Solar panels as "solar shingles"

Arqane
Arqane Solar Expert Posts: 31 ✭✭
in General Solar Power Topics #1
I've been researching this a bit, and want to get more information from people who have dealt more with installations. There are the solar shingles around now, which have their ups and downs, but mostly downs. They're less efficient, and the wiring is trickier, so there seems little reason to use them unless necessary. Then there's the standard panels. They're almost always the best bang for your buck. But since they have most of the characteristics of good roofing material, what are the real reasons they aren't simply used as roofing material? Here's the good and the bad that I've found so far, please add anything or pick on them:

The Good:
-Solar panels are highly durable, and built to withstand forces similar to a tile roof. In a lot of ways they mimic a tile roof.
-They are waterproof, so as long as they're fitted together well, with a little overlap space that isn't actual cells, they could create a waterproof surface.
-As I understand, the wiring is usually simpler than the solar shingles.
-Using solar panels instead of standard roofing materials would lower the materials cost with less mounting, and less redundancy (who needs 2 waterproof surfaces on top of each other?).

The Bad:
-Cooling issues. The back of the solar panels would be directly on the attic, which can reach 140+ in hot areas. On the other hand, with proper construction, you have a distinct place that can be used to cool the panels with ventilation or other methods.
-Issues with maintenance. Obviously covering the entire roof could make maintenance difficult, but a type of built in track system could potentially ease that.

The main thing I see is the high costs of redundancy. You pay for your roofing material, and you pay for mounts, to place panels which you pay part of the price to make them as weatherproof as a rooftop. The added materials cost and installation is now more than the panels actually cost. The question is, can that be done away with?
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Comments

  • South Africa
    South Africa Solar Expert Posts: 295 ✭✭✭
    #2
    Re: Solar panels as "solar shingles"

    I also looked a while back, before we extended thehouse, at solar roof tiles.

    Someone then said to me: Tile and metal roofs last, wot, 30-50 years.

    Solar shingles will have to be replaced after 20-25 years, depending on their quality.

    So, if you sell the power the back, or not pay for any, or little, electricity, then the savings could outstrip the +-20-25 year replacement cycle of panels.

    But, if the panels do not last that long, or not provide the savings, you may run into problems.
    5kVA Victron Multiplus II, 5.2kW array, 14kWh DIYLifepo4 bank, all grid-tied.


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  • Arqane
    Arqane Solar Expert Posts: 31 ✭✭
    #3
    Re: Solar panels as "solar shingles"

    I also forgot to add in the fire hazard. You would need to get through the system in case of a fire. A rack type system where you could slide them out would make it quick, but might be a problem if part of it melted.
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  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #4
    Re: Solar panels as "solar shingles"
    Arqane wrote: »
    I also forgot to add in the fire hazard. You would need to get through the system in case of a fire. A rack type system where you could slide them out would make it quick, but might be a problem if part of it melted.

    Don't worry if the firemen need to get through they will just hack the panel. There was some rumor around here in Phoenix that the fire departments would just let a solar house burn for fear of hitting the DC with any water.
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  • Arqane
    Arqane Solar Expert Posts: 31 ✭✭
    #5
    Re: Solar panels as "solar shingles"

    I actually just chatted with the local fire chief. It is actually a concern for them, though they have procedures for it. The shunt is the main thing they're concerned about, and they usually just tarp off the panels.

    But yes, please keep piling on the critique either way.
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  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #6
    Re: Solar panels as "solar shingles"
    Arqane wrote: »
    -They are waterproof, so as long as they're fitted together well, with a little overlap space that isn't actual cells, they could create a waterproof surface.

    That's glossing over a major problem which is how to fit them together in a waterproof way. The overlap that typical panels provide is not that much, and it's also not clear whether the frame is designed to withstand the weight of another panel on top of it. You may be voiding the warranty mounting them like that.

    IMO, the cost of plain old uninsulated metal roofing is not that great to warrant a complicated and potentially flawed solar roof. Just put metal roof + solar panels on top, no issues with water proofing and I don't think the costs of mounting gear is that great.

    FYI, heres a commercial inroof mounting system for frameless thin film modules: http://www.renusol.com/en/pv-mounting-solutions/intrasole.html
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  • solarix
    solarix Solar Expert Posts: 713 ✭✭
    #7
    Re: Solar panels as "solar shingles"

    There is a product called "easyroof" that came out of the Oakland solar incubator which turns a regular solar module into a large shingle. No need for any roofing underneath and has some good cost savings as a result!
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  • Arqane
    Arqane Solar Expert Posts: 31 ✭✭
    #8
    Re: Solar panels as "solar shingles"

    I'll look into that. Solar panel prices can only come down so far. And since they're already getting to be a small portion of the overall costs, there should really be more focus on lowering the other costs.
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  • Arqane
    Arqane Solar Expert Posts: 31 ✭✭
    #9
    Re: Solar panels as "solar shingles"

    The BIPV mounts do seem to be out there. Easyroof looks pretty good. They seem to be based out of France, but with distributors here in the US. I found a few others as well. So there are companies out there with this idea. I'll have to see which ones will work well in the Florida climate.
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  • AuricTech
    AuricTech Solar Expert Posts: 140 ✭✭
    #10
    Re: Solar panels as "solar shingles"

    While it isn't likely to be a deal-breaker in most cases, using the PV panels as the roof does prevent seasonal tilt adjustment for maximum efficiency. Of course, this approach may save enough money to allow for the addition of extra PV panels to make up for not being able to tilt them.
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  • Arqane
    Arqane Solar Expert Posts: 31 ✭✭
    #11
    Re: Solar panels as "solar shingles"

    In my project, that's being mitigated by the fact that it's new construction. We're designing a roof that's southern facing and at the optimal angle for Florida. It's not going to be perfect through the whole year, but it's pretty easy to get very good efficiency when the building is designed specifically to house solar panels on the roof. Better than most retrofits would be, at least.
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  • Arqane
    Arqane Solar Expert Posts: 31 ✭✭
    #12
    Re: Solar panels as "solar shingles"

    Did more research on the Easy Roof. It's still decently expensive, although probably cheaper than building the roof first and then adding the mounts. Still, there are some concerns. They have a warranty of 10 years, which isn't particularly good. They already have some 'venting' under each module, but it looks like a matter of a few cm or inches. We're planning on mitigating the attic heat anyway, but then that venting might be counterproductive since we might not be able to cool the panels as directly.

    Does anyone actually have any experience with this product or other that are similar?
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