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Power Hardware Science

Flexible, Fiber-Optic Solar Cell Could Be Woven Into Clothing 65

Posted by Soulskill
from the current-fashion-trends dept.
MrSeb writes "An international team of engineers, physicists, and chemists have created the first fiber-optic solar cell. These fibers are thinner than human hair, flexible, and yet they produce electricity, just like a normal solar cell. The U.S. military is already interested in weaving these threads into clothing, to provide a wearable power source for soldiers. In essence, the research team started with optical fibers made from glass — and then, using high-pressure chemical vapor deposition, injected n-, i-, and p-type silicon into the fiber, turning it into a solar cell (abstract). Functionally, these silicon-doped fiber-optic threads are identical to conventional solar cells, generating electricity from the photovoltaic effect. Whereas almost every solar cell on the market is crafted out of 2D, planar amorphous silicon on a rigid/brittle glass substrate, though, these fiber-optic solar cells have a 3D cross-section and retain the glass fiber's intrinsic flexibility. The lead researcher, John Badding of Penn State University, says the team has already produced 'meters-long fiber,' and that their new technique could be used to create 'bendable silicon solar-cell fibers of over 10 meters in length.' From there, it's simply a matter of weaving the thread into a fabric."
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Flexible, Fiber-Optic Solar Cell Could Be Woven Into Clothing

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  • Forget about the military applications, think about never having to charge your iDevice/Droid again! ...just plug it into your shirt. ^_^

    • by masternerdguy (2468142) on Friday December 07, 2012 @03:25PM (#42219397)
      Forget your phone, this could provide endless power for medical devices from insulin pumps to more exotic things like replacement limbs and those artificial eyes that are getting better each year (you get to see a 12x12 pixel image now! wooo, shiney). One of the problems with medical devices is finding a continuous power supply.
      • by sinij (911942)
        It won't - not enough power from solar cell even if you convert 100% of your surface area in a perfect light. Napkin calculation tells me it would take 48 sunlight to recharge your typical smartphone battery in ideal circumstances.
        • I assume you mean 48 hours, and that sounds wrong. The little "folding wallet" solar chargers do it in under a day.

        • by dgatwood (11270) on Friday December 07, 2012 @04:15PM (#42219935) Journal

          Your math is off by orders of magnitude.

          A solar panel produces 8-10 watts per square foot. A smartphone while charging (with the screen off) typically draws no more than 500 mA at 5VDC, or about 2.5 watts. Some support faster charging at up to an amp. Either way, it requires nowhere near your entire surface area; with traditional PV cells, a typical adult could produce that much power with just one sleeve in full sun, give or take.

          How that translates to flexible PV threads is anybody's guess.

          • by Nikker (749551)
            An interesting implementation would be an entire piece of clothing like a hat entirely woven with this material. One weakness of traditional PV cells is the angle it faces the source (the sun). A perpendicular angle to the source achieves maximum results, being circular allows to capture light at different angles to the source much more efficiently.
    • First thing I thought of too, but makes me wonder how flexible this would be, could it be folded? How about ironed and washed without damage? No idea about fiber optics (a minute on Google didn't help) but those seem to be pertinent questions before it's ready to be integrated into clothes. The whole multi-angle light collection seems like it could be pretty useful as well.
    • by roc97007 (608802)

      Plugs? How quaint. Charge wirelessly. Just having the phone on you results in charging it.

  • Just curious, how much energy would it generate given the surface area of power lines strewn along light poles for hundreds of miles.. Would it over those lengths generate enough energy to juice those power lines and power a grid? Or at least to help power it?
    • I'm not an EE, but it seems to me that just "adding more juice" along the power lines might not be a good idea. Might be hard to regulate?
      • by tulcod (1056476)

        Not only is it hard to regulate, I cannot imagine these fibers have an output of 200kV AC at exactly 50Hz.

        • I think we are barreling off toward the silly on the ideas front, but if you restrict it to HV-DC lines, a single cell usually puts out .5-.6 VOC, so you just need to string 400,000 of them together and voila, you are pushing power in. That has to be seriously small surface area even aggregated across miles of line. Anyone want to do the math?
    • by mcgrew (92797) *

      There's no way to tell from TFA, it didn't state how much electricity was generated.

    • by tulcod (1056476)

      If you're gonna spend money on solar panels close to power lines, then I have a weird suggestion for you: install actual solar panels close to power lines.

      • by peragrin (659227)

        better yet install solar panels on every roof of every house.

        Even if each house only generates 50% of the power they use the entire power grid would be far more stable

    • by suutar (1860506)
      If we assume a 15cm diameter power cable (which means a 15cm effective width; sure, the actual cable circumference is more than that but half of it's out of the sunshine and the rest isn't all perpendicular), a one kilometer length of cable would have a 'collection area' of 150m^2. Given full-time sunshine (dicey) and 40% efficiency of conversion (roughly state of the art, iirc) that one kilometer cable will generate about 84 kW. Assume that an average day has about 6 hours of full sunshine (wild-ass guess)
    • Power from sun = Direct Current, power lines = Alternating Current. Not the same and no help.

      Our country made the decision long ago to not pursue DC as our power supply. Power from photovoltaic cells creates a stream of electricity in one direction. The conversion and voltage (very high along power lines) makes it a fun idea, but not practical.
      • by Kremmy (793693)
        The conversion between AC and DC is such a disgustingly common act that I have a hard time figuring how you can be aware of both of them and yet still consider it an issue.
        • The problem is not converting it, the problem it doing so over and over on millions of miles of power lines...enough to make it of any value. This is not to mention the difficulty of replacing or covering all of the lines and then converting the power to much, much higher voltage A/C when the amperage is very low coming from the pv.

          My point wasn't that you can't covert AC to DC and back, the point is that it is not simply putting up a PV cell and plugging it into the power lines. Make sense?
  • Could we weave Begley Cloth now for or planetary colonization efforts?

  • by wcrowe (94389) on Friday December 07, 2012 @03:26PM (#42219413)

    Uh, yeah. Let me guess. It should be on the market in five years, just like every other solar technical wonder.

    • Also I'm currently on your lawn... should I leave maybe?
      • by game kid (805301)

        Also I'm currently on your lawn... should I leave maybe?

        by wcrowe (94389) ...

        by Sephwrath (2467088) ...

        ...probably a good idea.

    • by mcrbids (148650) on Friday December 07, 2012 @03:43PM (#42219627) Journal

      Uh, yeah. Let me guess. It should be on the market in five years, just like every other solar technical wonder.

      Oh please. If only you knew what was really going on, you'd have trouble breathing. Prices for solar power have dropped so rapidly and so consistently people are calling it "Moore's Law for Solar" [forbes.com]. A quote from the article: Solar modules prices have dropped from $300 per watt in 1956 to $50 per watt in the 1970s to $10 in the 90s to $1.05 a watt today. Just what did you think this should look like?

      Approximately half of all the generating capacity last year was from renewable energy sources. [kcet.org] The miracle of having an actually usable smartphone was a pipe dream just 5 years ago. Now, even most poor folks have one.

      Today, anybody can afford to board a high speed aircraft and travel at 350 MPH at 40,000 with safety that rivals our living rooms. Think about that. A chair, 40,000 feet in the air, travelling 350 MPH, affordable to nearly everybody, complete with magazines to read, and we mostly complain about the noise.

      Sheesh.

      • by h4rr4r (612664)

        What flys at 350MPH at 40k feet?

        Most commercial airliners are closer 600MPH. Mach .83 is what a 777 is rated for an A320 is 0.84.

      • by wcrowe (94389)

        Fine, come back in five years and show me your solar sport coat. I'll buy you lunch.

      • by roc97007 (608802)

        > Approximately half of all the generating capacity last year was from renewable energy sources. [kcet.org]

        Misquote. From the article you linked to,

        According to the Federal Energy Regulatory Commission (FERC), renewable energy projects -- including solar, wind, hydroelectric, geothermal and biomass -- made up almost half of all new power generation installations in the U.S. in the first 10 months of 2012. (Emphasis mine.)

        That's WAY different from "approximately half of all generating capacity" which wo

  • by Anonymous Coward

    They could also be woven into curtains to provide electricity for homes, enough perhaps for digital gadgets and some LED lighting.

  • How is this material any better than wearing a fiberglass t-shirt all day? Sounds pretty itchy - and unhealthy.
    • How is this material any better than wearing a fiberglass t-shirt all day? Sounds pretty itchy - and unhealthy.

      Probably because optical fiber != fiberglass.

    • How is this material any better than wearing a fiberglass t-shirt all day? Sounds pretty itchy - and unhealthy.

      That's what I was thinking when I read the summary. When you tell me something is:

      -These fibers are thinner than human hair, flexible
      , -optical fibers made from glass

      That sounds an awful lot like asbestos...another, long, thin fiberous crystal...

  • by Anonymous Coward

    Dear anyone with access to the abstract, does it include any information on efficiency / how much electricity this generates?

    Will this generate enough electricity to power my awsome christmas sweater where rudolf's nose lights up?

  • How would something like this hold up under real world use? Clothing is bent and folded, individual fibers are often pinched very tightly and broken. Since electricity requires a closed circuit, wouldn't a break and a fiber render that fiber useless for producing electricity?

  • by Anonymous Coward

    with a refractive index of -1. Now if I only can remember where I put it.

  • Wrong use case.... (Score:5, Insightful)

    by Anonymous Coward on Friday December 07, 2012 @03:55PM (#42219741)

    Everyone is speculating about how this could be used in clothing, but I think this is the wrong use case. Clothing has too little sun facing surface area to produce the amounts of electricity to be more useful than existing battery tech.

    However, the military uses a lot of cloth in large sun facing swaths. Ever seen a tent city? Tents are the perfect use case for this tech. Large surface areas, can be oriented towards the sun, rarely washed, never ironed, and only folded up for transport or storage. Integrating the solar tech into the fabric instead of an extra add on package would be ideal.

    • by mlts (1038732) *

      A more mundane use would be things like car or RV covers. Cover the rig, plug the cover into a smart battery charger, walk off.

      Even more simple, just something to toss over a roof and fasten into place with double-sided tape (perhaps Velcro.) The result would be useful power, but without sacrificing repairability, other than the added weight.

    • I want a set of sails made from this. Neatly solves a problem with solar panels on a sailboat: half the time they are in the shadow of a sail.
    • Clothing has too little sun facing surface area to produce the amounts of electricity to be more useful than existing battery tech.

      Not to mention that clothing is bent and rumpled in ways that would break optic fibers, even just in normal wearing.

  • "These fibers are thinner than human hair, flexible, and yet they produce electricity, just like a normal solar cell."

    Imagine the surface available for photon uptake in fleece form! Fleece, as in Helly Hansen - www.google.com/search?q=helly+hansen+fleece

    One square meter of standard, plain photocell surface would possibly be multiplied if made into some brushy/hairy type of material.

  • Now we can have powered "power ties".

  • Make half the shirt solar cells and half battery cells. I just want to be able to use this as a nice electric shock to unsuspecting people.
  • Sorry to post late, snag blackout.
  • Couple that with a peltier junction and you will have one happy soldier.
  • Enough said, sounds like a perfect new fiber for those.

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