Mounts needed for a clay tile roof

SchrodingersCat

I am in the process of roofing a shed.
I hope to mount solar panels on it in the near future. Now would be a good time for me to install the mounts so that there is less messing later on.
I was wondering, what mounts are needed for a clay tile roof such as this http://www.bluebangor.ie/product/planum-textured-clay-tile/ ?

Also, what offsets (maximum distance) should be between the mounts? Are there any other considerations that would be useful for me to be aware of? Any recommended suppliers for these mounts in Ireland?

Thanks.

buzz11

I've just completed the install of 7 panels on my garage which has clay tiles like yours (different brand).

Here are the brackets you need; https://solartricity.ie/k2-roof-fastner-for-flat-tile-15cm-h33-m10-a2/

I bought everything from Solartricity who are really helpful - I'd highly recommend them because support by phone is important for a self install.

If you are doing the roofing yourself then I'd probably wait until you are installing the full kit - its no big deal to lift tiles later to fit brackets and the panel layout will only become clear when you are setting them out.

SchrodingersCat

Thanks Buzz, its good to hear of someone with a very similar shed setup as myself. Your post is a great help. Especially your note on waiting until I am installing the full kit: I assumed that it would be much more awkward to retrofit the mounts after the tiles were up, and as the roof will get started soon, it would be handier for me to leave the installation of the mounts until later.
I had a look at solartricity there. Their kit designer tool is very useful for n00bs like myself and their prices seemed reasonable. I am looking to install 2x3 rows of panels, arranged horizontally. So the tool was able to recommend 24 mount points. Thanks!

buzz11

I had no experience with roofing when I started the job but it didn't take long to get a rhythm going.

If your tiles are nailed down, then its a bit tricky releasing the nails to slide the tile out, luckily I had kept spare tiles because I broke quite a few by rough handling.

I had two velux windows that split my row into 2 + velux + 2 velux + 3 so the cabling was much bigger job than I expected but it was a great lockdown project.

SchrodingersCat

Ive put through the order there for the 6 panels and the brackets you described above. From chatting to them on the phone, they confirmed that they were the correct ones.
Am I correct in assuming that as it is a DIY install, you cannot avail of any grants?

SchrodingersCat

To give an update, the mounts were very straightforward to put up in the end. I only broke one ridge tile in the process. The guide that solartircity gave said to screw the mounts into a secondary length of timber and having the secondary length of timber screwed into the rafter. However, from speaking to two roofer carpenters, they said it made more sense to them to screw them directly into the rafter so I went with that.

I have one of the six panels up, I should get to the rest soon. Thanks for the help!

buzz11

https://www.boards.ie/discussion/comment/117741378#Comment_117741378

Thats great that it worked out -- I also drilled straight into the rafters and when the whole thing is put together it seems very solid.

I notice you have the rails very close to each other - are the panels being mounted landscape orientation?

How have you secured the cables from panel to panel? I found this difficult to do because once the panel is clamped down there isn't enough room to cable tie the cables to the rails and the cables kept popping out of the rail channel

buzz11

Heres my finished setup

SchrodingersCat

Your setup looks great! :-)

That is reassuring that you drilled into the rafter too. Yes, they do seem to be very secure as they are. I know that the roof is not in a windy area by any means, so I am not too worried about them coming loose. Yes, I am running the panels horizontal as it will allow me to make the most of the limited shed roof space. I havent got to the stage of wiring up the panels yet. That is interesting what you said about running the cables in the cable channel. My first idea was to run them under the edges of the panels, cable tying them in place using the small pre-drilled holes in the steel of the panels. But to be honest, I havent put much thought into that part yet.

How did you connect your earth cable to the panels? Nothing came with the kit to do it. I bought some earth clamps that with some modification im hoping will do the job using the same pre-drilled holes.

Also, did you have just the one cable going from the shed to the house? If so, where on the circuit did you tap off power for the shed? I am planning on bring the power from the inverter over the AWG cable to a RCBO in the the consumer unit in the home.

I was going to buy a second RCBO to tap off the same point from the inverter to power the consumer unit in the shed. However, I am not 100% sure if this is the correct practice.

buzz11

Your right about the cables, the side edge of the panel will be ideal and you've holes already there for cable ties -- this will work better for you because your panels are horizontal.

Heres how the roof hook worked out, might be useful for someone else;

I simply tied the earth cable around a screw/frame hole, see pic below.

Hooks & rails ready for panels;

Because of the two velux windows, I had to do a lot more cable entry/exits so cut a small channel in the tile and used some hose pipe to give additional movement protection to the solar cable

On the final wiring up, I had an electrician do that part so no idea how it ended up - sorry can't help there But by that stage the two velux windows had wrecked my head so I was just glad to get a pair of cables for him to finish off the connections etc.

SchrodingersCat

Cheers for that information. I finished off the panels here too. They are wired up to the inverter. Il get an electrician to give it a look over and advise on connecting it up to the house before I power everything up.

That was a good idea to use the hose at the cable entries/exit. It looks tidy.

On the earthing, I used the outdoor earth clamps from Screwfix. They have holes on the side of the panels that allowed me to attach them. They were fiddly, it was tricky enough to tighten them, but they seem to do the job.

Im pretty happy with how they look.

@buzz11 , im probably getting off-topic here, but do you have any power monitoring system installed, for example an Owl meter or anything like that?

Im wondering how I will compare what PV power is being produced vs consumed.

buzz11

Very nice end result - they look great.

I'm using an owl intuition that I've had for years, its quite simple but gives me all the essential information such as house consumption and PV generation and exported amount. Its easy to see the impact of changing the immersion timer to daytime during the sunny weather and other changes that can be made.

My invert is a Solis/Ginlong which has a very handy app that shows instant generation and a graph of the day/week/month figures... pretty neat.