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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 icebike ( 68054 ) on Friday March 20, 2009 @02:45AM (#27265509)

    So if a production one costs 10 dollars, 3 time 10 is $30,

    Then, because its less, we have to subtract his costs of $30 from the production cost of $10, it costs him minus 20 dollars to build each one?

    You mean it was 1/3 the cost of a production unit.

    There is no such thing as "3 times less" of anything.

  • 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.

  • by ChameleonDave ( 1041178 ) on Friday March 20, 2009 @02:56AM (#27265543) Homepage

    So if a production one costs 10 dollars, 3 time 10 is $30,

    Then, because its less, we have to subtract his costs of $30 from the production cost of $10, it costs him minus 20 dollars to build each one?

    You mean it was 1/3 the cost of a production unit.

    There is no such thing as "3 times less" of anything.

    So, you're saying that "3 times less" means you get "3 times" and then subtract it. By that logic, "3 times more" would mean you get "3 times" and then add it. So, "3 times more" than $10 would be $40.

    This alone should be enough to make you realise that your usage of the terminology is idiosyncratic. In normal English, "3 times more" means you multiple by 3, and "3 times less" means you divide by 3. It is totally unambiguous. It may be colloquial English usage, but it is not incorrect.

  • by i'm lost ( 1247580 ) on Friday March 20, 2009 @03:22AM (#27265647)

    Screwed up moderating, posting to fix.

  • by nedlohs ( 1335013 ) on Friday March 20, 2009 @03:24AM (#27265651)

    Maybe you could try learning some English?

    Yes it's a phase not liked by some people, but it's been used for hundreds of years and anyone who isn't being an idiot understands what it means.

    Google actually has the Merriam-Webster's dictionary of English usage half page on it: []

    They are slightly more polite than me, but you can feel the "those commentators are idiots" between the lines...

  • 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 Vectronic ( 1221470 ) on Friday March 20, 2009 @04:30AM (#27265859)

    Or a lack of market, it's the same as any new(ish) product really, cars 120 years ago were expensive because they were all low-production, then mass manufacturing came in, prices dropped because they were suddenly everywhere, but the newest of the new was always 10x the price of the basic ones... computers, same thing 80 years ago, expensive as hell, because they were all custom, companies may have only made 3 of them a year, now they make thousands a year because there is a market for them, drives down the price, but the newest of the new is still 10x more than the basic...

    You can go down to Radio Shack (if they still existed) and buy a bunch of little cells for a couple dollars, because they are everywhere, there's probably like 3 or 4 of them in your house right now, calculator, weatherproof radio, battery recharger, etc... you can buy those for like 50 cents a piece, but they are useless to power your house, you'd have to cover your entire roof, garage, and neighbours house with them for it to work.

    Once the company (or people in general) realizes there is a market/use for them, they'll spend the time + money to establish a facility to build them in bulk, with 100 machines, instead of just the 3 machines they are using now, this demand drives down the prices of the materials they need to build them, which drives down the prices of mining the materials, they figure out better/quicker packaging, they establish stable shipping routes, etc etc etc... the faster it's going, the less force needed to keep it there, like pushing someone on a swing, first few pushes are hard, once they are swinging, you can keep them swinging with a pinky push...

  • 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.

  • Grammar (Score:1, Informative)

    by Anonymous Coward on Friday March 20, 2009 @05:18AM (#27265985)

    "This makes you wonder if we are NOT paying too much for mass-produced solar panels"... I'm sorry that is really bugging the shit out of me since jeroen8 doesn't know basic grammar. I think he was attempting to go for the common phrase "are we not ___" but instead ended up asking the question in negative. So now your question is backward, meaning a reply of Yes actually means No: "Yes, we are NOT paying too much" instead of "we are paying too much". And btw darkmeridian, there is no such word as 'jury'-rigged

  • by Anonymous Coward on Friday March 20, 2009 @06:27AM (#27266255)
    post as AC next time. it'll remove your modding and won't open you up to overzealous moderators, discouraging proper moderation.
  • 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.

  • by AstrumPreliator ( 708436 ) on Friday March 20, 2009 @07:45AM (#27266551)
    Did you even try googling it? Here, I found one [].

    Including the Simi Valley fire, there have been four incidences of fires in California linked to solar panels, Kateley said. One was caused by a homeowner-installed panel, she noted. 'It does happen' ... "It's a rare occasion, but like any kind of electricity there are going to be instances where it does happen," Dowd said.

    Yes it's rare, but that doesn't mean it can't happen if either the solar panel was made or installed improperly. I'm not quite sure how you were modded Insightful when you're clearly an idiot.

  • by Anonymous Coward on Friday March 20, 2009 @07:54AM (#27266591)

    Well a photovoltaic cell is like diode, if it (for some reason) isn't generating electricity then the electricity of the other cells will attempt to flow through it in reverse, causing the cell to heat up in spots (not evenly). The heat build up can be enough to shatter glass (due to uneven thermal expansion and the stress it causes within the glass) but could certainly also set something flammable ablaze.

    That's why commercial panels usually have some additional diodes to redirect (at least part) of the current in such a case. This builder didn't mention anything like that so i would expect he didn't have such precaution hence i believe the expressed worry is justified.

    Also, for reference, you can expect 1000 Watt / Square meter in direct sunlight, at 15% efficiency that's still 150 Watt. That's certainly enough power to cause a fire.

  • by interested pyro ( 1499899 ) on Friday March 20, 2009 @08:02AM (#27266643)
    remember, red goes to positive, black goes to negative.....
  • by Anonymous Coward on Friday March 20, 2009 @10:05AM (#27267715)

    Those panels come with the dioide integrated into the plug section. If what you say occurred, you or someone else physically removed the diode. I have two of those flexible panels and if anything, they run cooler than rigid panels normally. Did you ship the unit back to unisolar so they could determine what happened? I know the flexi panels don't have the real long term warranty of the rigid panels (only 3 years IIRC), but still, I bet they would like to look at it.

  • Re:Grammar (Score:3, Informative)

    by mcgrew ( 92797 ) on Friday March 20, 2009 @10:19AM (#27267883) Homepage Journal

    And btw darkmeridian, there is no such word as 'jury'-rigged

    Princeton University disagrees with you. []

    Language changes; the original phrase (now pretty much abhored by everyone) was "nigger-rigged", which was actually from the gear slave owners let slaves use; construction and repairs were haphazard, since it was "only" the slaves who would use it.

    In WWII it was changed to "Jerry-rigged", also a slur as the Germans were known as "jerrys".

    After the war was over "Jerry" in that context was meaningless, but juries were rigged by mobsters, which had pretty much the same effect on society as jerry-rigging a piece of machinery was to the machinery.

  • by Anonymous Coward on Friday March 20, 2009 @10:20AM (#27267901)

    Maybe *you* should quit embarrasing yourself.

              Sparking? I wouldn't see the sparks themselves as a problem, unless you have a gas leak or stored gasoline around your panels. The heat's the problem. But if you did have that bad a solder joint it would be the hottest spot in the system, and easily hot enough to catch fire.

              By your argument, laptop batteries should NEVER explode or flame out -- the voltage, it's too low. Oh they did? That's a shame.

              It doesn't matter if the voltage is low.. a 65 watt light bulb can start a fire. And that's not due to voltage, a 65W (12 volt) car headlight gets just as hot as a 65W (120V) house bulb. If your panel is then making 65 watts of output, with improper wiring a portion could get as hot as that lightbulb filament, and catch fire. In fact, in general for carrying a given amount of watts, low voltage at higher amperage generates *more* heat in the wiring compared to high voltage/low amperage. You ALSO have at least one large battery in the mix, which of course could also heat up *and* vent hydrogen depending on the battery type.

              A simple experiment (probably should do outside) -- try shorting a 9V battery, or even a AAA. This is MUCH lower total power than that solar panel. It WILL get too hot to touch.

              Not saying any of this is common. But of course it could happen if the wiring is improper.

Experience varies directly with equipment ruined.