Solar Panel Guide Discussion

John_Pierpoint

Lck wrote: »

I'm not getting anything like that - average 3 per day for this week. Have discovered that some of the panels are partly shaded until around 10am - I suppose that could be making a big difference. None of the panels are due south due to the shape of my roof, they're all east or west.

Have you got two inverters, one for each roof?

John_Pierpoint

rogerblack wrote: »

It depends.

Replacing a single panel is going to be a little problematic.
It needs ideally to match the other panels in the string in terms of current and voltage output, and also in size and fittings, and then you've got asthetics.

If you're willing to accept 'mostly matching' - then it's not _too_ bad.
If you want it to look exactly the same, it's going to be a problem.

I wonder if one ought to buy a spare right from the start?

energysavingexp

11.8kwh today for me panels in shade from 9 to 12.30

Care4Pets

Hi has any one got panels on a flat roof facing NW is it worth doing??

TrickyDicky101

If it's a flat roof, how can it be facing North West?

Care4Pets

Lol sorry we are having 8-10 panels on the front roof which faces SE the back roof faces NW but we have 2 dormer windows so part of the roof is flat does that make more sense:j

TrickyDicky101

So have your installers suggested you place panels on this NW roof? Did they say to place them on top of the dormers (which are presumably flat)? Have they talked about mounting systems if on the flat portion of the roof? You may need planning permission for this as it may not fall within Permitted Development (due to being more than 200mm from the roof structure).

If the panels are layed completely flat, they won't self-clean and thus their yield will be seriously impeded over time unless they are cleaned (eg by yourself).

What size of system are you looking at? How much roof space on the Southerly facing portion do you have? Some panels are considerably smaller than others (for the same power output) which can thus maximise system size (but which will often cost more).

I have limited space so have used Sanyo N235s which are a relatively small size and allows me to maximise my array size.

Also, if you split the panels you will either need 2 inverters or an inverter with a dual MPP tracker (eg an Aurora Power One).

Care4Pets

No he didn't think the flat roof NW facing was suitable (sales guy) But has put a note asking for survey guy what he thinks when he comes. Front roof also has dorma/flat roof and some are going on there he said they would be tilted. Estimate is for 10 Rec 240w panels to generate 2.4 KW
I didn't realise I would need planning permission

TrickyDicky101

Normally you don't but you might if a mounting system is used on a flat roof that protrudes further than 200mm from the roof structure (AFAIK). Is it a case that Rec are the only panel the installer fits (they are a good panel as far as I know) - or has he suggested any other panels also?

Care4Pets

When I was price haggling he said he could do a cheaper chinese panel but I didn't want that.