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New Solar Cell Sets World Efficiency Record 299

asoduk writes to tell us that a new world record has been set for the most efficient photovoltaic device. Topping the scale at 40.8% efficiency, the new solar cell differs significantly from the previous record holder. "Instead of using a germanium wafer as the bottom junction of the device, the new design uses compositions of gallium indium phosphide and gallium indium arsenide to split the solar spectrum into three equal parts that are absorbed by each of the cell's three junctions for higher potential efficiencies. This is accomplished by growing the solar cell on a gallium arsenide wafer, flipping it over, then removing the wafer. The resulting device is extremely thin and light and represents a new class of solar cells with advantages in performance, design, operation and cost."
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New Solar Cell Sets World Efficiency Record

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  • by clonan ( 64380 )

    How much do they cost and when can I get some?

    400 watts per meter would let me go solar without cutting usage at all!

  • very cool, but... (Score:3, Insightful)

    by TheSHAD0W ( 258774 ) on Monday September 29, 2008 @02:36PM (#25196283) Homepage

    Call me in 20 years when they're in production. Seems it always takes that long for these innovations to get to market nowadays.

    • by Anonymous Coward on Monday September 29, 2008 @02:39PM (#25196315)
      We'll have fusion by then. Electricity too cheap to meter ;-)
      • Re:very cool, but... (Score:4, Informative)

        by fuzzyfuzzyfungus ( 1223518 ) on Monday September 29, 2008 @03:03PM (#25196557) Journal
        Your smile says that you also know this; but fission was supposed to be "too cheap to meter". Wonderful how it worked out.
        • by zippthorne ( 748122 ) on Monday September 29, 2008 @03:25PM (#25196795) Journal

          Fission very well could be, but half-vast fission we've been saddled with as a result of the Carter administration's (the one president who should've known better, btw, what with his degree in nuclear engineering) machinations.

          Things tend to cost a lot more when you throw away (and have to devise elaborate means to protect yourself from) 98% of your fuel as "waste" because you don't want terrorists to be able to make nuclear bombs.

          • Re: (Score:3, Informative)

            by falconwolf ( 725481 )

            Fission very well could be, but half-vast fission we've been saddled with as a result of the Carter administration's (the one president who should've known better, btw, what with his degree in nuclear engineering) machinations.

            Except the nuclear power industry had about 20 years to reduce cost before Carter came along. Lewis L. Strauss [cns-snc.ca], chairman of the Atomic Energy Commission, said the "energy too cheap to meter" quote in 1955 not 1975.

            Falcon

          • Re: (Score:3, Insightful)

            ...because you don't want terrorists to be able to make nuclear bombs.

            You say that as if it's a trivial concern.

            • Re: (Score:3, Informative)

              by Hurricane78 ( 562437 )

              In the early years ('99) I found a complete construction plan for a nuclear bomb on the net. Including contacts. First I thought this was a joke, but nowadays I know better, because I know quite a bit about that stuff.

              The point is, that it's very easy to build a nuclear bomb... in theory!
              In reality, it's very very hard, because first, you have to have uranium 235 (or plutonium 239, if you can get it), which must be extremely purified. And because of this, it is horribly expensive. If you buy the cheap crap,

          • Re:very cool, but... (Score:4, Interesting)

            by Nadaka ( 224565 ) on Monday September 29, 2008 @05:28PM (#25198181)

            hey... Thats my argument!

            If we built 10 thousand square miles of solar thermal power plants in the US southwest and a few hundred feeder-breeder reactors elsewhere, we could completely replace the low efficiency and high pollution electrical production of the US while expanding our capacity to be 2 or more times its current amount.

            This would allow us to also switch over to grid powered electric rail lines and widespread use of economical electric cars. Even without dramatically improved battery technology, long distance private vehicles could become viable if a charging rail system was installed along interstates and major highways to allow short range EV to charge on the move.

            The cost of the initial investment would be high (a few trillion) but over the course of a few decades it would easily pay for itself (assuming electrical rates similar to today).

          • Re: (Score:3, Insightful)

            by Jeremi ( 14640 )

            Fission very well could be, but half-vast fission we've been saddled with as a result of the Carter administration's (the one president who should've known better, btw, what with his degree in nuclear engineering) machinations.

            Perhaps President Carter (with his degree in nuclear engineering) had some insight into the risks involved? Perhaps he made the right decision, or at least the right decision at the time.

        • Re: (Score:3, Insightful)

          by Perf ( 14203 )

          Nowadays, most music is too cheap to meter (or matter.)

  • yaaawwwwnnn.... (Score:5, Insightful)

    by RapmasterT ( 787426 ) on Monday September 29, 2008 @02:39PM (#25196319)
    cool? yes, but only in the most esoteric sense. I've said MANY times before, fantastic new photovoltaic technology is announced every 6 months or so, NONE of it ever reaches the market. Call me when the ROI on home solar breaks the 20 year mark in my area. Right now it's almost 100 years.
    • Re:yaaawwwwnnn.... (Score:5, Informative)

      by fuzzyfuzzyfungus ( 1223518 ) on Monday September 29, 2008 @03:14PM (#25196669) Journal
      I think it depends on what you mean by "the market". There are plenty of places where, due to low average solar energy/square meter and cheap grid power, solar will be unexciting until the day when you can get spray-on 95% efficient solar cells in a can. On the other hand, if you are paying 5 or 10 thousand dollars/kg to launch satellites, cutting edge solar cells might well be cost effective even if they cost as much, per square centimeter, as top edge microprocessors. All other markets fall somewhere between those two.
      • Re: (Score:3, Informative)

        by NaCh0 ( 6124 )

        He's obviously talking about the home market. Your squishy "it depends" answer doesn't cut it either. I live in Arizona where we have clear skys 300 days of the year. Nobody here is pushing solar because they all know it's an exotic technology that costs too much. I wish it weren't true, but it is.

    • Re: (Score:2, Insightful)

      The break-even point would immediately change to about 2 years if people had to actually (gasp!) pay for the damage their carbon emissions produce, or carbon emissions were capped at the level necessary to avert catastrophe.

      Just because you're not paying a cost, doesn't mean no one is.

      • We'll pay WHEN China and India decides to.

      • Re: (Score:3, Insightful)

        by operagost ( 62405 )
        Maybe you would have to prove that an individual's carbon emissions actually have any sort of impact on the climate. Maybe athletes have to pay more because they burn more calories. Would you penalize poorer people who have to drive to work in less efficient cars, or would you force them under threat of imprisonment to ride the bus?
    • by Dan Ost ( 415913 )

      Where are you?

      Are you already using solar water heating? Unless you're above the arctic circle, solar water heating will probably pay for itself in far less than 20 years in your area.

      Solar electricity might not be there for most areas for a while, but progress is progress.

      • Re: (Score:3, Informative)

        by b0bby ( 201198 )

        I'm not so sure. I use gas for hot water only right now; my gas bills are $15-20 a month. A fair chunk of that is the line fee, so if I install a gas stovetop, as my wife insists we will, I'll be paying that anyway. Even if I could disconnect it entirely, it's barely feasible to put in solar hot water & have it pay for itself in 20 years. I was all fired up to do it last year, but when I ran the numbers it just wasn't worth it.

    • Re:yaaawwwwnnn.... (Score:5, Interesting)

      by jd34 ( 599131 ) on Monday September 29, 2008 @03:28PM (#25196819)
      While I agree that these types of announcements are overblown (they are talking about high-concentration PV here, which is not a good idea to put on roofs at all for structural reasons, and it only responds to about 80% of the available irradiance anyway due to being limited to beam radiation), the ROI is highly dependent on the economic conditions of the owner. Solar can payback fast if you are a large electricity user in the upper tiers of pricing even without incentives, and with incentives the banks are loving it today in many locations. If you are off-grid in a sensitive environment, you may have little alternative... what is the ROI on that? If you are living in a tiny home in a mild climate with no air conditioning, your ROI could indeed be prohibitive... but blanket statements about ROI are NOT "insightful", moderators.
    • by raygundan ( 16760 ) on Monday September 29, 2008 @03:31PM (#25196857) Homepage

      I'm just curious-- not implying that your calculations are wrong. I'm at the extreme other end in Arizona, and payback appears to be in the 10-15 year range for us, not counting resale and using a constant price for power for the next 15 years. That's well within the system warranty time, but may still be a bit too much for people to pay for up front.

      Payback speed depends heavily on your local utility, their rates, their incentives, and whether they allow net-metering over the entire year, or just monthly. It also depends on whether or not you are willing to consider resale value as part of your payback time.

      I suspect Hawaii is even better than Arizona despite having more cloudy days, just because power is so freaking expensive there.

      In the long run, I think leases will win out. A couple of companies are offering deals where you lease the system and panels, and they promise your new smaller electric bill plus the lease cost will be lower than your current electric bill. A deal like this makes things suddenly interesting to people who don't have $20k to drop up front.

    • Re:yaaawwwwnnn.... (Score:5, Informative)

      by Heembo ( 916647 ) on Monday September 29, 2008 @03:40PM (#25196977) Journal

      "Complete" solar's ROI is 20 years, but solar hot water heaters here in Hawaii - where we get a lot of sun - with the federal solar tax credit - I'll make my money back in O N E year!

    • I agree with the first part... most of the new tech never makes it to market. I don't agree with the last. ROI has been 20 years or less for a long time in most areas except those with very little sun.
    • If you have an electric vehicle and travel 20k miles per year.

      The economic case for photovoltaics comes from transportation rather than domestic energy production. This is a trick the solar companies and BEV companies seem to be missing.

      One of these for instance.
      http://www.cleanova.com/public/sve/ [cleanova.com]

      Postal companies, couriers, taxis etc etc.
       

    • Call me when the ROI on home solar breaks the 20 year mark in my area. Right now it's almost 100 years.

      You don't get much sun where you're at do you? Here's [oynot.com] a spread sheet you can play with to calculate ROI, now I haven't looked at it so I don't know how good it it. This is the webpage [oynot.com] that links to it. Of course you'd get a better return by increasing energy efficiency.

      Falcon

  • Yet another break through in technology that we won't see for a long time and some how that is news worthy. But of course by the time we might actually see this new technology in commercial use somebody will claim 50-90% efficiency and yet again won't see any possible commercial availability for years to come.

    Yes my post's subject's acronym doesn't exist and no I have no idea how to pronounce it. :P

  • by TheRaven64 ( 641858 ) on Monday September 29, 2008 @02:40PM (#25196329) Journal
    At 40%, you're talking about 400W when in direct sunlight. With eight hours of sunlight per day the average house needs less than four square metres. Now, of course, you aren't going to be using the most power at the times when these are generating, but it can definitely put a significant dent in your electricity bills.
    • Now, of course, you aren't going to be using the most power at the times when these are generating, but it can definitely put a significant dent in your electricity bills.

      Solar power -> Air conditioner

    • by Brigadier ( 12956 ) on Monday September 29, 2008 @02:53PM (#25196469)

      I no longer get excited about stories like this, as it doesn't matter unless someone figures out how to mass produce this stuff and make it available for the market. If I'm not mistaken photovoltaic production hasn't changed in years despite all this new technology. Why not run a story on why mfgs are taking so long to adopt this.

      • Re: (Score:3, Insightful)

        by JohnnyGTO ( 102952 )
        You need to Google a bit, there have been steady improvements in efficiency, little incremental ones. The big improvement has come in manufacturing like First Solar.
      • by Dan Ost ( 415913 )

        Well, it's one thing to discover a better solar unit. It's quite another to discover how to mass produce it economically.

        You must have both pieces to the puzzle to bring these things to market.

      • Re: (Score:3, Insightful)

        by swb ( 14022 )

        IMHO, it's energy *storage* that matters more than generation. It seems like over time, even "normal" solar cells or wind power could build up an excess of energy that would cover night time, air conditioning, clouds, etc, but there's no practical way of storing the generated energy to use later.

        • by Brigadier ( 12956 ) on Monday September 29, 2008 @04:26PM (#25197485)

          I actually think there is a simple source to this. It's not so much to store energy but to re-direct it. If home owners with solar arrays are hooked up to the electrical grid they can sell power to the grid during the day to supply business and manufacturing. Then at night the grid will forward excess power not used by business back to the homeowners. There is no need to 'store' energy in the traditional sense.

    • With eight hours of sunlight per day the average house needs less than four square metres.

      Figure roughly five "solar hours" per day (depending on location, climate, access to sky, etc.).

      The "solar rating" is the number of hours with the panel directly facing the noonday sun it would take for the panel to receive the same sun exposure as a panel aimed at the noonday sun and not tracking it would receive during a day.

      Tracking the sun improves things somewhat. But sunlight has more energy to collect at noon t

    • Re: (Score:3, Interesting)

      by Ioldanach ( 88584 )

      At 40%, you're talking about 400W when in direct sunlight. With eight hours of sunlight per day the average house needs less than four square metres. Now, of course, you aren't going to be using the most power at the times when these are generating, but it can definitely put a significant dent in your electricity bills.

      Your math reads, to me: 400W * 4 * 8 hours * 365 days = 4,672kWh/yr

      Unfortunately, both the 8 hours per day and the average usage per year are incorrect.

      Average electricity use in 2001 was 1

  • by gumpish ( 682245 ) on Monday September 29, 2008 @02:40PM (#25196337) Journal

    Even TFA doesn't say what the previous record was or provide any quantitative comparison.

  • TFA (Score:5, Informative)

    by Anonymous Coward on Monday September 29, 2008 @02:42PM (#25196359)

    Was taking forever to load, so here's the article:

    Scientists at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) have set a world record in solar cell efficiency with a photovoltaic device that converts 40.8 percent of the light that hits it into electricity. This is the highest confirmed efficiency of any photovoltaic device to date.

    The inverted metamorphic triple-junction solar cell was designed, fabricated and independently measured at NREL. The 40.8 percent efficiency was measured under concentrated light of 326 suns. One sun is about the amount of light that typically hits Earth on a sunny day. The new cell is a natural candidate for the space satellite market and for terrestrial concentrated photovoltaic arrays, which use lenses or mirrors to focus sunlight onto the solar cells.

    The new solar cell differs significantly from the previous record holder - also based on a NREL design. Instead of using a germanium wafer as the bottom junction of the device, the new design uses compositions of gallium indium phosphide and gallium indium arsenide to split the solar spectrum into three equal parts that are absorbed by each of the cell's three junctions for higher potential efficiencies. This is accomplished by growing the solar cell on a gallium arsenide wafer, flipping it over, then removing the wafer. The resulting device is extremely thin and light and represents a new class of solar cells with advantages in performance, design, operation and cost.

    NREL's Mark Wanlass invented the original inverted cell, which recently won a R&D 100 award. His design was modified by a team led by John Geisz that further optimized the junction energies by making the middle junction metamorphic as well as the bottom junction. Metamorphic junctions are lattice mismatched - their atoms don't line up. The material properties of the mismatched semiconductors allows for greater potential conversion of sunlight.

    NREL is the U.S. Department of Energy's primary national laboratory for renewable energy and energy efficiency research and development. NREL is operated for DOE by Midwest Research Institute and Battelle.

    • The 40.8 percent efficiency was measured under concentrated light of 326 suns.

      So, as soon as we move to a solar system with 326 suns, this will be useful?

    • Re: (Score:2, Informative)

      by KiwiCanuck ( 1075767 )
      2 points. Getting the intensity of 326 suns on my roof isn't going to happen. GaAs wafers are not cheap. Here is are some recent prices, 3" n-type GaAs are $125 each (per batch of 25), 4" n-type Ge are $344 each (per batch of 25), 4" 100) n-type Si are $35 each (again per batch of 25). Note: 3" (4"?) is as big as you are going to find a GaAs wafer. The growth method does not allow for larger wafers. Also, this price for Ge seems a bit high.
      • Getting the intensity of 326 suns on my roof isn't going to happen.

        If your roof sees a decent number of sunny days each year, you can use heliostat [wikipedia.org] mirrors to get that.

      • Re: (Score:3, Informative)

        Getting the intensity of 326 suns on my roof isn't going to happen. GaAs wafers are not cheap.

        Use a concentrator and a heliostat. The fact that solar cells work better at higher intensities is a *good* thing: That 3-4 inch wafer can collect the sunlight from a 5-6 foot fresnel lens. At that intensity it'll need good cooling during sunlit hours, but that's free hot water.

      • Re: (Score:3, Insightful)

        by Shotgun ( 30919 )

        Gold isn't cheap, either, but you can find it spread across a $15 NIC card.

        Go figure.

  • Old? (Score:5, Informative)

    by pushing-robot ( 1037830 ) on Monday September 29, 2008 @02:43PM (#25196367)

    http://www.treehugger.com/files/2006/12/new_world_recor.php [treehugger.com]

    TFA is slashdotted, but a little googling shows this happened two years ago.

    • Re:Old? (Score:5, Funny)

      by bugnuts ( 94678 ) on Monday September 29, 2008 @03:04PM (#25196571) Journal

      No, that was 40.7%. Old and busted.

      This is 40.8%. :p

    • The URL also looks suspicious with that com_zippynews passed as some kind of affiliate link, perhaps.
      www.electricalengineer.com/index.php?option=com_zippynews&id=236&task=detailnews&cid=

      And this guy has another post about the same thing currently in the firehose and has never made a single comment(not unusual by itself, but another small bump in my off the cuff bayesian scam analysis score)

  • by Abstrackt ( 609015 ) on Monday September 29, 2008 @02:43PM (#25196373)
    We will have solar energy as soon as the utility companies solve one technical problem -- how to run a sunbeam through a meter.
  • ... what about fragility? Ultra-thin can have a downside.

  • ...that a 12 year old invented it. And that this new solar cell stores like fifteen times the energy of the sun.

    You can quote me on that.
  • Cool and not cool (Score:4, Interesting)

    by Kythe ( 4779 ) on Monday September 29, 2008 @03:16PM (#25196697)

    Indium is a very rare material, one which we're slated to deplete in less than 10 years or so at current rates of consumption, due in part to its use in display screens.

    I highly doubt that widespread use in solar cells would be feasible.

    Nice efficiency, though.

    • Re: (Score:2, Informative)

      by Anonymous Coward

      Indium is a very rare material

      Gallium is even rarer and is needed in equal quantities for this application.

    • by UdoKeir ( 239957 )

      Whilst some thin-film PV cells are made using Indium, not all PV cells are.

      I looked into this a while ago. Media darlings like First Solar and Nanosolar are using CIGS (Indium) technology, which, as you note, is in short and rapidly depleting supply.

      But companies like Suntech [yahoo.com] are using good old, reliable and abundant Silicon. And they're doing it today, not with vapourware. They're a much better bet for the long term.

    • RTFWikipedia [wikipedia.org]: "Indium ranks 61st in abundance in the Earth's crust at approximately 0.25 ppm [2], which means it is more than three times as abundant as silver, which occurs at 0.075 ppm"

      There's apparently a lot of it on earth, but not much purified. As it becomes more useful, we can get more.
  • GaInP and GaInAs are very(?) expensive, and poisonous to boot. I'm not sure this is the right way to go. Imagine having to deal with lots of discarded solar cells made of this stuff.

  • all this talking about waffels is making me hungry. Do these solar cells come with some good syrup?

  • ...what would the long-term savings of investing $700 billion in solar/wind/geo-thermal/etc. alternative energy be and how does that compare to the economic loss of not giving it to Wall Street?

  • by ChrisA90278 ( 905188 ) on Monday September 29, 2008 @03:56PM (#25197155)

    Why does everyone think these would be used to produce electric power for domestic use? Something like this is much better suited for use on spacecraft.

    When you are covering your roof you care about the power/cost ratio. On spacecraft you care a lot about power/weight ratio. This new type of cell address power/area which translates directly to power/weight

  • by macraig ( 621737 ) <[moc.liamg] [ta] [giarc.a.kram]> on Monday September 29, 2008 @04:09PM (#25197299)

    Does this need to be said again? There's no shortage of roof space and other places to locate solar cells, so the efficiency of the cells is only a marginal issue; the bigger issue is COST. Instead of focusing all the research on this penile my-cell-is-more-efficient-than-YOURS pissing contest, it ought to be focused on finding least toxic and least expensive means of production. Certainly large scale mass production will eventually reduce costs, but large scale adoption won't occur until they can be produced inexpensively enough in the first place to motivate widespread use. Efforts should be focused on finding the least expensive and least toxic method of production for now, and worry about improving efficiency once their use has become commonplace.

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