Advice on my PV quote

Stan_Dad

Hi all,

I'd be grateful for your advice on a quote I've had for solar panels. The quote is for 10 x 320w seraphim panels and a solis 3.6kw inverter, neither of which I've heard of. The roof is due south and I'm told, based on a 70% onsite usage, will payback in 6 yrs if I hand over £5k before Christmas. Problem is, I have a combi boiler and work full-time: putting aside the on-site use which seems high, is the price fair, and is the system any good?

Martyn1981

3.2kWp for £5k isn't awful but its not rock bottom.

Do I assume roof space is limited, otherwise push for 4kWp.

If you are out most days, I'd expect your consumption of generation to be at the lower end, perhaps 20%(ish), and also at the lower end of £80 to £160 pa.

Have a look at the PV FAQ's sections 1 & 2 for basic advice, and section 5 to get an approximate estimate of generation. From there you'll be able to guesstimate the FiT and export income element.

There are so many makes of inverter and panels now, that it's almost impossible for anyone to comment on them, but they are (at least) brands that have been mentioned before.

Mart.

Stan_Dad

Hi Martyn.

Thanks for the links.

Yes, its a small roof and can only take 10 panels (I was going to post a picture of a nearby roof but can't seem to find a tool for this?). I just need to know whether this price is keen and if there are people out there with experience of these brands.

Martyn1981

Stan_Dad wrote: »

Hi Martyn.

Thanks for the links.

Yes, its a small roof and can only take 10 panels (I was going to post a picture of a nearby roof but can't seem to find a tool for this?). I just need to know whether this price is keen and if there are people out there with experience of these brands.

Just a few thoughts, but only personal opinions.

£4k would be a nicer price for 3.2kWp, but time is against you before the government (probably) decimates the FiT.

Those panels are normal efficiency, they generate more by simply being bigger than normal at 1m by 2m, rather than the more common 1m by 1.6m.

Technically, BenQ 285W panels will produce more power to roof space, possibly 3.5kWp for the same space as 10 of those Seraphims. However, it will depend on the shape of your roof, so those 10 panels may be the best fit.

The Solis inverter is pretty cheap, but only has a 5yr standard warranty. For £50 more you could get a Samil 3.68kW inverter with a 10yr warranty. But ..... you need to decide on this, for all I know the Samil might fail at 10yrs and 1 day, whilst the Solis lasts 15yrs ..... your guess is as good as mine.

Mart.

Stan_Dad

Thanks for this Martyn.

I've had a 2nd installer come round who's proposing a 3.9KWp array with a 3.68 inverter. If the inverter can only handle 3.68KW however, should I reduce the array to 3.6KWp? The aspect is due south.

The price for this is 6K (I'm in London).