Consequences of placing panels less than 50cm from roof edge?

zx80

Currently looking at roof-top PV installation on urban semi-D with hipped roof and it appears that to fit a meaningful array on the roof it may be necessary to place panels closer to the roof edges than 50cm.

I believe that such a move will diqualify me from the SEAI grant (can live with that). Are there any other issues that need to be considered e.g. strutural integrity of roof in wind, planning permission exemptions, home insurance?

Has anyone out there gone down this path that can share their experiences?

bullit_dodger

The reason for the 50cm is as you mentioned for wind loading. leaving a distance has proven to mimimise the risk of wind catching under the panels and attempting to lift it.

Why 50cm? Well they have to put some line in the sand. Bigger the distance the less risk. Makes sense to keep some distance if you ask me. 20cm is probably prudent though in keeping most of the wind off the panel.

Aside: I'm just a regular punter probably like you I don't have any special insight here - and also as an "aside" my very first computer was a zx81.

slave1

Lot of money to be turning down, could you look at different sized panels, there's a plethora available now

zx80

https://www.boards.ie/discussion/comment/119561576#Comment_119561576

Great to hear there is someone else out there who knew Uncle Clive and got to interact with his work!!!

zx80

https://www.boards.ie/discussion/comment/119561599#Comment_119561599

Can you provide links for different panel sizes? What I'm seeing is residential panels are 65" x 39", haven't come across anything other than this in Ireland...

slave1

Any of the sellers in Ireland, mine are significantly larger than that, browse here for example...

https://midsummer.ie/

https://www.failtesolar.com/pv-module

jkforde

you coooould comply with SEAI limits, once grant is signed off and banked, rearrange to suit yourself...

the_amazing_raisin

What I find surprising is that there doesn't seem to be any recourse if you go within the 50cm limit but get it signed off by a structural engineer.

I mean you'd need planning permission anyway if you're doing that, so you kind of automatically would need to engage an architect and engineer

bullit_dodger

https://www.boards.ie/discussion/comment/119580625#Comment_119580625

True - but they have to put some line in the sand. Otherwise, they will be reviewing load bearing equations from every submission. It's not their job to understand that. They need to have a quick/easy formula that they can apply. I don't particularly agree with 50cm, why not 30cm.....or 60cm for that matter, but they have decided that 50cm is a good number to run with. I get it - kinda.

the_amazing_raisin

https://www.boards.ie/discussion/comment/119580648#Comment_119580648

I get what you're saying, but I don't think it's really any extra work for SEAI. They aren't going to review the engineers calculations, they're just going to check if an engineer signed off on it and if that engineer is accredited by EI or another suitable body

bullit_dodger

It's just easier I think doing it the way they are. Out with the measuring tape, is it 50cm? No?.....well that's a fail.

As opposed to checking that the installer installed the right bolts correctly and that a registered structural engineer has signed off on the wind loading from an appropriate computer model which has all the right parameters in it.

(Don't get me wrong, what your proposing would be a better solution, just that it's occam's razor here I think)