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DIY Solar Resources? 311

Posted by kdawson
from the bright-idea dept.
TihSon writes "I'm building a large shed out back and I want to power the lighting using a surplus solar panel. In searching for information on how to go about this, I have found a lot of rough DIY guides for various projects that are close to my goal. But none seem to explain the reasoning and theory behind using solar panels, so hacking their project to suit my own needs could be pretty much hit-and-miss. I don't want to do a hacked-up job, and future solar projects are not out of the question, so something a bit more in-depth is required. Do you have suggestions for books or Web sites you have used to learn the ins and outs of using solar panels? Something that starts with basic theory and ends with the ability to wire a house would be perfect."
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DIY Solar Resources?

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  • Well? (Score:5, Funny)

    by Anonymous Coward on Saturday June 21, 2008 @07:00PM (#23889545)
    I someone please shed some light on this issue.
    • by seanadams.com (463190) * on Saturday June 21, 2008 @10:30PM (#23890841) Homepage


      Shed lighting is pretty easy because the power requirement and the duty cycle (on vs off time) will be low, and you don't need voltage regulation. That means all you need is a largeish 12V battery (preferably rated for "deep cycle"), and a modest 12V solar panel of maybe 2-3 square feet. Test with a small setup first, and then if you want more run time (from a fully charged battery) add another battery. For more duty cycle, add another panel.

      Hook the panel to the battery with a diode in series, and then hook 12V lighting (eg track lighting minus the transformer) to the battery, and you're done. Solar panels are inherently quite compatible with lead-acid charging requirements, so you don't even need charge circuitry for a small setup such as this.

      If you want to power a small 110V device, you can use an inverter. You won't be running a table saw on one of those though.

      • by cnaumann (466328) on Sunday June 22, 2008 @02:19AM (#23892017)

        That is a good basic plan. The 'open circuit' voltage of the panel needs to be around 18V to charge a 12V battery. 12V CF lighting is available from a number of vendors, I would highly recommend it over 12V halogen track lighting:

        http://store.altenergystore.com/Lighting-Fans/Compact-Fluorescent/Compact-Fluorescent-Bulb-12V-7W/p1003/?source=froogle

        I don't really like these 12V bulbs that screw into a normal 120V socket, but what are you going to do...

        I would also suggest skylights. There is really no point is converting light to electricity and back to light.

        Honda also makes some super quiet generators that are less of a pita than solar.

      • by burni (930725) on Sunday June 22, 2008 @05:01AM (#23892623)
        I have to correct some things,

        1.) no voltage regulation

        a.) is bad because the more current you draw from a pv-panel the less voltage you will get thus you cannot charge a battery with
        (your solution is by adding a diode to prevent this)

        so a pv-battery charger and monitor is highly recommend, because lead-acid batteries need to be watched carefully you can ruin them by discharging them to their least.

        b.) pv-cells have no linear characteristic, not keeping this in mind will lead to a lower effeciency, they have a
        MPP - Maximum Power Point[1], the characteristics are mostly supplied with the datasheets,
        also the MPP is given. So using voltage regulation you can draw more power from the cells as you could otherwise.

        [1] http://en.wikipedia.org/wiki/Maximum_power_point_tracker
      • by expatriot (903070) on Sunday June 22, 2008 @05:54AM (#23892801)
        I sure the parent and many slashdoters understand basic electricity, but I want to warn against just connecting a marine battery and charger together.
        Improper use of these can, and have, cause fires, acid explosions, and serious burns from shorting a high current supply.

        DO NOT DO THIS UNLESS YOU ARE REALLY SURE YOU UNDERSTAND WHAT YOU ARE DOING.
    • Re:Well? (Score:5, Funny)

      by CopaceticOpus (965603) on Sunday June 22, 2008 @02:52AM (#23892133)

      Everyone is missing the obvious here. Simply remove the roof, and the sun will light the interior directly.

  • No, no, no (Score:3, Insightful)

    by gnuman99 (746007) on Saturday June 21, 2008 @07:04PM (#23889579)

    DIY project for wiring your house? Yeah, if you wish to invalidate your insurance and burn down your house. You need to properly wire the stuff. And if you can't figure it out, you can't do it with instructions properly either.

    Want to use solar that maximizes your bang for the dollar? Want a DYI project? Invest in some thermal solar cells, you can even make them yourself. Then you can heat your hot water or even heat your house if you have wanter radiant heating (geothermal heatpump augmented with solar cells - saves oodles of cash). And thermal solar panels are 95%+ efficient, not the 20% or something like that for electrical systems.

    • by ScrewMaster (602015) on Saturday June 21, 2008 @07:08PM (#23889595)
      Want a DYI project?

      I presume you meant a "Do Yourself In" project, which is what usually happens when people who don't know what they're doing attempt to rewire their homes.
    • Re: (Score:2, Insightful)

      by Anonymous Coward

      Wiring is not hard. Talk of burning your house down is pure hyperbole.

      • Re: (Score:3, Informative)

        by Anonymous Coward

        There are lots of little things with wiring that can have serious consequences. Where to put the ground? Please not too near a metal anything especially pipe. Why? It'll accelerate corrosion. Possibly greatly. You can screw up your neighborhood's cable this way too.

        There are fire risks for improperly installed wiring as well. Or just improper choice of materials. In a house there are other concerns such as fumes given off if cabling ends up in a fire irreguardless of what precipitated it. Builing c

        • Re:No, no, no (Score:5, Informative)

          by Fjandr (66656) on Saturday June 21, 2008 @08:21PM (#23890091) Homepage Journal

          There are lots of little things with wiring that can have serious consequences.

          No, there really aren't. There are a few little things and a few big things, and very few of them are arcane. Electrical systems in a typical residence are neither rocket science nor magic. A relatively good primer for residential electrical systems for a typical homeowner would be B&D Complete Guide to Home Wiring [amazon.com].

          Where to put the ground? Please not too near a metal anything especially pipe. Why? It'll accelerate corrosion. Possibly greatly. You can screw up your neighborhood's cable this way too.

          Please, please tell me you're not an electrician, nor are studying to become one. Either you WAY oversimplified to the point of making your statement meaningless or you know nothing about the ways galvanic reactions are mitigated in residential wiring. Any text on residential wiring will mention the problems and the very simple ways to avoid them ever becoming an issue.

          You're right though, there are fire risks if you don't take any care with your wiring practices. Good wiring practices are amazingly simple to learn. That said, most homeowners I'm aware of who undertake electrical work for themselves do not ever bother to do so.

          virtual impossibility of knowing all the minutia of one's own particular circumstance

          This statement is a crock. Residential wiring is pretty straightforward for anyone willing to crack any number of simplified wiring books. Solar systems are relatively straightforward as well. I'm honestly not sure why the submitter believes that any number of other project descriptions could not be adapted to a solar shed, unless they plan on tying it into something else at a later date.

          However, and it's a big one, solar intertie systems can be enormously complicated. If the submitter is planning on later tying the solar system in a shed to one in a house, said person is going about things bass-ackwards. An intertie needs to be planned from the ground up, or the likelihood of large (and costly) problems shoots through the roof.

          Many things need to be answered right from the start. Am I installing a system tied to the power grid? A backup system not tied to the grid? Are there going to be batteries involved? Do I plan to convert to AC, and if so do I need clean sine-wave power? Can my charge controller handle the potential expansion of solar panels? Can additional inverters and/or charge controllers be added to the system without a great deal of hassle should the initially chosen models not handle panel additions? Am I just planning to run dedicated DC lighting circuits? These answers should take into account future plans to expand the system, as picking one particular route and then later making substantial changes to the upgrade path can dramatically increase equipment expenses.

          Depending on the complexity of the situation and whether the DIYer actually intends to acquire the knowledge necessary to execute high-quality, functionally correct work, professional help may or may not be necessary.

          • Re:No, no, no (Score:5, Informative)

            by chuckjuhl (828094) on Saturday June 21, 2008 @09:59PM (#23890683)

            Don't know where you live, but in most areas of the U.S. you legally need a permit and an inspection to perform any electrical work on residential wiring. When I say "any", I mean even down to installing an outlet or changing any type of fixed fixture. Most areas require all electrical work to be in accordance with the N.E.C. and /or the I.E.C. Further, most jurisdictions require that the person doing the residential electrical work have a valid Electrician's license. Some jurisdictions allow a homeowner to do their own electrical work, but only on their own dwelling and not on properties they own that they rent to tenants. In many jurisdictions performing unauthorized and/or unlicensed electrical work is a crime, punishable by fine and/or imprisonment.

            As a licensed Master Electrician and former County building inspector, I can state with great confidence that simply reading a book such as "B&D Complete Guide to Home wiring" does not render one competent to undertake even moderately complex residential wiring projects. As I have witnessed, even seemingly straightforward tasks like stripping wires and using wire nuts can have devastating consequences when performed improperly.

            To advocate that an unlicensed and inexperienced homeowner take on this type of project without adequate, licensed professional supervision is irresponsible in the extreme. No licensed electrician would advocate such irresponsible and potentially hazardous course of conduct.

            • Re: (Score:3, Interesting)

              by russotto (537200)

              Don't know where you live, but in most areas of the U.S. you legally need a permit and an inspection to perform any electrical work on residential wiring. When I say "any", I mean even down to installing an outlet or changing any type of fixed fixture.

              Only state I've ever heard of that nonsense actually being enforced is Florida. What, should we go crying to Mommy Government or her anointed and licensed representatives every time we need to change a light bulb?

              To advocate that an unlicensed and inexperien

            • Re:No, no, no (Score:5, Insightful)

              by c6gunner (950153) on Saturday June 21, 2008 @10:49PM (#23890977)

              As I have witnessed, even seemingly straightforward tasks like stripping wires and using wire nuts can have devastating consequences when performed improperly.

              To advocate that an unlicensed and inexperienced homeowner take on this type of project without adequate, licensed professional supervision is irresponsible in the extreme. No licensed electrician would advocate such irresponsible and potentially hazardous course of conduct.

              Yes, and I'm sure that no licenced car mechanic would ever advocate that you do your own car repair and maintenance. Guess what - the last time I took my car to a "professional" to have new tires put on, the retard over-torqued the lugnuts so much that they warped my rotors.

              What did I learn from the experience? That since there's no way for a layman to tell good professionals from bad "professionals", you may as well skip them altogether and do the work yourself. It's either that or go and pay another guy from a totally different company to check over the first guy's work.

            • Re: (Score:3, Insightful)

              by Fjandr (66656)

              You might be surprised how many people don't give a rat's behind about permits. Or maybe not.

              To advocate that an unlicensed and inexperienced homeowner take on this type of project without adequate, licensed professional supervision is irresponsible in the extreme. No licensed electrician would advocate such irresponsible and potentially hazardous course of conduct.

              Most of my response to this can be summed up by re-reading the last section of the post you replied to. I also noted in my post that most homeow

    • Re: (Score:3, Interesting)

      by mrbluze (1034940)

      DIY project for wiring your house? Yeah, if you wish to invalidate your insurance and burn down your house.

      Nobody is saying you have to do it at AC 110V (or 240V / 220V). AFAIK running 12V or 24V cabling through your house does not require an electrician, and to achieve low resistance you can use T-bars or other large metal structures (or just some automotive copper) for return currents to avoid voltage drops, or alternatively transport the energy via AC/240V (might need professional work for that).

      Just have smaller, cheaper inverters at specific locations for the high voltage/AC appliances such as fridges, c

      • Re:No, no, no (Score:4, Interesting)

        by ScrewMaster (602015) on Saturday June 21, 2008 @08:05PM (#23890005)
        Low voltage power wiring can be more dangerous than regular 115/220 VAC. If a circuit is shorted the I2R losses will much greater. For example, I have a Hawker 6FV11 12V 105 AH battery that runs my sump pumps. It's capable of dumping tens of thousands of amperes across a dead short: if that ever happened the results would be Biblical. I took a number of precautions when building that system, one of which was to have 200 amp fuses mounted directly to the battery terminals and covered in heat-shrink tubing. Big battery arrays are dangerous, make no mistake. A neophyte is better off getting a book on home wiring and learning how to handle conduit and junction boxes rather than fooling around with a battery bank that's more dangerous than a tank full of gasoline.
      • by BLKMGK (34057)

        With enough amperage even 12volt wiring can start a fire. Don't think so? Go short the terminals on your car battery sometime...

      • Re: (Score:3, Informative)

        by Fjandr (66656)

        DC cabling is not going to be adequate to carry residential loads. While you could hack together a cheap system, you'll get the quality that you pay for.

        While I honestly couldn't care less if homeowners do so without permits, most jurisdictions do require electrical permits and inspections for installing DC systems. The "burn down your house" is hyperbole, but if you have homeowner's insurance you'll likely need to comply with permitting requirements. In the event of a fire or other damage as a result of wi

      • Re:No, no, no (Score:5, Insightful)

        by evilviper (135110) on Saturday June 21, 2008 @08:42PM (#23890213) Journal

        Nobody is saying you have to do it at AC 110V (or 240V / 220V). AFAIK running 12V or 24V cabling through your house does not require an electrician

        The fact that you think low current 120/240v is dangerous, but very high current 12/24V is safe, throughly proves the point that you do NOT understand electricity, and should certainly NOT be giving advice to others.

        and to achieve low resistance you can use T-bars or other large metal structures (or just some automotive copper)

        With amateur-installed T-Bars, I would fully expect the frame of your house to start slowly roasting itself in short order, if you're lucky, and not using quite enough current, it might not catch fire until the next heavy rain.

        Automotive cables are designed to carry the current of ONE small car battery over just a meter or perhaps two. Drawing power from multiple batteries, or over much longer distances, and those cables will be getting very hot. It won't take long for the insulation to melt off, and start cooking adjacent objects.

    • Re:No, no, no (Score:4, Informative)

      by Vectronic (1221470) on Saturday June 21, 2008 @07:27PM (#23889713)

      But he doesn't seem to want to wire his house... "I'm building a large shed out back and I want to power the lighting..." or even bother with other electrical devices, nevermind water.

      I'd have to agree, and other people have mentioned this already, use LED type lighting, this negates stuff like inversion to get 115/220 volts, etc. and requires far less power in the first places, which means less solar panels, less batteries, probably less wiring, and LEDs last longer than incandescent, and provide better lighting than neon.

      • by Fjandr (66656)

        Something that starts with basic theory and ends with the ability to wire a house would be perfect.

        RTFS? :)

    • by robertjw (728654)
      Wiring is not rocket science. There is no reason a person cannot get instructions, educate himself and do it properly. No one should just 'figure it out'. Electricians are trained an licensed to do their job - they aren't born with the skill.

      In my community, it's perfectly legal for a homeowner to complete work to their house as long as they pull a permit and have the work inspected. If this is an option (check your local laws) it's a good way to make sure you don't burn anything down. The inspector
  • 2 words Home Power (Score:5, Informative)

    by SubComdTaco (1199449) on Saturday June 21, 2008 @07:08PM (#23889597)
    Home Power is what you want to look at. http://www.homepower.com/home/ [homepower.com]
    • by BLKMGK (34057)

      Amen! This magazine can be found at many good bookstores and subscriptions aren't too bad either. This is an invaluable source of information on ways to save money and power IMO. I do wish they would bring back their guerrilla power features though :-)

    1. Dashboard solar panel intended to boost a car battery $50 AUD
    2. Car Battery
    3. 12V Light fittings intended for a caravan or similar
    • by jeiler (1106393)

      You forgot "4. Profit!!!"

      Seriously, there is one other thing to remember--a skylight. What good is it to run even "green" electricity in the daytime if you have sunlight available for the job?

    • by robertjw (728654)

      1. Dashboard solar panel intended to boost a car battery $50 AUD
      2. Car Battery
      3. 12V Light fittings intended for a caravan or similar
      Interesting. Purchasing a car battery is expensive (both up front and every 3-5 years when you have to replace it), plus environmentally bad. The battery will likely offset any gains to be had from the solar installation itself.
      • Interesting. Purchasing a car battery is expensive (both up front and every 3-5 years when you have to replace it), plus environmentally bad. The battery will likely offset any gains to be had from the solar installation itself.

        He could use a battery from a car with a dead cell. Lights will still work at 10V. A new battery should last more than five years. A cheap battery where I live is about the same price as the solar cell, and the application is not particularly demanding.

        You could always use a gell cell in place of the lead acid battery.

      • by peragrin (659227)

        but it is a requirement in any pure solar system. what happens when you want to turn the lights on at night? a Pure Solar system fails. You need a storage system for it. On the plus side with a steady charge, a small motorcycle battery will last 6-7 years powering a shed's lights.

        Batteries are going to be standard in all solar systems, until Ultra Capacitors become a reality. Who ever figures out how to mass build ultra capacitors will be billionaires. Once Ultra Capacitors begin to work. you can use

      • by karnal (22275)

        Is there any other technology battery-wise for a project like this that is feasable?

        I have done some basic looking at solar, and everyone seems to use lead acid banks. Similar to what's in UPSs. I can vouch that these batteries usually don't last more than 5 years in my own UPS equipment, and anything after the 5 year mark if they do last, the minute you need them they'll proabably fail.

      • by BLKMGK (34057)

        Properly disposed of and recycled I'd argue that lead cells aren't nearly so bad. Throwing them in the trash on the other hand would NOT be a good idea....

    • by xaxa (988988) on Saturday June 21, 2008 @07:55PM (#23889949)

      1. Dashboard solar panel intended to boost a car battery $50 AUD
      2. Car Battery
      3. 12V Light fittings intended for a caravan or similar
      No, not a car battery. Get a caravan battery (or one with a similar intended use). Car batteries are designed for high current draws for a short period of time, and draining them reduces their lifetime significantly. Caravan batteries are designed to be drained, and to have a low current draw.
    • by BLKMGK (34057)

      Not nearly enough amperage to power anything with these - I know because I have a couple. You might get AN LED or two going but not nearly enough to be happy. You could use these to recharge a couple of 12 volt batteries that would provide you with more amps for more LEDs but I do not think those panels have much in the way of protection from overcharging nor would there be protection from drawing the batteries down too far which will damage them. The panels are really just designed to help keep a charge wh

  • The Otherpower forum (Score:5, Informative)

    by knarf (34928) on Saturday June 21, 2008 @07:12PM (#23889637) Homepage
    Try the Otherpower forum. Not just solar but other independent power generation forms as well:
    • by BLKMGK (34057)

      Oh yeah! Great source for strong magnets too! Those guys do some really cool stuff but sadly I'm not located where I can do any of it myself. Their waterwheels in particular interest me since that's pretty steady power. Look into the Indian and other knockoff slow speed diesels for some really cool reading. They can be run on bio too but sadly it looks like importing them is no longer so easy due to recent emission constraints :-( One of those in the garage would ROCK for power outages!

  • Do-it-yourself solar is pretty simple, in theory. In practice, it's not easy to gather enough hydrogen in an empty area of space. Darned stuff keeps spreading out whenever you turn your back to get another batch.
  • ... you've got clouds and rain and much less than 12 hours of sunshine available on any given day year round.

    Check out the wind instead. Generators can produce power in very low winds if you've got the right windmill (the ones that look like upright cylinders seem best, not the big blades).

    Don't limit yourself to 110v, think about 12v and 24v DC lighting systems and battery storage and you'll be amazed at the inexpensive, 24/7, energy producing capabilities of the wind.

    I'd toss a few

    • Re: (Score:3, Informative)

      by MichaelSmith (789609)

      ... you've got clouds and rain and much less than 12 hours of sunshine available on any given day year round.

      It depends on where you are.

      At the Equator: solar

      At the Poles: wind

      In between: combination of the two
    • Re: (Score:3, Informative)

      by BLKMGK (34057)

      Sorry but axial generators are NOT an ideal solution at all - very inefficient. You will also find that your neighbors may not like you putting up a tower that sits so high above the surrounding trees - as it must in order to get clean air and be free of debris. On top of that the cost of the crane required to loft many of these is expensive. Add to that the fact that not *many* areas get enough wind to be useful and you'll find that wind isn't too great - especially for just a shed!

      This isn't the best char

  • by Original Replica (908688) on Saturday June 21, 2008 @07:19PM (#23889673) Journal
    I know a bit about solar from the perspective of a cruising sailboat, in that scenario you would take a 12V solar panel, some deep cycle 12v batteries (car battery would work) and a charge controller, connect solar panel thru the charge controller to the batteries and you are done. Everything on a boat is 12VDC lights, radio, etc so running straight from battery power is easy. You could get a inverter for regular 120VAC, but it consumes your battery charge fairly quickly. For learning the parts and functions on the cheap (solar stuff can be expensive) I would suggest taking apart a solar sidewalk light [aquasuperstore.com] and extending the wires to put the light inside your shed, and the little solar panel on the roof. To make good use of a larger solar panel you will need a larger battery bank, and probably a better charge controller. What is the output of the solar panel you want to use?
    • Re: (Score:3, Interesting)

      by cptdondo (59460)

      Look at RV sources as well; same stuff as marine, but 1/10 the price.

      One major caveat: a car battery will *not* work for this. A car battery is designed to provide very high current for a limited length of time, the exact opposite of a solar system need. A car battery will fail quickly in this application.

      You want deep cycle batteries; google for trojan batteries.

  • Do you need 120VAC, or can you go with low-voltage? Going with low-voltage, driving LED lights directly from the battery will probably help with efficiency over incandescent driven by an inverter, but I'm not sure about direct-drive of LEDs vs inverter-driven CFLs. For 120VAC, you may have to hire an electrician to comply with local laws. Either way, you'll need a charge controller to properly manage the current flowing from the panel(s) into the battery and to the lights.

    The Solar Living Institute (a cou

  • For your shed, presumably the reason you're thinking of solar is because you don't have AC wiring going out to it, which means you're talking about a non-grid-tied system. This raises some issues. (1) Running wiring from your house out to the shed is probably much cheaper and easier than doing solar and getting 110 V AC just in the shed. (2) A non-grid-tied system is actually a more complex, expensive, and and difficult project than a grid-tied system. You'd need a battery and a charging system. The batter

  • by Slugster (635830) on Saturday June 21, 2008 @07:43PM (#23889853)
    Generally speaking, if you already have on-site utility power, that's going to be cheaper over the long run than solar cells.

    But say you just want to do it 'cause it's nifty? One web forum is
    http://www.solarpowerforum.net/forumVB/ [solarpowerforum.net]

    You can set up a solar panel to charge a car battery, and run small things off that. Basically it goes like this: solar panel->battery regulator->battery->invertor-> small-wattage wall current appliance. Alternately, you can use 12-volt RV lights that can be run straight off the battery; there's LED lights now that don't draw squat for power. The battery regulator is a necessary device that prevents the batteries from overcharging.

    ...About that "wiring a house" business... There's not a lot of people out there who have solar+battery storage systems to run all the junk in their houses, 24 hours a day. Most of the residential systems (in the US) use solar panels with no storage batteries, the solar panels instead feed back into the electrical grid, which gets you credit off your electricity usage but usually not your total electricity bill (you still have to pay the line maintenance charge and the natural gas charge, if it exists).

    The only states where these are common is southern California and Arizona, with Nevada and New Mexico being two more possible candidates. It takes a lot of sun before solar panels are even financially worth considering. Also,,, Cali and Arizona have the biggest gov't rebate programs--and if it weren't for that, NOBODY there would have a solar setup. For what they cost, it simply wouldn't make sense.

    Because solar systems are so expensive, most people who want a whole-house system start by building a house that is as energy-efficient as practically possible.... So you see, there's no way to do this cheaply. Either you spend a lot of money to build a new house, or you spend a lot of money on the greater amount of solar panels to run a "typical" house off of.

    ...And even having done that, solar cells are generally not considered "cheaper" than utility power, even over the long-term. It will cost very close to what 30 years of utility bills would have totaled. What you get with a whole-house setup is--you're basically paying your 30 years of utility bills "up front", and you aren't dependent upon the utility company's reliability.

    In certain circumstances, a solar+battery setup can be cheaper than utility power. If you buy very remote property that is literally miles from the nearest power line, the fee that the power company may charge to extend the line to your property can run into the tens of thousands of dollars.
    In this rare instance, it can be cheaper to go solar.

    ------

    When I eventually move to the desert, I'd like to play with using some solar panels to run an air-cooling setup. Using solar power to run air conditioning in the desert just makes sense, and I don't know what else I'd run every day. Will probably try Peltiers first; I know their poor efficiency but the mechanical and electrical simplicity makes them attractive for a stand-alone setup, and easy to try on a small scale. In particular--they can be run basically straight off a battery, and need no invertor. The 3-phase invertor and the amount of solar panels you'd need to run a good-sized room air conditioner would cost six or seven thousand dollars, at least.
    ~
  • just steal a bunch of those ugly little garden lights. i'm sure that with those, a roll of duct tape and some speaker wire, you could figure a way to rig something up.

  • Seeing this question and various responses makes me sad. I've seen this song and dance repeated time after time. Don't forget to queue the people who keep trying to cram a kitchen sink into everything. ("Why not use wind?", "Better leave this to the professionals!", "It's as easy as 1, 2, ...1536. Profit!")

    Photovoltaic technology has been around for decades, and yet manufacturing a simple solar cell to trickle out a couple of watts is regarded as black magic, wrapped in ignorance, surrounded by controver
  • Try using a skylight. i.e. a hole or plexi-glass covered hole in the ceiling. Then, cover the rest of the shed's roof with solar panels to generate DC for charging 12V deep cycle lead acid batteries. Then use 12V droplight at night.

  • Me too (Score:5, Interesting)

    by HeyLaughingBoy (182206) on Saturday June 21, 2008 @09:31PM (#23890529)

    Oddly enough, I'm doing the same thing: in fact I just came back inside after a day of building.
    I'm building a coop for my ducks & chickens and am going to light it with power LEDs & surplus solar cells and perhaps keep the water liquid this winter using solar heating.

    Solar cells are pretty straightfoward. Just think of them as batteries and you won't be too far off.

    PM me if you want to run some ideas by me. I am an EE and I've done enough design work that this should be trivial. I'm also making my first attempt at a blog: http://softwarefromthefarm.blogspot.com/ [blogspot.com]

  • by dnight (153296) <dnight@lakkado[ ]om ['o.c' in gap]> on Saturday June 21, 2008 @09:31PM (#23890531)

    I recommend you check out "Home Power". It's a magazine dedicated to off-grid power production (solar, wind etc). It's a good read, very informative, and has a lot of good printed links to various resources.

    It's about $4 an issue.

    I dodn't work for them, but I love to read that mag.

  • by o1d5ch001 (648087) on Saturday June 21, 2008 @10:35PM (#23890859) Journal

    Since becoming a ham several months ago, I started learning all about batteries and 12V power and while I was at some solar energy stuff. Starting with a shed project is a great idea. I am assuming you are looking to light things, not run a planer.

    Oh yeah, treat all large batteries like they are bombs ready to go off. Store them outside, and if it gets below 0C then you might have to figure out how to keep them warm. Good luck with that.

  • by zogger (617870) on Sunday June 22, 2008 @11:39AM (#23894663) Homepage Journal

    Plenty of folks here have solar PV experience, several guys run whole house systems.

    Steps: Determine your mount, do you want a roof mount? Most likely. They make those you can buy, or you can fabricate your own, just starting out go ahead and get the mount from the same place you buy your panel. but make it accessible enough on the roof so that a few times a year you can access it and adjust the angle relative to the sun. This is determined by your latitude, you can find maps online that address this. Seat of the pants,this works just as good, once a season (solstices and equinoxes, 4 times a year in other words) go out exactly at noon, adjust the panel so that it perpendicular/flat to the sun.

    The panel itself will have a metal frame with a grounding hole indicated. You need to install a grounding rod at the shed base, big fun, you'll develop manly man muscles hammering that bad boy in. Here's a hint, dig a hole where you want the rod to go (after first determining you are *not* going to hit a waterline or some other underground man made obstruction of course, common sense rules there), soak that hole with a bucket of water (that gives you an idea on the size of the hole to dig, something that can take a few gallons and sit there and soak in) periodically for a couple days before hammering in the rod. Man it makes it much easier. Where you buy the rod, they will have grounding wire and a connector clamp. You'll need a nice maul to get it going, a normal hammer would be possible but I don't recommend it. alternatively a fence post pounder, maybe you can borrow one. Lowes/ Home Despot have all of that. At the panel frame, just a good stout bolt with lockwashers and regular washers is adequate for the ground wire. For lead wire, welding cable you can buy off the roll by the foot is good enough for your shed needs, and your run won't be that long anyway most likely. Conversely you can use exterior grade house wiring, again, by the foot. that is more resistant to sunlight/water/whatever. If you want or need by code conduit, again, cheap plastic pipe at the store and glue and a hacksaw and some clamp mount action.

    Next you need to run the raw output of your panel to a charge controller (those ship with wiring diagrams as well), then the feed from there will go to your battery. If you are using a smallish panel it will nominally output 0VDC at night with no visible moon to around 17 (maybe higher) or so VDC at high noon on high summer day. The charge controller adjusts this, better quality ones monitor the charge going to the battery and adjust as it is needed for optimum charging, which is a three stage process of voltage regulation. It will shut itself off when the battery is full, indicated by the colored lights on the controller (some have a little LCD panel with interesting little things to look at ;)). If you find yourself with extra juice potential (I bet you do) by early afternoon, lucky you, you can add an additional battery in parallel if you want that juice. I am a big fan of having lager than what you think you might need battery action, more and bigger. Makes them last longer.

    For battery or batteries, now your choices get varied depending on needs, but rule of thumb with batteries after all is said and done and all the marketing BS is out of the way is you are buying lead by the pound. that's it. More lead, more stored juice. Your cheapest solution is a normal 12 volt "trolling" motor battery they sell for boaters and fishermen. Those batteries are designed to run a trolling motor for hours, they should be sufficient for your modest lighting needs. You'll need ring connectors for your lead wires, attachment is straight up, positive and negative. Next step up would be two 6VDC batteries, or golf cart batteries. Those get wired in series to give you your 12, then in turn are wired from the controller output, on one battery it is the negative, on the other it is the positive. the two others are connected battery to battery, that is your series connection. To keep it sim

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