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Power Science Technology

80% Improvement In Solar Cell Efficiency 204

An anonymous reader writes "Chemistry researchers at Oak Ridge National Laboratory say they've improved the efficiency of typical solar cells by a whopping 80% by creating a 3-D nanocone-based solar cell platform. The technology tackles the problem of poor transport of charges generated by solar photons. These charges — 'negative electrons and positive holes' — typically become trapped by defects in bulk materials and degrade performance. 'We designed the three-dimensional structure to provide an intrinsic electric field distribution that promotes efficient charge transport and high efficiency in converting energy from sunlight into electricity.' Bottom line, they say, is they've boosted the light-to-power conversion efficiency of photovoltaics by 80 percent."
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80% Improvement In Solar Cell Efficiency

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  • Call me when it's on the market.
    • Re:Yawn (Score:5, Insightful)

      by Surt ( 22457 ) on Friday April 29, 2011 @03:54PM (#35979394) Homepage Journal

      Because like the rest of the world, slashdot can't care about pure research, but instead only what can be put on a shelf and advertised by google now now! now!!!!?

      • Re:Yawn (Score:4, Insightful)

        by Amouth ( 879122 ) on Friday April 29, 2011 @04:02PM (#35979474)
        its not that we are impatient..  BUT the fact the solar cells that are available today are basically the same as the ones 15 years ago and the new tech is always 5 years off every damn year..  its mainly that we all know that there are reasons we don't see these things and it has to do with making other people more money..

        i have zero problem with pure research.. just when it's just wonderful and they try to play it off that it will save the world or help us in the next so many years..  then it never shows up...  yea nothing seems to change.. 
        • Re:Yawn (Score:5, Funny)

          by Cytotoxic ( 245301 ) on Friday April 29, 2011 @04:12PM (#35979570)

          We are working on a fix for that.... it should be ready in about 5 years.

          • It's like the kids in the back seat on vacation...

            "Are we there yet?"

            "20 minutes"

            "Are we there yet?"

            "20 minutes"

            • by Thraxy ( 1782662 )

              And 90 years later we were finally there...

            • You're doing it wrong.

              Them: "Are we there yet?"
              Me: "10 minutes"
              Them: "Are we there yet?"
              Me: "10 minutes"
              Them: "Are we there yet?"
              Me: "20 minutes"
              Them: "Are we there yet?"
              Me: "30 minutes"
              Them: "Are we there yet?"
              Me: "50 minutes"
              Them: "Are we there yet?"
              Me: "80 minutes" ...

              Eventually, they get the idea. And it makes it more engaging because you have to remember where you were last time, as well get to enjoy using a different series each time. Fib is one of my favorite.

        • Re:Yawn (Score:5, Informative)

          by Rei ( 128717 ) on Friday April 29, 2011 @04:39PM (#35979832) Homepage

          BUT the fact the solar cells that are available today are basically the same as the ones 15 years ago

          BUT the fact is that you've clearly not paid one iota of attention to the price difference between today's cells versus those of 15 years ago (just so you know, they're about 1/3rd the cost now), nor the chemistry differences between today's cells and those of 15 years ago (go back to 1996 and find me a mass-market CdTe cell, won't you? The largest PV manufacturer in the world is now CdTe)

          • Re: (Score:3, Insightful)

            by thegarbz ( 1787294 )

            That's all good and fine, but an article claiming that solar PV cells are 80% more efficient come up on Slashdot about once a month, each using a different method. Yet the cells we have today are nearly as grossly inefficient as they were 15 years ago. I'm glad price is moving forward, but even if in 15 years time panels are free if I still need to blanket the entire roof with shiny panels that have a high carbon footprint to produce, then really what's the point.

            What we need is for these efficient cells to

        • Re:Yawn (Score:5, Informative)

          by Surt ( 22457 ) on Friday April 29, 2011 @05:03PM (#35980066) Homepage Journal

          Solar cells are actually significantly ahead of where they were 15 years ago. There's no huge jump, but there really can't be, as we're nearing the theoretical limit of simple pv cells. More complicated cells can do better, but again the maximum amount better is less than 3x, and that is all the improvement we can ever get.

          Have a look at
          http://en.wikipedia.org/wiki/Solar_cell_efficiency [wikipedia.org]

          and you'll see the slow but steady march of progress. That march is reflected in the commercial cells you can buy as well.

          • by geekoid ( 135745 )

            hmm, That article is suspect. They claim a payback of 1-4 years. I can't find any consumer cells that you can payoff in 4 years. I would like to see those numbers with with high end non-consumer grade cells pulled out of the equation.

            " That march is reflected in the commercial cells you can buy as well."

            where?

            • Re:Yawn (Score:4, Informative)

              by Surt ( 22457 ) on Friday April 29, 2011 @06:34PM (#35980940) Homepage Journal

              1-4 years to pay off the energy required to manufacture them. After which they are a net benefit to our economies.

              You can buy the cells anywhere. 15 years ago you could buy 14% efficient cells. Today you can buy 22% cells. Lab cells are approaching the theoretical limit of 29% for simple PV. That's a 50% improvement already, with another 30% on the table, whjch we will see gradually creep into commercialization over the next 15 years as we have over the last 15 years.

            • That article talks about energy payback, not $ payback. That is, how long it takes for the panel to produce the energy required to manufacture it. Typically the energy payback time is much shorter than the $ payback time.
            • Dollar payback is going to depend on whatever strange things your local power company is doing and how much the equipment you buy costs. In some parts of Australia due to a government handout and power authority handouts the dollar payback time is close to immediate but that's really a short term token effort by various groups pretending they are green by handing out relatively small amounts of money instead of building something big and capital intensive. That's effectively spending the money like advert
      • Every 2 months or so someone revolutionizes Solar Cells. Or at least that's what the articles suggest. Now I admit I don't keep to breast with current technologies, but has ANY of them reached production?

        • by Surt ( 22457 )

          Yes, lots. The steady pace of innovation is slowly but surely raising the efficiency of cells toward a limit set by fundamental physics.

        • when they have this [wikipedia.org]?
          • by Jeremi ( 14640 )

            when they have this?

            Awesome idea! Spread some of that sunless-tanning chemical on to your rooftop PV panels, and you'll be producing electricity 24/7!

        • Unfortunately, in the US at least, congress wimps out on the Production Tax Credit. This makes alternative energy more expensive than those existing industries that receive government funding in tax dollars. Since the consumer is only looking at their utility bill, they are under the notion that it cost them less (not recognizing the tax burden that may be factored into the lower utility bill), so they don't buy it. "When it cost as much as I'm using now, then I'll buy" attitudes prevent consumer adoptio

      • "Because like the rest of the world, slashdot can't care about pure research, but instead only what can be put on a shelf and advertised by google now now! now!!!!?"

        No, it's because posting this information so early that it's useless for decision-making means it's just entertainment.

        • by Surt ( 22457 )

          How is this too early for me to decide what grad school to attend for research in nanomaterials?

  • Misleading title (Score:4, Insightful)

    by vsage3 ( 718267 ) on Friday April 29, 2011 @03:45PM (#35979260)

    With this approach at the laboratory scale, Xu and colleagues were able to obtain a light-to-power conversion efficiency of 3.2 percent compared to 1.8 percent efficiency of conventional planar structure of the same materials.

    So the efficiencies went from awful to slightly less awful.

  • by Geoffrey.landis ( 926948 ) on Friday April 29, 2011 @03:47PM (#35979276) Homepage

    To be pedantic, they have boosted the efficiency of LOUSY solar cells.
    They've taken a 1.8% efficient solar cell and turned it into a 3.2% cell.

    I wish the world's press offices would declare a moratorium on announcing breakthroughs in solar technology.

    • I wish the world's press offices would declare a moratorium on announcing breakthroughs in solar technology.

      I don't complain because, since the deaths of FEDs and their ilk, I need something to take the place of the Display Tech. of the Week articles we used to get.

    • by c0d3g33k ( 102699 ) on Friday April 29, 2011 @04:07PM (#35979534)

      While I appreciate your snarky cynicism, Mr. Landis, not every advance in the world is measured in miraculous breakthroughs. Some things are hard and just improve incrementally through the hard work of people that give a shit. They work hard and figure out how to make things better a bit at a time. That's in contrast to the people that just sit back and do nothing while waiting for the miraculous breakthroughs. While asshats the world over snicker because these solar cells are "slightly less lousy", the people that give a shit will continue to bust their asses to make things better until the day when they cross the line that defines a "massively viable" solar cell. Then the critics will jump on board and ride the wave as if they had everything to do with it and were believers all along. Now THAT'S depressing and worthy of cynicism.

    • Re: (Score:2, Interesting)

      by MarcQuadra ( 129430 )

      Don't be silly, we're right on the brink of a major breakthrough!

      http://bravenewclimate.com/2011/04/25/npfb-1978/ [bravenewclimate.com]

      The 'greenies' have ben 'Microsofting* us for decades now. It's time to do something for -now- and plan for -later- when the big breakthrough lands.

      * Microsoft: verb; To announce a feature or product that negates the value of the most likely competitor, but never actually deliver the product. See als: Real Soon Now.

    • by Animats ( 122034 ) on Friday April 29, 2011 @04:21PM (#35979666) Homepage

      Right. The current record for an experimental solar cell technology is around 42%. Mainstream commercial products run 12 to 20%. That's up from 6% in the original Bell Labs solar cells in the 1950s. Single-layer cells have a theoretical limit at 34%, but multi-layer cells can beat that somewhat.

      • It would be handy if the 25 teams claiming a doubling of solar cell efficiency would get together and make one really super-duper one wouldn't it.
        I wouldn't expect their doublings to exactly multiply but it's bound to be, say, at least double as efficient. ;-)

    • by vadim_t ( 324782 )

      It's still important

      There's an use for decent but inexpensive cells.

      Cheap but very inefficient is useless -- no point in covering your roof if it's not even going to power the TV, even if it's nearly free. Installation takes time and effort, after all.

      Expensive and very efficient isn't that useful either. It might go on satellites, but 80% efficiency at $20/watt wouldn't make sense for most people.

      Now in between those lies the interesting range. And if a technology from the cheap but not very useful kind ca

  • Wonderful! Amazing! ...Just like the other half-dozen or so solar cell improvements I've read about over the past few years.
    But unless we can actually BUY these upgraded units soon, I'd like to add one more appropriate adjective: Pointless.
    (Okay, maybe not entirely pointless. But that's what it feels like when all of these more-efficient panels never seem to show up anywhere.)
    • Re:Fantastic! (Score:5, Insightful)

      by Surt ( 22457 ) on Friday April 29, 2011 @03:57PM (#35979424) Homepage Journal

      But innovations like this are exactly why solar efficiency has, in fact, slowly but steadily improved over the last couple of decades.

      • That sounds great when you mention it like that, but the reality is solar PV has an abysmal efficiency, and is still the single most expensive and realestate exhausting technology available. While I welcome every effort to improve it it does seem like there's a "breakthrough" in solar PV every month that never actually makes it to the market.

        At the snail pace we are going solar PV will likely become a viable option just in time for the demise of the human.

        • by Surt ( 22457 )

          PV has a theoretical maximum of 29%, so it isn't going to have any huge jumps from the current 22% efficiency. It will have to be a different fundamental design that goes higher than that (and perfect carnot conversion is only ~85% with solar, so we'll be lucky to triple today's efficiencies, ever.

          • PV has a theoretical maximum of 29%, so it isn't going to have any huge jumps from the current 22% efficiency.

            Wrong. Crystalline silicon based PV has a theoretical max efficiency of 29%. Other forms of PV such as GaAs multijunction cells have already demonstrated efficiencies in the high 40% range and are rising.

        • Are you whining about the abysmal thermal efficiency of nuclear plants, too?
    • by Daetrin ( 576516 )

      Just like the other half-dozen or so solar cell improvements I've read about over the past few years.

      They're taking the extra time to combine all the improvements together, so it gets delayed a little every time a new discovery is made. But when they're finished we should have solar cells that are 320% efficient at converting the sun's energy to electricity!

    • Maybe so, but the mainstream solar cell market is already at 18-24% efficiency. These clowns are only at 3.2%. If this one shows up on the market nobody will care even if they are dirt cheap and you can paint your house with them. The solar paint technology, as bad as it is, is already at 5% efficiency.
      • You know, some people are actually interested in research, not in current market value. Just because you are insofar typical for the main population that you don't give a fuck about anything beyond your very tiny horizon doesn't mean that people working on alternatives qualify as "clowns". You, on the other hand, would - if only you were funny and not just pathetic.
  • efficiency doesn't matter to me at all. Price / watt does

    I don't care if they are 100% efficient if they cost $20billion / watt.

    But show me one that is cheap enough to afford to cover my roof with that the end total wattage is enough to cover something close to my power use (or more) and I'll do it.

    The % efficiency make absolutely no difference to me at all, zip, zero, nada. DON"T CARE!

    • The problem with price per Watt, while that's certainly important, is that, say for example with current Tech, covering every square inch of your roof with solar panels gives you, let's say 1kW, that's the maximum you can get out of the area of your roof. You'd need more area to get more power.

      Now, increase the efficiency by 80%, and you get 1.8kW out of that same area. Of course, if the price increases more than 80%, then you are coming out behind, because even though you get more power, it costs more.

      The

    • by RingDev ( 879105 )

      "efficiency doesn't matter to me at all. "

      To prove you wrong, I will quote... you.

      "But show me one that is cheap enough to afford to cover my roof with "

      That is Price / watt.

      "that the end total wattage is enough to cover something close to my power use "

      That is Watt / m^2.... also know as Efficiency.

      As you have correctly, and incorrectly pointed out, efficiency does matter.

      $/kWh determines market adoption.
      Watt/m^2 (after market adoption) determines sales channels and installation sites.

      -Rick

    • Price per watt is the end user's opinion of usefulness. You cover your roof with cheap inefficient crap and pat yourself on the back for being "green". Yet these technologies have quite the carbon footprint involved in the manufacture of solar panels. When you take the efficiency into account you can potentially reduce this footprint. Some made up numbers for your understanding:

      10x 1m^2 panels, producing 10kW consumes 10MW during manufacture, and costs $1000 per panel. vs
      1x 1m^2 panel, producing 10kW, con

    • by tsotha ( 720379 )

      But show me one that is cheap enough to afford to cover my roof with that the end total wattage is enough to cover something close to my power use (or more) and I'll do it.

      On one hand you're saying you don't care about efficiency, but on the other you've put constraints on acceptable efficiency by stipulating the size of the array and the wattage. Efficiency matters, both because not everyone has an acre they can cover with cells and because there are costs that scale with the size of a solar cell array.

  • If this product can be reliable and cheaply produced it will rock the world. I feel that it will likely be buried away from public use or view for many decades.

  • The problem with current Solar cells is not efficiency. Well, in a way it is of course, because every improvement helps along the economics.

    The real problem is that the panels require a huge amount of energy to produce as they rely on highly refined materials. So much energy is required that it takes years or decades to break even.

    • The energy returned on energy invested is actually quite good. The issue is that the manufacturing process is so darn expensive that it isn't very economical at the moment. This is also why terrestrial applications rarely use the kind of solar cells that go on satellites. There are cells with close to 40% efficiency, they're just stupidly expensive.

    • Actually, most solar systems have a 'carbon' (read energy + transport) payback period of about 1 year. It's really good tech, it's just a shame so many geeks are obsessed with nuclear and so buy into the whole bashing solar routine, so you hear this kind of rubbish everywhere.

    • Check out the Sahara Solar Breeder Project http://en.wikipedia.org/wiki/Sahara_Solar_Breeder_Project [wikipedia.org]

      If you get enough of them, you can make the process self-sustaining energy-wise, even accounting for manufacturing the cells and panels.

    • *Citation needed*

      After a quick google search:

      "Crystalline silicon PV systems presently have energy pay-back times of 1.5-2 years for South-European locations and 2.7-3.5 years for Middle-European locations. The U.S. is less than 1.5 years currently."

      "two years for a PV system with monocrystalline solar cells"

      And the final one I looked at said 2-4 years with 10-30% of that coming from the energy it takes to make the FRAME you're using to mount the solar cells.

      So it takes years yes, but decades? That's not ev

      • Sorry, let me also add this as a reference:

        http://www.nrel.gov/docs/fy04osti/35489.pdf [nrel.gov]

        It's the one I felt was most unbiased (not done by a solar cell manufacturer for example.) It's done by the US department of energy.

        d

        • by geekoid ( 135745 )

          That all well and fine, but in the consumer world, tell me where I can get solar cells with a 4 year pay back.
          Everywhere I looked it was 10-15 years.

          • The original question I was responding to was a question of is the power used to create the solar cells is made up during the life of the panel. The different question you seem to be asking is a question of break even costs. That's a longer time as profit and non-energy costs are also part of that equation.

            d

    • Leaves on trees are actually not that efficient, it is just that it is so "cheap" for a tree to make new ones that it doesn't matter. If I could buy 250 W panels for $100, I would have my roof covered, even if they were twice the size of the current units.

  • Comment removed based on user account deletion
  • According to the article, part of the cell is composed of cadmium telluride. Both are toxic and various compounds of tellurium stink to high heaven. I wonder what happens if the cells get caught in a fire?

    • The cadmium telluride is 0.5 micrometers thin, so there isn't actually that much of it.

    • According to the article, part of the cell is composed of cadmium telluride. Both are toxic and various compounds of tellurium stink to high heaven. I wonder what happens if the cells get caught in a fire?

      Right, the cell is composed of cadmium telluride, which is a binary compound. That is different from saying the cell is composed of cadmium and tellurium, which are separate atomic compounds with different properties. Toxicity and fire studies on cadmium telluride are ongoing, but so far they have found th

  • by BlueParrot ( 965239 ) on Friday April 29, 2011 @05:28PM (#35980338)

    There are multi-junction solar cells with a decent efficiency. That's teh kind that go on expensive sattelites. The problem is that such cells cost an arm and a leg so it is still cheaper to use the single-junction cells that get a much poorer efficiency. The kind of solar breakthroughs that might make photovoltaic competitive is reductions in the cost of teh manufacturing process. If you can find a cheap way to make the multi junction cells then the price per kWh will come down drastically.

    Btw: The price per watt is useless as a metric because most of the time the cells don't give you their maximum power rating. What is interesting is the price per unit of energy averaged over a year. I.e $/kWh.

    • by Thyrsus ( 13292 )

      RFMD has licensed some NREL 3-junction technology, and is in the midst of the approx. 3-year project to take it from "we made one in the lab" to "we're mass-producing them in our foundry". I think they're going to rock the market in one to two years. http://www.semiconductor-today.com/news_items/2011/MAR/RFMD_030311.html [semiconductor-today.com]

      "All forward-looking statements are present expectations of future events and are subject to a number of factors and uncertainties that could cause actual results to differ materially from

    • >>Btw: The price per watt is useless as a metric because most of the time the cells don't give you their maximum power rating. What is interesting is the price per unit of energy averaged over a year. I.e $/kWh.

      Right, for example SunPower makes much more efficient panels than the ones I bought, but since I had plenty of square-footage on my rooftop, I went with the ones that provided the best bang for the buck, instead of bang per sqft.

      Efficiency of a panel is only one component - price is ultimately

  • Wasn't there some other article posted here a year or so ago about the problem of one photon equaling one electron being the problem and that someone had discovered something that created a cascade effect so that one photon could become more than one electron? When are we going to see that on the market?

  • Chemistry researchers at Oak Ridge National Laboratory say they've improved the efficiency of typical solar cells by a whopping 80%....

    So those crappy auto recharge panels I bought on clearance last month are almost twice as good now? How'd they do that from 2000 miles away? Wow, I gotta go plug 'em in!

  • Let's get the facts straight:

    "With this approach at the laboratory scale, Xu and colleagues were able to obtain a light-to-power conversion efficiency of 3.2 percent compared to 1.8 percent efficiency of conventional planar structure of the same materials."

    3.2% is pathetic. A quick Google search reveals some polycrystalline Cadmium Telluride cells developed by the National Renewable Energy Laboratory that achieved 15% efficiency. It was published TWO YEARS AGO. [solarserver.com]

    For once, FOR ONCE I'd like to see a genuine so

    • Oop, it wasn't published 2 years ago, it was last February. Damn European date format. Oh, well, argument still holds. The press release from Oak Ridge is deliberately misleading.

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