PV array on Loghouse?

jusmeig

phester28 wrote: »

@unkel google says pitch changes per season to get the most out of the panels. I would imagine that cloud acts as a diffuser but if we do get some direct sun would it not be more correct to have the panels at the optimum angle.

Ive spoken to a PV contractor. With the current pitch, there is only a 10% loss in efficiency annually. I'm happy with this as I think to get up to 30 degrees would not be worth it.

Making a cradle to change angle might not be a good idea, someone already mentioned that wind etc becomes an issue.

jusmeig

unkel wrote: »

Make sure you get the roof hooks and rails installed. Will set you back a couple hundred in materials plus labour

Once you have the budget to buy the panels, you and a buddy can fit the 10 panels easily in under an hour with the hooks and rails already in place

The PV contractor told me to go for a shingle roof, and not a metal one as it will be easier for them to install the panels at a later date. For the time being im going to have them add cabling as the cabin will have power to begin with, just not PV.....cost etc etc....

air

unkel wrote: »

Why? Pitch makes no difference. Hooks will go into rafters and rails connect to hooks.

How are you going to waterproof the hooks? Hooks are only used on slated or tiled roofs, which aren't viable at that pitch.
I suspect the contractor will use stainless through bolts, which are designed to seal against steel cladding and not shingles.

jusmeig

air wrote: »

How are you going to waterproof the hooks? Hooks are only used on slated or tiled roofs, which aren't viable at that pitch.
I suspect the contractor will use stainless through bolts, which are designed to seal against steel cladding and not shingles.

I gave the PV installer the roof options. He spoke to the guy who mounts the panels, and he advised getting a shingle roof? Im going to get him to double check, but this is the info I have got so far. Im sure there any multiple mounting options!

unkel

air wrote: »

How are you going to waterproof the hooks? Hooks are only used on slated or tiled roofs, which aren't viable at that pitch.
I suspect the contractor will use stainless through bolts, which are designed to seal against steel cladding and not shingles.

Yes, that's why I asked was he upgrading the roof to steel. It is a lot cheaper and easier to mount rails for solar panels to steel roofs, which will pay towards the upgrade costs for the steel roof.

jusmeig

unkel wrote: »

Yes, that's why I asked was he upgrading the roof to steel. It is a lot cheaper and easier to mount rails for solar panels to steel roofs, which will pay towards the upgrade costs for the steel roof.

Do you or have you done this type of work before?
I'm speaking to Solar Electric and they have said the opposite. Mounting to steel roofs presents much more of an issue - note this might just be in relation to how my specific cabin is constructed.

He basically said they can lift the shingles to install the mounts for the rails below. There are 4 or 5 rafters running the length of the cabin, so these can be used for fixing.

I'm no roofer...for the record.

air

Did you tell them the pitch of the roof?

I've installed PV to steel using solar hanger bolts, it's the easiest roof mounting system you could possibly install (that I'm aware of).
Granted I used oversized battens when roofing the shed so that I could fix directly into those instead of the rafters.
They are probably talking about coming to a roof blind, where they would have difficulty locating the rafters to screw the hanger bolts into.

jusmeig

air wrote: »

Did you tell them the pitch of the roof?

I've installed PV to steel using solar hanger bolts, it's the easiest roof mounting system you could possibly install (that I'm aware of).
Granted I used oversized battens when roofing the shed so that I could fix directly into those instead of the rafters.
They are probably talking about coming to a roof blind, where they would have difficulty locating the rafters to screw the hanger bolts into.

They have all the info on this thread! I sent them the drawing and yes they are aware of the pitch.

air

Fair enough, I had a look at the photos again, the pitch isn't quite as low as I thought so the shingle mounts might work I guess.
I just wouldn't touch shingles, you're just signing yourself up for a roof replacement every few years, which won't be made any easier with PV on top.

jusmeig

air wrote: »

Fair enough, I had a look at the photos again, the pitch isn't quite as low as I thought so the shingle mounts might work I guess.
I just wouldn't touch shingles, you're just signing yourself up for a roof replacement every few years, which won't be made any easier with PV on top.

Yeah well i'm working from their advice.

My guess would be that the PV panels will protect the roof for the most part, and its quite sheltered - wishful thinking?
Got 20 years out of a felted barna shed before ophelia took the felt