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Hardware Hacking Power Build

Building Your Own Solar Panel In the Garage 235

jeroen8 writes "A Dutch guy was able to build his own solar panel in his garage using materials that were a third as expensive as the mass produced solar panels currently available on the European market. He bought his solar cells on eBay and used them to create his own panel. His output price is only 1.20 Euro per Watt Peak (Wp). This makes you wonder if we are paying too much for mass-produced solar panels, which should, in theory, be a lot less expensive than something you create in your garage."
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Building Your Own Solar Panel In the Garage

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  • by TheLink ( 130905 ) on Friday March 20, 2009 @02:11AM (#27265393) Journal
    If they aren't brand new the reason why it's cheaper is because someone else has paid for much of it.
    • by Anonymous Coward on Friday March 20, 2009 @03:16AM (#27265629)
      I am fairly (95%) certain that these Cells have been stolen, probably by a person working at a solar cell manufacturing plant.
      Getting an 'uncounted' batch of 'mixed quality' just screams 'stolen'.. and then the price itself is also cheaper then the raw manufacturing

      But they are 'new', extracting Cells from used panels is not cost effective as commercial panels are laminated and string soldered which is very hard to take apart without breaking most of the cells.

      Also, when you buy good quality Solar Panels you usually get around 25 years of warranty and the knowledge that they have been throughly safety tested (and designed) so that they won't burn down your house when one cell short circuits or your getting a bit more sun then imagined. I would think that's worth something by itself.
      • Re: (Score:3, Informative)

        by i'm lost ( 1247580 )

        Screwed up moderating, posting to fix.

      • by Vectronic ( 1221470 ) on Friday March 20, 2009 @04:11AM (#27265793)

        "Getting an 'uncounted' batch of 'mixed quality' just screams 'stolen'"

        Not necessarily, "In October 2008 I bought my first 100 cells via Ebay.", "...I found another seller on Ebay who had the same cells ... But these were slightly damaged."

        The first set, could have been someone who bought them, to use as a weekend project sort of thing, but never got around to it, gave up, or moved, "the wife wants these things out of the garage, now!"... the second, being "slightly damaged" may have come from the reverse, a building that was torn down, or upgraded to newer/larger cells, or even something like those various solar car races, they did good, got a sponsor, ditched the clumsy setup they were using, or as someone else pointed out, factory rejects, or possibly damaged in shipping, thus having no warranty, can no longer be sold in a typical commercial way...

      • by mcgrew ( 92797 )

        I am fairly (95%) certain that the parent AC knows they're stolen, as he's the one that stole them! ;

        But they are 'new', extracting Cells from used panels is not cost effective as commercial panels are laminated and string soldered which is very hard to take apart without breaking most of the cells

        You would be surprised what a nerd can do with utter junk. When I was a teenager I would take used transistor radios that cost $10 new and turn thsm into guitar fuzzboxes for a heifty profit; the music store sold

    • It could be even cheaper. Imagine if he used these []!
      • That's a wicked cool hack (hacking donuts!). I can't read the voltmeter at the end. How much power is that (maybe 1cm^2) cell putting out?

        • by neomunk ( 913773 )

          It looks like the meter is topping out at around 40 microamps. I don't know the voltage, so I can't tell you the power.

    • by Mr Z ( 6791 ) on Friday March 20, 2009 @10:59AM (#27268467) Homepage Journal

      I came here to say something along these lines. Just because someone got a good deal on eBay and so his project ended up being cheaper than a mass produced panel doesn't mean that one can mass produce panels cheaply just by buying everything on eBay to solder in your garage.

      Either this guy got stuff that "fell off the back of a truck," or got lucky and paid less than what they were worth to a distressed seller. There's no good reason to believe that his experience is reproducible on any large scale. There was no innovative manufacturing process here.

      Now, if he'd figured out how to make the actual cells in his garage for cheaper than we can in a proper fab, that'd be a big breakthrough, particularly if he didn't run afoul of the local environmental authorities while doing so. Alas, making solar cells generally involves such fun things as arsenic or selenium and such, not to mention industrial solvents for etching, and those aren't the friendliest chemicals to play with.


  • Once again... (Score:5, Insightful)

    by ddrueding80 ( 1091191 ) * on Friday March 20, 2009 @02:11AM (#27265395)
    Only cheaper if your time is worth nothing. Still, very cool. But not particularly novel or groundbreaking.
    • Re:Once again... (Score:5, Insightful)

      by jacquesm ( 154384 ) <j&ww,com> on Friday March 20, 2009 @04:55AM (#27265931) Homepage

      The folks at [] have been doing this for years. The bigger problems are the sealing of the cells and the fact that since these are most likely rejects the cells might nog give their rated power.

      The article summary is dead wrong in suggesting that this is somehow proof that solar cells could be produced cheaper, these cells have probably been hijacked on the way to the recycler.

      'making' a solar panel in your garage does not start off with buying solar cells and hooking them up, it starts with sand.

      • Re:Once again... (Score:5, Informative)

        by jabithew ( 1340853 ) on Friday March 20, 2009 @05:15AM (#27265977)

        You could not make silicon in your garage. At least, not in any reasonable garage. The reduction of quartz by carbon only takes place at over 1800K. Then you have a pool of molten silicon full of crap, which you now have to purify to 99.9999% purity for it to be ready to dope and use. This is also not easy.

        I think what the guy has done is reasonably impressive given the inherent limitations.

      • Re:Once again... (Score:5, Insightful)

        by Ironsides ( 739422 ) on Friday March 20, 2009 @09:05AM (#27267073) Homepage Journal
        I think I've got another reason why these cells are so 'cheap'. He's extracting 15.5w with all of those panels combined. Lets say that is 1/4 meter^2, he gets 62w per meter^2. The expensive solar panels they compare it to get 240w per meter^2 (20% efficiency). Power density costs money.
        • Money Per Watt (Score:4, Insightful)

          by Doc Ruby ( 173196 ) on Friday March 20, 2009 @10:29AM (#27268031) Homepage Journal

          Power density costs money, but is it necessary? Maybe his panels do get only 25% the watts per square meter as an expensive panel. But they get something like 3x the watts per dollar. To get the same wattage, you do need 4x the area with his cheap panels. But since solar power in the Netherlands is about 100W:m^2 [] average across the year, a 1KW home gets in 10m^2 sunlight its consumption (before cell inefficiency, and using inefficient storage/retrieval HW). If he's actually getting 62W:m^2, he needs 16.2m^2. If that gets averaged by day/night, and is close to the average daylight (he posted 2 days before the equinox), and accounts for weather, then maybe he needs 200m^2 (that's 5% averaged annual efficiency). That's only 14x14m, about the size of a home that consumes 1KW.

          When roof space costs more than these cheap cells save, they're worth the higher cost. Or if the generated power can be sold back to the grid, then the higher density can be worth the higher cost (especially over time). But sometimes, cheap low density can be worth it. Which is why dye sensitized and other cheap, (relatively) inefficient generating materials are interesting. If they can generate power long enough to pay for themselves (including their lifecycle energy cost), they can make "hay" while the Sun shines, even as we make more dense cells become cheaper.

    • Re:Once again... (Score:5, Informative)

      by Lumpy ( 12016 ) on Friday March 20, 2009 @07:43AM (#27266537) Homepage

      Exactly Home Power had an article on how to do exactly what this guy did over 4 years ago.

      Some random guy does it in a garage and blogs about it and all of a sudden it's news.

      Guess what, the best deal I found is actually Harbor Freight. They have Solar array kits for very low price, lower than me buying reject cells and building a panel. [] 45W for $199US is cheap. I have 3 of those kits on my garage that supplies all my lighting and power needs out there including the garage door opener. (No I am not using their inverter/charger I'm using a real one)

      yes that includes me counting my labor as free.

      • Which inverter/charger do you use?

        Also, your time is ALWAYS worth something, it can be quantified. Sometimes evaluating the worth of your time can yield some surprising values. For example, building your solar solution was worth more than doing nothing; already you have made a value decision. Of course, if a stripper were to perform in your driveway, you would have stopped working on the solar panel. therefore, well, you get the idea of evaluating worth of personal time spent doing something.

      • by mcgrew ( 92797 )

        If you enjoy what you're doing then "your free labor" is a bargain to you. Bowling is physical work that some people get paid for but I don't see anyone complaining that when they go bowling their labor is free, they'll actually PAY to do this labor.

    • Re: (Score:3, Insightful)

      by pla ( 258480 )
      Only cheaper if your time is worth nothing.

      Why does someone always have to point that out in every single thread about DIY projects?

      Yes, we all know that "DIY" means spending time on the project. And yes, we all know that our time has value (I would even argue we each have a far more limited supply of time than (potentially) of money).

      But in the real world, with a realistic exchange of time for money (I don't work for AIG, dontchaknow), I can afford to spend 30 hours turning $2,000 worth of supplies
  • by Anonymous Coward on Friday March 20, 2009 @02:11AM (#27265399)

    I don't think it's that uncommon for used goods to cost less than new goods.

  • by im_thatoneguy ( 819432 ) on Friday March 20, 2009 @02:12AM (#27265403)

    Wow you mean to tell me if I buy factory defect products that carry no warranty on ebay I can save money!? I never knew! It seems as if the Dutch have found the secret to inexpensive solar power: Factories should ONLY produce bent and dent cells!

  • by Anonymous Coward on Friday March 20, 2009 @02:12AM (#27265405)

    I would've built it outside, but to each his own.

  • by fractoid ( 1076465 ) on Friday March 20, 2009 @02:14AM (#27265415) Homepage
    The main costs in solar array manufacturing are manpower, raw structural materials, and the solar cells. Remember that the prices for single solar cells are fairly constant, given that they're mass produced already. Same for the structural materials. That leaves (Cells + Materials) on the hobbyist's side and (Cells + Materials + Labour) on the mass production side. It's not surprising that a hobbyist can construct a panel for a competitive price if he doesn't count his time as a cost.
    • by Sandbags ( 964742 ) on Friday March 20, 2009 @08:01AM (#27266635) Journal

      I can't think of too many things I CAN'T assemble in my garrage for significantly cheaper than buying a complete unit. Computers, car repair, kitchen cabinets, pretty much anything that can be purchased as a set of parts is cheaper than buying an assembled unit. Why?

      - No labor included in price
      - No warranty included in price
      - Individual parts sold seperately are usually overstock or minor "defects"
      - Many parts sold online are parts no longer actively being produced
      - Assembled systems are stoced only for sale, parts are stocked for multiple reasons, meaning more efficient warehousing...
      - typically, no middle man. the vendor you buy a widget from is usually the 3rd or 4th company in line, parts can be acquired direct or through a flooring company, eliminating at least 1 tier of markup.

      Now, that said, it's obvious that some parts, especially commonly replaced wear parts, are highly profitable. Some items actually cost more to build from parts. In the case of solar panels, a lot of the components aside from the cells are very common items that can be found for deep discounts. (Wires, boarder metal, backing, etc). If the cells are readily availible, it;s not terribly complicated to assemble.

      What I'd like to see is:
      1: How does his home made panel compare to one manufactured with the same cells
      2: How many more cells/panels did he need to get full coverage (100% aggregate 24 hour power) vs professional panels, and does a typical roof have enough room to handle that?
      2: Over 15-20 years, what will he expect in maintanance and repair costs that would normally have been warantied
      3: Over 20 years, what's the actual difference in cost (factoring in comparative performance)
      4: What tax valuation was he granted and how much did his home value increase due the adding home made panels vs produced panels?
      5: How many house did he put into this?
      6: was he able to roll the cost under a mortgage of equity loan like I could do with a local reseller?

      Just saving the cash up front, even if you considder the labor a non-issue (or even rewarding), does not mean this is a good idea. It actually has to show 20 year savings as well. He may have saved on the panel cost, but he can't save on the electrical panels, the inverters, and the other components required to make solar panels actually work. I'd like to know how that factored into his cost. Did he also hire an electrician or has he a certified electrical contractor that could wire his own house (most of us are NOT, and would incurr substantial installation fees).

      • Very good points, I'd amend my post if I could to mention that as you said, this holds true for any home-assembled product made out of parts that are sold in sufficient numbers to warrant high volume production in their own right.

        Also the part about a registered electrician is a very good point - as with connecting deep-cycle 12v batteries up to form a battery pack for an electric vehicle, it's very possible to rapidly get into lethal voltage territory with just a few off-the-shelf parts. If you're dealin
  • Yeah, it's easy to build things cheap when you get the components cheap.

  • by darkmeridian ( 119044 ) <william,chuang&gmail,com> on Friday March 20, 2009 @02:34AM (#27265481) Homepage

    The author bought damaged solar cells from eBay, selected the good ones, then soldered those together. Then he jury-rigged his own waterproof casing and electrical connections. Used goods are cheaper but that does not mean new ones are over-priced.

    Let us know how long his cells last outside before insinuating all the solar cell producers in the world are selling overpriced gear.

  • by NixieBunny ( 859050 ) on Friday March 20, 2009 @02:36AM (#27265491) Homepage

    ...but you've only paid for the parts, not the labor or the engineering or the rent etc.

    The point that the packaging of solar panels is expensive is not lost on me. There's a local firm (Tucson) making thin-film cells which ought to be packaged as plastic-laminated roof shingles to keep the final cost down.

    But I admire his fortitude in building a panel. I have a stack of cells in my workshop that I don't see how I'll ever turn into a panel, since it requires lots of glass and care and sticky tape.

  • by bugnuts ( 94678 ) on Friday March 20, 2009 @02:53AM (#27265531) Journal

    Panels today have a usable lifespan of over 25 years.

    They have the proper connectors, and the appropriate gauge wire. They can handle 50mph hailstones and 90mph wind, and they're all UL listed. They're warranteed, usually for 20+ years. Some are hybrid (sandwiching amorphous Si and crystalline Si), which gather more light and produces more power per sq foot, something that can't currently be made in the garage.

    Purchased panels also cost about 3x the price of doing it yourself (maybe $4-6 /watt). However, I would strongly bet that the overall cost of ownership will be higher for DIY folks, who can't compete with the quality of fully-assembled panels. They will have to make their own mountable panels, and doing that right will not be cheap. They will have to be able to handle high winds and weather, too. And the UL listing will also mean that you can be grid-tied, since the utility companies won't allow you to connect non-UL-listed generating stations to the grid.

    Some cool things you can do with DIY panels is get exactly the shape you want. You can also add more bypass diodes to handle partial shading better. One of the biggest issues with PV panels is the significant drop in output with only minor amounts of shade.... A single leaf stuck over part of a cell can reduce the panel's output by 25%. But if you DIY, you can put many more bypass diodes into it, causing a much smaller fraction lost. You can even mount it on some sort of heat sink or antifreeze-filled copper plating to get better performance (PV cells work better when cool.)

    It's a cool project. But if you're trying to save money over the long term, DIY is probably not the way to go.

    • You can even mount it on some sort of heat sink or antifreeze-filled copper plating to get better performance (PV cells work better when cool.)

      If you're going to the trouble of doing that, it makes sense to transfer that heat to the hot water system. Say a pre-heating system on the hot water cylinder input, for example.

    • Re: (Score:3, Interesting)

      I saw a lot about wanting to have 20 or 25 years warranty on the panels you buy and that's quite sensible. But aren't we all just better off waiting 5 years, or ten years and paying the same amount of money for 10 times the power production, thereby in the long run generating far more energy from solar and ultimately reducing our carbon footprint by a greater amount despite starting later.

      Worrying about a 25 year warranty seems a bit daft when in a few years we can expect a panel a fraction of the size to

      • That's the general hardware upgrade cycle problem that we see everywhere, given the current speed at which technology moves. No matter when you buy, you know that a couple years later you could've gotten way more for your money. Eventually you've gotta just take the plunge. Today I could buy an 52" LCD television for a few hundred bucks less than I spent on a comparable quality 46" set eighteen months ago. Such is life.

        The people taking the plunge now are helping to drive the demand and fund the improvement

      • by khallow ( 566160 )

        But aren't we all just better off waiting 5 years, or ten years and paying the same amount of money for 10 times the power production

        No. You don't know that this level of cost reduction is possible. And you don't enjoy the benefits (such as they are) of solar cells while you are waiting.

        • No, he could have a point.

          I remember ten years ago reading an article somewhere about large-scale computing problems. One piece of advice they gave: if you have a problem that will take ten years to solve on today's hardware, wait two years to buy the computers. Then it would only take seven years to solve.

          Cost per installed watt of solar has been dropping by about half every six years, pretty much since photovoltaics were invented. If you take those numbers as law, then yeah, over the life of the syste

  • by wjh31 ( 1372867 ) on Friday March 20, 2009 @03:52AM (#27265729) Homepage
    for most people, im not sure that is the tricky bit, nor sticking it between some glass. I, and id suggest a fair few other people would stumble at figureing out how to connect this pannel to the grid in my home to make use of the electricity it generates. Would anyone be able to shed any light on this end of things?
  • by worip ( 1463581 ) on Friday March 20, 2009 @03:54AM (#27265737)
    The panel in the article produced 17 Watts, for a panel size of about 1m x 0.5m (approximated from photo with mobile phone in it). A quick google reveals a 43W polycrystalline panel of similar size for about 300 euros (about 7euros/watt peak)
  • by Sam Lowry ( 254040 ) on Friday March 20, 2009 @05:30AM (#27266051)

    The story is about the Europe where governments subsidise the solar panel use by giving enormous tax cuts to the buyers of solar panels and even going as far as providing 0-interest credits.

    This insane amount of state intervention spawns corruption in the production and supply of the solar panels, which explains such high prices.

    • Re: (Score:3, Insightful)

      Sorry, of course the US would never subsidise alternative energy sources []. It's only evil socialist Europe that does that.

    • Re: (Score:3, Insightful)

      by risom ( 1400035 )

      This insane amount of state intervention spawns corruption in the production and supply of the solar panels, which explains such high prices.

      [citation needed]

      Really, I know that "state intervention == inefficient" is a popular meme in the US of A, but is there any scientific proof of your assumption?

      • Really, I know that "state intervention == inefficient" is a popular meme in the US of A, but is there any scientific proof of your assumption?

        It's an unreflected-upon article of faith, which explains why it is so popular among the Republican party. Half the Republicans believe in Jesus and the free-market (both on faith). The other half look down their noses at those who believe in Jesus on faith, and instead channel all their irrational and love towards the free market.

        Of course, while a belief in the s

    • by pbhj ( 607776 )

      The story is about the Europe

      Did you mean "teh 3urope"?

  • Here's mine without any attention paid to weatherproofing. []
    And I just delivered two to high school in Africa for their science class last week.
    Video on the way.

  • "is three times less expensive than mass produced solar panels"... Hmmm. If it was "one time less expensive", it'd be free, so if it was *THREE* times less expensive, does that mean he got paid twice the normal cost? I think that probably means to read "one third the cost". Why can't Johnny do math?
  • by pz ( 113803 ) on Friday March 20, 2009 @08:08AM (#27266669) Journal

    The summary is bad.

    1. He bought damaged solar cells from a one-time vendor. There isn't a supply of them for anyone to make. They might have been stolen, they might have been a shipping write-off, whatever. They aren't new solar cells.

    2. He scrounged materials, like glass, for free. Manufacturers can't do that. Most people don't have that opportunity.

    3. He used wire that he "happened to have" (quoting the article). He bought it at some point, or found it. Again, not something you or I could normally do.

    And so forth. Comparing the cost of doing something this way to buying a new cell is invalid and misleading. The summary is bad. And the Slashdot editors are responsible for validating and endorsing the summary, suggesting that they were asleep at the wheel.

    Sheesh, can't we get some decent editing here? Has the entire field of news reporting gone to the dogs?

  • I notice in the two pictures of completed panels that there is significant reflection coming off the front-side glass. That sucks, because any light being reflected off the glass is light that can't be converted to solar power. Although it may not seem like a lot - glass being mostly transparent and all - it can cut down on your overall efficiency by a few percentage points. Commercially available solar panels (for residential and industrial use, anyway) use tempered glass with an anti-reflective coating
    • by confused one ( 671304 ) on Friday March 20, 2009 @09:43AM (#27267459)

      Right, he complained about the cost of the glass the panel manufacturer's use, then he uses cheap window glass pulled out of a trash heap. It's not tempered. It's not anti-reflective. It's not matched to the absorption spectrum of the cells...

      There's nothing to see here. Let me know when someone figures out how to make the cells, cheap, in their garage workshop.

  • Buys Solar Cells? (Score:3, Insightful)

    by nurb432 ( 527695 ) on Friday March 20, 2009 @11:31AM (#27268909) Homepage Journal

    So he really didn't build anything, he assembled something. Come back when he actually builds the cells too.THAT would be news worthy.

  • This project has been done before but this one is a good read for those that have the skills, time & patience.

    It can be much cheaper to build this panel yourself over buying one from a regular solar panel manufacturer as you will not be paying them for the labor or markup on materials. This noted, it will also take quite a bit of your time to put one together. But the flip side is that you can then brag about this accomplishment and the relati

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