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Power Science Technology

UCLA Develops Transparent, Electricity-Generating, Solar Cell Windows 163

Posted by samzenpus
from the look-at-the-energy dept.
Elliot Chang writes "A team from UCLA has developed a new transparent solar cell that has the ability to generate electricity while still allowing people to see outside. In short, they've created a solar power-generating window! Described as 'a new kind of polymer solar cell (PSC)' that produces energy by absorbing mainly infrared light instead of traditional visible light, the photoactive plastic cell is nearly 70% transparent to the human eye — so you can look through it like a traditional window."
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UCLA Develops Transparent, Electricity-Generating, Solar Cell Windows

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  • 70% ? (Score:3, Insightful)

    by Skarecrow77 (1714214) on Monday July 23, 2012 @11:49AM (#40737199)

    so, like about as transparent as your shower door with some soap scum on it? 30% obfuscation seems like a lot...

    • Re:70% ? (Score:5, Informative)

      by Chuckstar (799005) on Monday July 23, 2012 @11:52AM (#40737227)

      Transparency is merely how much of the light gets through. What you are talking about is translucency (i.e. scattering). There's no indication from the article that there is significant scattering. It would just look like you had tinting on the window.

      • ah my mistake.

        • by T Murphy (1054674)
          By the way, you might want to throw out your soap-scum-encrusted glasses and get a proper pair of sunglasses.
      • Re:70% ? (Score:5, Informative)

        by Spectre (1685) on Monday July 23, 2012 @11:56AM (#40737293)

        Transparency is merely how much of the light gets through. What you are talking about is translucency (i.e. scattering). There's no indication from the article that there is significant scattering. It would just look like you had tinting on the window.

        And not very much tinting, either. 70% transparent would just look like glass, if you didn't have something to compare it to. Even 90% tinting (10% transparent), as long as it is reasonably uniform at different color transmissions, doesn't interfere with vision at all ... sunglasses block more light than that!

        • by Gr8Apes (679165)
          70% transparent is noticeable, but generally a nice amount, especially on south/west facing windows.
          • by Chuckstar (799005)

            I think his point was that if you were inside a building that all the windows had the exact same 70% transparency, you'd have a hard time answering the question "is there tinting on this window". Whereas if someone said "here's two windows" and one was 70% and one was 90%, you'd be able to totally tell the difference. We're just not that good at detecting the difference between "full daylight" and "70% of full daylight", unless we're directly comparing the two.

            • by Chuckstar (799005)

              BUT, 70% might be low enough that when you walked outside and saw how bright it really was, you might think to yourself "oh, yeah... definitely that was tinted in there".

            • Actually I was in a lecture on photography that referred to that. Now if we only could make the windows blur out the things I don't like to see......

          • by v1 (525388)

            I was just thinking this sounds like a nice way to get some power from your tinting. But I wonder how useful it is in reality? And attaching wires to a roll-down window will increase mechanical complexity and add will eventually wear out the wires leading to the window or whatever track mechanism you're going to use to transfer power.

            I assume this has been tested to work with safety glass? And you can't tint your front or rear windows legally. Probably would make getting a window replaced significantly

      • by cpu6502 (1960974)

        Would be more effective to get rid of the windows entirely (or shrink them to tiny size), since there is more energy LOSS through the window than any other part of the house. Thousands of kilowatt-hours of heat (or cool) leak through glass via conduction. Meanwhile the embedded-solar would only generate a few hundred. Overall a huge net loss.

    • Re:70% ? (Score:4, Informative)

      by rhsanborn (773855) on Monday July 23, 2012 @11:54AM (#40737265)
      There is a photo in the article. It's more like tinting your windows.
    • Re:70% ? (Score:5, Informative)

      by Rei (128717) on Monday July 23, 2012 @12:30PM (#40737681) Homepage

      Given that untinted window glass is in the 80-90% range, 70% isn't bad at all.

      Remember that you don't perceive brightness linearly. Its several orders of magnitude brighter outside on a sunny day than it is in a very well-lit room inside, but it doesn't feel that way. Think of how many light bulbs you'd need to have to match 1000W/m^2, factoring in also that even fluorescent and LED bulbs lose the lion's share of their energy as heat.

    • Windows have what's known as a VT rating or visible transmittance rating. Just a plain pane of glass 3-4 mm thick has a VT of about 90-93%. Two such panes bring it down to 80-86%, and that's without any other kind of coating or anything else. Some windows on the market today have a VT of just 15%, and people still buy them . To most people at VT of about 60% looks clear. 30% on this technology would give a 70% VT if nothing else reduces it.
  • by CalRobert (2451626) on Monday July 23, 2012 @11:54AM (#40737263)
    Want to sound like a fourth grader shilling their science project? Use exclamation marks in your summary.
    • by Chris Burke (6130)

      Thanks! I was wondering how they found me out at the 4th grade science fair.

    • Want to sound like a fourth grader shilling their science project? Use exclamation marks in your summary.

      I'm not sure if the summary has been changed since you posted, but here is what I currently see:

      A team from UCLA has developed a new transparent solar cell that has the ability to generate electricity while still allowing people to see outside. In short, they've created a solar power-generating window! Described as 'a new kind of polymer solar cell (PSC)' that produces energy by absorbing mainly infrare

  • XSUNX Research (Score:5, Informative)

    by Anonymous Coward on Monday July 23, 2012 @11:55AM (#40737273)

    Disclosure: I am not an investor or employee.

    The company XSUNX has been doing this for a few years with Copper Indium Gallium Diselenide (as a competitor to Silicon and which theoretically is supposed to be better for the environment), generating thin film solar power that you can see through. Their first generation was a smoky amber glass with slight distortion; their current generation film is more like a tinted window.

  • by mitcheli (894743) on Monday July 23, 2012 @11:56AM (#40737287)
    I could use some for my Prius...
  • So I'm not interested.

  • by vlm (69642) on Monday July 23, 2012 @12:02PM (#40737351)

    produces energy by absorbing mainly infrared light instead of traditional visible light

    Unclear how much energy you get in exchange for adsorbing 30% of the visible light and probably all the IR. However, if its a lot of light, it might be worthwhile to dip old fashioned incandescent bulbs into this goo. Rather optimistically, if it can generate more than 40% of the nameplate wattage by adsorbing all the IR and 30% of the visible, then you'd get ahead by recycling that power back into the grid. Not a perpetual motion machine, because 70% of the visible is still leaking out the lampshade, but it would be like the world's weirdest phosphor basically eating IR photons and emitting visible photons.

    This does bring up the interesting point for unshaded windows, if it eats 30% of visible light, that merely means you need 30% more ultra-low-R value window area, or 30% more lightbulbs inside to brighten the room back up. So its not going to work well for windows in rooms where the drapes are always open and people are always inside. Great idea for my garage or bedroom (why do those have windows, anyway?) terrible idea for my office / kitchen / living room. Solar panel covered shutters seem like a good idea for the garage and bedroom... if the panels are rockin don't come a knockin or whatever.

    • Re: (Score:2, Insightful)

      by Anonymous Coward

      Bedrooms have windows so you have at least two escape route in case of fire.

      • by vlm (69642)

        Bedrooms have windows so you have at least two escape route in case of fire.

        A door would be cheaper and better insulated than any window.

        • by mattack2 (1165421)

          A door would be cheaper and better insulated than any window.

          What if there's a fire by that door? (Do you mean multiple doors?)

          Is a door really better insulated when there's usually a crack below the door (and it's likely not perfectly sealed on the other edges too)? It seems like most outside doors aren't insulated well.

    • by blueg3 (192743)

      It can't be more efficient than using light sources that don't emit the IR radiation in the first place.

      If a room is well-lit by windows, you don't need any additional window to remain well-lit. A 30% reduction in light for something that's well-lit, particularly by daylight, is not really noticeable. (Rather, you can only tell if you have both available for comparison. If you reduced the transmission of your windows by 30%, your eyes would simply adjust.)

    • We'll just make a heat reservoir and hook it up to a heat pump that pumps in heat from outside with a COP [wikipedia.org] of well-greater-than-1, and we'll surround the reservoir in highly efficient IR-absorbing panels, which will capture almost all of the energy, driving the heat pump and yielding energy to spare. Perpetual motion! Take that, laws of physics!

      Whether you're dealing with a physical "engine" or not, Carnot must be obeyed, because if he's not, a high-COP heat pump can pump in more heat against the gradient

    • by jfengel (409917)

      Generally, daylight produces more light than you get from light bulbs. Your eyes adjust so you see just as well either way, but most of the light is unnecessary and eventually devolves to heat.

      That heat is useful in cold climes, and obviously this device will be most useful in sunny places. At that, it might even help cool the room as well as producing electricity.

    • If efficiency is comparable to other cells, a good efficiency would be around 25%. Also, IR light is lower in the energy EM spectrum. I don't know how important it could in that case, we do not have much information about these new panels.

      In cold climates, these panels may not be a good idea since instead of reflecting IR, it absorbs it. So, a part of the energy spent to heat the building will feed these panels instead of heating the inside. Again, we need more data to compare both alternatives.

      • by Rei (128717)

        Well, as mentioned elsewhere, you're limited not just by the standard issues of solar cells, but also by more relevant entropy limits. If your solar cell is being hit by ambient radiated heat IR and is radiating IR in the same range, it's impossible to generate power without violating the laws of thermodynamics. Even though it's not technically a heat engine, you can treat a solar cell as an indirect heat engine subject to the limits of Carnot's theorum (as Carnot's theorum is simply a direct consequence

    • by T Murphy (1054674)
      Absorb and adsorb are two different things, they are not interchangable (however they are similar). If something absorbs water, it means it draws water into it, while if it adsorbs water, it means it holds the water to its surface. Either phenomena would result in the material picking up the water, so the end result is more or less the same. Unless you're sure you mean adsorb, just use absorb to refer to one object taking in another.

      That said, if adsorb really is the technically appropriate term here, I
    • by t14m4t (205907)

      Incandescent bulbs are hot from heat, not IR. There's a lot of IR, as well, which may make this kind of coating worthwhile; but, the heat will still radiate.

  • If this stuff could be further developed so that you would be able to turn it on and off like smart glass it would be a good alternative of shades, generating electricity from excess light. Trying to only convert IR light is a clever idea, but the electricity you get from that isn't much, you are much better off putting a panel on the roof.

  • Spy product (Score:5, Interesting)

    by vlm (69642) on Monday July 23, 2012 @12:11PM (#40737435)

    So if I replaced a section of optical fiber with this stuff, it would look on the OTDR like the worlds most uninteresting little bump (oh look, sloppy winding in the splice case results in a minor bump, eh who cares) and I could detect the electrical field... Sounds like a optical tap design.

    Of course a beam splitter would probably be a lot simpler, but supposedly there does not exist a beamsplitter design that doesn't inherently create what amounts to multipath that "looks like a beamsplitter" on a OTDR so simply doing something weird when you're tapping might help avoid detection.

    The only undetectable optical tap I can think of is chilled-PMT based... I think that would be fairly undetectable if done right.

    I haven't directly hands on done fiber since early 90s so I'm not sure. Probably fiber work is much like IT and CS, there is nothing new, just recycled old ideas along a baseline of slowly increasing speeds.

  • by Quantus347 (1220456) on Monday July 23, 2012 @12:12PM (#40737453)
    If it is absorbing mostly on the infrared spectrum, I bet it would help keep your house pretty cool on those hot sunny days.
  • If it could have used UV instead of infrared, we could have energy-generating sunscreen!

  • When first shown such a window, aren't we all going to say " I see what you did there" ?

  • The key issue with solar has always been price. It seems forever on the cusp of having a positive ROI, but it never actually breaks through. Hopefully the use of plastic as opposed to crystals will bring the cost way down.
    • by na1led (1030470)
      This is for Rich People who want to live off the grid, and brag how they are so eco-friendly. The rest of us will always be dependent on power from the grid.
      • by mattack2 (1165421)

        You don't need to be "off the grid" to have solar. In fact, having solar tied to the grid makes the most sense nowadays (IMHO).

        If you generate enough solar, you can still be zero net usage from the grid, but the grid is your "battery", so you still have power at night for example without your own energy storage.

        If you're using the power at night, it's (1) cheap, and (2) you're basically using the baseload power that was being generated anyway.

        Generating during the day, you're generating power at the most e

  • I saw something similar at some lame environmentalist convention I was forced to attend a few years ago...
    Way to claim you innovated something when you really didn't!
    • If you don't care about environmentalism then why go to a "lame environmentalist convention"?

      • by Thud457 (234763)

        If you don't care about environmentalism then why go to a "lame environmentalist convention"?

        obviously he's a demented fan of a wild, untrimmed thatch

      • Read the part "forced". You're not always free to choose what to spend your time on.
  • by webdog314 (960286) on Monday July 23, 2012 @12:24PM (#40737605)

    Depending on the efficiency, it might be an interesting choice for something like one (North or South) side of a large glass building, effectively giving you a large solar array for windows that you were going to put in anyway.

  • by mattr (78516) <mattr.telebody@com> on Monday July 23, 2012 @12:27PM (#40737641) Homepage Journal

    "With this combination, 4% power-conversion efficiency for solution-processed and visibly transparent polymer solar cells has been achieved."

    Okaay...

    • Re:4% (Score:4, Insightful)

      by Eightbitgnosis (1571875) on Monday July 23, 2012 @01:01PM (#40738211) Homepage
      As apposed to the great results we're getting from the 0% efficiency models? For most cases these aren't replacements for traditional solar panels, but rather a supplement.

      These could be particularly useful on large skyscrapers
      • by DarthVain (724186)

        Really depends how much that 4% costs.

        If the windows are a lot more expensive don't expect much conversion (pardon pun).

        Also the ease of use. If hooking up 4% worth of power to your home and/or the grid is expensive, also do not expect much conversion. (batteries, inverters, wiring, smart meter, etc... is it really worth doing all that for a handful of watts?)

        If you want conversion, make it economical and easy.

  • by dorzak (142233) <`moc.liamg' `ta' `kazrod'> on Monday July 23, 2012 @12:34PM (#40737753) Journal

    Blocking UV would have some benefits as well.

    I seem to recall IR it is blocking is also a major part of heat transference. There could be some definite savings on cooling bills throughout the sun belt/southwest.

    Anybody else reminded of the Heinlein stories where Solar panels took off when they started generating energy from the full range of cosmic radiation bombarding the Earth? Led to commuter roads in "The Roads must roll".

  • I'm a supporter of efforts like the development of these windows. The biggest difference in this world between the haves and the have nots is access to affordable energy. If you get that, you get clean water, refrigeration, air conditioning, transportation, etc.

    This is why I am in favor of technology developments that focus on energy generation. I'm against using state power to artificially drive conservation because most of the time that really means making access to energy more expensive. The end r
    • by Belial6 (794905)
      Beyond that, conservation alone is a dead end. It is an acceptance that we are going to run out, and we just want to make the party last one more day.
  • "Electricity-generating solar cell windows"?

    As opposed to solar cells that that generate, say, xenon and mummy dust?

IF I HAD A MINE SHAFT, I don't think I would just abandon it. There's got to be a better way. -- Jack Handley, The New Mexican, 1988.

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