you would need very little space in each flat. You could also connect them all to one Envoy gateway unit with a three phase connector. All of the flat owners get their own meter and can log on with a shared email sign in to view the entire array.