Solar roof tiles in 2024 - Page 1
Forum section: electronics / general

author: coppice
author_rank: Super Contributor
timestamp: November 04, 2024, 11:11:29 pm
content: It has been a while since solar roof tiles were discussed here. Last time around they seemed immature, very expensive, and a generally poor idea. Recently I have noticed a few houses in our area (York, UK) which seem to have some sort of integrated solar panels as roof tiles. I can find a few web sites about solar installations in the UK with recent pages listing several suppliers, and price comparisons showing higher prices than big rectangular solar panels, but nothing crazy. Has this technology matured into something workable, or are these sites just BS advocacy?

author: nctnico
author_rank: Super Contributor
timestamp: November 04, 2024, 11:55:20 pm
content: These kind of solar panels start to become common in the Netherlands for newly build houses. A big downside is fire safety. If there is a fire in the attic, the integrated solar panels make it next to impossible for the fire brigade to put the fire out from the outside. They basically have to use an excavator to tear the entire roof off. Whereas with ceramic / concrete tiles, they just pull the tiles off and kick in the interior lining, in order to reach the fire.Not integrated solar panels but a fully covered roof:Without the solar panels, they would have been able to contain this fire to one home but now 3 homes burned.

author: coppice
author_rank: Super Contributor
timestamp: November 04, 2024, 11:58:18 pm
content: Quote from: nctnico on November 04, 2024, 11:55:20 pmIs there something specific to solar tiles with the fire issue? Surely any solar panels on a roof represent high voltages and high power as a safety hazard when there is an emergency.

author: nctnico
author_rank: Super Contributor
timestamp: November 05, 2024, 12:00:30 am
content: It is not even about high voltages or electric fires, there simply is no access to get to fires in attics. At other levels, you can break the windows and spray water in but attics are problematic. Even more so as the roofs are typically constructed using wood where lower levels are typically build using stone / gipsum / concrete.

author: Someone
author_rank: Super Contributor
timestamp: November 05, 2024, 01:00:35 am
content: Quote from: coppice on November 04, 2024, 11:58:18 pmAppears to be a identical issue with anything other than a tile roof.https://en.wikipedia.org/wiki/Corrugated_galvanised_ironMaking the post more of the political posturing/misinformation that user so frequently pushes.

author: nctnico
author_rank: Super Contributor
timestamp: November 05, 2024, 10:29:52 am
content: Maybe do some research first.... A corrugated steel roof can be cut or unscrewed to gain access. The fire brigade has tools on hand for such cases.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 05, 2024, 11:01:18 am
content: I heard recently that solar roofs can actually be cheaper than tiles. For a new roof it seems like a no-brainer for locations that get sufficient sun.

author: tszaboo
author_rank: Super Contributor
timestamp: November 05, 2024, 12:39:38 pm
content: Quote from: mikeselectricstuff on November 05, 2024, 11:01:18 amDo you know any European distributor with list prices? The ones I saw were always "ask a quote". Which makes it difficult to compare to anything.

author: coppice
author_rank: Super Contributor
timestamp: November 05, 2024, 05:34:14 pm
content: Quote from: mikeselectricstuff on November 05, 2024, 11:01:18 amThe information I have found makes them appear comparable in cost to tiles + secondary panels. So, if you are having a total roof refurbishment they give you a nicer looking result, and no hassle with birds nests and insect nests under secondary panels, for around the same price. This seems like good news if the suppliers have really sorted these things out, and they truly have the predicted lifetime. Warranties don't really count for much with these things. If the product is good you don't need a warranty. If the product sucks they will go bankrupt too fast to ever serve a claim.

author: coppice
author_rank: Super Contributor
timestamp: November 05, 2024, 05:36:06 pm
content: Quote from: tszaboo on November 05, 2024, 12:39:38 pmYou are only going to see hard pricing for parts. The suppliers I have found only offer systems, either installed by them or installed under their supervision. So, they can only give vague guide prices until you show them the complexity of the site.

author: coppice
author_rank: Super Contributor
timestamp: November 05, 2024, 05:39:33 pm
content: Quote from: nctnico on November 05, 2024, 10:29:52 amThis is similar to EVs and car accidents. Fire services are well prepared to rip through almost anything to get to victims and fire, but are not prepared for things with high voltages present that lack a clear and accessible breaker. A fire in a building with solar panels is probably OK to deal with at night. Maybe you let the building burn until dusk.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 05, 2024, 05:45:16 pm
content: Quote from: coppice on November 05, 2024, 05:39:33 pmWhich sort of brain damage causes people to come up with this kind of crap?

author: coppice
author_rank: Super Contributor
timestamp: November 05, 2024, 06:36:56 pm
content: Quote from: nctnico on November 04, 2024, 11:55:20 pmDo you know any brands of panel that are used. Looking a bit more at what is available in the UK they seem to all be small players, some on the edge of bankuptcy, apart from Tesla. I assume none of them are making their own panels, but I haven't found who does. For examplehttps://solexenergy.co.uklooks OK until you notice they have been supplying solar systems since 2004, and have only supplied 150 solar thermal and solar PV roof systems. They imply they make the panels, but I can't imagine someone that small really does. I can find their panels being sold on ebay.co.uk The pictures on their site look like the panels I see on a couple of large local newly built houses, blended with natural slate tiles.

author: coppice
author_rank: Super Contributor
timestamp: November 05, 2024, 06:38:47 pm
content: Quote from: Siwastaja on November 05, 2024, 05:45:16 pmHuih?

author: nctnico
author_rank: Super Contributor
timestamp: November 05, 2024, 06:46:59 pm
content: Quote from: coppice on November 05, 2024, 06:36:56 pmI have found this one:https://www.wevolt.energy/This is a subsidiary of Wienerberger, a company specialising in building materials. Another random Google find:https://solinso.nl/en/But this seems to be a smaller company (at least it looks like it to me).

author: coppice
author_rank: Super Contributor
timestamp: November 05, 2024, 07:19:22 pm
content: Quote from: nctnico on November 05, 2024, 06:46:59 pmI would be interested in how the Wevolt panels work. They look nothing like tiles. There is no staggering to ensure complete coverage. Do they rely on sealants being 100% reliable for decades?https://solinso.nl/enlooks a bit sad. The "READ MORE" button right in the middle of their home page gives a 404.

author: Someone
author_rank: Super Contributor
timestamp: November 05, 2024, 08:38:19 pm
content: Quote from: nctnico on November 05, 2024, 10:29:52 amClassic you, add some more information after the fact which changes the statement substantially. So we've gone from anything but roof tiles are bad, to "well actually it's just an issue of uncontrolled electricity". Which is what the fire services would have said:https://www.rfs.nsw.gov.au/__data/assets/pdf_file/0004/247891/OP-1.2.22-Photovoltaic-Arrays.pdfUnscrewing or cutting roofing sheet is comparable to unscrewing or cutting panels.So yes, pretty much your entire post and the reply was misleading and shy of the truth.

author: Marco
author_rank: Super Contributor
timestamp: November 05, 2024, 10:45:16 pm
content: Quote from: nctnico on November 05, 2024, 10:29:52 amMaybe they should start making electricallyconductivefirefighter suits? Then they can just cut through the panels with the rescue saw too.

author: tszaboo
author_rank: Super Contributor
timestamp: November 06, 2024, 09:04:32 am
content: Quote from: coppice on November 05, 2024, 05:36:06 pmThis is a business practice, where they hide the actual prices and rely on the lack of information and convenience. I don't really like that, I find it dishonest and not inline with what I expect for this century.Also roof tiles are like 2 EUR each, they are very cheap, they last 40 years, and repairs are easy.I really want built in solar to succeed, but for that they need to do better.Quote from: Marco on November 05, 2024, 10:45:16 pmIssue is with the high voltage DC cables arcing. And I don't think it's a valid one, I find this issue much smaller than people installing highly volatile lithium ion batteries in their garages. As opposed to LiFepo, Na-ion or the future solid state batteries.

author: nctnico
author_rank: Super Contributor
timestamp: November 06, 2024, 09:46:06 am
content: Quote from: coppice on November 05, 2024, 07:19:22 pmIf you click on the NL page on the Wevolt site, you get to a page with more pictures (including how it works together with the roof construction). It looks like a staggered system. But there are probably many systems in use at this moment as the technology itself is still maturing. The system on the picture I posted above, is a retrofit. They probably put EPDM rubber on the roof to make it water tight and mounted the panels raised so the panels have cooling.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 06, 2024, 09:55:50 am
content: I would expect that as time goes by, someone has to be able to commercialize1) solar roofs,2) microinverters,preferably integrated into each other to become a single product,which are cost-effective and reliable.The current "separate" panels with the current mounting systems plus string inverters are clearly a compromise, just a very good status quo, which work so well and have massive economy of scales backing it up. Alternative needs to be significantly disruptive, executed nearly perfectly with great attention into all small details, plus then needs massive investments so that cost can be brought down from the start bypassing chicken-egg problem. But I'm quite sure some day we will see it. Now we are stuck in a pretty good local minimum/maximum, and most attempts trying to change the market fail because they are either prohibitively expensive, or get some important detail wrong, or are not disruptive enough.

author: coppice
author_rank: Super Contributor
timestamp: November 06, 2024, 12:28:54 pm
content: Quote from: nctnico on November 06, 2024, 09:46:06 amInteresting. I didn't try looking at the national pages before. The NL page has pictures of more diverse designs, which I find more worrying than reassuring. They seem to be using a scatter gun approach, rather than focussing on one or two approaches, and pushing them as hard as they can to get them right. Right being cheap and trouble free.Relying on something like EPDM layer for waterproofing sounds like trouble. I hope they would use a more fault tolerant approach.

author: nctnico
author_rank: Super Contributor
timestamp: November 06, 2024, 12:35:23 pm
content: After quite a bit of research into suitable roofing materials, I have used EPDM on my self built shed because it is said to last for about 50 years (compared to 15 years for bitumen). In the shade under solar panels, this should be much longer. IOW: I wouldn't worry about using EPDM rubber as a material to make a roof water tight; it is proven technology.

author: coppice
author_rank: Super Contributor
timestamp: November 06, 2024, 12:43:38 pm
content: Quote from: nctnico on November 06, 2024, 12:35:23 pmIts not the lifetime of EPDM that bothers me. Its the effects of minor damage. Practical outdoor design needs to be tolerant. Being under the tiles it might be EPDM is adequately protected, but I'd like to see how it really works out with the slings and arrows of outrageous weather conditions, and stuff getting blown about.

author: nctnico
author_rank: Super Contributor
timestamp: November 06, 2024, 12:52:34 pm
content: Quote from: coppice on November 06, 2024, 12:43:38 pmNo problem. I have a tree hanging over the roof and branches falling on it (while trimming the tree) is no problem. EPDM rubber for roofing is very sturdy and durable.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: November 08, 2024, 08:39:53 am
content: Quote from: coppice on November 04, 2024, 11:58:18 pmThe problem there is not solar panels are combustible, but that they severely compromised the fire rating with this installation.Such houses have internal fire walls right up to the roof line, and normally a fire goes straight up, but with panels mounted like that, flames funnel sideways and ignite the next roof cavity.Someone’s goofed there.

author: Marco
author_rank: Super Contributor
timestamp: November 08, 2024, 09:46:58 am
content: It's not like flames push ceramic tiles to the side, let alone standing seam metal roofs, they make a hole.

author: coppice
author_rank: Super Contributor
timestamp: November 08, 2024, 12:50:55 pm
content: Quote from: PCB.Wiz on November 08, 2024, 08:39:53 amNobody mentioned combustibility, although nctnico's suggestion of EPDM might be an issue there. The problem is the panels are producing power, inhibiting the ability of the emergency services to take action, during daylight hours. Breakers don't help when you have to attack the panels themselves, to get them out of your way. Breakers are generally pretty useless in emergencies anyway, as the responders won't know where they are.Whether you have ceramic tiles, ceramic and solar layered tiles, or ceramic tiles with secondary panels doesn't seem like its going to change the combustibility issues all that much. Very little of the solar kit's content is things like combustible insulation. When I see the remnants of a house fire the roof generally looks like it remained in place until the rafters burned through to the point of the roof collapsing inwards. I can't see any kind of panel changing that much.

author: Marco
author_rank: Super Contributor
timestamp: November 08, 2024, 01:17:41 pm
content: Given the large increase in high voltage fires they have to deal with, I think my suggestion of conductive suits is pretty reasonable. It's relatively light weight compared to the rest of their suit, just needs a bit of care connecting all the parts.

author: nctnico
author_rank: Super Contributor
timestamp: November 08, 2024, 02:44:21 pm
content: Back in 2018 Fraunhofer did research into fire safety of integrated solar panels and found that these -at that time- posed a 20 times higher chance of causing a fire for various reasons. The lesson to take away from that is that integrating solar panels in a roof requires a complete re-design and different mindset of roof structures. I believe it can be done safe and way better compared to retrofitting panels which are not really intended for use on roofs to begin with. But somebody needs to design it that way and proof the design is safe.

author: coppice
author_rank: Super Contributor
timestamp: November 08, 2024, 02:50:49 pm
content: Quote from: nctnico on November 08, 2024, 02:44:21 pmI presume the risk is mostly around connection quality, so many small panels (tiles) might be much riskier than a small number of large ones.