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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.
  • 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.
  • 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 darkmeridian ( 119044 ) <> 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.

  • 3*? (Score:1, Insightful)

    by redGiraffe ( 189625 ) on Friday March 20, 2009 @03:00AM (#27265561) Homepage

    three times less expensive - is that the same as a third of the cost?

    I'm not being a grammar nazi, just doesn't make sense (its morning here after a late night, so maybe the synapses haven't whatevered).

  • 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.
  • by Anonymous Coward on Friday March 20, 2009 @03:37AM (#27265683)

    "burn down your house when one cell short circuits or your getting a bit more sun then imagined"

    What? I challenge you to document s SINGLE case of a solar cell catching fire, let alone burning down someone's house.
    Seriously. your scare tactics mark you as an industry shill.

  • 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 abigsmurf ( 919188 ) on Friday March 20, 2009 @04:46AM (#27265913)

    Anything that generates a fair amount of power is a potential fire risk without well designed and maintained circuits. A bad bit of soldering will cause sparking, uneven power generation between cells risks current reversal (which capacitors and batteries love) without well thought out circuit design.

    There are many ways a bad solar panel setup could start a fire, especially if you're dealing with potentially damaged cells that have been removed by someone who knows little about circuitry.

    Your 'label critisism as being evil big oil person' tactics mark you as an idiot.

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

    by jacquesm ( 154384 ) <> 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.

  • by Hognoxious ( 631665 ) on Friday March 20, 2009 @05:36AM (#27266073) Homepage Journal

    But in both those cases they're second hand, rejects, or both. So the hysterical "OMG we're being ripped off 3x" in the summary is bullshit.

  • Re:Once again... (Score:4, Insightful)

    by Hognoxious ( 631665 ) on Friday March 20, 2009 @05:39AM (#27266085) Homepage Journal
    Someone who knows what he's doing's labour is cheaper, because he knows what he's doing. Regards, A Smith.
  • by MadMidnightBomber ( 894759 ) on Friday March 20, 2009 @06:01AM (#27266151)

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

  • by Anonymous Coward on Friday March 20, 2009 @06:43AM (#27266317)

    Yes and i can easily say that i bred a Pig and a Horse and out came a Giraffasaurus Rex, but you don't see people believing me.

    Documented proof: video, pictures, text isn't enough.

  • by risom ( 1400035 ) on Friday March 20, 2009 @07:12AM (#27266415) Homepage

    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?

  • by Anonymous Coward on Friday March 20, 2009 @07:32AM (#27266491)

    You are talking crap. Instead of embarrassing yourself further, why don't you stop spouting rubbish and spend 60 seconds looking up what voltage solar panels actually generate, then consider what p.d. you need to get these scary sparks you are fabricating.

  • 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?

  • Re:Once again... (Score:3, Insightful)

    by pla ( 258480 ) on Friday March 20, 2009 @08:29AM (#27266785) Journal
    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 into a $20k finished product. I can't, however, afford the $20k directly to buy the pre-finished project.

    So yes, time has value, but until the day the worms have my eyes for lunch, I have little doubt I'll have far more of the former than the latter.
  • by TheRaven64 ( 641858 ) on Friday March 20, 2009 @08:37AM (#27266843) Journal
    I haven't looked for a while, but you used to be able to buy solar cells very cheaply from reputable sources (the same ones that sold expensive cells and lots of other fun equipment) if you didn't mind irregular shapes and sizes (and therefore irregular outputs). Cells are (were? I don't think this is true with the latest fabrication techniques) made in circular wafers, like microchips, and sold in squares. The off-cuts were sold very cheaply and were great for home electronics projects where you had more surface area than you needed for the cells.
  • 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.
  • by Zeromous ( 668365 ) on Friday March 20, 2009 @09:32AM (#27267317) Homepage

    an electrical spark is pretty useless for starting a fire without ample combustible gas, or surface area.

    I'd be more concerned about my circuit working than catching fire in such a case.

    This is not to say one shouldn't be careful. But this burning down the house business is a quite an exaggeration. You'd have to have a helluva a short!

  • 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.

  • 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.

  • 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.


  • The problem isn't so much just one single cell, but a whole series of panels that when combined result in some fairly significant current.

    The grandparent post here about concern with the circuit design is completely valid here and deserves much more consideration when trying to design something proper for connecting to a household power supply as opposed to something you might design for a simply hobby experiment for running a consumer electronic device.

    I am assuming here that setting up an installation for a home is going to involve hundreds if not thousands of cells. Each one by themselves is trivial, but the point is to try and connect all of them together into a combined power supply. This is a similar issue to amateur electricians who put together an amazing Christmas light display without thinking about things like current draw on the outlet designed for ordinary consumer appliances. Sure, a single strand of lights is trivial, but the 40 or so that you have put together makes it a significant power issue.

    Even something so mundane as if you are connecting the circuits in series or in parallel (or in various combinations of that) make a huge difference in the design. I certainly see somebody being able to wire together cells of this nature where the voltage potential is in the thousands of volts if done improperly, or forgetting to use the proper wire gauge for something that can carry the current load necessary at that point in the circuit. Burning down the house is hardly an exaggeration if you really think this through.

  • 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 is lemma 1.1. We start a new chapter so the numbers all go back to one." -- Prof. Seager, C&O 351