Had second quote now off a local guy, £4500, but what are yours earning you please…..I don’t want to install them if there aren’t going to pay for themselves

I hope you mean 3.68kW (16A @ 230V) not 4kW.

Check Engineering Recommendation G83 and the ESQC Regs if you need to.

What they generate will depend on roof pitch, sun angle, your location and any obstructions. The installer should provide you with an estimate from modelling software. 4.5k sounds ok – check reviews for the supplied inverter.

IGM – a purist after my own heart!! I sold £3.68 kW systems but gio hammered by the 4kw brigade and the networks don’t seem to do anything to enforce the letter of the law.

OP – you need to say what angle the roof is, which direction it faces and how much shade, as well as your location before anyone can estimate your production. The good thing about PV Is that (shade notwithstanding) it is possible to predict with uncanny accuracy your production.

Post the answers (location =postcode) and I’ll tell you what you’ll earn.

£4500 is a good price btw so long as the company is reputable and can give you reference sites.

Smudger – I am the networks – round here anyway though I’m not looking after system design anymore.
We do ask people to apply at 4kW though it is unlikely there will be any charge. That said, the law above 16A at nominal voltage is different – you need a maintenance regime for example (which might well be easy to arrange). Also with the recent change to the old Mitchum Gardens ruling then below 16A per phase you can be reasonably sure if reinforcement is needed (excepting where it is on your service) you won’t be paying for it – above you will if it is needed.
So if you fit something over 16A and tell the DNO afterwards as if it was below 16A, then you are relying on their good will should reinforcement be needed.
But we’re nice guys, most of us, so you’ll be ok, probably.