Large Domestic Field Installation

[colincase]

I have decided to install a large PV system in my paddock next to my garden.
I am aiming at 9.99kWp to make the best of FIT break points. Around 50 to 55 panels, by the rough sums I have done. All in one long row of about 45m, mounted at 30/40 degrees and facing due South. Will hopefully net about £3,500 pa in FITs, savings and export, with a capital cost of around £28k. Space is NOT at a premium - relatively low efficiency panels are OK so long as they are cost-effective. This appears to be a fairly uncommon task for some of the potential installers I have spoken to.
And it raises a few questions:-
My house has only single-phase. This seems to be a problem at this power. My neighbour is definitely on a different phase - not sure about the next neighbour. How can I find out who is on which phase? And am I allowed to feed their homes with the appropriate phase? Can I charge them, say 8p per unit (between the 3.1 and 13p for export and purchase prices) And still get FITs and still export any excess on each phase? Or is there a better solution?
How do I choose a supplier for this type of system? Does anyone specialise in this size and field-mount?
Can I mount the inverter and meters in the field with the array? There doesn't seem much point bringing the DC to my house, only to have to re-distribute. And distribution losses should be downstream of the meter (preferably - obviously)

Impressed by the quality of helpful replies on this site, so I hope you can help in this case.
Thanks, Colin

 

[SolarCity]

Ground mount systems tend to be setup in two rows - one above the other as this makes the best use of space available and saves on ground works and mounting system.

You may well find that a 10kWp system is problem on single phase system but you'll never know until you ask the distribution network. It sounds like you're in a rural area which could mean you have a problem.

You cannot export electricity to your neighbours homes. How were you thinking of trying this?

You can mount the inverters and meters at the array and it is advisable.

 

[colincase]

Well - a very helpful response in only ten minutes! Thanks very much.
Good thoughts about a double row - thanks.
I was thinking that a 3-phase inverter would be needed, with each phase metered separately, with one phase coming to my house, and each other phase going to next door houses on different phases. Then we use a bigger proportion of the total output and reduce export and keep it phase-balanced (roughly). This makes more money as well as making it easier on the grid - we are indeed quite rural.
Otherwise, what to do with the "excess" power that isn't used in just my house? Storage sounds pretty difficult and expensive, and just wasting it defeats the green objective.

 

[MikeXl426]

I'm not sure ofgem nor your DNO would approve. Nor would your suppliers be able to get their heads round it. Is this green objective or a money making exercise? Probably the best way is for a 4Kw system approved by the DNO on a single phase.

 

[colincase]

I'm not sure ofgem nor your DNO would approve. Nor would your suppliers be able to get their heads round it. Is this green objective or a money making exercise? Probably the best way is for a 4Kw system approved by the DNO on a single phase.

Both (how honest is that!)

Feed in Tariff represent a steady return of something like 8% and revenue is linked to inflation. With pension annuities at around 4% when linked, and interest at 2% or so, and stocks doing what they are currently doing it is tough to find a better investment.

On the "green" side, anything that reduces the power my house takes from the grid MUST be good (whether insulation to reduce consumption, or micro-generation to supply my own) BUT micro-generation must be carbon-efficient for this to be valid. All micro-generation projects involve a carbon investment. Carbon must be used to make the devices, the steel etc and dry the concrete for installation. I have done pretty exhaustive research into the carbon balance of various micro-generation mechanisms and PV is substantially better than, say, wind power. PV gives a carbon payback of about 3.5 years and lasts more than 25. Wind turbines have a carbon payback of over 12 years - and that's before distribution and "rolling reserve" is taken into account.

So I am trying to secure a cost-effective income with a very clear conscience - and PV seems to be the answer! Am I the best PV salesman in the world? No, the answer lies in the maths. But how to actually DO it with a 10kWp system?

 

[Graeme Harrold]

You could look at it as a community PV project. You as the land owner are providing the space and capital for the project. Essentially you could fit 3x 3.6kW single phase supplying each of the houses, and you collect the FIT payment for each. You would probably be on the lower FIT payment, but you could suck that up by also investing in dual axis trackers. All of this would need planning permission.

This way you get a nice return on your money, and your neighbours get some free electricity.........

 

[colincase]

Well, with advice from some helpful chaps at UKSolarInstallers .co .uk and the post from Graeme above, it seems I have two options:-

Either persuade the nice chaps at Scottish Power (my DNO) that it can be an approved installation under G59, and get permission to export up to 10kwp on one phase (but depends on phase balance and many other things)

Or install 3 separate 3.9kwp domestic systems, one with my property address and the others at the address of two neighbours (each on a different phase). I get the FITs on all, but the savings and export only on my own. They get the free power from the other two, and their export income. Just like I had rented their roof, except they are renting my field space at 1p per annum.

Will either/both of these work? With the second option, a guide price for the investment would be about £39k (3*£13k) and the income to me with all FITs and my savings would seem to be about £4.5k giving a return of about 10% or 11%. And neighbours get some savings as well.

So thanks for the help all of you - now I need to find an installer.

 

[SolarCity]

So thanks for the help all of you - now I need to find an installer.

Your best place to look is UkSolarInstallers .co .uk - find a local firm!

 

[TedM]

Or install 3 separate 3.9kwp domestic systems, one with my property address and the others at the address of two neighbours (each on a different phase). I get the FITs on all, but the savings and export only on my own. They get the free power from the other two, and their export income. Just like I had rented their roof, except they are renting my field space at 1p per annum.

It won't work quite like that. Either your two neighbours would each have to set up a FiTs contract and assign the whole income (FiTs plus export) directly to you (so their only benefit would be the free electricity) or they keep all the money and you have a separate contract just between the three of you to allocate the funds by some % method. And remember the agreements would have to remain effective for 25 years, including for any new neighbours who might move in.

OFGEM fraud dept might take an interest too, to make sure you were on the right tariff.

 

[Graeme Harrold]

Or install 3 separate 3.9kwp domestic systems, one with my property address and the others at the address of two neighbours (each on a different phase). I get the FITs on all, but the savings and export only on my own. They get the free power from the other two, and their export income. Just like I had rented their roof, except they are renting my field space at 1p per annum.

In the grand scheme, the export and savings are peanuts compared to the FIT..... Export at £150pa on 12kW and £5-700ish on savings............