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Science Technology

A Step Closer To The Optimum Solar Cell 107

Posted by timothy from the warmth-too dept.
An anonymous reader writes "Besides cost, solar cell efficiency is the second most critical criteria. Scientists from Berkeley Lab and other institutions, have announced a new solar cell material that may be able to achieve an extraordinary efficiency of about 50 percent -- twice the amount of the current record holder."
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A Step Closer To The Optimum Solar Cell More

A Step Closer To The Optimum Solar Cell

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  • This is the last you will hear of this (Score:4, Funny)

    by AtariAmarok ( 451306 ) on Wednesday April 14, 2004 @10:26AM (#8859451)
    Ah, an efficient solar cell. This is the last you will hear of this! Halliburton and Big Oil will immediately buy the patent and sit on it, just like they did the antigravity saucer, the 300 mph carburetor, cold fusion, and Skynet microchips from the future. Save your cache while you can!

  • interesting story, dependance on crystal growth (Score:4, Informative)

    by ubiquitin ( 28396 ) * on Wednesday April 14, 2004 @10:30AM (#8859482) Homepage Journal
    In 1999, Walukiewicz and others at Berkeley Lab were working with solar-cell designers at DOE's National Renewable Energy Laboratory, who were trying to build a three-junction cell. The NREL researchers inadvertently created the first photovoltaic semiconductor with a split band gap. But at first they didn't realize it.

    "They needed a new material with a 1-eV band gap and a crystal lattice structure that matched the other layers of the cell," Walukiewicz explains. "They used gallium indium arsenide nitride alloys in which just a little nitrogen could achieve the desired band gap, and an almost perfect lattice match."

    Since the band-gap reduction was unexpected, Walukiewicz set out to find out how it worked. The answer, it developed, was that the few atoms of nitrogen, which are much more electronegative than the host atoms (much more strongly attractive to electrons) produced a narrow energy band of their own, splitting the GaInAs conduction band into two parts. The gap to the lower of the two conduction bands was the desired 1 eV.

    In the case of GaInAs, other characteristics of the split bands made for a poor solar cell material. Nevertheless, Walukiewicz and his colleagues continued to investigate the phenomenon and developed a model of the split-band phenomenon known as "band anticrossing."

    ...

    Yu admits that forming highly mismatched alloys is "challenging from a crystal-growth point of view," but there is hope that crystals can be grown epitaxially (the growth on a crystalline substrate of a crystalline substance that mimics the orientation of the substrate). One good sign, he says, is that Japanese researchers have already grown thick oxygen-doped crystals of a related material, zinc selenium.

  • ...when I see it (Score:4, Interesting)

    by samael ( 12612 ) <Andrew@Ducker.org.uk> on Wednesday April 14, 2004 @10:31AM (#8859490) Homepage
    I used to jump for joy whenever I saw things like this.

    But experience generally showed that Breakthrough X which would produce cheap power/double battery life/allow 5 terabytes in my computer never actually arrived at the market.

    I'm still waiting for holographic storage from 10 years ago!

    • Re:...when I see it (Score:3, Interesting)

      by gl4ss ( 559668 )
      yeah, because you don't use a multi ghz computer, have the possiblity of buying hd's that are hundreds of gb's or use a cellphone that's ridiculously small compared to models available in 80's.

      • Re:...when I see it (Score:3, Interesting)

        by samael ( 12612 )
        All of which are incremental changes.

        In my experience things get slowly better - anything promising a vast improvement overnight tends to be a little less likely to appear.
        • those incremental changes wouldn't be possible without those breakthroughs.

          without such breakthroughs cpu speeds would have been limited to the numbers they were in the 80's.

        • Re:...when I see it (Score:4, Insightful)

          by julesh ( 229690 ) on Wednesday April 14, 2004 @01:57PM (#8861923)
          Largley because the incremental process tends to catch up with it before the new idea becomes commercialised.

          That's what happened to all the funky things we tend to hear about. We don't all have massively parallel computers because Intel etc didn't all get stuck at 4-500MHz as was predicted some time in the mid 90s.

          We don't have holographic storage because, quite frankly, it just ain't worth it when magnetic storage can pack hundreds of gigabytes in a device that is, honestly, about as small as you really need it to be.

          If there was a demand for these items, even a perceived one, they'd get produced. But there isn't.

          Now, a 50% solar cell...?
          • If there was a demand for these items, even a perceived one, they'd get produced. But there isn't.

            Now, a 50% solar cell...?

            While demand in the alternative energy market is iffy right now, you'll definitely have demand for more efficient photovoltaics at _any_ price in the space industry.

            Lifting mass into space is expensive. If you can get a 2-3x improvement in power to weight ratio of your solar arrays using materials like this, the world will beat a path to your door even if you don't have a way to gro
    • holographic storage???!!???!!
      I'm still waiting for my flying cars that where promised in Back to the Future!! ;-)
      • Why does everyone want a flying car? We already have planes and helicopters. Just use one of those when you want to fly.
        • We already have planes and helicopters.
          Yeah, but with these you can't:
          • Park them in your garage (at least, not easily).
          • Land them in any parking lot, e.g., to go grocery shopping.
          • Ride with the top down.
          Now, you can do some of these things with ultra-lights, but ultralights aren't very comfortable and don't go very fast.

  • No Solar For You! (Score:3, Insightful)

    by Henry V .009 ( 518000 ) on Wednesday April 14, 2004 @10:32AM (#8859502) Journal
    The calculated efficiency of a single-junction solar cell made with this material would be a remarkable 57 percent. But while the single-junction architecture is elegantly simple, many questions have to be answered before ZnMnOTe or any of its highly mismatched cousins prove they can do the job.

    So not only does it not work yet, but any article that starts off with the words "besides cost..." is obviously talking about an economic impossibility.

    We're stuck with cheap oil until it runs out in a few decades. And then we're stuck trying to rebuild civilization with coal.
    • We're stuck with cheap oil until it runs out in a few decades. And then we're stuck trying to rebuild civilization with coal.

      Something wrong with nuclear power?
      The gap between running out of oil and igniting fusion can be filled with fission based reactors.
      Sure, fission-waste is not something you want. But it sure beats the crap out of coal.

      • Something wrong with nuclear power? Oh yeah... (Score:1, Insightful)

        by Anonymous Coward
        "Something wrong with nuclear power?"

        Oh yeah. It is extremely expensive and dangerous, and the waste is so nasty that no-one has found a safe way to get rid of it yet. Cool down, Mr. Burns.

        "Sure, fission-waste is not something you want. But it sure beats the crap out of coal."

        Really now? OK. You have a choice. A bucket of fission waste under your bed, or a bucket of coal. Which one do you choose?

        • Re:Something wrong with nuclear power? Oh yeah... (Score:5, Insightful)

          by Councilor Hart ( 673770 ) on Wednesday April 14, 2004 @11:30AM (#8860187)
          t is extremely expensive and dangerous,
          If I am not mistaking, nuclear power is the cheapest.

          A bucket of fission waste under your bed, or a bucket of coal.
          Don't compare these things. The first is a waste product, the second is the raw material.
          The choice should be between a bucket of fission waste and a room filled the ashes and gasses that resulted from burning coal. I am not sure what would kill you first.

          I don't want either of them. But the fission waste can be stored and handeld. I a century or so, we might find a solution for it. The gas on the other hand goes in the atmosphere. You try getting it out. It too might be possible in a century. At least with fission waste the poles don't melt and the climate doesn't change. Although I do have to say that the sun is also partially responsible for a temp-rise.
          I don't understand the problem people have with fission. Sure it aint pretty, but it's the best we have so far.

          • Re:Something wrong with nuclear power? Oh yeah... (Score:5, Informative)

            by dbIII ( 701233 ) on Wednesday April 14, 2004 @02:43PM (#8862500)
            If I am not mistaking, nuclear power is the cheapest.
            Sorry, you are mistaken. Perhaps Thatcher didn't build any more nuclear plants because she was a raving greeny (for those who don't know any recent history, Thatcher was a long way to the right), not becuase of the enormous losses of British Nuclear Fuels. Nuclear power is only cheap if you cook the books by not counting subsidies - it's a very expensive way to boil water.
            The choice should be between a bucket of fission waste and a room filled the ashes and gasses that resulted from burning coal. I am not sure what would kill you first.
            This is just silly, enough of either will kill you - gas at a few hundred degrees will certainly burn, ash will bury. The nearest office building to you may well contain a lot of coal ash used to make lightweight concrete - the majority of ash is silica in some form or another. Suphur and Nitrogen oxides are not good things to be released, which is why coal fired plants have "scrubbers" - the NOx and SOx is dissolved when the hot gas bubbles through water. It's not an expensive technology at all and has been in use for decades in most of the world. Carbon dioxide is the problem, but nuclear power is still just a 1950's white elephant used as the nice side of nuclear weapons. There are a lot better things to do with radioactive materials than boil water - it costs a huge amount to contain a process like that. Don't blindly believe the advertising agency line for nuclear power - "clean" is not the word that should be used for anything that will kill you on contact or in close proximity.
            But the fission waste can be stored and handeld
            Name one successful long term storage project. Synrock showed enormous promise, the the funding was cut before the project was finished. Dumping the stuff in the ocean in stainless steel drums, or stacking the stuff in tunnels is the current answer.

            Anyway, this is a discussion on solar cells, which lend themselves to distributed power generation of some form or another - they don't have to be big. More efficiency there makes the solar powered laptop easier to acheive.

            • This is just silly, enough of either will kill you
              Yes, that was I meant. But if it takes you a week to die from radiation poisoning, but only a day to die from lack of oxygen. Then the coal killed you. But for all I know it could be the other way around.

              More efficiency there makes the solar powered laptop easier to acheive.
              Yes, I was wondering why I haven't seen that yet. Except in some film. Then again I didn't know solar cells were that inefficient.

            • ...gas at a few hundred degrees will certainly burn, ash will bury.

              You were aware that coal ash is highly toxic as well as radioactive, weren't you? With direct exposure to nuclear waste, you could die from radiation sickness (needing something like >10,000 rems to do that) or get cancer somewhere down the road. With direct exposure to coal ash, you could get poisoned by toxins, die from cancer somewhere down the road from that exposure, or die from cancer from the outputs of that power plant in the

                • Tinfoil hat warning on the above link. Come on, if things were like the article said we wouldn't bother to mine uranium, we would pick up lumps of it lying in the street outside coal fired power plants.
                  • Except that the uranium and thorium are dispersed throughout all of the ash, not in "lumps ... lying in the street."

                    From the article: "Coal ash is composed primarily of oxides of silicon, aluminum, iron, calcium, magnesium, titanium, sodium, potassium, arsenic, mercury, and sulfur plus small quantities of uranium and thorium. Fly ash is primarily composed of non-combustible silicon compounds (glass) melted during combustion. Tiny glass spheres form the bulk of the fly ash."

                    If anything is tin foil, it was

              • You were aware that coal ash is highly toxic as well as radioactive, weren't you?

                No I'm not - knowing some basic chemisty I know what highly toxic actually means, and knowing a bit about the ash recovery process i can tell you that ash is mostly silica. Ash is removed from the bottom of the boilers, and also from the flue gasses (the final stage is electrostatic precipitation to get all of the light material). The ash is handled wet and pumped into an ash dam, where the heavy material sinks. The light ma

                • i can tell you that ash is mostly silica

                  "Coal ash is composed primarily of oxides of silicon, aluminum, iron, calcium, magnesium, titanium, sodium, potassium, arsenic, mercury, and sulfur plus small quantities of uranium and thorium. Fly ash is primarily composed of non-combustible silicon compounds (glass) melted during combustion. Tiny glass spheres form the bulk of the fly ash.

                  "Since the 1960s particulate precipitators have been used by U.S. coal-fired power plants to retain significant amounts of fly

                  • "Coal ash is composed primarily of oxides of silicon, aluminum, iron, calcium, magnesium, titanium, sodium, potassium, arsenic, mercury,

                    The article forgot to mention all of the other elements in the earths crust but that is the way it is going. Coal ash is mostly silica, with the other constituants in small amounts varying depending on where the coal comes from. I suggest you look it up in a reputable source. What you quoted is not a reputable source - cenospheres may be silica but they certainly are not

                    • "Chenobyl was not a hydrogen bomb - it was a steam explosion that scattered radioactive materials - simple mundane heat and water. It was still a disaster. "

                      Not entirely true! There was a steam explosion ... but this was not the only one.

                      After the chain reaction in the reactor went out of control, the cooling system overheated and finaly exploded. This first stem explosion lifted of the cover plate of the reactor, but released only some fission products to the atmosphere. After the first (steam) explosio

                    • You do see the game that the author of the article is playing don't you? He's given you the number in the form of a percentage of a small percentage to make the number look bigger.

                      Fair enough. But let's be completely fair. We've had over a hundred years to refine coal power production. Nuclear power has come into its own much faster than coal. You say that nuclear is an expensive way to boil water. Fine. Light water reactors can only get 3-6% of the actinide-based material to fission. Light water r

                • "Did you know that radioactivity in and around coal plants is higher by two orders of magnitude than those found outside a nuclear power plant?"

                  "No I didn't, and I suspect the only people who do know have read some pamphlet on behalf of the nuclear industry. It sounds very unlikely to me - where is it all going to come from? "

                  I am not sure, if the grand parent is right, regarding radiation around coal power plants. However the point that coal power plants produce highly radioaktive waste is correct.

                  The e

                  • However the point that coal power plants produce highly radioaktive waste is correct.

                    No, it isn't.

                    Highly radioactive waste by definition is material which emits particles in large numbers- ie shows evidence of radioactivity. It can be easily shown whether something does or doesn't fall into that catagory. That small amount of radioactive material that you will find in a few hundred tonnes of coal when concentrated twenty times (assuming 5% ash) still doesn't add up to much at all. It's certainly less

              • "If ANY industry were held to the same safety standards as nuclear, they would be bankrupt. As it stands, nuclear is still competitive. If such ornerous (ridiculous) safety checks were not in place, it would be substantially more reliable and cost effective than any alternative."

                Hm ... in Sovjet Russia, there were not these ridiculous checks ...

                Reliability and cost efficency was proven on 25.4.1886 in Chernobyl.

                Ok, this is a bit trolling, however the extend of the damages caused by accidents with nuclear
            • I think it depends what you are talking about with cost. Although the initial capital investment for nuclear energy is much larger than a thermal plant, the actual cost of 'boiling water' from the nuclear fuel is much cheaper per megawatt than any other means of producing energy from fuel (excluding Hydro/Wind/Solar, however they do not burn fuel to boil water, so I am not counting these). Before you try to debunk, I'll let you know right now that I have worked in energy transmission and I got to see the

          • The problem with fision has a name... (Score:1, Insightful)

            by Anonymous Coward
            ...it's Chernobil.
          • It is the cheapest. Or was circa 1970-80 when I worked for NSP. The problems were political and legal. I heard a lot of talk about subsidy, but I never saw any proof thereof. The only thing proposed is an insurance liability limitation. Since Nuclear power is safer from the mine to the plant, that's only a reflection of real costs, not a subsidy.

            And if you wait a century, you don't have much beyond cold metallic waste. At one point the anti nuclear folk thought they'd stop the plants by refusing any

          • At least with fission waste the poles don't melt and the climate doesn't change.

            Oh god, not another "greenhouse effect" true believer. Show me some real evidence that the amount of extra CO2 we humans produce has any real effect on our atmosphere. What I find even more ludicrous about these near religious beliefs is that we all admit that fossil fuels are limited. Even if the CO2 we produce is enough to produce those kinds of global climatic changes, we will have consumed all of our fossil fuels (or at le
        • Since when is nuclear power dangerous? There have been two nuclear accidents that anyone remembers in the last half century. Once was caused by a piss-poor reactor design (Chernobyl) and one was caused when operators screwed up (but almost no radiation was released). You get exposed to more radiation on an *airplane trip* than you will in a nuclear power plant. And coincedently, you also get more radiation from a coal power plant than from a nuclear power plant; see below.

          As for the choice of a bucket of
      • Energy expense is the thing. Especially once the cost of mining rises due to the increasing expense of oil. (All that heavy equipment runs on gasoline, not electricity.)

      • Something wrong with nuclear power?

        Face it, dude. We're fucked. We're fucked in a big way. I don't mean to sound overly pessimistic or anything, but real like completely fucked. Our power infrastructure is goatse.

        Here's the problem. Let's say oil is peaking right now, as Bush's energy advisor has said. So oil production drops, demand continues to grow, and so forth. Let's say the whole process to reach economic bankruptcy when oil becomes too expensive takes, oh, 30 years. Let's just say.

        How lo

    • Last report I read on oil reserves and predicted consumption, put the time at 75 years. Things could always change, if say China increases thier consumption.

      • I don't believe that we need to worry about running out of oil any time soon. As oil becomes scarcer, prices will rise and consumption will decrease, that's a fundamental economic law. The real question is when we're going to reach peak oil production. Industry reports seem to be saying 10-30 years for that (it's not at all a certain guess, because they are factoring in things like predicted consumption and predicted discoveries and such). And once peak oil is reached, prices have nowhere to go but up.
        • The real problem is the way oil is collected. In the North sea and other offshore locations, they pump water in and it forces the oil out. Only problem is, this technique (for whatever reasons) only gets about half the oil out. Then they cap it and move on.

          So, solution to world's oil problem: Find a better
          way of getting the oil that is there out. There's
          plenty left.
          • You can be sure that once the price of oil gets high enough, they'll go back for the expensive to extract stuff. Still doesn't get us cheap oil.
          • The problem with using water is that it is an immiscible fluid, and much of the oil will tend to remain stuck in pores in the rock rather than flow out under the small bouyancy forces caused by water.

            You can get around this by using a non-polar solvent instead of water. Liquid carbon dioxide is good for this, with two further benefits:

            • CO2 is a byproduct of combustion, so is plentiful, and
            • Putting CO2 into the earth is a good way of sequestering it, so using recovered CO2 to dissolve and lift oil can simu
    • We won't have to rebuild with coal. They oil companies will reengineer for mining Methane clathrate [wikipedia.org] out of the ocean and buy out the thermal depolymerization [wikipedia.org] industry long before they relenquish to the coal industry.

      Don't underestimate their ego.

  • Solar energy . . . the big picture . . . (Score:5, Interesting)

    by StateOfTheUnion ( 762194 ) on Wednesday April 14, 2004 @10:47AM (#8859671) Homepage
    Though a lot of the green crowd have been big proponents of solar cells, solar cells are pretty nasty beasts containing gallium, tellurium, and other heavy metals and nasty components . . . manufactuering them also produces a significant amount of nasty byproducts and waste.

    One things that I've never seen is the lifetime and disposal costs of solar cells . . . that never seems to be factored into the so called "solar renewable energy" equation.

    • Re:Solar energy . . . the big picture . . . (Score:5, Informative)

      by Infinite93 ( 664963 ) on Wednesday April 14, 2004 @11:07AM (#8859941)
      The last issue of HomePower www.homepower.com [homepower.com] contains a list of RE myths 'debunked'.

      The ROI (for retail and manufacture cost) and the Enviromental impact of production is addressed.

      Granted the source is an RE magazine, but they do list references on some of the studies if you want to follow up.

      • Some of their anti-myths are questionable. They state that the long dark days of a northern winter can be balanced by long bright summers. However, they expect the storage to be done by the power grid. And they want it for free, selling in the summer and buying in the winter. However, northern summers are peak electricity use times for cooling, just like elsewhere.

        Tanstaafl

      • Re:Solar energy . . . the big picture . . . (Score:4, Interesting)

        by ttfkam ( 37064 ) on Thursday April 15, 2004 @12:01AM (#8866025) Homepage Journal

        I find it odd that the first page says "Myth: Solar living means sacrificing conveniences," while later on it says, "A PV system provides the required electricity. This type of design is not the norm by far--it's just a little too expensive
        up front for most people--and it might require the owners to put on a sweater indoors a few times a year." Turning up the heat when you're cold is a convenience. Having to put sweaters on, however simple and beneficial a solution it may be, is NOT a convenience. Hint: If you are forced to seek an alternative, it is not as convenient.

        Myth: You can't use solar energy in far northern latitudes.

        When it's sunny, yes, you can use it in northern latitudes. What happens during the rainy season? In many northern states, the rainy season is at least half the year. Go on battery the whole time the sun isn't visible? What happens if (when!) the battery goes dead? Americans used

        And let's discuss cost. The brochure you presented states that costs are so bad. Last I checked, good solar panels for the home were upwards of $30,000. If you are already paying for a new house, the extra cost of setting up solar is marginal. For folks who are just getting by (everyone with kids in college), $30,000 just isn't there. Costs from environmental damage where we don't immediately see the price tag? That's fair. Absolutely that's a fair statement to make. Then again so is saying, "What about the hidden costs of completely ripping out an established infrastructure in favor of a new one?" Isn't that fair too?

        The idea is to minimize the impact of microhydro by following some simple rules. Always leave enough flow in the stream bed for aquatic life. If migratory fish use your stream, make sure that they and their fry can swim past our diversion, and cannot be drawn into the enstock intake. Always put the diverted water back into the same stream bed in a way that does not cause erosion.

        Once again, a fair statement. However how is microhydro going to handle the macro scale when you (a) can't pack them closely together and (b) cannot disrupt the normal activity of the surrounding water? Put more in to get more energy? Remember the 1st Law of Thermodynamics. As it is not created nor destroyed, if you use a sufficient amount of energy in one system, that amount is removed from another system. Environmentally sound? Reducing the energy by a significant amount would be environmentally sound? Most of the world's creatures live at or near a coastline. Carefully consider whether or not you want to mess with this substantially.

        Nukes produce nuclear waste, and even after spending billions of taxpayer and ratepayer dollars, no acceptable disposal solution has been brought to the table.

        This one kills me. First of all, the term "nukes" usually refers to "nuclear weapons." The requirements for nuclear power are dramatically different from those of bombs. You might as well assert that electricity should be banned because electric chairs are made. It has no place in a power generation conversation. Second of all, there are nuclear reactors such as IFR (Integral Fast Reactor) [anl.gov] which were designed specifically to address critics' problems with nuclear. It does not rely on coolant, computer control, or human interaction/intervention to prevent accidents; Safety is dependant upon natural phenomena and the laws of physics to operate. The working prototype for IFR [anl.gov] conducted a series of tests where coolant was shut off and all of the usual precursors to a meltdown were put into place. No damage. No leakage. Nothing but a safe, controlled shutdown -- without human or computer interaction. This is not hypothetical. This is historical fact. In fact,

        • I agree that RE in general is not a solve all for the nation's power problems. I am a clean nuclear advocate myself, if not so well informed and well spoken.

          My problem is that most people seem to think that solar panels are trash because they are not anywhere near 100% effecient. Even at today's standards most panels will return their manufacturing energy investment and a users financial investment well before the end of their life.

          In the right application, they are extremely useful. Running a remote

          • You are of course correct. And while I have come across as quite strident in my views, I am actually an advocate for solar, wind, and to a limited extend tidal. Our energy shouldn't come from just one source.

            I am however utterly convinced that coal, oil, and natural gas should not be energy sources we fall back upon. (Note: 51% of today's power generation is from coal.)

            My only other comment on this is that switching infrastructures -- such as widespread adoption of home solar panels -- will not be a qu
        • While I agree with your argument in general, I think that you need to make a slight correction:

          Multiply that by 8 (average number of hours in the day with usable sunlight)
          [...]
          And this assumes that it's daytime -- the sun is shining at the time.

          You already took daytime into account with the 8-hour figure.
          Accounting for clouds and rain would probably reduce the daily sunlight average low enough that energy needs wouldn't be met.

          An effective way to use renewable energy exclusively is to build huge solar ar


          • Thanks for the correction. In truth, I was spending some time on that comment (that very few will probably ever read). In the editing/revision process, that ended up as an unwanted artifact from an earlier draft.

            An effective way to use renewable energy exclusively is to build huge solar arrays in space (where there is lots of room) and beam the energy to Earth as microwaves.
            Using asteroids, etc., as raw materials will reduce the pollution/energy costs associated with producing the materials on Earth and

            • What I meant was to use asteroids as the raw materials for building orbital solar panels.
              What would be launched into space would be factories that would capture asteroids and build solar panels out of them.

              So we don't have to "get the huge solar arrays into space", because we build them out of material (asteroids, comets, etc.) that is already there.
              What has to be launched are the factories.
              Or go one step further: launch one or two factories into space that use an asteroid/comet to make many solar panel fa
          • Whether power is produced by centralized nukes, big hydro, coal plants, or solar space satellites beaming power to big rectenna farms on Earth, the power must get to the consumer. Typically that is though an electric grid. Right now, about half or so of an electric bill can be delivery cost -- the cost of maintaining the grid. So, it will make no economic sense to buy power from a grid once local solar falls below about $0.06 / killowatt-hour. This is in about 35 years w/o major breakthroughs by current tre

        • Once again, a fair statement. However how is microhydro going to handle the macro scale

          Exactly how old is the Niagra Falls plant? Hydro is a tried and true technology refined over a century. Scaling down is a lot harder than scaling up.

          With the methods used in IFRs, the materials are no more usuable as nuclear fuel than uranium ore you mine from the ground.

          I suspect that is a major reason there are none of these plants operating. You may recall that the only plants built over more than the last decade h

    • Re:Solar energy . . . the big picture . . . (Score:5, Informative)

      by raygundan ( 16760 ) on Wednesday April 14, 2004 @01:38PM (#8861628) Homepage
      The panels you can buy and use for your house today have a 3-4 year energy payoff. (ie, they make an amount of energy equal to what was put in to them in production) They last in the neighborhood of 20-30 years.

      There are some nasty chemicals required for production. The total environmental impact, however, is significantly smaller than obtaining the same lifetime amount of power from any other source available. The waste produced by a similar amount of power from coal, nuclear, gas, etc... over a similar lifetime is significantly larger.

      The pollution only happens once, for 20-30 years worth of power. The pollution from any other option doesn't stop unless you stop using it.
      • The panels you can buy and use for your house today have a 3-4 year energy payoff. (ie, they make an amount of energy equal to what was put in to them in production)
        Which accounts for about half the cost of buying and installing said panels. So you can expect them to pay for themselves in about 8 years - except by then you'll need a new set of batteries. So ~10 years until it starts earning you money.
        In fact I think swapping batteries at least 4 times in 30 years will provide a more significant form of p
        • Don't use batteries. It's not cost-effective. They're huge, high-maintenance, and have to be replaced regularly. It's better to run a grid-tied system and hope somebody else figures out how to handle storage more effectively.

          Nonetheless, I wouldn't suggest to most people that they try this to save money. It's at the point where you can break even in 8-10 years, but that's still the sort of time frame where it appeals mostly to folks who are doing it because they want to, not because it's a financial ga
    • In production and disposal, though, you're talking about 2 one-time costs. With the other options (oil, coal, nuclear), you're constantly generating pollution during the duration you use that energy source.
    • The suggestion that solar cells contain a whole heap of nasty components is ridiculous. I work in the solar cell industry, and 99% of commercial solar cells are made from silicon. The same silicon which makes up the chips in your computer (which lasts 3 years). In fact the silicon that is used in solar cells is the seconds material from the IC industry. The remaining parts of these devices inluce glass (mainly silicon also) and some aluminium and silver. Solar cells last in the field as long as they are not

  • The only equation that matters (Score:4, Insightful)

    by Dr. Bent ( 533421 ) <<ben> <at> <int.com>> on Wednesday April 14, 2004 @11:21AM (#8860098) Homepage

    When it comes to adoption of solar power, there's only one calculation that really matters:

    C = Cost of installing solar panel
    R = Revenue generated (or money saved) per year
    M = Maintainence costs per year

    (R - M) >= C * 20%

    In plain english, when you can get (somewhere around) a 20% return on investment from installing a solar panel, you'll start to see them on top of office building, parking garages, and just out in the middle of open fields, soaking up money.

    Until then, solar power will be a technical curiosity for use in special situations (outer space) and for those with a political agenda.
    • this equation matters if you are planning on investing in a solar power plant. I would believe that there is a market for solar powqer for people that would like to live off the grid. unlike nuclear or coal power it is plausible to have a solar power generator for a house and a neiborhood.

    • Re:The only equation that matters (Score:4, Insightful)

      by SB9876 ( 723368 ) on Wednesday April 14, 2004 @02:26PM (#8862302)
      The fact that most people miss is that solar cells have started to push past this goal. They now take less energy to manufacture than they capture in their lifetime (always a bonus), and the cost per kWh is pushing down to 2-3 times grid electricity. Given that solar cells have demonstrated a steady decline in cost for the past few decades, chances are good that we'll start seeing large scale adoption in the next decade.

      There's also other factor encouraging the use of solar cells. For one, they're much more durable. There's some cells now that can be used rdirectly as roofing tiles where you can put nails through them and walk on them. They aren't the best panels out there but the ruggedness factor is attractive. Also, most power companies now let you sell off excess capacity back to the power grid these days. That development alone can make solar cell arrays in sunny areas pay for themselves in 10 years or so.

      Unfortunately, I live in Seattle, land of little direct sunlight and no steady wind. Renewable energy for me is out until those solar cells get another 50% decline in $/kWh.
    • Actually I've seen many figures that say there is atleast that much return on investment. Its just that its an investment many people don't know about, isn't highly advertised, and not everyone wants to bother with.
      • Unfortunately, that's largely true. Although solar has made inroads on things like shipboard use and little garden lights, most people just don't think of it as a primary power source.

        I suspect that once solar power gets to the point where it can pay for itself in under a year, you'll see public attention start hitting it. I am encouraged by those little solar powered lawn lgihts, though. As cheesy as they are, they are popular and start to subconciously affect people to think that 'Hey, solar power *do

    • Re:The only equation that matters (Score:1, Insightful)

      by Anonymous Coward
      Are you saying that people won't invest in something until their return is at least tax free 20%?

      If I could get buy an investment that would give me a tax free return of 7% I'd leap at it. I say tax free because saving money isn't taxed. A penny saved is more than a penny earned because a penny earned is taxed.

    • We did the time warp again? (Score:4, Insightful)

      by dbIII ( 701233 ) on Wednesday April 14, 2004 @02:57PM (#8862649)
      Until then, solar power will be a technical curiosity for use in special situations (outer space)
      Ever seen a pocket calculator? They don't plug into the wall anymore - they started to run on batteries, and now run on solar power. Marine navigation lights don't burn parafin, they have little solar panels on top of them. A lot of microwave relay towers are solar powered. Yachts have solar panels. I would have said the exact same things in the 1990s and it is now 2004. A better solar cell helps in those applications where they are already in use, and makes other applications easier to implement.

      In plain english, there are other design criteria other than a very simple equation even an economist could understand. Economies of scale mean that in most cases it is cheaper for a business to get power from a grid, no matter what powers it.

    • No, the other formula is:

      (cost of solar) (cost of grid power).

      The cost of grid power has seen a steady increase of about 6%/year, and the cost of solar is coming down. With net metering and time-of-use metering (i.e. you sell your electricity to the power company), a residential solar system can start paying for itself on day 1.

  • Great news (Score:3, Funny)

    by b-baggins ( 610215 ) on Wednesday April 14, 2004 @11:48AM (#8860386) Journal
    Now we can run 5 100-watt light bulbs per square meter in death valley in full sunlight.

  • This underscores the need for ... (Score:3, Interesting)

    by WindBourne ( 631190 ) on Wednesday April 14, 2004 @02:32PM (#8862363) Journal
    Major research into energy storage. The 2 major problems that we have in energy generation is either
    1. the peak total of plants are pretty much maxed out and will require building of new plants
    2. Alternative energy is sporadic and can not be counted on (except for tidal).
    Right now, we have money going into generation, but really need to spend it on storage as nothing really works well. I would love to money put into Beoings use of salt and a stirling engine for doing this. But I doubt it will happen.
    • Large scale energy storage is particularly important for solar adoption. Right now, the sell-back system with the power grid works since there's only small amounts of power coming from home power grids. However, as soon as it goes mass-market, the off-peak power market's going to implode. While that's great for aluminum refiners, it means that the economic advantage of solar is largely negated.

      Whatever happened to the idea of superconducting power rings? Did the magnetic flux intensity just prove too g
      • Whatever happened to the idea of superconducting power rings?
        I have not seen anything on that in a long time. Last I heard of superconductors were still below liquid nitrogen temps, therefor requireing liquid helium/hydrogen (both too expensive). But that is certainly why a funding for storage needs to take place. Interestingly enough, I was thinking that this could even help nuke plants. They are always hot and capable of 24/7 production. So this can increase the output by quite a bit. Cheap way to increa
        • I did a Google and there are actually commercially available systems out there that are being sold for power conditioning and UPS service for businesses. They use liquid He and old school superconductors because of teh higher current density possible. There's still talk of city scale units but it sounds like the economics haven't caught up to practicality of those just yet.
      • Whatever happened to the idea of superconducting power rings? Did the magnetic flux intensity just prove too great for practical use?

        The main problem with superconducting storage is that high-temperature superconductors break down at relatively modest [for power storage] field strengths (in the range of 1 Tesla), and liquid helium cooled superconductors are only somewhat better (best I've heard is 8 Tesla for particle accelerator magnets cooled to 1.8K).

        It turns out that the situation is even worse, thou
        • What about a Sabatier reaction? 2H20 -> 2H2 + O2 | CO2 + 2H2 -> CH4 + O2. I know that Zubrin in his Case for MArs stuff built a fairly high efficiency setup that fit onto a pegboard. IIRC, the synthesis rate wasn't too spectacular but it's a process that can be scaled up fairly easily.

  • Cheap spray-on coating that generates electricity! (Score:3)

    by DoraLives ( 622001 ) on Wednesday April 14, 2004 @06:39PM (#8864254)
    The good news is that one of these days somebody's actually going to do it.

    The bad news is that shortly thereafter, everything will turn an odious dull black.

  • Other development (Score:4, Informative)

    by codeButcher ( 223668 ) on Thursday April 15, 2004 @04:39AM (#8867101)
    Research [innovationfund.ac.za] done here in South Africa by Prof. Vivian Alberts et al has turned up some more promising results. From another article (here [152.111.1.42], unfortunaltely not in English) some of the highlights:
    • Cu, In, Ga, Se and S are deposited via a vacuum & diffusion process
    • Can be deposited on plain glass (same stuff used for window panes)
    • 1 micron of this stuff absorbs more sunlight than 350 microns of Si (about 99% of light - don't know how this translates to efficiency, though - article not too technical).
    • Panels like these would cost roughly a tenth of the price of those currently available.
    • Pilot plant for manufacturing was expected to begin manufacturing somewhere in April (this month), manufacturing panels 400mm x 500mm @ 20W
    • Pilot plant (100 sq m) to cost about US$ 2.3 - probably within reach for many developing countries.
    Unfortunalty there's not much more detail or Web references....
    • (about 99% of light - don't know how this translates to efficiency, though - article not too technical)
      [...]
      manufacturing panels 400mm x 500mm @ 20W

      That says they're speccing them to about 10% efficiency.

  • Try Low-Tech First (Score:3, Insightful)

    by Shipud ( 685171 ) on Friday April 16, 2004 @01:22PM (#8883075)
    In many Mediterranian countries, water is heated using solar panels which utilize the greenhouse effect. The idea is that blackened water pipes are running through a glass panel installed on the roof, facing south. Hot water is stored in a tank. In summer, and in many winter months, this removes the need for heating water electrically. Coming to a sunny part of the US, I was pretty astonished not to find that. Well, at least not in Cali. Makes you wonder why how much this new development will be implemented.

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