Solar Roofing – Flat and Metal Roofs with Integrated Solar Panels

In this article we will discuss solar roofing systems, which integrate roofing materials with solar PV panels or solar thermal systems. Specifically we will cover, metal roofs, PVC flat roofing membranes and asphalt shingles. Although most roof-mounted solar systems are installed on top of an existing roof – be it an asphalt shingles roof or any type of flat roof – these solar systems are not integrated into the roofing material, and therefore are not solar roofs.

Why Are Solar Panels Installed On Roofs?

Most solar systems are installed on a roof of a house or a building. The exception are solar farms or ground-mounted solar installations, but these are rare, and are usually 100% commercial solar systems. There are a number of reasons why most solar systems are installed on roofs. The primary one being limited space – especially in an urban setting, where roofs represent significant unused space. Another reason is that usually roofs are not shaded by trees, nearby buildings, etc – they are the highest point of a building with great sun exposure, which makes them perfect to install solar panels on.

Image of solar panels installed on a commercial flat roof

What Is a Roof-integrated Solar Systems?

Solar roofing is a final product, which integrates solar panels with the roofing material suitable for either a sloped or a flat roof. The solar panels used in solar roofing are usually thin-film photovoltaic laminates. Most popular Solar PV laminates commercially used today, are the Unisolar thin-film PV panels.



Unisolar thin-film PV laminates were originally designed to fit into and be integrated with standing seam metal roof panels. Unisolar panels are 15.5 inches wide and fit perfectly into a 16″ standing seam panels, and are attached or laminated with special butyl adhesive that is on the back of each Uni-solar PV panel.

However, unlike with metal roofs, solar integrators were having flat roof leak repair issues with solar systems they installed on flat commercial roofs. After they installed solar mounting racks and attached them to the roof deck, the fasteners would start leaking after a while.

Roofing manufacturers adressed this issue with different versions of flat roofing materials that integrated Unisolar PV panels – one such system is IB Solar Roof. There are many types of both solar metal roofs and solar flat roofs, using solar PV panels from various manufacturers (though as I said, most do use Unisolar PV laminates).

Solar Metal Roofing

The most common type of solar metal roofing is the standing seam metal roof with integrated Unisolar PV laminates. Unisolar PV laminates were initially designed to fit in the pan of standing seam panels, with the connection terminals concealed by the ridge cap. Because the connectors or terminals of these PV panels are not UV stable, they need to be hidden from the sun, while the rest of the panel is of course exposed to the sun to generate solar electricity.

The benefits of standing seam solar metal roofing include fast installation, easy troubleshooting, and lifetime leak free roof performance. Additionally, in the US, you can get the 30% solar tax credit for installing a metal roof, as it is a part of the solar system.

Solar Metal Shingles

Another type of solar metal roofing would be solar metal shingles. The concept is similar to solar standing seam roofing, but since metal shingles are much smaller, the solar PV laminates have to be adjusted to the size of the shingle. Also, all the terminals must be connected during the installation – if you miss just one, the circle will be broken and the solar system will not work. Imagine finding the broken link when you have hundreds if not thousands of metal shingles to take off to find one broken connection!

Image of Solar Metal Shingles being installed on a mock-up roof.

Price-wise, I think that standing seam solar metal roofing is much more viable, as there is substantially less installation labor involved and much less potential troubleshooting, if something goes wrong. Imagine hiring a solar integrator and a professional metal roofer at $75-100 per hour – each – to find what is wrong with your solar metal shingles roof. Even if everything is peachy, the amount of time that will be used to install solar metal shingles is much more than that of a solar standing seam roof. The total solar system price will be significantly higher just from all that extra labor.

The bottom line is that the choice of solar metal roofing system that you decide to use will be more of a personal preference. Both will work great when professionally installed, and will last a very long time.

Solar Flat Roofing

The main reason why flat roofing materials manufacturers began developing solar flat roofing systems was to A) eliminate roof leaks associated with flat-roof solar installations, and B) sell more flat roofing materials, which is their main business after all.

Solar Flat Roofing is a great concept, but has some limitations. First, the angle on the solar panels is flat, so these panels will not catch as much sunlight as tilted or sloped solar panels. Second, solar flat roofs will be much more effective in warm climates vs. colder northern climates such as New England, as in the winter, flat roofs are completely covered with snow and sunlight does not get through to the solar panels.

That said, the benefits of solar flat roofs far outweigh their drawbacks in colder climates. The solar PV panels that are integrated into the roofing membrane eliminate 99% of roof penetrations, considerably reduce the weight of the solar system and the total solar system price. Not only are the solar panels prices lower for roof-integrated solar systems, you also eliminate the entire rack-mounting system (which costs about $1 per watt of your solar system) – and that is not small beans – you will save about 10-15% off your total solar system cost. Also, since the roof solar system weighs much less than regular solar panels mounted on racks, you also eliminate substantial weight, and your building construction costs will be much less, because you can reduce roof load requirements.

Solar Asphalt Shingles

Solar asphalt shingles are very similar to solar metal shingles described above. The main difference is that they are designed to work with 3-tab or architectural asphalt shingles instead of metal roofing shingles.

Although solar shingles may seem like a great concept, please consider the following factor, which makes them not such a viable option when it comes to solar roofing. Solar shingles, just like metal solar shingles, take a very long time to install, as each shingle must be connected to the rest of the solar system in the series. However, unlike solar metal roofing shingles, there is no room to conceal the terminals under the shingle, so all connections must take place inside the attic space. Holes must be pre-drilled for each shingle, and terminals are fed inside the attic where they are connected.

This slows down the installation process significantly, and usually you cannot finish this in one day. If it starts to rain, your roof is toast. There are too many penetrations under the solar shingles, and it is very easy for water to get in. Of course, there are ways to prevent the roof from leaking even if it rains and the roof is not finished. You can run the last row of shingles and overlap it with roof underlayment, which will prevent the roof leak. Still, this makes the total job that much more complicated and costly.

One more thing to consider is the fact that asphalt shingles only last about 15 years and will have to be replaced down the road, where as a metal roof will last pretty much forever, or at least the lifetime of your house.

Solar Roofing Resources

Solar System Guide – everything you need top know when designing a residential Solar PV system – positioning of your roof toward the sun, shading and angles of your solar panels, choosing the solar panels and inverter, etc.

Metal Roofing Materials – learn about different metal roof types and which metal is better to use – steel, aluminum, copper, zinc, etc., as well as learn more about metal roofing prices.



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  1. There are two building-applied solar veterans that make what they call solar shingles but may be better described as small, rectangular solar panels that are installed without traditional racking systems.

  2. Solar roofing is going to be the new age standard pretty soon and it ought to be. Anything we can do to for a greener living is vital at this point.

  3. Solar roofing is becoming more and more poplar and providing a green solution to our environmental issues. I enjoy educating folks about this as its a dual benefit and better for everyone.

  4. Solar system integrated with the roof is the one for the future, infact a start has already been made with the advent of solar shingles but currently a bit expensive but in future rates are sure to come down.

  5. Solar roofing is future with so many environment friendly products coming up and government is also giving impetus in the form of tax relief that in coming years, with better technology, prices will come down and solar roof would be more prevalent than they are now.

  6. Having solar panels on the roof is the best utilization of the roofing space, lots of energy is saved and lower energy bills during extreme weather. Solar shingles launched by Tesla is a great move in that direction, though currently very expensive but with time, prices are certain to go down.

  7. With the brisk innovation in the field of solar energy, cost of solar equipment has gone down and with innovations like solar shingles, it has become very easy to install an effective, stable and complete solar system on your roof.

  8. Very informative article, installing solar panels on the top of the roof not only reduces your energy bill, you can sell back extra energy back to the grid. Tesla has just launched solar shingles, which will not only protect the roof but also generate electricity!

  9. This is always a great idea to do a solar roofing. This article is nicely described about solar roofing in various different roofs like flat and metal roof. Save energy and Use Solar roof.

  10. Having solar panels on the roof in the locations where there is a history of sunlight for a long period of time is a great idea, very eco-friendly and cost effective in the longer run. But I am curious to know, do these solar panels survive hail storms?

  11. It looks like most comments stopped about 3 years ago. I’m building a house near Raleigh, NC that will have a metal roof and I’d love to incorporate solar. However, I hate the look of the bulky solar panels, but it seems that the laminates weren’t all that great. So now it’s 5 years from the original post and 3 years since the last one. Where has the industry evolved to and who, if anyone, is producing good quality, efficient solar laminates panels?

    • Hi Tim,

      The company that manufactured these laminates (UNISOLAR) filed bankruptcy a few years ago. While their products still sell, I’m not sure who will take care of warranty if any issues arise.

      At the same time, I have not heard of any real issues with UNISOLAR panels. And if you can find them now, they should not be that expensive (compared to how much they cost 3-5 years ago). If it were my home, and I could get these at $1-1.50/Watt, I would not hesitate, even though manufacturer is out of business.

      On Amazon they sell these panels for about $224 for a 136 WATT strip. =Back in the day, these used to be $3.50-4 / watt.

      You can also call some Solar suppliers to see if they have some left. I know Soprema – a large roofing manufacturer – had a deal with Unisolar 5-6 years ago, and had purchased over 1 million watts of panels, and then had to sell them for pennies on a dollar, because regular solar panels dropped in price dramatically.

      There was another (Chinese) company that manufactured similar laminates with higher efficiency. The company or product name is Xunlight. However, I’m not sure about their reliability or quality. I recommend you do some research about this. I will also ask a few people in the industry.

  12. Dear Sir/Madam.
    Sunny greetings from Malaysia.
    1. Is your company represented in Malaysia or in the Asia – Pacific region ?
    2. What are the types of PV panels and laminates does your company deal with – the country of origin , quality
    certification, warranty and other relevant information would be useful?
    3. Would your company be interested to collaborate in setting up a joint- venture set-up in this part of the world?
    Your kind understanding and co-operation in this matter is most appreciated.
    Thank you.
    Best regards
    M. Wee

  13. Hello how are you today ? This is jeff I would love to know if you can do
    perfect job for my Full Roof Replacement also let me know if you accept
    visa/master card as mode of payment.

  14. Solar roofing is something that should be a viable option to anyone who is looking to replace their roof in the near future! The idea that you can use otherwise wasted space to generate some extra power for your home is a great idea. The commercial roofing in Hawaii is one of the best places to view how well this works! There are homes all over that utilize this technology because of the gorgeous weather that we have here!

  15. The last thunderstorm we had really took a toll on my roof and now it leaks. I was looking for a bucks county roofing company to see if they will fix it but I really like the solar shingles you mentioned. If I have to replace my roof anyways I might as well go big. Can any roofer install them or do you need a special person? What kind solar roof would you recommend?

  16. Those solar shingles look like a great solution and aesthetically speaking, it looks good as well. I wonder if it is as efficient as the other solar panels. I will definitely consider using them.

  17. Daniel Blair,

    On pg. 4 of IRS FORM 5695 it also says before that:

    “any labor costs properly allocable to the onsite preparation, assembly, or original installation of the residential energy efficient property and for piping or wiring to interconnect such property to the home.”

    BIPV/TIPV can be part of the roof or any part thereof. If you wish to circumvent damaging rack penetrations even if it were a potentially more expensive comprehensive system, you have no cap limitation and there exists no power output requirement. There is great latitude to invest what you want on your home regardless of expense.

  18. Daniel Blair,

    Wouldn’t you have to have money to short a stock? ECD FAN doesnt have money because he has no job! Thats why he has all the time in the world to piss every one else off! He,he,he

  19. @ Dan,

    Thanks for the followup. I read the form and you are correct this is what I have been looking for, but it is not as “clear” as you claim. Per the form:

    “Qualified solar electric property costs. Qualified solar electric property costs are costs for property that uses solar energy to generate electricity for use in your home located in the United States. This includes costs relating to a solar panel or other property installed as a roof or a portion of a roof. The home does not have to be your main home.”

    @ ECD: I have seen you all over the web trolling. Ok we get it, you hate PV systems and you think it is all one giant scam. There is possibly “zero watts” of connection between Solyndra going bankrupt, getting raided and the tax credits that I asked about. I have listened to your advise after doing some research about Unisolar & ECD and I now refuse to use their product on my home. The original poster is correct that almost every laminate here on the east cost is Unisolar so your market analysis of CA has zero bearing to the discussion.

    It will be interesting to see if you are right about ECD going bankrupt in a year. If you are confident have you shorted their stock to profit off your insight?

  20. ECD FAN knows doesnt know anything about roofing. This solar nerd is lost when solar evolves into more simplified designs becoming an integral part of a roof. This is the realm of the roofer and it will stay this way as more roofers from all over take up interest in hooking up solar.

    Heres what the Florida Construction Industry Licencing Board had to say on August 12, 2011 about TIPV:

    ALEJANDRO ARGUELLES – PETITION FOR DECLARATORY STATEMENT
    Mr. Arguelles was not present but was represented by his nephew.
    Mr. Biggins presented this case stating Alejandro Arguelles filed a petition for a declaratory statement on July 14, 2011. The petition was noticed in the Florida Administrative Weekly on August 5, 2011. Mr. Biggins noted that the petition requests interpretation on Section 489.105 (3)(o), Florida Statutes, and whether a licensed general contractor must be a certified or registered solar contractor or contract with a solar contractor in order to apply Tile Integrated Photovoltaics to roofing. Mr. Biggins asked the board to consider whether or not the petition meets the criteria for a declaratory statement, and to dismiss or answer as appropriate.
    After discussion the board determined that the petitioner is a substantially affected party and that the petition had standing. After further discussion the board voted that the license categories all Division I contractors and Roofing contractors can install the product listed in paragraph 2 of the declaratory statement.

    http://www.myfloridalicense.com/dbpr/pro/cilb/documents/cilb_minutes_0811.pdf

    As you can see, the days of Chinese traditional c-Si solar panels on racks and leaky penetrations are nearing a close! He,he,he Homeowners will want more integrated systems because they just make sense!

    Dan

  21. Daniel Blair,

    You will have to forgive me for not introducing ECD FAN, he is the resident internet basher that fabricates lies and spews vitriol 24 hrs a day without the need for compensation. His real name is Robert V Bauer, self proclaimed “Polymath”. That means a “Mr. Know-it-all” for the rest of us mere mortals. You can read about his early departue from Unisolar here:

    http://www.linkedin.com/pub/robert-bauer/8/124/768

    You can read here what a Solar Engineer from Twin Creeks thinks about this anonymous coward:
    Time to repeat this
    John Foreman 02/28/10 5:24 PM ”

    If you guys notice, ECD.Fan tries use arguments of Uni-Solar’s low power density (6%) and integration design mistakes, to apply this as is the “whole BIPV” industry / market is perpetually doomed… despite CIGS thin-films now reaching c-Si efficiencies and I bet if they had the same “economies of scale” applied to their industrial processes, would and will drop way below c-Si in terms of $/W. Even with the small amount of rare-earths used, no different than the rare-earths used in his favorite thin-films CdTe based from first solar, which had Walmart to help them scale.

    Plus he always ignores that no one wants, hundreds of roof penetrations, heavy racks, heavy modules, weighing their roof down. Uni-Solar led the way with inventive form factors (1st generation), including their failed SHR-17 shingle product. Dow’s powerhouse shingles share little in common 1.) double the power density, 2.) far less wiring (their tabbed shingled interconnect and self-ground). 3.) uses the best CIGS cells from Global Solar at 13-15 efficiency depending upon if one speaks of aperture or cell efficiency. 4.) He ignores the labor and integration savings to be had by a winning BIPV product… whether it be nail-gun installable shingles, laminates with better adhesives for metal roofs and laminates.

    If you notice also, anytime anyone posts any news release on PV thin films (now including CIGS, or any other technology)… he’ll be the first to come in and trumpet First Solar and CdTe in panels and big Silicon. He has a horse in the race, because if you do your research it’s been leaked he’s close to NY/Russian fund managers. Russians have a lot of poly-Si facilities, so it’s obvious his motives.

    If you google “ECD.Fan Todor Mitev” you will find he is likely linked (or is) Todor Mitev of the Temujin Fund. Which means he has a horse in the race to use Uni-Solar’s woes to try and short any up and coming technology like CIGS at 11-15% efficiency and rising.

    He is a fund manager, who does nothing but blog all day, so be VERY skeptical of his arguments for sure. He can post lots of numbers and always calls out people (attempting to squash their thoughts). Don’t buy into his vitriol.

    FYI – I’m not a fund manager, just an engineer / scientist sick of seeing this guys ill-conceived posts all over the place that misguide the public in a direction he wants. In fact his blog-spot is now closed to the public and he’s been kicked off the ECD board on Yahoo (ENER). Probably by court order.

    ECD FAN has a a dishonest agenda….

    Dan

  22. Daniel Blair,

    I never recieved an answer on this from Leo or Admin. Check out IRS FORM 5695 its very clear. If your new flat roof is done at the same time as your thin film installation, the 30% fed tax credit includes the roof because the new roofs acts as an anchor for the thin film. It also says that you can rely on a certified manufacturer statment that the roof qualifies and you need only keep it for your records. This is without cap limitation and is not limited to the solar footprint. Thats why it is called BIPV. BUILDING INTEGRATED PHOTOVOLTAICS.

  23. Daniel Blair:

    Mr. Dan Arguelles is a well-known rip-off artist (just google for ripoff and Artezanos), so you should believe anything he says at your own risk. Plus, he has zero Watts of grid-connected rooftop PV systems installed (his proposed installations are illegal). A company called Solyndra (now bankrupt) also claimed to have received an IRS ruling regarding their “roof-integrated” PV system – but FBI recently raided the homes and offices of its management, so you should take that tax credit claim with a grain of salt as well. I suggest you hire a reputable tax attorney and ask her to give you an opinion in writing (or, even better, to help you obtain an IRS “ruling”) regarding your question. So when IRS comes after you, you know who to sue!

  24. Admin or Leo,

    As a followup to Dan’s question above, I have been told by multiple sources that thin film solar laminate adhered to a new flat roof membrane installation (solar roof) allows for the roof and PV system to both be eligible for the 30% tax credit just like the metal.

    1. Is this correct?
    2. Is there written evidence for this? I have checked the DOE and IRS and I have found no documentation for this claim.

  25. My company (US owned and manufactures our products in US) makes solar integrated shingles for home and business. We also have a flat roof system.Our products are warrantied for 90 years and are fire, wind hail, snow proof and are very light weight. Please contact me.

  26. I too am wondering the benefits verse the cost of installing solar roofing in parts of the country where there is less sunlight due to either weather or climate. It seems like a no brainer in areas like Florida but say northern Maine or Michigan I’m not so sure

  27. I have been studying solar roofing for the last week. Sorry, I just got started on the subject.

    Anyhoo, here is my general question. I live in a condo in Charlotte, NC that has very strict regime / HOA rules. What options can I use to combine solar to my condo. My HOA allows TV dishes, so I am hoping to find a solution that is small yet powerful. I have looked at solar generators such as the Powerhub 1800, but I am just not sure based on my situation.

    Yes, I realize that my question doesn’t really match the article about ‘roofing’ but I am hoping you have a suggestion based on your knowledge of solar overall.

    Also, this is another important question. Does solar roofing work ok in the winter in areas such as mine where the winter months are consistantly overcast? We dont get alot if any snow in my immediate area, but we also don’t get alot of direct sun from November to March.

  28. ADMIN,
    Seems like there are some questions that are looking for answers. Would you be so kind to answer mine?

    Dan

  29. Sorry, I guess the next question is whether you have a UK distributor or outlet I can explore feasibilities and costs with?

  30. Am a UK based installer and struggling to find a flat roof mounting solution that does not require making the installation sink into the ground due to the amount of ballast required or having to pepper the roof with holes. So the flat roof option you present is interesting and logical, however being flat what are the implications for cleaning? At 30 degrees most panels are considered ‘self-cleaning’ but the inclement weather in the UK makes for frequent ‘dirty’ rain. And the local birdlife doesn’t much help. So a flat panel may struggle a bit. Thoughts?

  31. Leo,

    I think my question is relevant to solar roofing. Can you please answer my question? Do you have a documented example of a metal roof with PV thin film qualifying the entire Metal Roof investment for a 30% Federal Tax credit as “Qualified Solar Electric Property”?

    Thanks ahead for your answer!

    Dan

  32. Leo,

    Can you please give some examples of a job that was 30% Federal Tax Credit for the whole metal roof with some PV Laminates on it? Have you seen this done yet?

    Dan

  33. Wow Leo, you are a prime example of why people from your neck of the woods are so disliked here in Florida.
    What total arrogance. I ask a simple question about how my guys will have to CLEAN those solar roofs someday, and you take my head off. Click on the website in THIS link, and see what I represent. I am FAR from Spam.
    I am a roof cleaner in Tampa Leo. How will “advertising my website” help me in your neck of the woods ?
    The jobs we do here in Florida average between 2 and 400 dollars, hardly enough to drive to your neck of the woods and back, EH ?

    • Chris – this has nothing to do with me being arrogant. I think you do know that algae does not grow on solar panels. Most you will get is dust / dirt, which is washed off with water. Therefore asking how to clean algae off the solar panels is “spam” in my opinion.

      Your comment was “irrelevant” to solar roofing, in the way you’ve presented it, and appears as advertisement, with no useful information to add to the topic. As far as you driving up to Massachusetts – I never suggested that – placing link to the website advertises your company, and not only in MA – our blog is read everywhere in US, and Florinda is in the top 5-7 states when it comes to number of site visitors.

      I assume that you are a smart man, and I will not engage in the “How will “advertising my website” help me in your neck of the woods ?” discussion – we both understand that this is about sticking in the link to the website.

      Chris – It’s not personal – I just think that if I do approve comment, it has to be valuable to site readers – not promote someone’s business. If you do post a comment that is about the topic of the post, i will approve it with the link.

      Here is an example – on our roofing job profile in Lowell MA (https://www.coolflatroof.com/flat-roofing-blog/roofing-lowell-ma/) – you left a comment saying your uncle lives in Charlestown, where we did a restaurant roof for him. We never did a restaurant roof in Charlestown. So explain the nature of that comment to me please.

      BTW, the comment links are are “nofollow” and have little benefit for you. If you want – write a post about”green” roof cleaning, and how it can extend the life of the roof, which will benefit the environment (in terms of not throwing shingles into the landfill, until they reach the end of service life), and I can post it for you with the reference to your site and your credentials.

  34. I think the Solar integration is a great idea. Might as well use free energy from the Sun. I don’t know much about solar panel efficiency, but can’t imagine it will work well with Roof Algae Growth blocking the suns rays from the solar panels ? This means these roof will require cleaning. This is my interest in them, since I head the Roof Cleaning Institute Of America where we train, and certify roof cleaners. Our men will encounter these roofs one day, and I would like to know what they are made out of, to determine the best way to instruct our students to clean them.

    • Hi Chris,

      How is this relevant to solar roofing? I get it – you want to advertise your roof cleaning business. However, if you want to post meaningless comments, I will remove your website from it. If you post something worthwhile – your website will be displayed. Bottom line, we closely moderate our blog, and do not want spam.

  35. Admin,

    You claim early on that a thin film solar laminate on a standing seam roof would qualify for the 30% Federal Tax Credit as well as the metal roof.

    “The benefits of standing seam solar metal roofing include fast installation, easy troubleshooting, lifetime leak free roof performance, and in US, you can get the 30% solar tax credit for the metal roof also, as it is a part of the solar system.”

    What evidence do you have to support your information?

    Thanks,

    Dan

    • Solar Metal Roofing is an integration between a roof and a solar PV system, where metal roof acts a support structure for the solar panels adhered to metal roofing panels – pretty much as a rack-mounting system is part of a Solar PV system using regular crystalline PV panels.

  36. I have always been interested in solar roofing since I live in Tampa Florida. Solar panels are quite common here, but large scale solar roofing is seen very little. I enjoyed reading the roofing article, and found this blog in a Google search.

  37. SIT did not actually file for bankruptcy, despite the fact they had ran out of cash and were losing tremendous amount of money. ECD/Unisolar came to the rescue and bought the company for less than the value of Unisolar inventory on SIT’s books. Had they not done that, the market would have been flooded with cheap inventory, and the truth about Unisolar’s uncompetitiveness would have been exposed much earlier – by “purchasing” SIT, ECD delayed the reckoning by a few months.

    I am not aware of a fire caused by SIT’s panels, but yes, the SIT solar system at the National Archives and Records Administration (NARA) in Waltham, Massachusetts is dead since August 2009, according to SIT’s own monitoring system ( http://gsanara.rem-systems.com/ ) – what an incredible waste of taxpayer money (the thing apparently cost $13 per Watt: http://www.gsa.gov/graphics/ogp/VSummer2007FINAL.doc )!

    The situation with “solar metal roofing” on the East Coast, especially on the residential side, must be very similar to that in California. I doubt that all the metal roofing manufacturers combined have done even 200KW of residential installations with Unisolar laminates on the East Coast over the past 19 months. Unless, of course, you have some hard data to disprove my claim.

    The installation that ASHRAE was referring to is pictured here, after they fixed the sliding “panel,” of course ( http://www.smm.org/sciencehouse/about/ ). Nailing the laminates should probably hold them from sliding, but don’t raise your hopes too high. See what happened on this small roof in Florida after just two years:

    http://picasaweb.google.com/fan.of.ecd/FloridaInternationalUniversitySolarInDistress

  38. Greetings,

    I have been wanting to put a solar roof on my house for some time now, but was not sure if doing so in CT was wise because of dreary New England winters. I have been looking at the company linked to in my name – eaglerivet.com, but just found you guys and thought you might be able to offer some insight into a few questions I have.

    How much does the climate you are in effect the value of the investment in a solar roof? Does it only really make sense for Californians and Floridians?

    Also, do you know if there is a federal tax credit for going solar or if it is state-based – or both?

    Lastly, I am a high-tech handy geek of sorts and was thinking about buying the material and putting it up with a group of buddies. Does this seem reasonable to you?

    Thanks in advance for your advice,
    Max

    • Hi Max,

      I will answer your questions out of order.

      California / Florida gets about 25-30% more sun light than we do in New England – therefore they generate that much more electricity per dollar invested. Plus I believe they get better solar rebates from the state, though solar dollars run out fast and Cali is on the verge of bankruptcy, so I’m not really sure what their solar rebates are right now.

      There is a federal tax credit of 30% for solar PV and other approves solar installations. Keep in mind though it is a credit. They apply it to your tax liability.
      There should be CT state rebates for solar, but they constantly run out of funds, so you should do your reasearch.

      If your roof is simple with no penetrations, you can certainly do it – install the roof yourself that is. You will need an electrician for the solar part. Apply solar panels on the ground – not on the roof. Clean the panels before applying solar laminates.

      If your roof goes into moderate to difficult category – hire a roofing contractor in ct – us for example 🙂

      Best of luck.

  39. About SIT (Solar Integrated – correct me if I’m wrong here)

    From what I understand they went into bankruptcy and were bought out. They were also closely working with Sarnafil / Sika on their PVC solar flat roofing. Problem with SIT / Sarnafil’s solar roofing was more of a panel design than delamination problem. Unisolar custom produced PV modules for them with terminal connectors facing down, instead of up, like their normal Solar panels. This was done to conceal connectors from UV and hide all the wiring under the roof. Problem is that the wiring overheated and I think there was a big-a$$ fire. Apparently, Sarnafil Solar roofing is not allowed to be installed in Massachusetts (their home state) … or maybe its just the government buildings / projects.

    Most of the info above is UNCONFIRMED. Basically its what I hear when talking to roofing / solar professionals on the inside of commercial roofing market. it is also a mix of information acquired at different times over last few years and I may have made some mistakes / omissions, as this info is rather old, and I begin to slowly forget it.

    About solar metal roofing – like I said – these installations are on the East Coast – i don’t know the state of affairs in the south, mid-west or west coast.

    Image of Solar Metal Roof

    One other thing I need to mention – solar metal roofing by default requires that the ridge cap covers the are of the panel where terminals are, and “z-bar” is crewed to the roof deck through the panel(special area designed for panel penetration), holding down the panels, so i’m not sure how they can slide out. it’s impossible unless they were not installed correctly.

  40. Dear admin:

    I disagree that solar metal roofs (the ones using Unisolar laminates) are installed left and right (metal roofs with regular PV panels mounted with clamps, like those from S-5!, might be another story). Here is my evidence:

    The California Solar Initiative ( http://www.californiasolarstatistics.ca.gov/reports/8-04-2010/Dashboard.html ) keeps good data about the installations in that State (and California accounts for about 50% of the solar installations in the US). Take a look at the kilowatts reserved (and not-canceled) for each month since January of 2009 for residential systems (defined as having DC system size of less than 10KW).

    Here are the total KWs reserved:

    200901 2293.9
    200902 2368.6
    200903 2902.4
    200904 4352.2
    200905 5875.9
    200906 6860.9
    200907 4664.4
    200908 10218.7
    200909 5520.8
    200910 7166.8
    200911 6084.8
    200912 4949.1
    201001 4797.9
    201002 5192.5
    201003 11412.5
    201004 13612.9
    201005 6437.5
    201006 7323.7
    201007 7068.6
    201008 935.5
    Total: 120039.6 kW

    Here are the reservations with Unisolar laminates:

    200901 6
    200902 5
    200903 0
    200904 0
    200905 11
    200906 5
    200907 4
    200908 5
    200909 9
    200910 0
    200911 2
    200912 5
    201001 8
    201002 0
    201003 3
    201004 5
    201005 0
    201006 0
    201007 0
    201008 0
    Total: 69 kW

    As you can see, Unisolar’s share in the residential PV market in California is a mindboggling 0.05%! Basically, zero. So, if ATAS, Drexel, Firestone or Unisolar are making claims that they have ANY kind of success with Unisolar laminates in the residential market, they are simply lying. Period. Apparently, the residential customers are less gullible than someone might expect.

    Yes, the adhesive issue might be more widespread in the membrane solar roofs segment, and it did not end in 2004. Here is what ECD’s 8K/A filing with the SEC related to Unisolar’s acquisition of their largest customer, SIT (specializing in membrane PV roofs), revealed on November 5th, 2009 ( http://investor.shareholder.com/ovonics/secfiling.cfm?filingID=950123-09-57767 ): “Management changed its estimates of the warranty liability [an increase of about $30 million] due to product performance issues discovered which were not fully covered under prior estimates. That information resulted in a significant increase in the warranty expense recorded in the six months ended June 30, 2009. Previously, the warranty estimate was based on historical warranty claims and warranty work performed. The current warranty estimate is based on an evaluation of certain aspects of the Company’s products and systems which indicated that increased failure rates may occur over the typical twenty-year warranty period arising from specialized adhesives used in the SIT manufacturing process and from certain product handling and installation methods. The Company continues to assess its estimate of warranty obligations each reporting period to determine if its accrual is appropriate.” Subsequent to that filing, the warranty liability estimate increased further.

    So, yes, apparently the adhesive issues are serious and widepsread.

    Of course, the adhesive issues might be the least of Unisolar’s problems. According to fatspaniel monitoring system, Unisolar’s largest rooftop installation, a 12MW membrane PV roof for GM/Opel in Spain, is dead ( http://siteapp.fatspaniel.net/siteapp/simpleView.jsf?eid=308211 ). And then there was that incident on the rooftop of the Long Beach Convention Center in February of 2008 where the Unisolar laminates (glued to Velcro?) ignited. Finally, Unisolar’s cost of manufacturing for their 6.3%-6.7% efficient laminates was $2.95 per Watt in the March quarter (compare to 13%-14% efficient Chinese crystalline PV panels made at $1.20 per Watt), which results in huge and persistent losses. Things like that.

    My site is currently closed to readers (but I am considering opening it for public access again).

  41. The solar shingles shown on your picture (SHR-17) were taken off the market and lost their UL certification (the holes might have had something to do with it).

    I am unaware of any “solar metal shingles” that have have been UL approved and on the market.

    The “solar metal roofing” with Unisolar laminates has suffered quite a bit of problems due to issues with the adhesive. For example, according to a 2007 ASHRAE report ( http://findarticles.com/p/articles/mi_m5PRC/is_1_113/ai_n25007378/pg_7/?tag=content;col1 ), in “2004 … [the] PV panels [at a high-profile demo installation] slid on the roof, causing a ground fault.”

    There are reasons why solar shingles and “solar metal roofing” have been losing share in the market since 1998 (their share is currently significantly less than 1%) – cost, PV performance, and reliability.

    • And yet we see solar metal roofs being installed on residential roofs left and right all along east coast (not sure what’s going on in the rest of the country), and Metal Roofing Manufacturers like ATAS, Drexel, Firestone, etc., are partnering with Energy Conversion Devices or ECD or Uni-Solar, in bringing the solar metal roofing to residential and commercial market. Besides, the 2007 article talks about 2004 adhesive failure. What is the current status or state of the adhesive – has it improved?

      I know that some flat roofing manufacturers had delaminating problems where panels came loose off the flat roof – namely EPDM rubber membrane, which tend to chalk – and were blown off. Some mod-bit manufacturers like are using their own adhesive to hold the panels down, and are not relying on uni-solar’s butyl adhesive.

      Image of unisolar thin-film pv laminates installed on a modified bitumen flat roof.

      If these adhesive issues are that serious and widespread (I imagine that this is mostly a problem in hotter southern climates), I do hope Unisolar is working on solving them, as the system design and idea of combining flexible thin film PV panel with a roofing material is great, and it would really suck if they let it slide.

      Btw ECD fan – what is the point of adding your site if it is by invitation only? I remember I was able to read it before. Why did you close it off?