Shed roof self-install

stephenchilds

Hi,

Am getting 2.96 kwp panels installed on main roof via SEAI installer.

Was thinking of supplementing with 6 panels on roof of log cabin in back garden. Materials come in around 2400 for panels plus inverter on solartricity.

A few questions:

Is it better to invest 2.5k in these extra panels or a battery for the main system?

Cabin roof slopes back 7 degrees in the wrong direction. Steel roof, trapezoidal I think. What mounting system would I need to raise the panels to the right elevation?

Is it a DIY job to fit panels on roof and wire back to inverter? Then electrician would just be connecting up inverter to existing consumer unit in log cabin?

Would a second inverter work ok? Assume I would have two separate monitoring web interfaces.

Thanks

Stephen

graememk

What about over specing the Seai one? Sounds like you'll only have 1 string on the main roof.

Put a 6kw inverter in for the grant, only use one string,

Then when it's all cleared just add the shed roof to the second string?

stephenchilds

Shed is about 11 m from house plus then another 5m? up to inverter in attic.

Is that not a long run for DC cabling?

graememk

https://www.boards.ie/discussion/comment/119194654#Comment_119194654

My panels are a good 70m away from the inverter. It is run on 6mm2 cable though.

But the first 10-15 are on standard solar cable where it comes down from the roof into the fireman switch.

SD_DRACULA

https://www.boards.ie/discussion/comment/119194654#Comment_119194654

This is fine I have the exact same setup on the standard 4mm DC cables for about 4kw of panels on my shed and no issue.

Get n 6kwh inverter and you'll have two strings. If you get inspected make sure to disconnect the shed string from the inverter so they cannot take that into consideration and ask for all sorts of 🐂💩 to be "fixed" as per some of their ridiculous standards.

stephenchilds

https://www.boards.ie/discussion/comment/119195164#Comment_119195164

Thanks for advice guys. Installer will do a 6kw dual string for 300 extra.

What I really need is a Solis 6kw hybrid but looking on solartricity there's a big jump in price, maybe 8-900 extra over non hybrid.

Also they are saying Solis not available until August.

stephenchilds

Hi still working with installer to see what we can get inverter wise. Stock is low everywhere!

Now another question:

the shed roof slopes back at 7 degrees in the wrong way (front is SE, back is NW)

It will fit 2 x landscape + 4 x portrait.

If I attach panels flat to roof (e.g., K2 minirail) the elevation will be wrong. They will be facing NW but only 7 degrees elevation.

It looks like it might be complicated getting mountings to elevate them particularly with the mix of orientation.

How critical is it to have the right angle?

connesha

https://www.boards.ie/discussion/comment/119210661#Comment_119210661

See "Does my Site Location make a difference?" section in the "Read this FAQ first" thread, here: #1

In particular, plug your proposed setup into this, and you can see the effect of the angles. https://re.jrc.ec.europa.eu/pvg_tools/en/#PVP

Mr Q

The K2 Minirail has got more expensive, like most probably, and short on supply it seems. But I have these on a trapezoid roof and I think they are a really good job.

You could try something like Novotegra if you are on a tight budget for the the fixings. Ordered some recently and they were much cheaper than the K2 equivalent, which was the Microrail in this case. This is also for a North West facing roof with a low angle.

What size is the roof?

graememk

The mini rails are super quick,

Screw directly into the steel.

As for orientation. At 7degress it doesn't make much difference! You'll lose a bit but not much. (Summer time will be your friend!)