Reasonable cost

tunnel

Ok, you are looking at 12 panels in a 4 x 3 portrait pattern. Now you need to get the quotes for that, believe it or not there are panels at 330W which can get you a 3.96kWp system but will cost you a premium, I say premium but I believe no more than £6k is achievable. That's a damn site better than you've been quoted so far.
If you wanted to pay a little less then 12 x 285W panels with a capacity of 3.42kWp should come in around the £5k price tag. Don't listen to any salesmen that only offer 250W panels, they clearly do not have a clue as to what is in the wider market.

SamRose

Great thanks Tunnel, I feel significantly more informed and ready for our next wave of quotes. Fingers crossed I'l be reporting good news by the end of the week!

Martyn1981

tunnel wrote: »

Ok, you are looking at 12 panels in a 4 x 3 portrait pattern.

Apologies T, but can I be really, really, really pedantic and suggest if 5m by 5m is total space, rather than useable space, then it's more likely to fit a 4 x 3 landscape pattern.

I'm thinking that 4.8m wide on a 5m wide roof, may be ok, just, pushing it to the edges, but just getting away with it, and 4m high on 5m would be ok. But 4.8m high on 5m high roof would be too tight given the necessary gaps at the bottom and top for planning rules, and run-off into gutters etc.

I know this is extremely petty, but just trying to dot the i's and cross the t's (make the T's cross!) so SamRose is fully informed, in case an installer abruptly says 3 panels high won't work, and confidence slips.

Regarding panels, I reckon you're dead right, has to be 270-285Wp panels to get that generation up. If that comes in at £4k to £5k then a very good investment. The roof would probably also fit 15 of the Panasonics in a 3 by 5 pattern, so 3.75kWp. [Edit: Nah, scrap that, the price premium of the Panasonics over the BenQ 285's just isn't worth it, my bad! M.]

Needs a good installer to have a proper thunk now, me thinks.

Mart.

tunnel

Martyn1981 wrote: »

Needs a good installer to have a proper thunk now, me thinks.

Mart.

I'd say it needs someone on a ladder to clarify the 5m x 5m because any discrepancy may or may not mean either portrait or landscape will get 12 panels on.

EricMears

tunnel wrote: »

I'd say it needs someone on a ladder to clarify the 5m x 5m

There are several ways to measure a roof. I'd always go for the 'climb up a ladder and walk about on the roof' method - but I'm blessed with a very shallow roof and low eaves. It's not quite that easy for most folk

It's reasonably easy to measure the width of a roof just by standing on the ground; measuring from gutter to ridge is a bit harder. If you can get inside the attic easily, it may be convenient to measure the underside of the roof - that will usually be slightly different to the real measurement but an error probably means the roof is actually a bit bigger than you've measured. If you can get up a ladder to gutter height, you may be able to push a stiff tape measure up to the ridge and read off length directly; or perhaps you could find a long bit of wood (e.g. a slater's lath) to push up and measure that; or just measure length of (say) three or four tiles and scale that up to the number of tiles visible.