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Solar Panels on Flat Vs Pitched Roof. Which is Better/Cheaper?

  • 28-05-2020 12:27pm
    Registered Users Posts: 1,365 ✭✭✭ blobert

    Hi Guys,

    I'm working on the design for a new build house which will have a very large (it's a big bungalow) south facing roof which I want to put a lot of solar panels on.

    From a design perspective I think a flat roof house looks better but as I'm planning to cover this roof with a lot of solar panels I'm wondering if a mono pitched roof might not work better.

    If you have a look at this design it shows the 2 options on one house that has both a flat and a pitched roof:

    If I were going with the pitched roof it would be clad in sheet metal like this, and I believe it's very easy to attached panels to it, there are just clips that attach to the seams in the metal.

    I think (and I could be wrong) if I went with a flat roof I'd then need to have some sort of metal racking that I'd attach panels to (a bit like in the pic here).

    While you might be able to get a better angle using these racks (the monopitch roof would be a very low angle so probably not 100% ideal for max solar gain) I'm guessing there would be additional expense with the racking, though I've no idea how much.

    I also have vague concerns about wind. I'm not sure if clipping tonnes of panels on to an aluminium/steel light weight roof is a great idea, I can see them blowing off and taking the metal with them if it's stromy.

    Anyway if anyone had any ideas on the benefits/disadvantages of either system I'd really appreciate it. Have to make a call on the house design with architects in the next day or two.



  • Registered Users Posts: 4,076 ✭✭✭ gman2k

    Design the roof what way you prefer it/ suits your house plan etc first.
    Solar panels can be laid horizontal, yes they won't make as much elec as one tilted optimally to the sun - solution is to simply add more panels then to suit your requirements. Panels are cheap these days. Look into east/west configurations as these are better suited to flat roofs.