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Power Science

New Record For Solar Cell Power Efficiency 351

mdsolar writes "Renewable Energy Access is reporting that a consortium led by researchers at the University of Delaware has achieved 42.8% efficiency with a silicon solar cell. The method uses lower concentration (factor of 20 magnification) than the previous record holder (40.7% efficiency) so that it may have a broader range of applications, since tolerances for pointing the device will be larger. They are now partnering with DuPont to build engineering and manufacturing prototypes. They expect to be in production in 2010. On a roof, such cells would require less than half the surface area to produce the same amount of power as today's standard solar panels, which have an efficiency of about 17%."
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New Record For Solar Cell Power Efficiency

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  • by Anonymous Coward on Wednesday August 01, 2007 @05:46AM (#20068321)
    ...than price per watt. We got plenty of space we can cover with solar cells so it's not important that they are extremely efficient, just cheap enough so it doesn't cost much to cover large areas.
  • by montyzooooma ( 853414 ) on Wednesday August 01, 2007 @05:47AM (#20068329)
    I think you failed Humor 101.
  • by suv4x4 ( 956391 ) on Wednesday August 01, 2007 @06:05AM (#20068393)
    However, the solar power you could produce from the surface of a car is not enough to give you mobility.

    They use conventional panels (17%). This one is 42%. Also I'm suggesting they won't run on pure solar, but support the electric motor in the same way the electric motor supports the diesel one in hybrids nowadays.

    It may drop your fuel consumption 15%, using "free" solar energy, still worth it.
  • by dwandy ( 907337 ) on Wednesday August 01, 2007 @06:51AM (#20068577) Homepage Journal

    It takes more than 3 years to pay back your monetary investment.
    "Three years" should not be a 'too long' perdiod to re-coup your investment.
    • That's less than 4% of an average lifetime.
    • I'd take an investment that was guaranteed to pay back 100% every three years.

    I don't see energy getting any cheaper on this planet, and I don't see energy consumption decreasing.

    The problem is it's not just the solar panels: it's the batteries and other infrastructure (and then maintenance!), and the last time I looked at it, it was closer to 20-yrs to pay back a whole system, and the system had a 20-yr life expectancy. That's break-even assuming it makes it to life expectancy.

    What I am interested in is directly attaching an AC unit to a solar panel. Where I live it's generally only hot when it's sunny, so the AC would run for free.
    Since the AC is one of the most expensive things to run it's win-win-win-win:

    • I can run it guilt-free
    • It runs whenever it's hot
    • I don't need the other infrastructure
    • I will still pay for the panel in a relatively short time.
  • Re:hmmm. (Score:2, Insightful)

    by lauwersw ( 727284 ) on Wednesday August 01, 2007 @06:57AM (#20068615)

    There's another idea about this gaining attention. Suppose people do care and start conserving energy. They pay less for their energy bill, so that means they own more money. What do they do with this money? Spend it on other things of course! So that means other people are earning more money, for example in other parts of the world that are currently using less energy. What will they do with this extra money? Yes, spend it and in that process use more energy than they would have before!

    Net result? 0

    Maybe this is just a general law in nature: a species will use up all resources it can find. The only real solution would be a real clean source of energy. Your alternative would work too, but is way less attractive ;-)
  • by tekrat ( 242117 ) on Wednesday August 01, 2007 @07:09AM (#20068653) Homepage Journal
    So, run this by me again;...

    Consider that, aside from police cars and taxis, most cars spend most of the time PARKED, either in a parking lot at work, or a driveway at home. The average car's lifespan is mostly spent at rest, with about a 1/2 hr drive to work and a 1/2 hr drive home.

    Why is it NOT prudent to build a solar panel into the roof and/or engine hood to help recharge the batteries while the damn thing spends 8 hrs per day parked in the sunshine?

    Hell, if we could take the heat that builds up inside the car on a hot summer day and convert that into electricity, I bet I could drive home just on that!

    Brian C.
  • Re:hmmm. (Score:4, Insightful)

    by JaredOfEuropa ( 526365 ) on Wednesday August 01, 2007 @07:22AM (#20068689) Journal

    There is also the huge number of people who believe that the consensus of thousands of scientists on climate change is a "global conspiracy" and their fear that it may eventually mean, shock horror, more taxes.
    This believe is partly justified. The conspiracy isn't by the scientists, and isn't a global conspiracy either, but the climate scare has given the meddlers of any political stripe the perfect pretext to push their own agendas. The climate debate has been thoroughly politicised, at the expense of proper science. That does not mean that all conclusions are incorrect or made up, but very often peer reviews are sorely lacking, and many reports have had chapters and sections stricken in the final draft, because those sections could cast doubt on the severity or existence of human impact on the climate. In many cases scientists voicing such doubts have not been gainsaid, but fired from "scientific" institutions. Because a widespread doubt in our impact on the climate would spoil the party for the meddlesome politicians. The political stakes are huge, perhaps the largest of any issue in our history.

    Why are long term trends not taken into account in these reports, for example. It is rubbish to say that we cannot accurately predict climate that far into the future because our short-term predictions are not very good. After all, we cannot predict the little ups & downs in next month's weather, but we can predict that winter will follow summer and autumn, and we know what the trends are in each of those seasons. The long-term trends in global weather can be predicted as well.

    On a geological timescale, we are in high summer. Winter is coming, and in 10.000 years we'll be in an ice age. The start of the downward trend in average temperatures is imminent (which means anywhere between now and 1.000 years)... Perhaps that is why the IPCC report does not look any further than the year 2100, the scary hockeystick curve will flatten out after that year, and if you look even further it will drop. Our distant descendants (if any) may even be grateful for the extra CO2 we have released, since it might make the next ice age a little less severe.

    But with all that said, conservation and reducing our dependancy on a limited resource is a good thing. But I refuse to join in the mindless panic.
  • by Doc Ruby ( 173196 ) on Wednesday August 01, 2007 @08:02AM (#20068893) Homepage Journal
    Concentration of a larger solar input area onto a smaller solar cell is nearly always better than straight 1:1 reception. The efficiency goes up with these materials, which of course is good.

    But also the concentrators are a lot cheaper than the cells. The concentrator is usually a cheap (compared to the cell) lens or mirror. So a 20x concentrator gets 20x the input energy, but for a much lower cost than 20 cells. And that cell is operating at higher efficiency, on 20x the input. So a $10 cell fed by 20 $5 concentrators costs only $110 instead of $200. 5% more efficiency in the cell is applied to all 20 concentrators, not just the 1 cell, for 200% efficiency. So it's double the efficiency at 55% the price, or over 3.6x the $:energy efficiency. In reality, the concentrators are better than 5x cheaper, and the efficiency gains can go higher than 5% greater.

    And then there's all the savings from cheaper replacement concentrators, which could even last longer than the cells (though the cells typically last >30 years), and dropping all the other HW from the 19 (or however many) extra cells in favor of "dumb" concentrators. In fact, since concentrators are so cheap, the cells might not require HW to track the Sun for maximum absorbtion, but just array the concentrators in an arc (or bubble) that always leaves an array of concentrators facing the Sun (and the rest off-axis), without consuming energy to move. Or extra parts, or computing, and saving all the maintenance costs, too.

    So the more concentration, the better. After all, that's how the engineers thought up this stuff.
  • by zqwerty ( 686798 ) on Wednesday August 01, 2007 @08:49AM (#20069203)
    Its 20 years since I looked into solar cells in my engineering job, but the figure quoted above must be close to theoretical maximum because solar cells amount to a forward biased diode and can never get to 50% efficiency, they also have poor temperature performance which falls off rapidly as they get hotter, so enclosing them and reflecting more sunlight onto them is exactly the wrong thing to do, they run most efficiently when cool. As said in this thread the big problem is cost and having to store the electricity when the sun is not around at night.
  • by Rocketship Underpant ( 804162 ) on Wednesday August 01, 2007 @08:57AM (#20069293)
    "Now, you could buy solar panels at $5000 per kW (and 20 pounds). Assuming double efficiency is treble the price - you need $15,000 per square meter, so you'll pay $150,000 for solar on your car. Is it worth to drop your fuel consumption 50%? Or completely?"

    This is the point where the central market planners jump in and shout that we should subsidize solar panels. But why does that solar panel cost $15,000 per square metre? Because of all the resources, energy, and labour consumed in producing it. Chances are those more than offset the gas you're not burning.

    When the manufacturer can make panels efficiently enough to be more affordable than gasoline, it'll be because they're finally less wasteful and polluting overall.

    A similar principle holds with recycling, by the way. In the instances where recycling actually saves on energy and raw materials, there is a cost savings as well, and the recycler will pay *you* for your bottles and cans. If the government has to make you do it, it's because the process is not cost-effective overall, and more waste is taking place in the recycling process than the recycling itself saves.

  • by bri_eh ( 989961 ) on Wednesday August 01, 2007 @09:31AM (#20069681)
    The power of Bush compels you! The power of Bush compels you! But seriously, transfer 1/16 of the money from the oil wars to research on making more efficient and cheaper solar cells and we will will have a energy independent North America and far less air pollution before the 2050 point of no return.
  • by dbIII ( 701233 ) on Wednesday August 01, 2007 @09:39AM (#20069779)
    If you are running AC then solar thermal in one of many forms is a better idea - use that heat to move heat around instead of making electricity and turn it back into heat to move heat around. Then you use your panel for your electronic stuff runing on DC - suddenly you don't need a very big panel anymore.
  • Re:hmmm. (Score:3, Insightful)

    by RocketScientist ( 15198 ) * on Wednesday August 01, 2007 @10:12AM (#20070241)
    I think you have a valid point but you need to look at why this happened.

    Among the general public, basically they've had the "global warming" concept beat into their heads, but they're watching the people doing it fly around the world in private jets and live in houses with 4K/month electricity bills.

    Among the geek skeptics, like myself, what I see is not science, it's religion. It's "we've solved this problem, we know it's happening, so NO MORE DEBATE ABOUT IT!!!!". That's not science. We're still debating gravity, we're still debating inertia, we're debating light as a particle or wave. That's science. The "no more debate, no more discussion, this is happening and anyone who doesn't believe must be shunned" vibe from most environmentalists is simply religion, not science. Not that the other side's better, buying off scientists and spinning science to meet a political agenda funded by energy companies. But therein lies the problem: this is a political issue, not a scientific one.

    My main problem is that we're extrapolating a 4 billion year old climate with about 150 years of directly observed but partial data and 30 years of directly observed global data. The tree ring studies originally done were riddled with accounting problems and were, very likely, fraudulent, and the remaining indirect methods seem to point in many different directions. Further complicating the issue is the ad hominem attacks every time a study comes out that supports either side. If I was an environmental scientist at this point, and no matter what I published I risked physical threats to my security, I'd probably find another line of work. That's the position we've put these people in. They can't publish science anymore, everything they publish is a religious tract, hoping to sway one camp or the other to provide them protection and cash so they can continue their work.

    Back on topic: Solar cells are nice, but once you factor in the environmental cost of production they're not efficient. Greenhouse gases are not the only pollutants, they're just the fashionable ones to bitch about right now. Arsenic, volatile and carcinogenic organics, acids, and heavy metals are created/liberated as a byproduct of solar cell production. The problems of these pollutants haven't been solved, they've just taken a back seat to greenhouse gases. When you consider the immediate problem of groundwater pollution against a backdrop of a possible global warming problem, solar cells seem to sell out the immediate problem in favor of the long term one. We've got the technologies to solve both problems with a minimum in absolute terms of toxic byproducts, but ironically the environmental movement hates it.

    go nukes.

    We have the solution to the problem, we just need the environmental movement in this western world to actually go through the enlightenment and discover that maybe, just maybe, science might fix this problem instead of religion.
  • by 45mm ( 970995 ) on Wednesday August 01, 2007 @10:20AM (#20070363)
    Damn, did somebody urinate in your coffee this morning?
  • 2.1% big deal... (Score:1, Insightful)

    by DarthVain ( 724186 ) on Wednesday August 01, 2007 @10:43AM (#20070703)
    Am I reading this right? This story is about breaking the record and increasing by only 2.1%? Is that really news? If it was 50%, 25%, hell even 10% that might be something. But 2.1%, gimme a break! Not only that, but this is a singular event, not something being currently translated into the 17% technology....
  • Re:feasible (Score:4, Insightful)

    by xappax ( 876447 ) on Wednesday August 01, 2007 @11:28AM (#20071581)
    You deliberately buy things that aren't as cost-effective as other stuff, but that reduces CO2-emissions. Unfortunately your money aren't "lost", someone will get rich, such as the bank, or the company CEO, so even this method isn't 100% convincing to me.

    Seems like if you deliberately spend money on things that are less polluting than the mainstream offerings, you're helping to make that industry more economically viable. For example: if you buy residential wind turbines, the company that makes them will profit. Yes, some of that money will probably be spent on things that cause pollution, like employee salaries or airline tickets, however it will also be spent on improving and marketing a product that can reduce pollution dramatically.

    No institution or individual can ever have zero negative impact on the environment, but they can have a greater positive impact, so that their damage is offset overall. The question becomes, is a supposedly "green" institution really helping the environment more than they're hurting it? Some companies really are, and it's great to give them business, but some are just using environmental concerns as a marketing niche, and giving them money will do nothing but enrich them, and possibly allow them to create more pollution.

    I agree with your general sentiment, though. The key is being critical and informed about where your money goes. When you spend money, it doesn't just disappear - it goes on to pay for things that may be destructive or immoral, and couldn't happen without your money. Or, it may go on to pay for things that are constructive and really awesome. Though the amount of money you spend may be similar, the difference between these transactions is vast when you consider the consequences.
  • Duh! (Score:2, Insightful)

    by Anonymous Coward on Wednesday August 01, 2007 @11:29AM (#20071601)

    On a roof, such cells would require less than half the surface area to produce the same amount of power as today's standard solar panels, which have an efficiency of about 17%
    It makes no difference to me whether they cover the entire roof, or just half. Space on my roof is free. The important question is, which solution is cheaper? I wish they would give us cost efficiency, as in dollars per watt. Watts per square inch is only important when land or space is terribly expensive.
  • High tech one offs (Score:3, Insightful)

    by Danathar ( 267989 ) on Wednesday August 01, 2007 @11:43AM (#20071863) Journal
    I think most people would be surprised what can be created with technology when you only have to make a few of them. It's the mass manufacture of "scifi" like devices that is HARD.

    If I wanted to create super sci-fi stuff for my spy that's not so hard, custom made stuff with lots of money behind it can do amazing things.

    I'm really hoping that their method is mass manufacturable.
  • Re:hmmm. (Score:3, Insightful)

    by CommieLib ( 468883 ) on Wednesday August 01, 2007 @12:13PM (#20072443) Homepage
    Why are long term trends not taken into account in these reports, for example. It is rubbish to say that we cannot accurately predict climate that far into the future because our short-term predictions are not very good. After all, we cannot predict the little ups & downs in next month's weather, but we can predict that winter will follow summer and autumn, and we know what the trends are in each of those seasons. The long-term trends in global weather can be predicted as well.

    I've got to disagree with you from both sides of the political aisle. I will argue that we cannot make accurate climate predictions (at least within the range that is relevant to the anthroprogenic global warming debate) because we have utterly failed to do so in the past. That data that the IPCC use show no warming after 1999, which doesn't even fit the past of the model, let alone the future.

    I think really what the whole problem is with the debate is that there's a huge difference between the approaches of the typical person and the scientist to uncertainty. A scientist eats, drinks and bathes in uncertainty, and is comfortable with saying, "Gee, we just don't know. Maybe we'll know more in the future, but this is our best understanding currently, and it is almost certainly at least partially wrong." The typical person deals with decisions made on imperfect information in their daily life, and regards uncertainty as incompletion, or at worst, weakness. That's why we have people who believe in UFO's, ghosts, or fricking Sasquatch rather than saying, "I just don't know what the hell that was. I probably never will."

    As the previous poster pointed out, the whole debate is INCREDIBLY useful to authoritarians, as is any crisis which justifies sweeping powers and changes to society.
  • by Squirmy McPhee ( 856939 ) on Wednesday August 01, 2007 @12:34PM (#20072923)

    What matters to me: Do those new cells finally "produce" more energy during their life than they required during manufactoring?

    What do you mean "finally"? They always have, though nowadays they recover the energy used in their production much faster than they used to. A few years to recovery is typical, and you really have to be trying to make it more than a decade. By contrast, the solar panels themselves are waranteed for 20+ years and thought to have useful lifetimes of 30+ years.

  • Re:feasible (Score:3, Insightful)

    by xappax ( 876447 ) on Wednesday August 01, 2007 @04:07PM (#20076637)
    If it's profitable, it usually means their customers are making money by buying their power too. Which means that their customers now have more money to spend. See above.

    I think you're presupposing that all possible things someone can spend money on have the same CO2-emission potential. $1 worth of burnt coal (in the form of electricity) produces X amount of CO2. If MiracleTurbine becomes successful, and I get to keep that dollar, I'm not necessarily going to spend it on something that also emits X CO2. In fact, it'd probably be pretty difficult to do worse than paying a company to burn up as much coal as possible for $1 and give me the energy produced. Buying gasoline could be as bad, maybe, but most alternative uses will not be, therefore there will be less "CO2 emissions-per-dollar-spent".

    the most efficient way of reducing CO2-emissions is to not earn a living.

    Actually, given the premise that consumption in general is the cause of CO2 emissions, the most efficient way of reducing emissions would be to earn a living and then not spend any of it. After all, if you refuse to work, your potential employer will just take that money and do something else with it, right? Something that will probably contribute to CO2 emissions. So the most efficient thing to do would be to earn a lot of money and then sit on it - literally, take it out of the bank (banks invest your money in CO2 emitting companies/governments) and put it under your bed, or just destroy it entirely. This is the only way you can really be sure it won't be used for CO2-emitting consumption, and the more money you "take out of circulation" this way, the less consumption is possible.

    The problem with this strategy is, unfortunately, that the government creates as much money as they want. If money is taken out of circulation, they can just add more in to replace it and keep the cycle of consumption going. Really, money is only effective when spent, which brings me back to my original point. Strategically spending money (give money only to institutions which are helping to reduce CO2 emissions, boycott outright those which increase it) is possible, and unfortunately in a capitalist economy, probably the best available way to create a net positive impact on CO2 emissions.

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