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Laser Scribing Promises More Efficient Solar Cells 97

Posted by samzenpus
from the new-and-improved dept.
cylonlover writes "A new manufacturing method that incorporates laser technology may result in thin film solar panels that are less expensive and more efficient than anything presently on the market. Currently, a stylus is used to mechanically etch microchannels into such panels, which electrically connect the individual solar cells and allow them to form an array. Researchers from Indiana's Purdue University, however, are developing a technique in which an ultrafast pulsing laser is used to do the etching. Not only will it hopefully be quicker and cheaper than mechanical 'scribing,' but it should also produce cleaner, sharper microchannels that offer superior performance."
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Laser Scribing Promises More Efficient Solar Cells

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  • Won't solar panels be so cheap in 5 years that only rich people will burn candles and/or oil?
    • by TheLink (130905)
      Would solar panels (photovoltaics etc) be cheaper than using reflectors e.g. solar thermal?

      If we are going to cover a total of 100km by 100km (or more) with panels the material costs are significant.
      • I am betting that if you look at the service life of both systems PV might still be cheaper. A lot of the energy cost of manufacturing PV cells is in heating up masses of silicon so maybe a plant could make its own cells and use solar thermal power for part of that process. A solar thermal system would need a lot of maintenance while PV cells just sit there and push electrons around. And mirrors aren't cheap either. I wonder what their manufacturing cost is vs PV cells?

        • by mangu (126918)

          A solar thermal system would need a lot of maintenance while PV cells just sit there and push electrons around

          As someone who has worked with electronics for over 30 years, I beg to disagree. Imagine the number of bad joints in the billions of cells that would be needed to replace one large electric power plant.

          Assuming a size of 10cm x 10cm for each cell, that's a hundred cells per square meter, a hundred million cells per square kilometer, at least two hundred million soldered joints. All that to generate no more than 1000 MW at noon on a sunny day.

          With wind slightly bending and moving each panel, dust, dew conden

          • my guess is that PV cells are not scalable to the dimensions needed to replace a significant part of our society's electric consumption.

            Maybe but we were comparing PV with solar thermal. A thermal power system would have to be powered down and cooled every night. Components will expand and shrink. They will fatigue and fail. Pumps and heat exchangers would need ongoing maintenance. I suspect that faulty PV panels would just be replaced and their materials recycled. They are not 100% reliable, but still more reliable than most things with moving parts.

            • by mangu (126918)

              The problem is in the sheer number of cells needed. With hundreds of millions of cells, even assuming zero cost for a replacement cell, the cost of finding and replacing the failed cells would be significative. Thermal cycling would be a factor causing degradation of a solar thermal plant, sure, but it would also affect PV.

              If I had to choose a solar plant design, I would go for a linear alternator powered by a free piston Stirling engine [wikipedia.org]. Stirling engines are more expensive than other thermal engines, but t

              • by Zerth (26112)

                If you're carpeting Arizona with solar cells, you can probably do what Google does: just ignore the failures until enough of a unit is bad to justify the manpower, then pull it.

              • Thermoacoustic is more elegant and less maintenance.
            • Liquid salt heat tanks. Oh, and the materials for solar thermal are much more resilient due to their very nature. The mirrors would be practically eternal, and the number of collectors would be magnitudes smaller. Oh, and funny how incandescent lights burn out from evaporation way before fatigue sets in. Not to mention the many car engines that get started every day for many years.
          • by spitzak (4019)

            I think the engineers are smart enough to figure out how to make a solar power plant that keeps working even when some of the cells fail. Even though apparently you think it is impossible.

            • by mangu (126918)

              Some (or a lot of them) may fail, but they eventually need to be replaced, or the power output will eventually be zero.

      • by necro81 (917438)
        Solar thermal (for electricity generation, not just heating stuff) is really only effective at large scales: tens of megawatts to start with. You aren't going to put that on your roof; even the manicured suburban grasscapes aren't big enough. A several-kilowatt solar thermal installation, sized for a typical home, would be a terribly inefficient beast requiring constant maintenance and tuning. On the other hand, you can pretty much fit all you'll need for your own home on your own roof with photovoltaics
    • by Seumas (6865)

      Unlikely.

      When I looked into solar panels a few months ago, the case was still that the expense of buying, installing, and maintaining panels were so expensive that you would not begin to save money until after their warranty and estimated 20-25yr life span had already expired. It's going to take a lot of work to make these efficient, durable, and cheap enough that people are going to install them on a widespread basis.

      Not to mention, having a battery system (so you can store excess energy for later use) com

      • by Anonymous Coward

        Here in Belgium, excess energy is fed back into the electrical system: your counter will run backwards - so will your bill - and you have no need for ugly and big battery systems... + the nature and stuff :)

        • by Seumas (6865)

          Without a battery system, you're stuck without power when your power company has an outage (which in certain places is more often than others). If you're not interested in saving money, you can just cut out the whole "solar power" thing and save yourself a TON of trouble by paying your power company a lot more money for supposedly "green energy" that supposedly comes from renewable resources and wind power and so on (right, suuuure it is). Also, you have to take into account the energy required to produce a

          • by Anonymous Coward

            Don't get me wrong - I'm no eco terrorist as I'd like to call 'em :) - But hey, I like it when I see my electrical counter count down instead of up! Plus we get a crazy amount of 'sponsoring' from the government when installing solar panels here, which means that in some cases your investment is payed back in around 5 years.
            About the power outages: honestly I'm 29 years old and I can only remember like 2 or 3 outages... so that's REALLLY not an issue here.

          • by necro81 (917438)

            Also, you have to take into account the energy required to produce and maintain the panels in the first place.

            Can we please lay this tired strawman argument to rest? A solar panel will produce many times more power over its lifetime than it took to produce. Spend a few minutes on Google [google.com] and see the different numbers from dozens of different sources: they all indicate that, yes, solar panels produce more than they require to produce.

            If that isn't enough, consider this very basic argument: if it real

        • by mangu (126918)

          Here in Belgium, excess energy is fed back into the electrical system: your counter will run backwards - so will your bill - and you have no need for ugly and big battery systems... + the nature and stuff :)

          That might be good for you as an individual, but last time I looked, Belgium is a country so small that It's totally in the dark [wikipedia.org] at certain times.

        • by morgauxo (974071)
          It works that way in the US too. You have to have a special switch that disconnects your house any time the power goes out otherwise your solar panels can electrocute the line workers who are trying to fix the problem.
      • That was my conclusion also. Add to that the high chance your investment will become obsolete, and photovoltaics are really not worth doing. I'd like the payback to be no more than 10 years.

        Solar thermal, that is, heating water, is a better bet. No $10000 inverter and battery system needed to collect all those DC outputs and convert them to 120V AC or whatever standard you're on. Efficiency is much higher too. Last I heard, commercially available photovoltaics are still around only 15% to 20%, while

        • by kmdrtako (1971832)

          $10,000 inverter? What are you looking at?

          I've looked at covering half of my roof with 16 230W panels (my house is east/west facing.) For that I would need a single $1,000 inverter.

          Under ideal conditions though that would only produce about 50% of what I consume in a day. And conditions will never be ideal. Before subsidies I figure the break even point is around 16 years.

        • by DamonHD (794830)

          Apples and oranges for your solar thermal and PV: the former gathers low-grade heat and the latter high-grade electricity. 1kWh of electricity can provide far more than 1kWh of usable heat (see the definition of a heat-pumps's Coefficient of Performance) and indeed the ratio is about that between PV and thermal nominal capture efficiency. (ST is more like 50% capture efficiency AFAIK, BTW.)

          And I have my (small) roof covered with PV that generates twice what we consume in a year to make us net-zero-carbon.

          • by WorBlux (1751716)

            Apples and oranges for your solar thermal and PV: the former gathers low-grade heat and the latter high-grade electricity. 1kWh of electricity can provide far more than 1kWh of usable heat

            depends on the size of the gradient.

            • by DamonHD (794830)

              Unless you're heating water wayyyy beyond DHW requirements, not so much. Look at my favourite "ECO-CUTE" CO2 refrigerant air-to-water devices. Indeed, pair a Sanyo HIT PV panel (module efficiency 18%+) with a Sanyo ECO-CUTE ASHP (CoP ~3).

              Rgds

              Damon

      • by adolf (21054) <flodadolf@gmail.com> on Monday March 14, 2011 @03:38AM (#35477120) Journal

        Agreed. I've looked into solar, and even in the best case, it's expensive enough on a household scale that getting off-grid and having it pay for itself is a very far-away proposition: FFS, the roof under the panels is likely to need repaired before the panels themselves have returned their investment... And nevermind ice damage (sure the homeowner's insurance will cover it, but at what cost?) or other acts of God: In Ohio, we gets every sort of weather there is except for hurricanes.

        And so, such is the payback period on a big solar array that I often refer to the calculations espoused by solar proponents as being "new math."

        That said, solar isn't always big and difficult-to-justify. There are other applications which are far more useful, and some of them are rather small:

        I (just the other day) bought a solar panel from Lowe's, for the paltry sum of about $17, despite having shunned solar power for every purpose except for electronic calculators and other toys since I was a kid.

        I'm not going to use it to help bring my house off the grid. And I'm not going to use it to solve world hunger.

        Instead, I'm going to use it to try to spend less money on car batteries: My daily driver has been consuming batteries about once every 12 months ever since I put a Garmin GPS and keyless entry/remote start into it, and has subsequently twice left me to jump-start the car on very cold winter mornings. (And no, I can't be bothered with turning the GPS off: The time-to-first-fix is sufficiently annoying that such a simple solution isn't really useful to me.)

        Sure, I could buy a battery with a longer replacement warranty, but it's a real hassle to get them swapped out, and screwing The Man in this way is (at best) dishonest. I could also get a fancy-pants battery like an Ultima, but that doesn't fit easily into my car, and it's not a solution that is likely to actually save me any money.

        For $17, the miniscule several Watts of power produced on the brightest of days should serve well to keep things charged. This will reduce wear on the battery (fewer, or less-intense discharge/charge cycles), and will in turn improve longevity. (I live in the north, and generally park with the rear window facing the south: Rear-deck solar panel == Win.)

        I expect to be monetarily paid back within the next year or two, or way more if it means that my existing battery never needs jumpstarted again once it turns cold out and the solar charger prevents me from being late for a job.

        I'll likely also take it hiking, if I ever find the time to do any of that again: Keeping a phone charged for the price of a few ounces of photovoltaic strapped to my backpack sounds a whole lot more useful than keeping a bunch of alkalines on hand, and periodic radar maps from the Droid sound like they'd be a really awesome thing in the mountains (along with its battery-powered offerings of proper GPS and a backup magnetic compass in the odd event that I get lost and lose my other compass).

        And depending on how my measurements in the car work out, I'll be buying another one for the battery in the lawn mower, since at this price even such a small and cheap battery would be well-served to have a bit of help over the winter and during the days when the grass is growing but isn't ready to cut.

        I might even buy one for the 32-year-old Firebird, even though it has no history of battery issues (when I turn it off, it's off), just because it spends most of its days sitting in the driveway and it often goes several weeks (or months, if it's wet/cold out) between runs.

        Now, of course: All of these vehicular charging applications would be more-effectively served by just plugging in a small trickle charger whenever they're not in use, but that's a pain in the ass involving extension cords and nonexistent outside outlets, any of which would cost more than this little solar widget did -- and I can't take it with me, plus the installation is would be more difficult and time-consuming than this simpl

        • by 517714 (762276)
          A low voltage cut-off costs less, it turns off the GPS when the battery hits 10.4 volts which is enough to start the car. It works with covered parking.
          • by adolf (21054)

            I've thought of that before. Trouble is, a low voltage cut-off kills the settings on my stereo, unless I wire around it. But if I do that, then I'll also wire things to keep the GPS powered up, and the box for the remote start/keyless entry. And I might as well wire in the engine computer so it doesn't forget the fuel injection and ignition settings that it has learned...and then I'm back to not really having a cut-off switch at all.

            Please recall that the root of the problem is that I'm already unwilling

        • by deimtee (762122)
          Don't forget to stick a diode in the circuit, or the thing will drain your battery overnight. Pretty good chance they skipped that on a cheap panel.
        • by drinkypoo (153816)

          I've looked into solar, and even in the best case, it's expensive enough on a household scale that getting off-grid and having it pay for itself is a very far-away proposition: FFS, the roof under the panels is likely to need repaired before the panels themselves have returned their investment... And nevermind ice damage (sure the homeowner's insurance will cover it, but at what cost?) or other acts of God: In Ohio, we gets every sort of weather there is except for hurricanes.

          The "traditional" timber, paper, and shingle roof is a total idiot boondoggle. Trusses, plywood, tar paper, tar shingles... all bullshit guaranteed to fail. Or you could have a steel roof which costs the same or less, lasts twice as long, and which can have thin-film solar panels applied to it with adhesive. If it's struck by hail it will dent but still function properly.

          If you want to not kill your car battery with that charger you're going to need a charge controller. A diode will help you not murder it i

          • by adolf (21054)

            The "traditional" timber, paper, and shingle roof is a total idiot boondoggle. Trusses, plywood, tar paper, tar shingles... all bullshit guaranteed to fail. Or you could have a steel roof which costs the same or less, lasts twice as long, and which can have thin-film solar panels applied to it with adhesive. If it's struck by hail it will dent but still function properly.

            Agreed, absolutely. But it's funny you mention this: My house has recent steel standing seam roof, and I'm currently waiting for a nice

            • by drinkypoo (153816)

              Agreed, absolutely. But it's funny you mention this: My house has recent steel standing seam roof, and I'm currently waiting for a nice enough day to recruit some help to get a ladder up there and figure out why in the fuck it was leaking some during the most recent torrential downpour. :)

              Yeah, no plan is perfect. It's still better and easier to fix than the "traditional" stuff. The house we're renting needs a new roof...

        • by Meeni (1815694)
          You don't need solar panel, you need a new alternator for your car...
          • by adolf (21054)

            Alternator is good. It produces rated minimum current at idle speed, and rated maximum current at higher speed, within reasonable tolerances.

            It provides proper charging voltage. I check it check it now and then when the car is running using the car's OBC, which has a 4-digit VOM built-in, and which I've sanity-checked against a proper meter.

            Perhaps you're from somewhere warmer -- it gets rather cold here, and it only misbehaves when it is cold. When warm, things operate properly all of the time, no matte

      • by Belial6 (794905)
        Are you saying that the PVs are ugly? As opposed to sheets of tar covered paper that have been sprinkeled with gravel? I have heard the complant that solar panels are "ugly". There is nothing ugly about them. The just are not what people are used to seeing. Composite shingles. Now that is ugly. It is just the ugly we are used to.
      • by RockDoctor (15477)

        a battery system (...) complicates matters (...). Additionally, they're ugly and are not allowed by a lot of HOAs or city ordinances.

        While the specifics of American local housing policies (HOAs being one class of these, I guess) are unimportant, as someone who is reluctantly in the market for moving locations I'll have to remember to keep my eyes peeled for such restrictions. I know that the UK is not the "Land of the Free", and that I've never heard of any such restrictions in Britain, but I'll have to mak

    • by SeaFox (739806)

      I was thinking something similar. With all these advances in solar technology I keep hearing about from different groups, all with 3-10 year forecasts to be cheaper than conventional fuels, wouldn't it be cool if they all put aside the normal competitive "all-for-us" mentality of businesses and just got together and worked out a way of using all their new ideas in one product? By pooling their resources and know-how we could already be there.

      • by khallow (566160)

        I was thinking something similar. With all these advances in solar technology I keep hearing about from different groups, all with 3-10 year forecasts to be cheaper than conventional fuels, wouldn't it be cool if they all put aside the normal competitive "all-for-us" mentality of businesses and just got together and worked out a way of using all their new ideas in one product? By pooling their resources and know-how we could already be there.

        Why would this be any better than usual competition? As things currently stand, no competitor is dependent on someone's technology not being vaporware. There's also the "hold up" problem [wikipedia.org], where businesses, which should be cooperating, delay their output for advantage.

        My view is that this technology needs to be proven first. After that, there's plenty of private funds for developing the coordinated infrastructure you speak of.

    • by leaen (987954)

      Won't solar panels be so cheap in 5 years that only rich people will burn candles and/or oil

      But only for 15 years. After that we get free electricity from nuclear fusion

    • "findings"? What "findings", exactly?

      The research project will continue for a three year period, by the end of which which the scientists hope to have established the scientific basis for their laser-ablation technique.

      Wow! Lasers! This is the kind of news I get up early for. Will there be film at 11:00?

    • by necro81 (917438)
      Ha, I get my light from burning $100 bills!
    • 5 years sure seams optimistic to me. Right now, only rich people can afford solar.
  • Blast from the past! (Score:5, Informative)

    by blind biker (1066130) on Monday March 14, 2011 @01:45AM (#35476834) Journal

    Laser scribing/ablation has been used since the 80's, for reducing the cost (and hence price) of solar cells. E.g. buried contact solar cells..

    Using laser ablation to reduce the manufacturing cost of solar cells is so old news, that I almost don't even remember it, it has been so long ago.

    • by Khyber (864651)

      We have much finer lasers now than we had back then, and we can control the pulses much better.

      This means much finer channel creation, which means more channels, and thus more area for photon capture.

      It may not be new but it has reached a new step.

      • We have much finer lasers now than we had back then, and we can control the pulses much better.

        This means much finer channel creation, which means more channels, and thus more area for photon capture.

        It may not be new but it has reached a new step.

        When Intel introduces something new in their fabrication process (low-K for high integration, high-K for DRAM, etc.) you don't headline it with "Intel invents the MOS transistor!"

    • After Japan and Libya, wind and solar are likely to get a bit of a boost.
  • Solar panels cost more per watt now than 5 years ago, and their lowest cost per watt was about 6-7 years ago. Even if we are getting more efficient at making them the demand is going up much faster, on top of that sooner or later we are going to run up against the limited availability of raw materials.

    • by mark-t (151149) <`markt' `at' `lynx.bc.ca'> on Monday March 14, 2011 @03:17AM (#35477046) Journal

      Limited availability of silicon?

      On this planet?

      Not bloody likely.

      The limiting factor will be the limited availability of the production facilities, not the raw materials.

      • by Isaac-1 (233099)

        Ok, processed material may be a better choice of words here, in the case of silicon the problem is often lack of purity.

        • by mark-t (151149)
          If raw material supply is not a limiting factor, but processed material supply is, then that entirely simplifies to limitations on the availability of the facilities that produce the material in a processed form. Which is what I had said.
    • by arcite (661011)
      Run out of silicon?????
    • by ShooterNeo (555040) on Monday March 14, 2011 @03:28AM (#35477080)

      Source? You can pick them up for $0.98 a watt right now, or $1.76/watt for a complete system. Go to sunelec.com for where I found some. Are you telling me these prices were lower 6 years ago? I doubt it.

      • by Isaac-1 (233099)

        I admit I had not checked the prices at Sunelec lately which seem to have came down since the last time I checked about 6 months ago (a great company to buy from), I bought a 55 watt Evergreen brand glass front panel from them in 2004 for about $2.25 per watt which is less than similar size panels are selling for now ( try checking their prices for any panel under 100 watts most are in the $2.75 - $3.75, larger panels may be cheaper per watt now). Now if you think bigger is always better, it depends on you

        • For very small orders, shipping and transaction costs are going to be much larger than for bigger orders. Sunelec would rather sell you $5200 worth of panels in one order than just over $100 in one order. Doesn't change facts, though : the cost per unit of capacity of solar is WAY down, enough so that it is practical for more and more applications.

          And the recent disaster in Japan shows something : Nuclear power plants are very dangerous, and the cost to make them reasonably safe makes them so expensive th

          • by Kokuyo (549451)

            WHICH nuclear power plants?

            Seriously, people... there's more than one way to generate power from nuclear fission.

    • by Anonymous Coward on Monday March 14, 2011 @03:31AM (#35477094)

      Solar panels cost more per watt now than 5 years ago, and their lowest cost per watt was about 6-7 years ago.

      Not true. See, for example this data [solarbuzz.com]

    • by DamonHD (794830)

      Not on this planet, and particularly not in the UK and US.

      http://solarbuzz.com/facts-and-figures/retail-price-environment/module-prices [solarbuzz.com]

      Rgds

      Damon

  • Wow. Has it been a month already, since the last amazing breakthrough I heard about, concerning solar panels. Seems like i've been hearing stories like this since the late 90's. And, yet I still cant afford them. Sure, they are in my calculators... They are not in my car nor my house, nor any other car or house I see. I live in a pretty average middle-class neighborhood. What gives? I must have read over 30 articles like this in the last 5 years. (One every two months, I know) Why do I see rolls o
    • by DamonHD (794830)

      Sure, apathy is a great leveller. But if you put PV on your roof then there will be some on your neighbourhood.

      While you've been musing, PV prices have been falling, and GWp have been installed worldwide.

      I still don't own a car: does that prove that cars are useless and unchanging?

      Rgds

      Damon

      • Thats a nice off-topic dance you did around my points. I found a nice little article to bakc me up here. "At, say $10 a watt, you're looking at a $46,000 cost for a very small solar power system. " http://www.ehow.com/about_5347941_average-put-solar-panels-house.html [ehow.com]
        No date on when this estimate was made. :(

        "I still don't own a car: does that prove that cars are useless and unchanging?" Do you see new cars on your way to work or in your neighborhood? Do you see them changing and improving? My perso
        • by DamonHD (794830)

          No, I'm hitting your points on the head IMHO.

          I still "can't afford" a car. I decided that PV was more important to me over the last few years for example. And yes I see PV going up on roofs around me (and I'm working to make it happen faster).

          Typical install cost of a typical 2.5kWp installation in the UK is now ~£10,000, which would probably be not far off $10,000 in the US like-for-like. That system will deliver about 50% of typical UK household's electricity consumption BTW, so you might have to

  • by vvaduva (859950) on Monday March 14, 2011 @09:08AM (#35478230)

    You know, I've been hearing these kinds of announcements from the solar panel industry for over 5 years now. Revolutionary technologies, breakthrough announcements...blah blah blah. Costs have not gone down substantially and I still haven't seen anyone breaking the $1/watt barrier, not unless you buy the panels by the pallet. I will believe them when they deliver.

    • People are just spoiled by integrated circuit scaling, and get bored with regular technologies that don't get exponentially cheaper and better. I'm here to tell you that we will never see some great giant leap in solar cell performance or price like some people expect.There is limited room for improvement in solar cell efficiency because currently available cells output close to the theoretical limit that is possible for a solar cell to output (same order of magnitude at least). Even if you doubled the area
  • Kind of funny reading the debate on whether solar is finally ready for prime time since I see it dam near everywhere here in Germany. The country is pumping A BILLION euros per MONTH into solar installations. http://en.wikipedia.org/wiki/Solar_power_in_Germany [wikipedia.org] Pretty impressive what an economy unencumbered by a couple foreign wars can afford to invest in. Enjoy.

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