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Power Earth Technology

Dow Chemical Rolling Out Solar Shingles Next Year 168

Several users wrote to tell us that Dow Chemical plans on selling solar shingles as early as next year. The solar version can be integrated with normal asphalt shingling and will be introduced in 2010, with a wider roll-out scheduled for 2011. "The shingle will use thin-film cells of copper indium gallium diselenide (CIGS), a photovoltaic material that typically is more efficient at turning sunlight into electricity than traditional polysilicon cells. Dow is using CIGS cells that operate at higher than 10 percent efficiency, below the efficiencies for the top polysilicon cells -- but would cost 10 to 15 percent less on a per-watt basis."
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Dow Chemical Rolling Out Solar Shingles Next Year

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  • by PeterAitch ( 920670 ) on Monday October 05, 2009 @06:55PM (#29651311)

    It seems unlikely that these will weather very well, so we'll have to see how they cope with thermal cycling and storm stresses. Nice to note that things have moved along since I worked on Si photovoltaics - it's taken longer than I expected, though

    • by thewils ( 463314 )

      Hopefully they'll have the kinks sorted out when I need a new roof in twenty years!

    • That's a good point, maybe we should cover them with some sort of protective layer. Hmmm, we could make sure the protective layer has good traction too so people can walk on their roofs safely without falling. I know, we can cover them with sandpaper! I'm surprised this hasn't been thought of before. =P
      • by icebike ( 68054 ) on Monday October 05, 2009 @08:19PM (#29652055)

        The point about walking on roofs is a key issue.

        Over the life of a house, people have to do this more often than you might imagine. The article is thin on details about just how durable and walkable these things are.

        Probably not for snow country, but anything that could absorb some of the air conditioning load would be welcome.

        • Re: (Score:3, Insightful)

          It says they can be mixed with regular shingles, so I would imagine one would make "walkways" of regular shingles to access things like roof-vents, gutters, swamp coolers, chimneys, etc.

        • Re: (Score:3, Informative)

          by Anonymous Coward

          You can't walk on slate shingles either yet people still find ways to work on slate roofs. I doubt that they don't have a solution.

          • You can't walk on slate shingles either yet people still find ways to work on slate roofs. I doubt that they don't have a solution.

            A point that deserves modding up. Include tile roofs and probably other kinds. I think this amounts to scaffolding, temporary platforms, and generally avoiding such walking.

            • Re: (Score:2, Interesting)

              by Jukeman ( 1522147 )
              I had an old farmhouse for 30 Years with steep (45 degree) slate roof, lots of repair people had to walk on it (a lot of brick chimney repair and flashing, very little slate repair), some without ropes. No one ever broke one by walking on them. Personally, since they are all held in with two loose nails, I though one should slip out when stepping on them; but none ever did.
          • Re: (Score:3, Informative)

            by Bob-taro ( 996889 )

            You can't walk on slate shingles either yet people still find ways to work on slate roofs.

            I worked in roofing for a while. You can easily walk on a surprisingly steep pitch once you're used to it (I doubt I could anymore). Usually, though, we would walk on boards that were set on metal brackets that hung from nails under the shingles. Even on a low pitch, we would usually put at least one row of boards near the bottom, in case someone slipped. When the roof was done, we'd slide the brackets off the nails, then slide the bracket over the nail head and under the shingle and hammer the nail flu

        • The point about walking on roofs is a key issue.

          Oh I don't know instead of worrying about the traction of said solar shingles, why not just purchase some special purpose shoes? Certainly steps toward off the grid energy independence far surpasses concerns of roof traction.

          • by icebike ( 68054 )

            Traction?

            No no, I was worrying about the shingles and damage to the wiring grid to which they are connected when sattelite tv guy stomps up there to screw his dish down.

            • Re: (Score:2, Insightful)

              by Jarik C-Bol ( 894741 )
              and then runs 4 screws through one of your solar shingles. tell me that's not going to cause some problems with them.
        • Sounds similiar to the same problem that putting solar panels in assfault roads.

        • air conditioning load

          insulate your house !

          • insulate your house !

            Doesn't help very much if you're in an area where the temp doesn't drop below 100 even at night during parts of the year.

            A good idea in such cases would be to build/insulate your house correctly for the climate, then power AC to make up the remaining requirements via solar. Whether this be by solar panels powering a heat pump or using direct thermal heat to power an absorption chiller.

    • Re: (Score:3, Insightful)

      It seems unlikely that these will weather very well, so we'll have to see how they cope with thermal cycling and storm stresses.

      I'd think that people can be reasonably expected to be somewhat unhappy when their roof doesn't last as long as it should. So I'd think Dow would have put a bit of effort into making sure that these things don't break that easily.

      • It seems unlikely that these will weather very well, so we'll have to see how they cope with thermal cycling and storm stresses.

        I'd think that people can be reasonably expected to be somewhat unhappy when their roof doesn't last as long as it should. So I'd think Dow would have put a bit of effort into making sure that these things don't break that easily.

        I hope nothing in these make them less fire resistant than proper shingles these days.

        (Yes, I live in Southern California. How did you guess?)

        • Re: (Score:2, Interesting)

          by PeterAitch ( 920670 )

          If they are caught in a fire, the combustion products will hardly be bio-friendly; in fact "toxic" would be a better description. That said, they are not going to be inherently combustible, unless there are lots of organics left in any binder which might be used to keep them on the substrate (i.e. the shingles). Most likely, the shingles are post-treated to produce a rather thick "thin-film" and then given a top coating (a) for anti-reflection purposes and (b) for mechanical/abrasion resistance. As sever

          • Re: (Score:3, Interesting)

            by icebike ( 68054 )

            By the time your roof is on fire, toxicity is the furthest thing from your mind.

            Asphalt shingles burn well, once lit. The graduals really only protect it from flying embers. And the smoke is fairly nasty.

            Disposal is a larger issue. Even you average wood shingle is will last 100 years in a land fill. Asphalt is anyone's guess.

                 

      • I'm going to hazard a guess that they are basically the same 30 year asphalt shingles they already sell with the PV film fixed to it somehow and a universal connector system that automatically lines up and connects with regular installation.

    • Re: (Score:3, Interesting)

      by moon3 ( 1530265 )
      The notoriously pricey roofing costs, with electric shingles the maintenance might skyrocket and one can easily lose all the potential electrical "savings". They wire each shingle ? I would like to see some pilot deployment in action >>
      • Re: (Score:3, Interesting)

        by hedwards ( 940851 )
        Unlikely, given the speedy installation, it's a pretty good bet that the system is installed as a set of larger shingles pre-attached to each other. These are most likely then wired into whatever electronics handle the power management. There's a trade off between percentage of roof covered per unit and cost of replacing a broken or defective cell.

        If you need a new roof, this might be a decent deal, but if you don't, the break even point for these appears to be roughly the same as with tradtional cells.
        • Unlikely, given the speedy installation, it's a pretty good bet that the system is installed as a set of larger shingles pre-attached to each other.

          They don't necessarily even have to be pre-attached. If they have relatively large contact plates, placed so that they'll touch in the regular overlapped configuration, it could be as simple as just wiring the top row of shingles in a section.

          • I'm confused why we're still using asphalt shingles in the first place. Wouldn't it be easier/faster/better/cheaper to do something else?

            For example, one of these:
            1. Spray a water proof coating onto the wood roof.
            2. Stick a water proof sheet to the wood roof.
            3. Cover the roof with galvanized steel or hard plastic.

            I will never understand people's fetish with covering their houses with at asphalt shingles instead of almost anything else. When considering energy costs during summer, dark shingles made of tar

            • Re: (Score:3, Informative)

              by swillden ( 191260 )

              Tar shingles are cheap, easy to install (anyone can learn how in a few minutes), self-seal given just a couple of warm days and even self-heal to some degree.

              Where I live winter heating costs significantly exceed summer cooling costs, so I'd think the best choice is a slippery black roof so snow would slide off and the sun could heat the attic. Even better, of course, would be a power-generating roof which could be used to heat during the winter and cool during the summer.

    • Re: (Score:3, Insightful)

      It seems unlikely that these will weather very well, so we'll have to see how they cope with thermal cycling and storm stresses. Nice to note that things have moved along since I worked on Si photovoltaics - it's taken longer than I expected, though

      They'll be sold with a 20 year warranty, and trust me: they wouldn't be willing to offer that warranty without being confident that they wouldn't have to pay up regularly.

    • by Brigadier ( 12956 ) on Monday October 05, 2009 @09:25PM (#29652505)

      Not sure why this is being posted as if it's a new product. Eagle Roofing based in California has been carrying a fairly successful product for some time now. Not only do they have a warrantied usable product but it also supports LEED cool roof requirements. see link below to check it out for yourself.

      http://www.eagleroofing.com/greenBld_eagleSolarRoof.htm [eagleroofing.com]

      • by afidel ( 530433 )
        Sorry but I'm a lot more impressed by a 20 year warranty from DOW then even a 50 year warranty from a company that's only existed for 20 years (though I guess that's better than a new startup). The likelyhood of DOW being around to pay up on the warranty is a heck of a lot higher =)
        • by Luyseyal ( 3154 )

          Obviously you don't live where there's a lot of hail damage. The only reason we get long warranties in central Texas is because the insurance company uses that warranty as the basis for their depreciation of the roof. You will not have your roof for 20+ years. It will be replaced in that timeframe time and time again. However, with labor costs increasing yearly, it makes more sense to buy a 30 year shingle so that the depreciation won't outpace the replacement cost (zero out of pocket).

          -l

  • Installation? (Score:5, Interesting)

    by seanadams.com ( 463190 ) * on Monday October 05, 2009 @06:59PM (#29651347) Homepage

    They say these can be installed by standard roofing techniques... I don't know if anyone else has ever nailed down asphalt shingles but it's about as low-tech as it gets. So the question is how do these interconnect electrically?

    I could imagine a couple ways - perhaps there are contacts that need to be aligned prior to nailing. Either that, or they intend for an electrician to come in after the roofers and attach a bus bar or something. Anyone got the full story?

    The future for residential solar is not in the highest-tech, highest efficiency panels. Rather, it will be the system which gives the lowest $/W after ALL costs, including installation, depreciation, and in this case, savings because it also serves as your actual roof. Sounds like a great idea to me.

    • The article states "can be integrated with" rather than "built into". They also quote a generic install time as compared to existing solar panels, not a time per square or some similar thing.

      I don't know what temperature solar cells can handle but the shingle lines I've seen run coat with asphalt at around 200C. They also run around 1200 feet per minute, so you'd have to be laying those cells down pretty damn fast.

      • by hoggoth ( 414195 )

        Perhaps English isn't your native language, but I cannot parse what you are trying to say:

        > the shingle lines I've seen run coat with asphalt at around 200C
        What does that mean? When they get hot does asphalt condense out of thin air to coat them?

        > They also run around 1200 feet per minute, so you'd have to be laying those cells down pretty damn fast.
        This one has me really perplexed. Do the shingles get up and chase after you?

        • the shingle lines I've seen run coat with asphalt at around 200C

          What does that mean? When they get hot does asphalt condense out of thin air to coat them?

          I had to recompile a couple times, but it does actually parse:

          shingle = adjective
          lines = means "assembly lines" (subject)
          seen run = means "seen running"
          coat is the active, transitive verb, referring to the process of coating the shingles with asphalt

          Or something like that. In other words, he's talking about how they're manufactured.

        • Re: (Score:3, Informative)

          English is not my native language but I've been speaking it quite a long time. But I did fuck up that post.

          Shingles are typically made by passing a thin fiberglass reinforcement under what is essentially a pipe out of which asphalt is pouring. The asphalt is about 200 celsius. The fiberglass reinforcement is moving at a speed of about 1200 feet per minute.

          The possibility exists that the solar panels are added to the shingle in a separate process, glued on or the like, after they've been produced on a tradit

    • Re:Installation? (Score:5, Interesting)

      by microcars ( 708223 ) on Monday October 05, 2009 @08:44PM (#29652241) Homepage
      There is a home that my son-in-law built just north of Chicago that has "Solar Slate" installed in portions of the roof that match the asphalt shingles. It was installed by a local roofing company around 2003, you can see a photos of the install HERE [revelle.net].
      Did not RTFA and while these are slightly different than what is mentioned these things have apparently held up very well so far for the people that live there.

      Sort of an aerial view of one part of the house with the slates installed here [revelle.net].

      If you can't see the photos you probably crashed the guy's server, I think it is hosted on his home computer...

    • I'm not sure if it was Dow, but I read the install instructions for one brand of solar shingles. The shingles are installed like regular shingles except that first you drill a couple of holes in the roof and drop a couple of wires into those holes. Then, when the shingles are all nailed down, someone goes into the attic and connects up all those wires.
    • I can see where the shingles are pre-drilled, one could possibly used a 2" screw. I live close to the beach, so if I can get 1/3 life out of the electronic product, that's break even. My main roof parasites are Moss, and Sea Gulls. So how much would a 10'x20' roof cost?
    • They say these can be installed by standard roofing techniques... I don't know if anyone else has ever nailed down asphalt shingles but it's about as low-tech as it gets. So the question is how do these interconnect electrically?

      I could imagine a couple ways - perhaps there are contacts that need to be aligned prior to nailing. Either that, or they intend for an electrician to come in after the roofers and attach a bus bar or something. Anyone got the full story?

      The future for residential solar is not in the highest-tech, highest efficiency panels. Rather, it will be the system which gives the lowest $/W after ALL costs, including installation, depreciation, and in this case, savings because it also serves as your actual roof. Sounds like a great idea to me.

      It uses Tesla technology to transmit the energy through the air and through your roof into a single point in your home that is identified by a homing beacon.

  • Recycle? (Score:4, Interesting)

    by NaCh0 ( 6124 ) on Monday October 05, 2009 @07:00PM (#29651357) Homepage

    What happens when the CIGS cells wear out?

    Are they toxic? Can they be recycled?

  • I beg to differ. (Score:5, Insightful)

    by NoYob ( 1630681 ) on Monday October 05, 2009 @07:01PM (#29651375)

    Dow Solar Solutions said it expects "an enthusiastic response" from roofing contractors for the new shingles, since they require no specialized skills or knowledge of solar systems to install.

    What?!? Roofers just lay out the shingles and nail them up there with pneumatic nail guns. They may not have the skills to wire them, place the wires correctly under the regular shingles to not only preserve the solar shingles but to make sure none of the shingles leak, and I'm sure you can't treat these things like regular shingles: drop them off the truck on to the ground, crane them up to the peak of the roof and let them fold over it and sit there for a couple of days until the installers get there, walk on them, and every other abuse can commit against asphalt shingles because they can take it, after all.

    There will have to be some sort of training or there's going to be some really unhappy home owners when their new solar roof doesn't produce as much electricity, if any, as they thought because of screwed up shingles.

    • Re: (Score:3, Interesting)

      TFA says "thin film" cells, so I'd imagine they're fairly flexible.There's also a known pattern to how they'll be installed (overlapping horizontal rows that are each offset by about half the length of one shingle), which could probably be used to print wires on the upper part of the top side and the lower part of the back side such that they'll make fairly good contact.
      • by serbanp ( 139486 )

        The CIGS PV cell is called "thin film" because the photoelectric sandwich is deposited as thin layers on top of a GLASS plate. Oh, and they apparently are (very) moisture-sensitive, so having them last 20-25 years will be difficult.

        • Re: (Score:3, Interesting)

          The CIGS PV cell is called "thin film" because the photoelectric sandwich is deposited as thin layers on top of a GLASS plate. Oh, and they apparently are (very) moisture-sensitive, so having them last 20-25 years will be difficult.

          The substrate isn't necessarily glass. Flexible metal substrates have been used already by other companies. They do bend, and they're encased in a flexible moisture barrier and offered with a warranty that lasts as long as the lifetime claims. I don't think that the companies selling these would be willing to offer the warranty without a reasonably good expectation that the cells would actually last that long.

          • The CIGS PV cell is called "thin film" because the photoelectric sandwich is deposited as thin layers on top of a GLASS plate. Oh, and they apparently are (very) moisture-sensitive, so having them last 20-25 years will be difficult.

            The substrate isn't necessarily glass. Flexible metal substrates have been used already by other companies. They do bend, and they're encased in a flexible moisture barrier and offered with a warranty that lasts as long as the lifetime claims. I don't think that the companies selling these would be willing to offer the warranty without a reasonably good expectation that the cells would actually last that long.

            The Dow site [dowsolar.com] says they are manufactured on a flexible substrate. Since it's Dow Chemical that's making these I bet there is no glass involved anywhere.

    • Re:I beg to differ. (Score:4, Interesting)

      by apoc.famine ( 621563 ) <apoc.famine@g m a i l . com> on Monday October 05, 2009 @07:28PM (#29651631) Journal

      Agreed.
       
      I highly doubt that two guys with a case of beer, a couple of utility knives, and a nail gun can lay these down and have them work as they are supposed to. Shingling a roof really doesn't require any skills, other than doing the peaks and valleys. If you can put down a shingle, and nail it to the roof, you're golden. If you can hack the excess off that hangs over the side with a knife, you can shingle 95% of a house.
       
      Ignoring any interconnections between the shingles that must be lined up, (because, that's beyond a roofer's knowledge base) you still have to tie it into the house electricity. And you have to be able to slap the roof down in the beating sun, while standing on it, and driving nails through it. How exactly does that work if the roof is generating electricity as you do so?

    • by catmistake ( 814204 ) on Monday October 05, 2009 @09:46PM (#29652637) Journal
      Everything is relative. Perhaps these solar shingles take a few extra steps beyond regular shingles, but have you seen what a pain in the ass the nuclear reactor shingles are to install? You need a friggin' nuclear engineering degree! Sure, the effeciency is through the roof, but at what cost? As unlikely as China Syndrome is, it's an insurance nightmare. And personally, I don't want my great great grandchildren toiling to replace a spent uranium ceiling. Solar it is!
    • Well, that's not what the article really states. It says "solar shingles can be integrated into rooftops with standard asphalt shingles" and doesn't give much more of a hint. As a guess I'd say that they might easily lay in place of a row of regular shingles or something like that, but the article says nothing leading one to believe that they can be nailed or easily wired.

      It's also seemingly not very exciting news as companies such as Uni-Solar [uni-solar.com] have been doing similar stuff for several years now, altho
    • Re: (Score:3, Insightful)

      by forand ( 530402 )
      These are similar to slate shingles if my reading is correct. You cannot:

      drop them off the truck on to the ground, crane them up to the peak of the roof and let them fold over it and sit there for a couple of days until the installers get there, walk on them, and every other abuse can commit against asphalt shingles because they can take it, after all.

      with slate shingles. So while any random guy off the street cannot put on a slate roof there are quite a few business specializing in this in most areas of

  • by audubon ( 577473 ) on Monday October 05, 2009 @07:01PM (#29651379)
    Sally sells solar shingles by the seashore...
  • by Penguinisto ( 415985 ) on Monday October 05, 2009 @07:02PM (#29651387) Journal

    The traditional mono- and polysilicon panel makers catch hell for using things like lead (leading to RoHS solder being used and etc)... what's the plan for recycling these puppies?

    (don't get me wrong, I'm loving the idea, but you know someone's gonna bitch about it...)

    Also, since there are places that see annual windstorms which tend to rip the occasional shingle off of the roof, err, how much would it cost to repair/replace?

    It'll be hammered out eventually (err, s'cuse the pun), but it's something I hope that someone is thinking about all this today, instead of the being blinded by the whole 'gee-whiz' factor that may come around to bite the whole renewables movement in the butt later on.

    (disclosure - I work IT in this industry - take it as you will).

    • by winwar ( 114053 )

      "...what's the plan for recycling these puppies?"

      Well we don't recycle asphalt shingles that contain nasty chemicals at the present time. I doubt that these are any worse. Therefore we don't.

      As you noted, people will whine. But you don't see them whining about regular shingles. Therefore we ignore them.

    • Also, since there are places that see annual windstorms which tend to rip the occasional shingle off of the roof, err, how much would it cost to repair/replace?

      Perhaps you would want to look into securing the shingles properly in the first place? Or if you live in places where your roof is going to get ripped off anyway, either move or don't build using expensive to repair/replace materials in the first place.

      Just like how people living in Venice [wikipedia.org] don't build their houses out of mud bricks [wikipedia.org].

      For some strange r

    • by Inda ( 580031 )
      We don't have shingles in the UK, we have tiles. Before I moved into my house, I made sure the old asbestos tiles were removed and replaced. Every other house in my street has asbestos tiles.

      I wouldn't worry about recycling.
  • by gestalt_n_pepper ( 991155 ) on Monday October 05, 2009 @07:04PM (#29651399)

    We're talking contractors here. Assuming they *don't* steal your money outright, you're lucky that the shingles stay on at all, much less have well connected, insulated wiring.

    • My brother (Score:5, Informative)

      by poptones ( 653660 ) on Monday October 05, 2009 @08:12PM (#29652015) Journal

      Yeah, he puts on "rooves."

      Now, let me ask YOU this: can YOUR whiny ass carry a pack of shingles up a ladder in 100 degree sun? Have you ever even been ON a roof?

      Contractors are responsible for the contracts, not the roofers. It's not the greasy, sunburnt guys working their asses off who steal your money - it's the well dressed fellow sitting in the truck watching them work who takes your money.

      That said, I don't think any of you have read TFA. These are thin film shingles. There are demo videos on youtube - you can see them press holes in the shingles, even drive nails through them and they still work just fine. These are not silicon and glass, they are thin film on some sort of flexible substrate. And it's about time.

      • Re: (Score:3, Informative)

        by afidel ( 530433 )
        Yes, I've stripped a double layer roof, replaced half the under-sheeting and put on a new roof including rubber matting to combat ice-dams in a long weekend. It's not really that hard. I did have my father as foreman who ran a midsized roofing company 25 years ago but most of the labor was just me and my brother. It's really quite simple if you have airguns =)

        Oh, and a funny story about corrupt roofers, my coworkers wife caught the crew doing the neighbors roof putting shingles on bare wood. Turns out the
  • Direct Link to DOW (Score:4, Informative)

    by swanzilla ( 1458281 ) on Monday October 05, 2009 @07:05PM (#29651417) Homepage

    Dow Solar [dowsolar.com]

    FTA

    "This is just one example of how Dow's $1.5 billion annual R&D investment is allowing us to deliver practical solutions for some of the world's most critical challenges," said Dow Chairman and CEO Andrew N. Liveris.

    They might have hit this one out of the park if the projected $20 billion by 2020 is remotely close.

    • by syphax ( 189065 )

      The article you linked to links to another relevant article [newscientist.com]:

    • Unfortunately same goes for other things like lithium and Neodymium. Not that they're really that closely related to this, but one of the things that nobody likes to talk about is that a lot these really important elements are just not common enough for the amount of use we need. We'll need more high efficiency technologies and to use less at some point in the equation.
    • Which is an estimate based on current reserves and production levels. Indium is rare, but it's not THAT rare:

      Indium ranks 61st in abundance in the Earth's crust at approximately 0.25 ppm,[13] which means it is more than three times as abundant as silver, which occurs at 0.075 ppm.[14]

      The quoted article says Indium was up to $1000 per kilo. Silver is around $500 per kilo, and is 3 times less abundant.

      You also have to understand that before LCD screens, there wasn't a big demand for Indium. Basing any concl

      • your understanding of resources is horribly flawed.... it doesn't matter if indium was 100 times more abundant if the processing of it isn't fesible. because indium isn't in concerntrated deposits like silver, it's horribly hard to mine. you need something else there as a sweetner to make it economical. if you bother to read the very next line in wikiperdia it states "Fewer than 10 indium minerals are known, none occurring in significant deposits"

        sure you could just strip mine bulk tonnes to get at it to m


        • your understanding of resources is horribly flawed.... it doesn't matter if indium was 100 times more abundant if the processing of it isn't fesible. because indium isn't in concerntrated deposits like silver, it's horribly hard to mine.

          I in fact DO understand that.

          if indium deposits really are out there you'd see a lot of announcments about projects to mine it - there aren't.

          That's a rather large assumption. Indium prices are very volatile. As recently as 2003 prices were at $80/kg. It's since gone up t

    • Indium is relatively rare. So what? Don't expect it to be included in every single solar cell!
      Si-based solar cells 'only' have 25% of efficiency. So what? Just put some more m^2!
      Hydrogen conversion is a waste of energy. So what? It has nothing to do with solar panels, and if you don't like it, don't use it.

      That's a disappointing article from "The new scientist"....

  • Saving energy? (Score:4, Interesting)

    by QuoteMstr ( 55051 ) <dan.colascione@gmail.com> on Monday October 05, 2009 @07:22PM (#29651565)

    Wouldn't it be easier to just paint the roof white so that the building reflects more heat and needs less cooling in the summer? (In the winter, insulation will keep the heat inside.)

    And wouldn't it also help to use lighter pavement to reduce the urban heat island effect?

    It just seems like photovoltaic shingles are pretty low on the net-payback list.

    • by syphax ( 189065 )

      Why either / or? I suspect we'll need both.

      In southern CA, you'll see plenty of warehouses with white roofs and PV mounted on top. With an air gap, the PV provides further shading.

      PV is relatively low on the net-payback list, but the experience curve marches on- the more we install now, the closer we get to grid-parity economics.

    • Re: (Score:2, Informative)

      by NoYob ( 1630681 )

      Wouldn't it be easier to just paint the roof white so that the building reflects more heat and needs less cooling in the summer? (In the winter, insulation will keep the heat inside.)

      No. First of all, no house is energy efficient enough to do that. Much of the heat comes in and out through the windows. The materials used in construction are not good insulators and there are many ways the heat comes in and escapes out through the house: cracks and gaps, vent pipes, chimneys, air leaks around receptacles , opening and closing of doors, kitchen vents, etc....

      The best you can hope for in a home is to make it as energy efficient as you can.

    • by pavon ( 30274 )

      I don't know how it would compare to solar, but according to a report I read about here [arstechnica.com], painting roofs white was one of the least cost-effective forms of geoengineering options that they studies (see second page).

      • by afidel ( 530433 )
        Their cost/benefit analysis completely ignored the reduced cooling load needed. They also attribute 100% of the cost of the painting operation to reflectivity efforts but since most roofs need some maintenance anyways the marginal cost might be minimal. I know my company's HQ building that we just finished uses white rubber roofing material to both reduce cooling loads and offer a good long-life water barrier thus reducing maintenance costs vs a traditional tar roof.
  • by T Murphy ( 1054674 ) on Monday October 05, 2009 @07:27PM (#29651615) Journal
    Why would I want solar-powered shingles? My shingles never needed to be powered in the first place.
  • These are nice, but I still think photovoltaic SIPs [sips.org] is a better way to go... so why isn't anybody making them?
  • Copper indium gallium diselenide, that's like so yesterday. We all know that human hair is the future.

    Teenager Invents Cheap Solar Panel From Human Hair [slashdot.org]

  • DoW Chemicals? (Score:5, Insightful)

    by ijakings ( 982830 ) on Monday October 05, 2009 @07:55PM (#29651843)
    Paint them red, they will charge faster.
  • 5 months out of the year, there's a foot of snow on my roof. How will these hold up against ice dams? Has anyone factored in to the equation that they won't be generating a single watt of electricity for almost half the year?

  • Dow Chemical Rolling Our Solar Shingles Next Year

    I hope I'm included in "our"...I want my solar shingles rolled!

  • solar themal energy [wikipedia.org] is simple, low tech, and recovers much more energy. of course, it's heat, not electricity, that it generates. then again, the sun is mostly heat, already. students make them [aprendendofisica.pro.br] for science projects...
    • Simple? Low tech? Have you ever actually seen one of these plants? Are you aware of the technical challenges in making cheap, reliable Stirling engines?

      If in your world steerable mirrors, Stirling generators and the electronics and computing needed to drive them is simple and low tech, then welcome to this planet, my friend, but I'm afraid you will find us very backward.

  • by timmarhy ( 659436 ) on Monday October 05, 2009 @11:38PM (#29653255)
    buy shares in indium exploration companys then, because they don't have enough known resources to produce all these solar shingled roofs. sure you could use othe heavy metals, but they are rather nasty.
    • There was that Indian kid that made a solar panel out of human hair, maybe we could just use the hair to make our panels and not need that high cost indium. However, you will see alot more scalping going on from now on,....especially in places like Dominican republic where instead of taking your kidneys, well they take your scalp!

  • Will home insurance be more expensive with these things installed, considering roof replacement is one of the most common claims?

  • You also have that special paint you can apply to get more, so in combination with this, lay the shingles down, then spray a thin film of the solar paint, and then voila extra voltage output from solar shingles as they are now covered with a much higher yield paint then itself, plus if any of the paint comes off over the years, well the bottom IS solar panel to boot, so you technically could just leave it.

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