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Avalanche Effect Demonstrated In Solar Cells 234

Posted by kdawson
from the when-the-rain-washes-you-clean-you'll-know dept.
esocid writes "Researchers at TU Delft (Netherlands) and the FOM (Foundation for Fundamental Research on Matter) have found irrefutable proof that the so-called avalanche effect by electrons occurs in specific semiconducting crystals of nanometer dimensions. This physical effect could pave the way for cheap, high-output solar cells. Solar cells currently have relatively low output, typically 15%, and high manufacturing costs. One possible improvement could derive from a new type of solar cell made of semiconducting nanocrystals and could theoretically lead to a maximum output of 44%, with the added benefit of reducing manufacturing costs. In conventional solar cells, one photon can release precisely one electron. However, in some semiconducting nanocrystals, one photon can release two or three electrons, hence the term 'avalanche effect.' This effect was first measured by researchers at the Los Alamos National Laboratories in 2004, and since then the scientific world had raised doubts about the value of these measurements. This current research does in fact demonstrate that the avalanche effect can occur."
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Avalanche Effect Demonstrated In Solar Cells

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  • Wait and see (Score:5, Insightful)

    by Bananatree3 (872975) on Tuesday May 27, 2008 @12:39AM (#23552033)
    as with all emerging technology, I am going to wait and see as to how this R & D develops into a commercial application.

    However, I'll bet the keys on my keyboard that solar is going to be a lucrative market in the near future. Heck, it already is for solar cell manufacturers.

    • I'm often confused when I see articles about how great it is to improve the efficiency of solar cells.

      To me, the big issue is not efficiency but cost per watt. Many regions of the world have plenty of the land, particularly energy guzzlers like the US. What we really need is a super-cheap way to use that land for solar generation.

      • by dakameleon (1126377) on Tuesday May 27, 2008 @01:39AM (#23552419)

        To me, the big issue is not efficiency but cost per watt.
        Read the bloody summary even!

        could theoretically lead to a maximum output of 44%, with the added benefit of reducing manufacturing costs
        So if the summary is to be believed, you're increasing output nearly threefold, and reducing cost of manufacture. The cost-per-watt ratio moves the right way on both sides.
      • by syphax (189065) on Tuesday May 27, 2008 @01:53AM (#23552507) Journal

        Efficiency matters, for a few reasons, including:

        1. Indirect costs (installation labor, racks, mounts, etc.) scale with the area of the array. The area of array required for a given power output goes with the inverse of efficiency. These costs are pretty significant, so efficiency has a direct impact on installed costs.

        2. There's lots of area available for solar panels, but solar energy is pretty diffuse, so you need a lot of area anyway. If a 1% efficient system cost a dime per watt installed, great, but you'd have to cover huge areas to generate significant amounts of electricity. There are practical limits. Even at 10-20% efficiency, you're still looking at large areas to generate a meaningful amount of juice.

      • by SQLGuru (980662)
        The general assumption is that improving the efficiency improves the cost per watt. If something that costs $10 produces 1 watt at 15% efficiency, then it should produce 2 watts at 30% efficiency; halving the $/watt.
    • by necro81 (917438)
      And if you're wrong, well, that keyboard probably isn't worth much anyway.
  • by Doc Ruby (173196) on Tuesday May 27, 2008 @12:41AM (#23552043) Homepage Journal
    Manufacturing solar PV cells is usually said to cost quite a lot of energy. But how much exactly (on average)?

    How many joules are consumed from raw materials to a deliverable PV cell of a given output wattage? Of the old "about 15%" (really about 20-25% these days), and of these new proposed "avalance" PV material ones?

    I want to compare that energy cost to the cells' projected energy contribution over their lifetime, which is about 30+ years for today's PV cells. How long would the new ones last in typical service?
    • by Animats (122034) on Tuesday May 27, 2008 @01:00AM (#23552177) Homepage

      The head of Applied Materials' solar division said in a 2007 talk at Stanford that their current production process costs about 2 years of output for a solar panel. He thinks they can get that down to 6 months of output; he said some things about improvements to the sputtering process. which is derived from IC manufacturing technology where the wafers are smaller.

      They'll probably do it. What Applied Materials does is improve semiconductor process technology. They're the world's largest maker of semiconductor fab equipment. This led them into making LCD displays, and then solar panels.

    • by syphax (189065) on Tuesday May 27, 2008 @02:03AM (#23552551) Journal

      The numbers [energybulletin.net] are all over the place and constantly coming down with new technologies, but you're looking at breakeven after 1-5 years or so.

      This is pretty good (EROEI is >> 1), and will continue to get better.
      • Re: (Score:3, Interesting)

        by Doc Ruby (173196)

        Published on 16 Jun 2006 by Energy Bulletin. [...] This review has concluded that the likely energy payback of a typical domestic sized rooftop grid connected PV cell is approximately four years.

        A domestic rooftop grid can receive something like 400W:m^2 (averaged across weather/seasons/night) here in NYC, generating 72W:m^2 (at the more likely 18% efficient PV). My building is 7.6x21.3m, 162m^2, or 11.655KW. We have 4 apartments, which consume (as the average household in NYC) about 2KW each. So we've got

  • APDs (Score:5, Informative)

    by Wilson_6500 (896824) on Tuesday May 27, 2008 @12:44AM (#23552063)
    Avalanche photodiodes of certain semiconductor materials have been around for a while now. I believe the novel part of this research is that they're confirming other researchers' data showing that lead selenide semiconductors can exhibit electron cascade effects.
    • by IorDMUX (870522)
      Does anyone know if the "avalanche" behavior observed in these solar cells is in any way related to diode/photodiode avalanche breakdown? If so, could someone explain to me how energy can be produced in this manner?

      During a photodiode's avalanche breakdown, for example, the act of a photon hitting a reverse-biased photodiode diode excites an electron into the conduction band. The excited electron gains energy from the strong reverse bias potential and "smashes" into other electrons on its way down-potent
      • Re:APDs (Score:4, Interesting)

        by bperkins (12056) on Tuesday May 27, 2008 @10:21AM (#23555769) Homepage Journal
        It's hard to say without seeing the article in Nano-letters, but based on the diagram and a vague description, I'd guess that it works something like this:

        A high energy electron hole pair is created by a photon, which then relaxes down to a lower energy state. But, instead of emitting a phonon (heat), it creates another electron hole pair, and you end up with two. I suppose this process could repeat itself, so that many different wavelengths would all produce energy with reasonable efficiency.

        This is in all likelihood facilitated by the complex energy band structure of the (essentially) polycrystalline semiconductor.

        I'm not so sure how directly applicable all of this is. I suspect that some theorist postulated that this could happen, but it was difficult to prove experimentally. It seems to me that the hard work of actually producing an workable device hasn't been done yet.

        From what I can tell, this work is done in PbSe, which I don't think is a suitible for huge volume production.

        But I could be wrong in all this.
  • Los Alamos (Score:5, Informative)

    by TubeSteak (669689) on Tuesday May 27, 2008 @12:45AM (#23552073) Journal

    The avalanche effect was first measured by researchers at the Los Alamos National Laboratories in 2004. Since then, the scientific world has raised doubts about the value of these measurements. Does the avalanche effect really exist or not?
    This is the Los Alamos stuff they're talking about:

    http://science.slashdot.org/article.pl?sid=04/05/20/1436213 [slashdot.org]

    Solar Cells Get Boost
    Posted by michael on Thursday May 20 2004, @02:15PM
    from the juiced-up dept.
    Science Technology
    An anonymous reader writes "Researchers from Los Alamos National Laboratory have tapped the efficiencies of nanotechnology [trnmag.com] to double solar cells' potential energy production. The key to the method is the use of lead selenium nanocrystals which can produce 2 electrons where 1 was produced before. Other optical applications can also benefit."
  • by Jane Q. Public (1010737) on Tuesday May 27, 2008 @12:46AM (#23552079)
    Somebody else said this the last time solar cells were brought up, and it is just as relevant here:

    SOMEBODY PLEASE BRING SOME ACTUAL "IMPROVEMENTS" TO MARKET!!!

    If all the "improvements" to solar cell manufacturing I have read about in recent decades became actuality, we would all have homes and cars powered solely by a 1-meter-square panel on the roof and the panels would cost $1 apiece.

    Please, either DO SOMETHING with this, or stop making predictions!
    • Re: (Score:3, Insightful)

      by QuantumG (50515) *
      Yes, to the ever increasing market of solar cells. They put em in calculators and on caravans and ummm.. uhh.. those remote weather sensors and, uhhh, emergency phones on the side of the highway.... oh yeah, and satellites and NASA robots. As you can see, clearly the market is massive and the competition is cut-throat.

      • Re: (Score:3, Interesting)

        by Cairnarvon (901868)
        A lot of governments give incentives for installing solar cells on your roof, and a lot of people *are* getting them installed as a result, so yes, there is a market, and a pretty big one at that. The fact that the US is lagging behind doesn't make that disappear.
        • Re: (Score:3, Insightful)

          by QuantumG (50515) *
          A subsidized market is hardly a market at all. The *fact* is that there are few manufacturers of solar cells.. and most of them are differentiated anyway, so they don't compete.

          • Re: (Score:3, Insightful)

            The subsidies are a temporary measure that serve to kick-start the build-out of the infrastructure to support a new market in the face of opposing forces, such as cheap coal or subsidized nuclear.

            IMHO, "free" markets are not always the most efficient way to achieve change, especially when there is a large capital barrier to entry.

      • by syphax (189065)
        ... you forgot Germany, Spain, California, NJ, MA, [solarbuzz.com] etc.

        World solar photovoltaic (PV) market installations reached a record high of 2,826 megawatts (MW) in 2007, representing growth of 62% over the previous year...The PV industry raised nearly $10 billion in 2007. 84 identified financial transactions accounted for $7.5 billion in 2007, Of this amount, $5.3 billion came in the form of equity financing, while $2.2 billion came from debt financing.

        3 GW (peak), isn't much in the grand scheme of things, but I t

    • by gorim (700913)
      Was about to say the same thing. At least twice a month something about new improvement in solar cells is posted, but they never materialize into something people can use!
    • Re: (Score:2, Funny)

      Yeah, you tell 'em. And while your on it ask them what's holding up my flying car? Now where did I put my phone-watch?
      • Re: (Score:3, Insightful)

        Phone watches have been available for years now (so have television watches, but not watches that do both).

        What is holding up your flying car is not the car itself, it is infrastructure. Letting everybody who could afford to fly go wherever they wanted to, uncontrolled, would be pure mayhem. Death, destruction, and injury on a massive scale. Until they get absolutely reliable tracking and automated control, there will be no commonly available "flying cars". And the technology to do that, i.e., a distribu
      • Flying Car? (Score:4, Insightful)

        by camperdave (969942) on Tuesday May 27, 2008 @02:22AM (#23552661) Journal
        And while your on it ask them what's holding up my flying car?

        Anti-grav units? Powerful downward facing thrusters? Wings? Rotors?

        Truth be told, there's nothing holding up your flying car except the name. It's not a flying car. It's a personal aircraft, and they come in many different sizes and shapes, from ultralights, LongEZs, and autogyros, to Beavers, Cesnas and Learjets.
    • by wellingj (1030460)
      Do something yourself if you think development and science are so easy.

      I'm pretty sure if it was beyond revolutionary and economically feasible then it would be along faster than you can spit "I want it, and I don't know how it works, but I want it now!"

      Or would you rather they make something that can't turn a profit, and just have the government subsidize it?
    • by jberryman (1175517) on Tuesday May 27, 2008 @02:02AM (#23552545)
      We need to wake up, and start the new Manhattan Project for energy; I don't think we can wait on the Free Market for this one.
      • Re: (Score:3, Interesting)

        We may not need something as drastic as a Manhattan Project. How about the Apollo program instead?

        When JFK pledged to put a man on the moon in 10 years, we did it -- even though the Cold War arguments re: national security were a bit hysterical.

        Why can't we have a leader pledge to reduce America's dependence on oil by 50% in 10 years? Sounds just as possible to me as Apollo XI would have in 1960. And it's obviously more practical.

        • by mhall119 (1035984) on Tuesday May 27, 2008 @09:45AM (#23555259) Homepage Journal

          Why can't we have a leader pledge to reduce America's dependence on oil by 50% in 10 years? Sounds just as possible to me as Apollo XI would have in 1960. And it's obviously more practical.
          It's significantly harder if you go and think it through. The Apollo project required the efforts of maybe several thousand people, where as reducing consumption of oil will require the efforts of millions of Americans. The Apollo project required the construction of several facilities and large infrastructure in only a handful of locations, where as reducing fossil fuel use will require a nationwide architecture upgrade, and at least hundreds of large facilities.

          If the Apollo program were at the scale required for reducing oil consumption, we'd have colonized most of the moon by now.
          • Re: (Score:3, Interesting)

            by dpilot (134227)
            It doesn't require effort from millions of Americans.

            All you have to do is make more economical energy generally available. It's still a project with participation in the thousands or tens of thousands. Once a way to save money is readily available, the millions will do so.

            The hard part is when the way to save money is available, but not readily. In other words, when it's available, but you have to make substantial changes or investments in order to realize it. For instance, imagine photovoltaic panels
      • by houghi (78078)
        Free market? This will be heavily patentented so that any gain will be lost in the nice way of scre-I mean-doing business.
      • Re: (Score:3, Funny)

        by jollyreaper (513215)

        We need to wake up, and start the new Manhattan Project for energy; I don't think we can wait on the Free Market for this one.
        ZOMG!!!! COMMUNIST!
    • by JonBuck (112195)
      Hear hear!

      Get out of the lab, get onto my roof!
    • Re: (Score:2, Interesting)

      by Obvius (779709)
      If I remember correctly from my old physics undergraduate days, the total available solar power across the entire spectrum is only just over 1kW per square metre at the Earth's surface. It's a useful thing to bear in mind when considering the viability of solar power. even with 100% efficient solar panels, we're unlikely ever to run a house on a single small panel.
      • by SQLGuru (980662)
        Last time I checked, my roof is a good bit bigger than 1m^2. The south facing side is probably in the 300m^2 to 450m^ range (purely estimate). Since the only purpose that is serving is keeping the weather out, lining it with solar panels is perfectly fine with me. I don't really need to run my house off of a single panel.

        But in order to install that solar, I need the cost to come down such that break even falls within the five year range (or less)....assuming constant / current energy prices and usage.

        La
        • by Ihlosi (895663)
          The south facing side is probably in the 300m^2 to 450m^ range (purely estimate).



          That must be a really, really large house. How many m^2 floor space does it have ?

        • Re: (Score:3, Informative)

          by Ioldanach (88584)
          The south facing roof of a 35'x40' house (1400 square feet per floor) with a 7:12 slope is roughly 800 square feet, or about 76 square meters.

          An example of a currently available solar panel [affordable-solar.com] intended for roofing application is 136 watts, and about 30 would fit on that sample roof, for a total possible 4,080 watts at any given point. Where I am, I can expect an average of 4.5 hours of full production per day, or 18 kwh/day, or 540 kwh/month. That's possible, but would require avoiding high load items like

          • Re: (Score:3, Interesting)

            by Ihlosi (895663)
            Still doubt it could handle heating (excepting heat pump or geothermal).

            Don't forget _solar_ heating. That way, you can squeeze a bit more efficiency out of the space on your roof, plus it can be used to cool the solar cells, which improves their efficiency also.

    • by Kupfernigk (1190345) on Tuesday May 27, 2008 @05:59AM (#23553661)
      Do you have any idea how long it takes to commercialise a technology in volume? Obviously not.

      If you actually read up on solar cells instead of sounding off like an idiot, you would know that the cost per watt is dropping quite fast, durability has doubled in the last 5 years, that Sharp are making cells which are nearly twice as efficient as much of the competition and they are being sold as roof panels, that the recently opened German factory can sell everything it makes for many months ahead.

      Nobody has ever pretended that a 1 sq M panel would power anything large. There is only so much sunlight, and nobody has ever pretended the second law of thermodynamics would be broken. No-one has ever pretended that 1 sq M panels would cost $1 apiece; you could not make a structure to withstand wind loading that cheaply. There is a huge difference between actual forecasts of an eventual $1 per peak watt, and $1 per sq M. $1 per watt works out at about $140 per sq M for a 14% efficient panel.

      To the people who modded this insightful: if you can't tell an obvious troll from engineering reality, plase hand in your geek cards now and go play with Facebook.

    • by Xandu (99419)
      If all the "improvements" to solar cell manufacturing I have read about in recent decades became actuality, we would all have homes and cars powered solely by a 1-meter-square panel on the roof and the panels would cost $1 apiece.

      Hmmm. We'd need other advances as well. Forgetting the fact that there are clouds some of the time and the sun is below the horizion about half of the time, and assuming that the roof of your house/car is pointed squarely at the sun at all times (slightly possible if you have po
    • Re: (Score:3, Funny)

      by ckedge (192996)
      FAR FAR easier to stop having IDIOT reporters report on RAW FUNDAMENTAL research results as if they were going to be immediately applicable or as if they were guaranteed to be capable of going to market.

      The problem isn't research. This is exactly how research goes. You investigate 1000 things for 10-20 years, and ONE comes out the door to use in widespread industry.

      So - 1000 slashdot stories, times 10 dupes and repeats over the 10 years, times 10 because it's re-reported on all the other bloggies/forumish
  • Thermaldynamics? (Score:5, Interesting)

    by mlts (1038732) * on Tuesday May 27, 2008 @12:46AM (#23552083)
    Without violating thermaldynamic laws, I wonder how much electricity output this will add. I don't think it would double the current flow with 2-3 electrons popping out for each photon that strikes the array, but I know this should add a significant amount of efficiency.

    I just hope all these advances, especially ones that make solar cells cheaper to manufacture go into production. There are huge chunks of the world that are lifeless desert, and would be perfect for large solar and wind arrays, assuming one could find a way to transport the generated electricity to cities without too much current loss. Perhaps some chemical reaction that pulls carbon from the air directly to make ethane, then another reaction that converts the ethane to ethanol to be piped to places that can burn the ethanol for electricity. Yes, the chemical reactions to pull carbon from the air, and get it into ethanol are wasteful, but for very long distance transfer of energy (100-200+ miles), it would be less wasteful to do that, than to use standard power transmission lines. Even though the ethanol electricity generating plants would be adding carbon into the air, it would be carbon neutral due to the carbon being extracted at the solar/wind site.
    • by Anonymous Coward on Tuesday May 27, 2008 @01:06AM (#23552203)
      I frequently try to break the laws of thermaldynamics. Especially ones involving Intropy and the Carnal Cycle.
      • I don't know... You got moded Funny, but I can't think breaking the Carnal Cycle could be any funny.
    • Re:Thermaldynamics? (Score:5, Interesting)

      by Yetihehe (971185) on Tuesday May 27, 2008 @04:33AM (#23553247)

      Perhaps some chemical reaction that pulls carbon from the air directly to make ethane, then another reaction that converts the ethane to ethanol to be piped to places that can burn the ethanol for electricity.
      Would methane be ok? If so, it is already done with CO2 and sunlight [slashdot.org].
      • Re: (Score:3, Interesting)

        by mlts (1038732) *
        Methane works, but ethane is a lot easier on metal compounds (far less corrosive) and safer in general (although its still highly flammible). Drink ethanol (assuming not denatured), one gets drunk (or dies from alcohol poisoning). Drink methanol, and the optic nerve gets permanently polymerized by the by-products such as formic acid, which renders a person permanently blind.
        • "Drink ethanol (assuming not denatured), one gets drunk (or dies from alcohol poisoning). Drink methanol, and the optic nerve gets permanently polymerized by the by-products such as formic acid, which renders a person permanently blind."

          Are you now using a brail keyboard? Or are you the lucky one who drank the ethanol and typing while drunk.
    • by Ihlosi (895663)
      Perhaps some chemical reaction that pulls carbon from the air directly to make ethane, then another reaction that converts the ethane to ethanol to be piped to places that can burn the ethanol for electricity. Yes, the chemical reactions to pull carbon from the air, and get it into ethanol are wasteful, but for very long distance transfer of energy (100-200+ miles), it would be less wasteful to do that, than to use standard power transmission lines.

      Why turn perfectly good ethane into ethanol ? That doesn't

    • Without violating thermaldynamic laws

      You can get a 95% efficient PV cell without violating those "thermaldynamic laws".

      • by Ihlosi (895663)
        You can get a 95% efficient PV cell without violating those "thermaldynamic laws".

        Citation needed.

        Sunlight isn't just visible light. If you want to get that high efficiency and use sunlight, you would need solar cells that are sensitive far into the far infrared range, which means that you'd essentially have to convert heat directly into electricity. Second law of thermodynamics says that that's a no-no.

        Of course, if you can somehow shine monochromatic light on a solar cell which is sensitive to exac

  • Developing nations (Score:3, Interesting)

    by William Robinson (875390) on Tuesday May 27, 2008 @12:48AM (#23552093)
    This is great news, especially for developing nations whose energy demands are on rising trend. Countries like Indonesia, India and other middle east countries, where sun light is available in abundance, will benefit most.
  • Let's be realistic (Score:5, Insightful)

    by actionbastard (1206160) on Tuesday May 27, 2008 @12:49AM (#23552099)
    Whether they're hairy [slashdot.org], nanotube [technologyreview.com], or amorphous [wikipedia.org], cheap, efficient solar cells are always going to be thirty years away as long as there is 'cheap' oil around.
    • Since when is $135/barrel "cheap"?
    • by syphax (189065)

      I know a couple people who made/make their money in private equity and managing investment funds, people who hard-nosed financial types, who are convinced it's more like 5 years away.

      There's been a huge run on Si that's kept Si prices high and solar prices slightly up; once a ton of in-process Si capacity turns on, it should get interesting (hint: don't go long on Si right now).

      BTW the qualifier to your prediction isn't that valid these days...
  • by flyingfsck (986395) on Tuesday May 27, 2008 @01:11AM (#23552231)
    Using sunlight for electricity is not particularly attractive, but for the neat 'no moving parts' aspect. It is far better to use solar power for light, water and space heating - those remarkable innovations called windows and skylights for example.
    • by phantomfive (622387) on Tuesday May 27, 2008 @01:20AM (#23552295) Journal
      Man, let me tell you about skylights. I have a skylight, and I thought it was cool. Here's how it works: I get free light all day long, except at night when there isn't enough light coming in through the window.

      I get free heating all summer long, but in the winter it's too cloudy to make a difference. Yeah, skylights sound good and all, but give me a solar panel over that any day.
    • This may come as a shock, but you can do both at the same time.
      • by RuBLed (995686)
        Real nerds use RTG for electricity and heating, perfectly suitable for basement use.
    • by TubeSteak (669689) on Tuesday May 27, 2008 @02:40AM (#23552719) Journal

      Using sunlight for electricity is not particularly attractive, but for the neat 'no moving parts' aspect. It is far better to use solar power for light, water and space heating - those remarkable innovations called windows and skylights for example.
      Tell that to the entire African Continent which has an abundance of sun & empty space, but a deficit of fresh water, power & air conditioning.

      I look forward to a future with solar powered desalination plants.
      It's a much brighter outlook than continent wide water wars forcefully giving everyone a skylight.
      • As the middle east runs through oil reserves, it might very well become feasible in many areas to research more into solar power, and set up efficient solar farms, etc.

        When I was last in Australia, I was quite impressed at the various little things they did to use solar power (vs here in Canada where snow cover makes it rather less useful for a good part of the year).

        I'd imagine that a middle-eastern country could set up major solar-electric centers, followed by climate-control (air conditioning) powere
    • by 1 a bee (817783)

      You do realize, though, that if the solar generated electricity is consumed inside the building, the laws of thermodynamics dictate that the electrical power consumed eventually dissipates as heat inside the building. I have nothing against skylights, per se, but this is the same heat you're worried about letting in through the skylight. And besides, what are you proposing here? steam powered laptops?

      --
      [FaunOS [faunos.com]]

    • Water heating - sure! Light - sure. But heating? There's not enough angle when the sun strikes the earth in the wintertime, that's why it's cold - the energy is absorbed by the atmosphere.

      However, photovoltaics is excellent for powering something else - air conditioning. If you stick photovoltaics on your roof, you get a double whammy: Less heating from the sun because the photons are either deflected or converted into energy, and electricity to power the air conditioning at daytime. I imagine this is parti
      • Re: (Score:3, Insightful)

        by Ihlosi (895663)
        Water heating - sure! Light - sure. But heating? There's not enough angle when the sun strikes the earth in the wintertime, that's why it's cold - the energy is absorbed by the atmosphere.

        Erm. Some of my colleagues heat their (superinsulated) houses with solar, with a small electric auxiliary heater. This year, they didn't have to use the auxiliary heater from late January on.

        So, sure, you may not be able to heat your house with solar all the time, and in all latitudes, but you can use it to significan

  • by hyades1 (1149581) <hyades1@hotmail.com> on Tuesday May 27, 2008 @01:12AM (#23552237)

    We seem to cavil about a few million dollars, or even a few hundred million, being spent to jump start emerging energy technology, but we have no problem spending billions on oil industry subsidies.

    We need to acknowledge that any new tech investment involves high risk. Success brings high rewards. We accept exactly this reasoning when oil executives tell us that oil exploration is expensive and risky, and therefore requires continuing subsidies even when record profits are rolling in. A few million spent on alt energy research that tanks, however, is usually reported as a "this is what happens when you listen to the tree huggers" story.

    An attitude adjustment as 'way overdue, and a rediscovery of our spirit of adventure and innovation. Perhaps putting some money into finding out whether this kind of solar cell works and can be mass produced would be a place to start.

    • by LynnwoodRooster (966895) on Tuesday May 27, 2008 @03:03AM (#23552813) Journal
      We seem to cavil about a few million dollars, or even a few hundred million, being spent to jump start emerging energy technology, but we have no problem spending billions on oil industry subsidies.

      Maybe because most alternative energy sources are big money losers? Take a look at page 16 of this report [doe.gov] for the actual numbers about subsidies...

      I predict once you can start to get alternative energy sources like solar and wind down an order of magnitude or so in terms of cost you'll see things turn around. However, for now they're getting somewhere around 100X the subsidy per Megawatt-hour that "Big Oil" gets.

      An improvement from 15% to 40% simply isn't enough - natural gas and oil get around $0.25 per MWhr, while solar and wind get 100 times that amount per MWhr. And remember, those nasty "Big Oil" companies also pay over $3 in direct federal taxes for every $1 in profit. Over $200 billion flows into the Federal government every year in terms of direct taxes and fees (that's not including the taxes you're paying on consumption of their products).

      Right now, and for the last 20 years, wind and solar have been huge money-losers, and only exists BECAUSE of the massive subsidies. If we subsidized wind or solar at a level to get useful output levels, we'd spend literally trillions more per year.

      And then there's that whole baseload thing...

      • Re: (Score:2, Insightful)

        by dmgxmichael (1219692)

        The problem isn't oil - it's the abuse of it. Like an adict we've allowed oil to change the entire structure of our nation and our society. When the oil is gone this structure will not be sustainable.

        It won't be armageddon. People will simply move back into the cities. The suburbs will become ghettos just as the inner cities are now and then they will die out. By the end of the century New York, Chicago and the other large cities of the US will contract back into the boundaries they had in the year 1900

        • Re: (Score:3, Insightful)

          by dpilot (134227)
          I generally agree with your scenario, with one exception. I expect to see some fraction of the suburbs survive with telecommuters. Similar to energy costs pushing physical workers back close to their workplace, I expect to see those costs push "telecommutable" jobs into telecommuting, and an expansion of technologies that enable telecommuting.

          The other piece of work that needs to be done behind all of this is to make the suburbs more foot-friendly. Once you don't need to drive to work, the next thing is
      • Right now, and for the last 20 years, wind and solar have been huge money-losers, and only exists BECAUSE of the massive subsidies. If we subsidized wind or solar at a level to get useful output levels, we'd spend literally trillions more per year.

        Nice try, troll. Countries like Denmark have had tremendous success [foxnews.com] with alternative energy sources such as wind power. Currently about 20% of the energy used in Denmark comes from wind power, and there is about a $5 billion market in exporting turbines. Currently over a third of the wind turbines used worldwide [wikipedia.org] are built by Danish manufacturers such as Vestas.

        On windy days, Denmark actually generates "too much" power from wind (about 40%) so they are working on an electric car system [theregister.co.uk] to act as

      • by hyades1 (1149581) <hyades1@hotmail.com> on Tuesday May 27, 2008 @09:10AM (#23554833)

        Your overlook many of the less obvious subsidies. For example, the Army Corps of Engineers routinely dredges canals used by the oil industry at taxpayer expense. The explanation is that they're staying in training. Canals that don't serve oil tankers, regardless of need, do not receive such treatment.

        There are many, many examples of such hidden subsidies, none of which are accounted for in your numbers. I invite you to seek them out for yourself rather than take my word for them.

        An article in Nature 445, 147 (11 January 2007) published online 10 January 2007, and "Money Down the Pipeline: Uncovering the Hidden Subsidies to the Oil Industry" by the Union of Concerned Scientists are good places to start your investigation.

  • by Anonymous Coward on Tuesday May 27, 2008 @01:25AM (#23552321)

    This current research does in fact demonstrate that the avalanche effect can occur.
    Oh boy, that's a good one.
  • by Mathinker (909784) on Tuesday May 27, 2008 @02:19AM (#23552647) Journal
    There is no such thing as irrefutable in science. In fact, some people attempt to define science as the pursuit of knowledge which can be corroborated and refuted using the "scientific method" (to preempt a lot of comments: I said "attempt to define", because this definition rapidly becomes circular unless you are very careful, and it is not clear that defining the "scientific method" is easier than defining science itself).

    OTOH, I rather doubt that the scientists themselves claimed irrefutability here. The journalists are probably to blame.
  • You know how much it would hurt to get hit by a rolled up snowball of electrons though? Anyway, this is totally sweet but I don't get it. If a photon has the energy to move more than one electron significantly, why couldn't they just simply layer or stack them somehow in a nice, flat way instead of having to do it on some fancy crystal where they have to collide and "avalanche" in a certain pattern and all that? If the photons in fact don't have the energy to move 2-3 electrons with the same energy as it
    • Re: (Score:3, Informative)

      by marcosdumay (620877)

      I am surprised nobody asked that before, but the answer is surprisingly simple. The photons obviously have enough energy do move several electrons, but the photovoltaic cell (junction) is a tiny laywer over some opaque substrate (normaly silicon). So you only have one chance of absorbing those photons.

      There are some manufacturing processes that could create one junction over another, but those processes are very expensive and the material isn't completely transparent. Probably because of this (I don't know

    • by AdamHaun (43173)
      Because photons can't move more than one electron. An electron absorbs a photon, giving it enough energy to move, then whacks another atom, freeing some more electrons in the process. There's a well-known avalance effect in ordinary diodes [wikipedia.org], so it's not particularly exotic. But the article is talking about lead-selenide crystals, not silicon, so I'm not sure how applicable this finding is to the current generation of solar cells.
  • by dmgxmichael (1219692) on Tuesday May 27, 2008 @03:35AM (#23552991) Homepage

    Imagine for a moment if we geeks hadn't come up with DNS but instead tried to use a small handful of machines to handle domain name resolution. The Internet would collapse rather quickly no?

    Funny then that to date our power grid is based on a centralized model. Sadly, as much as 20-30% of all power generated is lost during transmission over the grid.

    Now effective solar panels and batteries to go with them would allow us to move to a more decentralized model. Imagine whole neighborhoods creating most - though not all - of their power needs. If the panels can get to around 80% of the needs of the house then the current power plants we have can be the only ones we need for awhile.

    Or even better, instead of having massive plants with a huge footprint make use of smaller pup nuclear reactors - about the size used in a naval ship. One of those could be placed where the power substations are now and pick up the slack that the solar panels can't fulfill. They wouldn't present any real contamination danger as once their fuel was spent after 30 years or so you truck out the entire unit and refurbish (i.e. refuel) it under controlled conditions in a remote area - while in service the internals of the thing aren't opened up.

    These things also wouldn't have to make as much power as the current power stations because, by virtue of being closer to the customers they serve, they wouldn't lose as much power in the lines.

    • Re: (Score:3, Interesting)

      by MrKaos (858439)

      Or even better, instead of having massive plants with a huge footprint make use of smaller pup nuclear reactors - about the size used in a naval ship. One of those could be placed where the power substations are now and pick up the slack that the solar panels can't fulfill. They wouldn't present any real contamination danger as once their fuel was spent after 30 years or so you truck out the entire unit and refurbish (i.e. refuel) it under controlled conditions in a remote area - while in service the inter

  • http://www.treehugger.com/files/2007/04/stateoftheart_m.php [treehugger.com]

    So if this is an improvement up to 40%, then it is FAIL. If it can be applied to the existing 40% cells to make them even more efficient then Solar power is about to take off in a big way.
    • by Ihlosi (895663)
      So if this is an improvement up to 40%, then it is FAIL. If it can be applied to the existing 40% cells to make them even more efficient then Solar power is about to take off in a big way.

      I'd rather have 40% efficiency solar cells at half the cost than 50% efficiency solar cells at the same cost.

      Solar power is going to take off in a big way once the price of the panels drops enough. Let's hope this discovery helps with that.

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