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Power Science Technology

Not Transparent Aluminum, But Conductive Plastic 96

michaelmalak writes "Scientists at the US Department of Energy's Brookhaven National Laboratory and Los Alamos National Laboratory have fabricated transparent, thin films capable of absorbing light and generating electric charge over a relatively large area. The material, described in the journal Chemistry of Materials (subscription required), could be used to develop transparent solar panels or even windows that absorb solar energy to generate electricity. The material consists of a semiconducting polymer doped with carbon-rich fullerenes."
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Not Transparent Aluminum, But Conductive Plastic

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  • by suso ( 153703 ) * on Saturday November 06, 2010 @11:51AM (#34147422) Homepage Journal

    Sounds like this would be great for skyscapers, where you have huge windows all the way up and direct sunlight for long periods of the day.

    • by Bigjeff5 ( 1143585 ) on Saturday November 06, 2010 @12:24PM (#34147600)

      These would be great in windows, but I don't see why it should be limited to windows, since it's a coating that could be applied to all sorts of things.

      A covering for housing siding, for example, or attached to roofing sheets. Something like this, if it ends up being cheap (and it should, it's a super simple process to make - the trick was getting the chemical solution right), would have a lot more applications than just in windows.

      Cross your fingers, I say.

      • Since it could be applied to any surface, it would practically ideal for use on the surfaces of devices (smart devices anyone?) to work much as the way the early solar-cell calculators did. Even if it did not totally provide device power, it would probably be a nice supplement. Heck, see what wavelengths work best with certain configurations (mixtures) perhaps even body heat might work.
      • didn't RTFM... but one of the biggest problems with roofing shingles is UV, hopefully that's the same radiation this stuff is supposed to absorb... so, coat your roof in it and your roof lasts longer, bonus electricity.

    • by goombah99 ( 560566 ) on Saturday November 06, 2010 @01:55PM (#34148024)

      How can a transparent thing absorb a large fraction of the energy? This sounds like an oxymoron.

      • Re: (Score:1, Funny)

        by Anonymous Coward

        1/7000000000000000000000000. See how large that fraction is?

      • Re: (Score:2, Informative)

        by Anonymous Coward

        Humans are only able to "see" a very small portion of the spectrum of light. This leaves a lot of IR and some UV available for absorption without humans noticing.
        Wikipedia has a nice chart of the spectrum here []

      • by sosume ( 680416 )

        So windows would be a bad application, as it would leave out the natural heating from outside, and even pickup the heat from inside as well. You'd need to increase the central heating inside to compensate, probably costing more energy than the sheet absorbs.
        This raises the question why it's transparent in the first place! (puts on his tin foil hat)

      • I'm not sure if anyone's saying this stuff would "absorb a large fraction of the energy". If anything, its absorption would probably be rather pitiful compared to even polycrystalline silicon cells.

    • Not to mention the safety factor of having windows that wouldn't shatter and rain death on those below.

      BTW, don't know where I saw it (might have even been on /.) that someone was actually working on that transparent aluminum thing.

  • Coming soon (Score:5, Insightful)

    by pooh666 ( 624584 ) on Saturday November 06, 2010 @11:59AM (#34147480)
    to a manufacturer in China..
    • Re: (Score:3, Insightful)

      Don't worry, the US patent owners will earn a lot more profit on it than the Chinese (they don't give a damn about patents, but if they want to sell it in the US they need the license nonetheless).

    • Re:Coming soon (Score:4, Informative)

      by the gnat ( 153162 ) on Saturday November 06, 2010 @02:45PM (#34148294)

      I work for the DOE (at a different lab), and from what I've seen, patented technology is almost always licensed to American companies. If it wasn't, a major argument for the existence of the national labs goes out the window, and Congress would probably throw a fit. I don't know if patent licenses come with strings attached (like "thou shalt not offshore manufacturing"), but my guess is that any company wanting to profit from publicly-funded basic research has to tread carefully.

      (Obvious disclaimer: I speak for no one except myself - I'm just a lowly programmer anyway.)

  • tinted glass? (Score:5, Interesting)

    by HungryHobo ( 1314109 ) on Saturday November 06, 2010 @12:00PM (#34147492)

    I assume they'd act like tinted windows since they'd be absorbing some of the light.

    car windows which gradually charge the battery perhaps?

    • That's what I would expect too. My hope is that, since it is a fairly simple process (just super-tiny water droplets filled with the proper chemical spread out on a sheet) they will be able to produce reasonably efficient solar panels for much less than they cost now. Since they can be created on plastic, I'd like to see it used as some kind of siding. Then you wouldn't have to worry about them being very transparent either (i.e. more densely packed hexagons).

      Either way, it's very cool.

    • Re:tinted glass? (Score:4, Interesting)

      by FatdogHaiku ( 978357 ) on Saturday November 06, 2010 @02:45PM (#34148290)
      Why stop with the windows? Auto bodies normally have a "clear coat" over the pigmented layer, so why not have the entire vehicle surface act as a collector?
      • Exactly what I was thinking: make the hood, top and trunk coated with this material and you have a cheap way to help charge the batteries in a hybrid or electric vehicle. It doesn't need to do all the charging to be effective, just a significant fraction for the average person. Granted, this might not be the best application for much of western Europe, but in much of the western hemisphere and elsewhere, it would be worthwhile.

        Would also be interesting for rooftops of commercial and apartment buildings,

        • Re: (Score:2, Interesting)

          by Anonymous Coward

          Also if the battery is topped off on trickle charge, would it still make enough juice to run the vent blower? Would be nice to have a car that runs the fan and brings in fresh outside air while parked during those hot summer days.

          • A normal sized car has about 4 m^2 of area, so it results in about 24 kWh per day in sunny CA at 100%. More likely it would be 2.4 kWh with all the loses or about 100 watts average.
  • Apocalypse averted (Score:5, Interesting)

    by Zerth ( 26112 ) on Saturday November 06, 2010 @12:03PM (#34147504)

    Now when we run out of indium-tin oxide(or the chinese just stop selling it to us), we can still make LCDs, OLEDs, and EL wire.

  • If it is transparent but also absorbs light, which parts of the spectrum does it absorb? PV panels typically only convert a limited part of the spectrum, so if these transparent panels absorbed only green light you would not get white light coming out but purple.
    This wouldn't be an absolute show stopper, but coloured windows are not all that appealing.
    • It's not going to absorb all the light, most of the light getting through is going through the middle of the hexagons, while most of the light being absorbed is at the edge of the hexagons.

      I would expect more of a darkening effect than a color change - the edges of the hexagon are basically opaque, so there shouldn't be any light going through them. A portion of the light gets blocked, and of that blocked light a portion gets turned into electricity.

      Looking in from the outside they might have some kind of

  • So... (Score:1, Funny)

    by Anonymous Coward

    "windows that absorb solar energy to generate electricity" so... that would be unlike "transparent solar panels" how?

    *shakes head*

  • by RevWaldo ( 1186281 ) on Saturday November 06, 2010 @12:05PM (#34147518)
    The more transparent it is, the less energy it can absorb. What level of efficiency can it achieve?

    • by Raleel ( 30913 ) on Saturday November 06, 2010 @12:24PM (#34147598)

      the question is, transparent to what, really. If it's opaque to everything _except_ human-visible light, that's still a pile of the spectrum and of energy.

      • by Bigjeff5 ( 1143585 ) on Saturday November 06, 2010 @12:30PM (#34147638)

        It's transparent because the film has a hexagonal structure - extremely thin (and therefore transparent) at the center of the hexagon, thick (and therefore opaque) at the edges of the hexagons. The electricity is generated at the edges, as that is where the light is absorbed and that's where all the electrons are ready to be knocked off their molecules. It's not blocking certain wavelengths and allowing others through (well obviously to some degree it is, but not in the visible spectrum). It's blocking light in certain parts and allowing light through in others.

        It's basically going to tint the windows, how much will be determined by how densely the hexagons are packed - more hexagons means more electricity but also a darker tint.

        • by JustinOpinion ( 1246824 ) on Saturday November 06, 2010 @01:12PM (#34147804)

          It's transparent because the film has a hexagonal structure - extremely thin (and therefore transparent) at the center of the hexagon, thick (and therefore opaque) at the edges of the hexagons.

          Actually it's a little bit more interesting than that. In addition to being thinner at the center, the light-absorbing polymer is not well-ordered (amorphous) in the center region, which leads to it being worse at absorbing light. At the edges of the hexagons, the polymer orders better, which allows it to absorb light more efficiently. This makes the structure more intelligent, in principle: if the honeycomb structure acts as one half of the conduction pathway (necessary for a photo-voltaic), then it makes sense to have the material close to it do the light-absorbing, and have the material further away (center of hexagons) which cannot participate in light harvesting, just be transparent. So this in principle allows one to design more efficient semi-transparent solar cells.

          Peeling back the layers of hype a bit, however, these kinds of solar cells are horribly inefficient. The best materials we currently have to make plastic solar-cells ("organic photo-voltaics") have pretty poor efficiency. Making a solar cell that's semi-transparent just makes the efficiency (per unit area) even worse. But, this is fairly fundamental research: by demonstrating that they can tune the light-absorbing capabilities of the polymer based on its ordering (and control ordering by using the honeycomb patterning and preparation parameters), this provides useful information about how to make higher-performance plastic solar-cells. So this research may actually end up being more important for conventional solar cells ('opaque') than it is for window-coating solar-cells or whatever.

          P.S.: The materials used in the paper have an absorption maximum at 503 nm (green), so they probably create a purplish tint. The absorption spectrum can be tuned to change the tint, however this will impact the solar collection efficiency.

          Disclaimer: Some of the co-authors are colleagues of mine. However I wasn't involved in this work in any way.

          • Peeling back the layers of hype a bit, however, these kinds of solar cells are horribly inefficient.

            That's true, but this is made up for by the fact that you can place them in more places. For example, high-efficiency silicon solar panels can never be used as windows. It is simply not an area available for solar collection even though we generally place windows in areas that get a lot of sunlight. That's because a window is useless if we can't see through it, obviously.

            So this is going to generate solar power in areas that currently cannot be practically collected. In that sense, it's infinitely more

            • by JustinOpinion ( 1246824 ) on Saturday November 06, 2010 @01:45PM (#34147976)

              your efficiency per square foot may be crap, but your square footage can be huge. That's assuming, of course, this stuff ends up being cheap. The manufacturing process should be ultra cheap, but I don't know about producing the solution. It should be a lot cheaper than traditional panels, but will it be cheap enough to make it worth it? That's the question.

              That's exactly right. The promise of organic photo-voltaics is that they will be so much cheaper to produce that the lower efficiency won't matter. But one of the harsh realities is that a photo-voltaic setup has certain fixed base costs (think of how much it costs to physically install each 1 m^2 panel, and tie it into a house's electricity system). Thus, according to industry partners, there is actually an efficiently level below which a solar material is not worth using even if it were completely free to produce. So, for organic solar cells to become commercially viable, they need to improve efficiency, even while reducing costs. Of course we're now reaching levels where it is indeed viable to use organic photo-voltaics, see for example Konarka's flexible solar panel [] that is built into a bag, so that it charges your cellphone; but there is a threshold of efficiency necessary to offset fixed installation costs.

              • Re: (Score:3, Insightful)

                but there is a threshold of efficiency necessary to offset fixed installation costs.

                This threshold will become lower as the costs of fossil fuel goes up. Assume for the sake of argument that the cost basis of solar tech like this doesn't change, the rising costs and shrinking supply of traditional sources will make things like this more attractive. Of course, it is likely that the costs for this tech will decrease over time...

                • That's assuming that fossil fuel costs must go up. There is currently such a great supply of fossil fuel that it would be far cheaper to lobby the governments to allow it's use/production. As I see it, even if the world does last longer than the supply of oil, coal, etc, we would likely have changed how we think of energy. Perhpas we will be more effecient with it. Also, the "fixed" installation cost might lower by then from more effecient production.

                  I don't think that this particular technology will make

              • but there is a threshold of efficiency necessary to offset fixed installation costs.

                Very true, but we really don't know what it is. The installation costs on existing structures would likely be excessive, but if future architectural designs are changed to accommodate for such panels, installation costs would be greatly reduced.

                There are lots of things they could do. For example, run aluminium strips underneath the siding to allow for all the windows (on that story) to easily connect together. Now I'm no architect and there are likely far better ways to do this - but my point is that

          • That's pretty interesting, though I'd think that someone's idea of replacing skyscraper windows with these would be a worthy endeavour, assuming the process is relatively cheap, and the resulting product relatively long-lasting. Would it be worth the effort of doing something like that? And would it have any effect on the amount of air-con needed in summer? Some of the light being blocked from entering the building would cool it, but I'm assuming the panels heat up more due to the electrical current, and wo

          • by emt377 ( 610337 )

            The best materials we currently have to make plastic solar-cells ("organic photo-voltaics") have pretty poor efficiency.

            But if it's a transparent film, even in the absorption spectrum, you could stack it several layers deep and possibly give each layer a slightly different absorption spectrum. Behind the stack you sandwich a mirror so residual light reflects out for a second trip. Maybe the mirror or a top film could be made to fluoresce as well to bring more energy into the absorption spectrum.

        • microwave door analogy :)
      • They should make it so you can filter whatever frequency bands you want. I've always wanted a blue tan.
    • Re: (Score:3, Informative)

      by jo_ham ( 604554 )

      It really depends what part of the spectrum it is absorbing in. If it absorbs strongly in the near IR region but completely passes visible, then how transparent it looks to us really isn't going to affect how efficient it is. Some chemical bonds just don't absorb energy in the visible region, which is hopefully what they are going for here, so that the primary function of the window itself is not compromised.

      Ideally you want to absorb the energy above the visible region - it's more energetic after all, but

    • Re: (Score:3, Informative)

      It's only part of the solar panel. I'm over-simplifying, but solar panels are a sandwich of three layers: the transparent conductor (currently indium doped tin oxide), the semiconductor layer (silicon), and the back collector (metal). This discovery will replace that pesky transparent conductor layer.
  • Great idea (Score:4, Insightful)

    by RogueWarrior65 ( 678876 ) on Saturday November 06, 2010 @12:09PM (#34147528)

    This is the kind of implementation that actually makes sense. You don't need dedicated hardware or real estate to set it up. Granted northern exposure probably would work but put this stuff all over southern exposure windows in a whole city and tie it all onto the grid. It's akin to not using food crops for biofuels. Algae and switch grass make more sense.

    Now the big key is getting the cost per kilowatt down where it's competitive with traditional power generation. And of course you really need a large scale storage system. I remember a Popular Science article about giant underground flywheels.

  • Kudos for adding a link to the original research article. Not a lot of blogs, news sites, etc. do this. BTW the supporting information [] to the article is available free of charge (nitty - gritty experimental details). (This is common among paywalled articles)
  • Windows that effeciently absorb light are NOT windows. They would be called WALLS.

  • Personal energy consumption is a benefit of wealth. Lowering the cost of energy generation should increase the ability for larger proportions of mankind to increase their own personal energy consumption and move one step closer to a rightfully just existence.
    • Personal energy consumption is a benefit of responsibility. If larger portions of mankind used the capital and energy they already have in more responsible manner they would be living the same existence as the rest of us.

      • By that argument, at each stage of history, we would have benefitted from 'responsible capital use'. In your world, we would not have been allowed to develop the automobile until all of mankind had the finest horses and carriages available.

        in my world, wealthy people clamoring for automobiles creates a market that leads to Henry Ford's model-t, which led to cars for everyone. In your world, they'd all still be knee deep in manure.
        • In your world, we would not have been allowed to develop the automobile until all of mankind had the finest horses and carriages available.

          I'm not sure where you get this impression. You're the one clamoring for "social justice" (which is just a euphemism for wealth redistribution), not me.

          Besides, the first automobiles were steam-powered, and could run on wood, a perfectly renewable resource.

  • Sorry if I'm just being dense, but what, exactly, is the difference between "could be used to develop transparent solar panels or even windows that absorb solar energy to generate electricity."

    • i think it's a spatial thing, one goes on the top of the house, the other on the side.

      I agree with your point, transparent solar panels seem fairly useless since their efficiency is directly related to their opacity, windows that absorb solar energy seems pretty slick.

    • Not much, obviously. But, then again, what's the difference between a pile of dirt and rocks and a nuclear reactor?

      • Re: (Score:3, Insightful)

        by znerk ( 1162519 )

        Not much, obviously. But, then again, what's the difference between a pile of dirt and rocks and a nuclear reactor?

        Engineering :)

        Well, that and the fact that one of them generates gobs of power, while the other just kinda sits there.

        • one of them generates gobs of power, while the other just kinda sits there.

          Not [] true [].

          • by znerk ( 1162519 )

            Sorry, I guess I should have been more precise in my response.

            A "pile of rocks", regardless of whether it is a "naturally-occuring nuclear reactor", is not usable to generate power that is immediately available for use by humans. A "nuclear reactor" is a purpose-built facility designed to do exactly that.

            Oh, and Oklo is more of an out-lier than you seem to imply, seeing as it is the only one of its kind (and the reactions occurred 2 billion years ago).

            As for Petratherm's Paralana Geothermal Project, you're

  • by Animats ( 122034 ) on Saturday November 06, 2010 @01:01PM (#34147744) Homepage

    Again, we have some minor bit of progress in materials science being touted as a big breakthrough. They haven't fabricated anything but a hexagonal membrane, which has been done before. They're not even able to make a small prototype device. From that, it's a huge jump to "Imagine a house with windows made of this kind of material, which, combined with a solar roof, would cut its electricity costs significantly. This is pretty exciting.". There are lots of other solar cell technologies which are much further along and still don't yield useful products. Nanosolar [], a hype-based solar panel company, comes to mind. The enthusiasm for thin-film solar has decreased since ordinary solar cells became cheaper, and thin-film cells got stuck at half the efficiency of regular ones. This is turning into a manufacturing problem, not a technology one. "We grow every year with double revenue and almost double capacity. At end of the year, we will have 1.8 gigawatts of capacity and will have grown from 4,000 employees at the beginning of this year to more than 11,000." - Fang Pen, JA Solar, Shanghai.

    Conductive plastic isn't a big deal. Conductive plastics [] are commercially available. The foam in which ICs are packed is conductive.

    This is Los Alamos and Brookhaven, the old atomic labs, struggling to avoid more downsizing.

    • by Animats ( 122034 ) on Saturday November 06, 2010 @01:14PM (#34147820) Homepage

      What's really going on in solar is that big US companies with real manufacturing expertise are moving in.

      • Dow Chemical [] is about to release solar shingles. "About to release" means "passed UL certification last week" and "volume shipments in 2011". Solar enthusiasts have blithered about solar shingles for a decade, but Dow actually solved all the real world problems, like the roof not leaking, the interconnect system being safe, and the installation being do-able by a typical roofer.
      • General Eletric [] is now active in solar. They make not only panels, but major parts you need to really get things done, like megawatt-sized inverters.
      • 3M [] now makes solar panels.

      This is where the action is. Solar is a heavy-manufacturing business, and it's the companies with experience in running big factories that are now taking over.

      • Re: (Score:3, Interesting)

        by belthize ( 990217 )

        You can't have a manufacturing business until you figure out the technical details. There's a reason Dow invests 1.2B a year in R&D. Ten years from now I suspect there'll be an article on some new conductive something or other and somebody will point out what a waste that is because you can already buy windows for Andersen Windows that act as transparent solar panels.

        Last year there were numerous scoffing posts at the announcement that Dow would be rolling out shingles next year.
        http://hardware.slashd []

  • by znerk ( 1162519 ) on Saturday November 06, 2010 @01:06PM (#34147770)

    Some links that have more information, without having to give money to the Chemistry of Materials: [] []

    Oh, and one more thing:
    Buckminster Fuller strikes again! AHAHAHAHAHAhahahahahaha... hah.

    I want my Dymaxion []

  • Transparent panels (Score:1, Interesting)

    by Anonymous Coward

    Have existed for years already. Low power and expensive, but they have existed. Paint on PV exists as well, a company in the UK was going to incorporate it into sheet metal for buildings, the siding and the roof.

    Except a lot of this stuff disappears after it is announced, you never hear of it again. Once or twice, a coincidence, now that it has been twenty years and change I have been following solar breakthroughs, and noticed that hardly any of these breakthroughs, dozens and dozens, actually make it to re

    • In 1987 I saw a functioning hybrid car which was sent out to run at a mine - electric underground, fuel above ground and regenerating power from the brakes. Consider how long it was between that finished specialty product and a mass market hybrid vehicle like the Prius (ten years).
      It's the same deal with these other things. You might not be hearing about them but that doesn't mean that they are not in use in some niche somewhere.
      • Re: (Score:3, Interesting)

        by Anonymous Coward

        That may be true, but I know for a fact that a lot of entrenched industry on the old money energy side hates the idea of solar and has gone way out of their way to make it not happen, because it threatens their business model. Solar can break the perpetual check to them, because eventually it can be paid off. You can NEVER pay off your local utility monopoly, and that's the way they like it. And speaking of hybrids, read up on large NiMH batteries and chevron, an oil company and how they bought up the pate

        • by dbIII ( 701233 )
          All that is moot globally because China rarely gives a shit about those patents for internal use and will probably be happy to stall things in court for five years to sell the stuff to the USA as well. The bastards that want to run conspiracies are going to find they are now small players. Besides, innovation is not happening so much in the USA anymore so they'll have nothing to sit on anyway.
          Bought government interference is annoying but won't stop everything. In Australia for instance we had a wind far
  • So we can use these in windows to both block out the sunlight and power indoor lighting? Talk about killing two birds with one stone!
  • Either there's a glitch in the matrix or I feel like something similar had been created about 8 or 9 years ago. I remember reading about it either here or on engadget around 2004. After some googling back in time I managed to find this: [] which is the closest thing that comes to mind. I wish I had better source. Can anyone please explain how the two differ?
  • by noidentity ( 188756 ) on Saturday November 06, 2010 @02:04PM (#34148076)

    Here are some improved article headlines:

    Not Transparent Steel, But Conductive Plastic

    Not Non-Conductive Plastic, But Conductive Plastic

    Not Green Eggs And Ham, But Conductive Plastic

  • What?? We're doping plastic now? Just imagine what other innocent materials could also be sullied with 'performance-enhancing' substances!
  • by OrangeTide ( 124937 ) on Saturday November 06, 2010 @02:44PM (#34148284) Homepage Journal

    My watch is made with Transparent Aluminum [].

  • by bigtrike ( 904535 ) on Saturday November 06, 2010 @08:45PM (#34150730)

    Why are our tax dollars funding things like this when we're losing a war and faith based initiatives are underfunded? We need to shrink our government and trust that if there were any hope for this to work, private industry would be investing in it so they could maximize their long term profits.

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