PV array on Loghouse?

jusmeig · 06-10-2018 4:12pm #1

Hi there,

I'm planning on getting one of these -> https://www.loghouse.ie/product/wicklow-log-cabin-6m-x-4m

I've spoken to the guys who make them and they have told me that I can mount PV panels on the roof. Couple of questions I am unsure about tho:

Planning Permission!?: I already have 1.85kw of PV on house (one half my roof space is covered). This is a shed however, so i'm not sure if you fall into Conditional Planning Exemptions -> https://www.seai.ie/resources/publications/Conditional_Planning_Exemptions.pdf
Nothing about sheds in this?!

Pitch of the roof, I've read 53 degrees is ideal for Ireland?
Would appreciate any help or advice!

Thanks

Gumbo · 06-10-2018 11:38pm

The exemption allows for 12Sq. M or 50% of the roof within the curtilidge so my guess would be that they are not exempt. Lodge a section 5 application for clarification.

rolion · 08-10-2018 9:56pm

Do you really think that someone will complain that you have fully covered your loghouse roof with PV panels !?

I'll go full roof...make sure it does a good return on the install, coverage, shading and length of cabling.
I'll make a metal frame so that I can adjust angle for summer vs winter to get maximum return.

Good luck...

unkel · 10-10-2018 9:40pm

jusmeig wrote: »

I'm planning on getting one of these -> https://www.loghouse.ie/product/wicklow-log-cabin-6m-x-4m

Very interested in this. Also that model and size (planning exempt). And I would also plan to fit solar PV to it.

How far are you in the process? What extras are you going for if any? Any insulation? Are you getting a steel roof for easier (and cheaper) PV installation?

Is there any negotiating on those advertised prices? On the foundation and install prices?

11-10-2018 10:36am

I wouldn't stop at the roof. Solar veranda would be nice too if it doesn't compete with internal habitation light gains.

There's a rare breed of glass on glass panels you can get for semi-translucent roofing.

unkel · 11-10-2018 11:01am

rolion wrote: »

I'll go full roof...

It's 6 * 4m, and the roof looks like it has quite a bit of overhang on both sides, so should fit 2 rows of 6 panels, for 3.6-4kwp in total

Hoagy · 11-10-2018 11:21am

unkel wrote: »

What extras are you going for if any? Any insulation? Are you getting a steel roof for easier (and cheaper) PV installation?

Steel roof is a must IMO.

I would also definitely recommend wall insulation. I have a 4mx4m home office with 45mm thickness walls and it bakes in summer and freezes in winter.

I doubled the roof insulation thickness but it made no noticeable difference, if I was doing it again I would go for 70mm walls.

unkel · 11-10-2018 11:26am

Not cheap though. The cabin is a bit over €5k with floor insulation, but with installation, foor and wall insulation and a steel roof it's touching on €10k

jusmeig · 15-10-2018 4:36pm

unkel wrote: »

Very interested in this. Also that model and size (planning exempt). And I would also plan to fit solar PV to it.

How far are you in the process? What extras are you going for if any? Any insulation? Are you getting a steel roof for easier (and cheaper) PV installation?

Is there any negotiating on those advertised prices? On the foundation and install prices?

Im dead in the water. So the pitch on this roof is only 7.5 degrees, which is no use. They would need to raise the highest height to 4.4 meters to get a 30 degree pitch, at a cost of 2k

This price is prohibitive.

So i've asked the solar installer can the desired pitch be got by mounting on this roof, but using the mounting system to get the desired pitch...

U can expect to be paying 10k for a fully insulated Wicklow loghouse. I was going to go with the steel roof yes.

jusmeig · 15-10-2018 4:48pm

PV company said that the difference in the pitch will only amount to a decrease of 10% in overall efficiency. So the cost to achieve the ideal pitch is not really worth it. He recommends installing them on the 7.5 degree pitch, as you would be a VERY long time marking back the 2k cost.

Good point about wall insulation, but that is really pricey, comes in at 1300 extra for insulation and TG cladding on inside, does not list thickness but id say 100mm

unkel · 15-10-2018 6:08pm

Yeah I thought the wall insulation was pricey too. And yes your installer is right. PV panels are so cheap and it doesn't matter all that much what way they are facing and at what angle. Even flat and even north facing! Just stick 12 panels on that roof

jusmeig · 15-10-2018 6:12pm

unkel wrote: »

Just stick 12 panels on that roof

Going to put 10, 12 would not allow for a 500mm gap to the edges...thus enraging the Irish planning gods.

unkel · 15-10-2018 7:30pm

I guess if you are putting up more than 7 panels, you need planning permission anyway, so if you are going for that, you might as will keep to the regulations

jusmeig · 16-10-2018 11:53am

unkel wrote: »

I guess if you are putting up more than 7 panels, you need planning permission anyway, so if you are going for that, you might as will keep to the regulations

I know my neighbors well, and find it highly unlikely they will object.
Also I cannot see the council blocking a renewable project, but I wait to be amazed on that point!

air · 16-10-2018 9:40pm

The bigger issue with low pitch is that once you go under about 15 degrees you need to clean the panels, rain won't do the job effectively.

jusmeig · 17-10-2018 9:57am

air wrote: »

The bigger issue with low pitch is that once you go under about 15 degrees you need to clean the panels, rain won't do the job effectively.

Good point, Is there anything to that other than a ladder and a rag? IE some special care?
The labour of doing it would not brother me.

unkel · 17-10-2018 10:14am

pressure washer + 10 seconds per panel should do it. I would put the pressure washer on as low pressure as possible though, just in case. Probably no need for using any detergent in most cases

Gumbo · 17-10-2018 11:14am

jusmeig wrote: »

Going to put 10, 12 would not allow for a 500mm gap to the edges...thus enraging the Irish planning gods.

jusmeig wrote: »

I know my neighbors well, and find it highly unlikely they will object.
Also I cannot see the council blocking a renewable project, but I wait to be amazed on that point!

10 panels will still exceed the exemption limits, so what's the point adhering to the 500mm edge rule?
If your going to be in breach of Planning exemptions, then you may as well go all out and add the extra 2 panels.

The Council will not block the project, but if they get a complaint then they will legally have to act on it, forcing you to either remove the panels to below the exempted limit, or get you to apply for a planning to retain the panels as constructed.

SemperFidelis · 17-10-2018 12:26pm

Can you get around planning issues by making the roof out of solar panels.

Gumbo · 17-10-2018 2:12pm

SemperFidelis wrote: »

Can you get around planning issues by making the roof out of solar panels.

No

jusmeig · 17-10-2018 2:41pm

My "Plan" is to get the Shed installed, no planning permission.
Then I can apply to have the panels installed on the roof. The planning is for the panels...not the shed, they shed is shed, im not living in it.

Am I right in this ^^^ ??

Gumbo · 17-10-2018 4:01pm

jusmeig wrote: »

My "Plan" is to get the Shed installed, no planning permission.
Then I can apply to have the panels installed on the roof. The planning is for the panels...not the shed, they shed is shed, im not living in it.

Am I right in this ^^^ ??

Shed can be exempt up to 25 Sq. M in internal floor area, max height of 3m with flat roof or 4m with a pitched roof. You must then have 25 Sq. M of rear garden space remaining.

You can then of course apply for planning for a bigger Solar PV array. You will most likely get granted planning, but the application process is a formality.

jusmeig · 17-10-2018 4:33pm

kceire wrote: »

Shed can be exempt up to 25 Sq. M in internal floor area, max height of 3m with flat roof or 4m with a pitched roof. You must then have 25 Sq. M of rear garden space remaining.

You can then of course apply for planning for a bigger Solar PV array. You will most likely get granted planning, but the application process is a formality.

I can confirm it will be pitched and will be 1m short of 25sq!
Will def have 25+ sq left!
Thanks.

air · 17-10-2018 5:05pm

Yes that sounds correct.

17-10-2018 6:07pm

kceire wrote: »

10 panels will still exceed the exemption limits, so what's the point adhering to the 500mm edge rule?

To mitigate turbulent wind loading and making your gutters redundant.

jusmeig · 19-10-2018 1:11pm

Ive attached a render of the cabin for anyone interested.
I cannot do the PV and cabin in the same job due to cost, but the plan is to add cabling for PV during install of cabin, the panels will go on in 2019....budget/planning permitting...

unkel · 19-10-2018 1:19pm

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

Subcomandante Marcos · 19-10-2018 1:21pm

To increase the pitch of the panels could you not fabricate a cheap cradle for them that lifts the back end to augment the natural pitch of the roof?

air · 19-10-2018 1:23pm

Not sure how easy it will be to mount rails to that type of roof given the low pitch.

unkel · 19-10-2018 1:28pm

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

phester28 · 19-10-2018 1:54pm

@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.

jusmeig · 19-10-2018 2:12pm

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 · 19-10-2018 2:14pm

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 · 19-10-2018 2:25pm

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 · 19-10-2018 3:54pm

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 · 19-10-2018 4:29pm

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 · 22-10-2018 11:15am

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 · 22-10-2018 11:22am

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 · 22-10-2018 11:29am

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 · 22-10-2018 11:32am

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 · 22-10-2018 11:36am

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

PV array on Loghouse?

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