DIY Solar Resources?

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."

Comments

Well?

[Anonymous Coward]

I someone please shed some light on this issue.

Re:Well?

[ehrichweiss]

I didn't read it as the pv panels were the sink but rather the synchronous power inverters were at fault. And there are companies like nanosolar that are getting 1 Kw per Kg of solar material, IIRC their technology doesn't require the "panels" to track the sun and they're working toward $1/watt pretty quickly.

But then there's thermal energy derived from the sun and there are nearly limitless possibilities there since the development of that carbon nanotube material that absorbs 99.8% of all light that hits it. I imagine that in many parts of the country that could be converted to heat water, create steam and drive turbines, or the new stirling engine technology if it's getting along, or even just store it underground for later use. Then one could combine that technology with the brilliant idea where they essentially put the solar-thermal collector in a vacuum so that the heat couldn't boil back off of the collector and it instead got passed quickly away to an insulated tank. It was viable over 10 months out of the year and even worked on cloudy days. I'm sure it was posted here a while back.

Re:Well?

[Heembo]

I'm glad to see you quote Nanosolar. That is the company to watch. A few years back most solar R&D went into 2 camps - one camp tried to advance the underlying solar technology and mostly failed. Another camp went the route of just trying to fine-tune manufacturing (to reduce cost for mass production). That's where Nanosolar comes in. The technology behind Nanosolar in terms of energy creation is old news - but the fine tuning in the manufacturing process (super cheap "plain air" facilities) is what is so stellar about the company. Their thin-film solar panel stock is currently sold out until 2009 since several large municipal solar power generation plants bought their stock already.

Re:Well?

[Score Whore]

They're not energy sinks. They're financial sinks.

The analysis makes the premise that every penny spent on energy will be spent on energy regardless of source. This is false. Some people are willing to pay extra for energy from a specific source that they value more. Think of it as a sunglasses budget: someone might spend $300 for a pair of hand made Italian sunglasses, but if they couldn't get those specific hand made Italian glasses, they won't go and buy 100 pair of the $3.00 special on the counter at Seven Eleven.

Re:Well?

[Ex-MislTech]

Converting from DC to AC wastes power, stay DC and use LED
lights because some have life spans and power usage that is
lower any other kind.

The only draw back on LED is it costs a fair bit more up front.

The good news is you could use a cheaper/smaller battery, and
don't have to pay for an inverter at all.

At some point LEDs for lighting will go mainstream and mass
produced and the cost will start to fall.

http://en.wikipedia.org/wiki/LED_lighting

For daytime lighting of the shed you might try to make
your own Solatube.

http://en.wikipedia.org/wiki/Light_tube

Re:Well?

[CopaceticOpus]

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

Re:Well?

[CAIMLAS]

So basically, what you're saying is this: that solar power is just about image.

Whether you say that solar power costs more per watt or that solar power wattage is more expensive due to increased energy requirements at the production side, the net result is the same.

Re:Well?

[Score Whore]

No it's not about image (well for some it may be, but the same can be said about anything.) I'm saying it's about more than just getting energy. For some people, they know that their grid is supplied primarily via coal power. Which, even with all the technology available to us, is still quite dirty. I know it may come as a surprise to you, but some people prefer not to shit in their drinking water, both literally and analogously. Maybe they're willing to pay a little extra to reduce their impact.

I'm not sure what you are saying in your second paragraph. I don't think it has anything to do with Don's article. You might want to take the time to read it before you start blathering about what assume it says. (I'll give you a hint: it doesn't make the claim that it takes more energy to build a solar PV system than you get from that same system. Because, you know, that's not true either.)

The point of the linked analysis was that for a given number of dollars you can generate more power via other mechanisms than you can with solar PV. Then concludes that therefore it is a net energy loss because less is generated than could have been for the same money. Which is false. A person buying a $10,000 solar PV system isn't cutting down their energy usage because it costs more for them, they're using the same amount of energy, just paying more.

He's right in that, for a lot of people, it's not economically sensible. But he's wrong in making any kind of connection between the generating costs of various sources and a gain or loss of actual energy.

Re:Well?

[eugene ts wong]

Also, solar panels might allow a person/group to set up an energy source that is far away from the grid. The cost of bringing out batteries, of power cables, or of generators would be too expensive, I assume. Solar energy would have to be cheaper in those situations.

Re:Well?

[Zebra_X]

"one camp tried to advance the underlying solar technology and mostly failed."

That is simply not true at all. December 6, 2006 http://www.boeing.com/ids/news/2006/q4/061206b_nr.html. 40% is nothing to scoff at, and it does use a different underlying technology.

Nanosolar has done great things - but to say that advancements in underlying solar technolgy have not been made in recent years is in accurate.

Nanosolar is also the only company that I know of that has fundamentally streamlined the solar panel production process.

Re:Well?

[berashith]

i have a greenhouse that needs new power run to it. An aerial line would just be flat ugly, an trenching requires removing a ton of concrete and several possible code violations. Solar for me is a near perfect fix, and the extra costs of the panels are a wash with the labor that could be involved. Then there is a plus that I can run other things from the greenhouse, and depending on efficiency, I may move some battery chargers to that system for more "free" energy.

There are some applications where solar is just best.

Re:Well?

[bjohnson]

Then they should license the fucking patents to someone who WILL manufacture for the consumer. The problem with their approach is that solar energy is actually MORE efficient in a decentralized production environment. Solar power stations for utility monopolies are inefficient, compared to solar panels on every roof.

Re:Well?

[spoco2]

Yeah, that'd work wonders at nighttime.

Because you _never_ do work in a shed at nighttime.

No, no, no

[gnuman99]

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.

Re:No, no, no

[ScrewMaster]

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:No, no, no

[Anonymous Coward]

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

Re:No, no, no

[mrbluze]

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, computers etc.

Re:No, no, no

[Vectronic]

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.

Re:No, no, no

[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 codes exist for a reason. The 1 in 10 occurances are obvious enough and easily avoided, it's the non-intuitive 1 in 10,000 occurences that take a little foresight. With 100s of thousands at stake for millions of home owners, and the virtual impossibility of knowing all the minutia of one's own particular circumstance, best to go with building code safe as opposed to back of cocktail napkin sorry.

That said: A solar shed is probably pretty straight forward. You know the voltage you want, get battery configuration that will give the amount of stored current you want, and set it up for the voltage you desire, and just run the shed off a properly installed and secured stack of batteries with the solar charging them. They probably have a weekend workshop at a Home Depot or Lowes that would get one at least half way there.

As another person above states that's not the biggest bang for the buck, but it's certainly doable as a little project.

Re:No, no, no

[ScrewMaster]

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.

Re:No, no, no

[Fjandr]

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.

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

[Fjandr]

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 wiring, your insurance may not pay even if the work you did played no role in the damage to the structure.

Using small, cheap inverters at point-of-use is going to introduce problems. For one thing, the power produced by cheap inverters is by no means high quality. Most cheap inverters produce modified sine-wave power, which can be problematic for certain appliances (computers, battery chargers, A/V electronics, some electrical appliance motors). You're unlikely to be able to find out whether a particular appliance is affected until after you plug it in. Another problem is that transporting DC at lower voltages means you need conductors larger than a typical AC run would require for the same distance. I'm not sure if you've checked copper prices recently, but it adds up pretty quickly.

For an AC-DC system, the best-practice route would be to install one or more inverters at the location of the mains entrance to the house. This allows for typical residential AC wiring practices to be used, which vastly simplify the situation. It'll save time, money, and headaches in the long run, though the system will initially be a fair bit more expensive. Even an on-the-cheap installation is really anything but cheap.

Re:No, no, no

[evilviper]

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

[wellingj]

All Americans suck because they attempt to rewire their homes.

Re:No, no, no

[chuckjuhl]

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:No, no, no

[russotto]

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 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.

Of course no licensed electrician would do so; when people do their own work it means less money for licensed electricians. Never mind that if you want to do anything even slightly unusual that no licensed electrician will touch it anyway. Building codes are all about "do it the way it has always been done, that has been worked out to be safest over the years"; they may prevent injury, but they also completely kill any sort of innovation.

Re:No, no, no

[c6gunner]

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:No, no, no

[fast turtle]

AFAIK running 12V or 24V cabling through your house does not require an electrician.... Depends on your local laws. Where I live - Solar Power is a viable alternative and yes any PV system has to meet minimum Federal Electrical Standards for DC systems. Furthermore, it's quite easy to overload standard 12volt Automotive grade wire with a PV panel if the amperage is high enough. The big question to ask is how many amps of 14-18 volts is being output by the panel or is the panel configured for 24volt operation (28-32 volt output).

Making a blanket statement as you did tends to result in severe cases of "Foot in Mouth" disease. FYI a 50watt 12v PV panel requires a minimum of 8ga wire to connect to the busbar while a 200watt panel requires at least (4)0 wire (quad aught) to handle the amperage it can easily output and most PV panels over the 150watt rating are configured for 24v output.

Now depending on what the OP wants to do with the PV system is going to determine what he needs. If it's simply lighting for a shed, then the issue is even simpler. Get a small PV powered light unit (Brinkman/Others) from the local Home Improvement Center or order it online and use it to light the shed. If it's anything more then lighting, then you need to consider appropriate wire gauge to minimize voltage drops, Purchasing of DC rated switches (standard household switches aren't safe due to arcing).

In regards to the 120/240 AC voltages, you're actually better off putting the Inverters near the batteries and running standard house wiring because of safety factors. We're damn familiar with AC power and there's plenty of standards to follow when working with it. PV systems with high amp DC circuits are very dangerous Common Automotive Batteries can output in excess of 1200A when the posts are shorted, so you damn well better protect those batteries.

Right now the best solution would be to head over to Mr Solar where you can find plenty of PV related equipment and kits for numerous projects.

Re:No, no, no

[Fjandr]

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 homeowner wiring I've had the "pleasure" to encounter showed that they clearly cared nothing for learning to perform high-quality work (at least I believe it was this post, I'm feeling lazy and am not going to go back and read it to be sure). This is a bad thing, and the only way to attempt to rectify it is through education.

I also never claimed that an inexperienced person should attempt to tackle an entire house from the start, or even a moderately complex project. Since this is ostensibly a homeowner working on their own residence, the "unlicensed" portion has no relevance. It tends to be implied. Most jurisdictions that are not in major metropolitan areas or otherwise heavily restrictive states do allow homeowners to perform their own permitted work. Providing a starting point should this person choose to not go the professional route is vastly more responsible than taking the "no sex before marriage, we won't even discuss the possibility that you might" approach. It doesn't work, and pointing someone in the direction of an informed decision has a much higher likelihood of success than refusing to even contemplate the possibility that they might choose a route you disagree with (or which is illegal). The people to be scared of are those who don't bother asking and just do it.

Your credentials may allow you to discuss with relative authority matters pertaining to electrical work, but they obviously haven't done much for insight into human nature and failings, and attempts to mitigate those failings to some extent through education.

While a pissing match regarding qualifications to speak on certain topics might be amusing to engage in for a while, it is ultimately irrelevant to the discussion at hand. Certainly, in any task where the person performing the work is not willing or able to learn proper methods, professional help is the only reasonable option. There are people who will choose to go the DIY route even if they would be better off using professional help. If they make an attempt to educate themselves first, that's at least better than going in blind. Or, perhaps the submitter decides to get professional help and still wants to learn more about the subject. In that regard, who has helped that person more? You? To beat the argument to death, abstinence-only education doesn't work. Pretending it does causes more harm than good.

Re:No, no, no

[TooMuchToDo]

The call is low-voltage. On ILEC phones that run over copper from the CO to your house, the ringing is almost 100VAC.

Re:No, no, no

[jacqdesign]

I have re-wired large portions of 3 houses I owned. And your mentality, and the fact that your right about many locals having governments nose in the homeowners ass way too much is annoying to me. Your rant comes across like the boss I had in a college co-op talking about how hard all the computer shit he does is, and how he has to do it. And I figured out why, he was scared as hell that someone would come along and expose his incompetence that he was probably overpaid for.

If we are talking about 220 circuits or higher, or work at the box, then sure, most people probably should call an electrician, but should the government be up my ass about it, and should you be trying to convince me that I am too incapable of changing a light switch, and expect me to value your over charged service?

Seriously man, your not that smart, and residential wiring isn't that hard. I don't get on here and bust your balls about your bad website code, or your open wifi router that I steal bandwidth from, and demand you go hire the Geek Squad cause your too incompetent.

Basically chill out and leave people to shock the shit out of themselves if they want. It's kind of a good time anyway.

Re:No, no, no

[DMUTPeregrine]

"in" is a Latin prefix, meaning into, onto, or against. inflammable means capable of turning into flame. unflammable is not capable of turning into flame.
On the "with regard to/regardless/irregardless" issue, all 3 are words. The first and last have the exact same meaning. ir means without, so irregardless means without having a lack of regard to, id est "with regard to". Irregardless is both redundant and often used to mean regardless, which means the exact opposite.
That's enough time playing Latin Grammar Praetorian for today.

Re:No, no, no

[kipman725]

As somone who has lived in houses I have whitnessed the same things from so called profesionals. I would rather do it myself and know it has been done correctly than have a fancey permit for something potentialy leathal. Also I don't know how anyone in the US can talk about electrical safty with 2 pin plugs and bathroom soccets.

Re:No, no, no

[drinkypoo]

A 220 circuit isn't too complicated. I mean, seriously. You have three or four wires, right? A ground, a neutral, and then one or two hot wires. The two wires have opposing sine waves on them, so if you pull from both you get 220, and if you pull from one and the neutral you get 110. Just don't fuck up! That's the one thing that most people get wrong :) Seriously though, just keep which wire is which more or less straight, and keep things balanced, and you can wire up all kinds of shit.

If you don't want to burn anything down or kill yourself, follow simple rules, like assuming every circuit is live if you don't know if it's live, and testing everything before you touch if even if you "know" it's not shorted out or cross-connected or whatever. I shouldn't admit this but I've been shocked with all kinds of stuff (not including 220V, but including the signal off the CRT card on a VGA monitor, whee!) and I'm still here because when I was being stupid enough to get shocked, I was smart enough to keep one hand in my back pocket. If you're going to be stupid, be as smart as possible while you're doing it.

None of this is going to convince anyone to let me wire their house, but it's not that fun anyway. The fact is that it's really quite simple, and only the steep potential penalty for failure should scare anyone away. Use quality parts, use the boxes, follow the code when all else fails, and don't let anyone with a professional certification tell you what to do just because of a piece of paper. Remember, not that it applies directly here, but MCSE == "Moron Confused by Sun Equipment" and CNE == "Certainly No Experience". Electricians have to have experience, but they don't have to come down off their ivory tower.

2 words Home Power

[SubComdTaco]

Home Power is what you want to look at. http://www.homepower.com/home/

Re:Free energy

[xaxa]

Hook up the battery to an inverter (to make 115V AC)

Plug light into inverter.

Why not skip this bit, and use a lower-voltage bulb? An LED array might be best, for the very low power needed.

The Otherpower forum

[knarf]

Try the Otherpower forum. Not just solar but other independent power generation forms as well:

• Solar
• Wind
• Steam
• Hydro
• Controls
• Storage
• Mechanical
• etcetera...

Re:Free energy

[Ken_g6]

Since you're doing the lighting from scratch, and you want it exclusively powered by solar, I'd suggest looking at low-voltage DC lighting. DC bypasses the inverter, so it's more efficient for the same type of lighting. It's also probably less likely to kill you/burn down your shed if you make a mistake.

Disclaimer: IANAE - I am not an electrician

Solar is hit and miss ...

[jxliv7]

... 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 links out except that you'll have more fun exploring on your own - you'll find exactly what you need the more you look around.

Re:Solar is hit and miss ...

[MichaelSmith]

... 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:Solar is hit and miss ...

[BLKMGK]

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 chart but perhaps this will help http://www.awea.org/faq/usresource.html

P.S. Wind isn't 24X7 in many places either. I have a wind gauge on my roof on top of a pole and can go for hours with ZERO wind, I go DAYS without useful winds for power generation too.

DIY hack = take apart consumer stuff.

[Original Replica]

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 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:DIY hack = take apart consumer stuff.

[cptdondo]

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.

Step #1: $pend money....

[Slugster]

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/

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.
~

Re:Car and Caravan components

[xaxa]

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.

Re:DIY? Why?

[FarmerGeoff]

Why not? I am off-grid with two sets of solar panels (house and well). Did the whole thing mysef with a little help from my friends at Home Power. Not a problem unless you're totally clueless, which, being a Slashdot reader, you're obviously not. Got to homepower.com, buy the CDs.

Re:Free energy

[Anonymous Coward]

And then you need the damn huge cables to go with it. DC current has huge line losses unless you're willing to buy expensive, fine-stranded cable at #4AWG or bigger. That 1500W monster power supply you have sitting in your living room suddenly requires 125 amps of 12V power at full load. That'll melt the insulation right off a standard 14-2 solid copper AC line.

Re:Free energy

[Bill, Shooter of Bul]

Even better, just run as much stuff on dc as possible. There are dc Florescent, and led lights you can buy. Its sort of ridiculous creating dc power with the panels, converting it to ac, only to have your light bulb switch it back to dc. Some inverters also have a dc out for this purpose. They also have dc refrigerators and other small appliances as well. I'd give the questioner more advice, but I did my conversion project in a third world country where the electrical code was non existent. So we just did the best we could, following the relevant us codes we knew about.

Why *IS* this so hard?

[f2x]

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 controversy. It always begins with the assumption that you just "happen" to get hands on photovoltaic panels.

"Surplus solar panel"? Obviously these mystical artifacts either grow on trees or have to be pumped out of shale, because no one seems to know how to make them from scratch. In any event, think of it like an array of conventional self-charging batteries that only works in daylight.

Next, you'll want to take what energy you can get out of it and store it into something that has a more reliable on-demand containment... Let's call it a battery! It must be new technology because Chevron owns the patent on all of them and thus prevents us from freely whizzing around in electric cars. Oh, and disposing of them when they expire requires an act of congress to transport them to a cave inside of Yucca mountain.

The charge controller can almost be ignored. They just pop out of the ground when you need one. This gets placed between the solar panel and the battery. Pick up the wireless version if possible to keep things simple.

Finally, you'll want to go out and buy a bunch of proprietary light fixtures that are manufactured by an obscure gnome in the land of "Walmartia". In the event that one of the fixtures ever goes bad, you must then go to "Lowesia" to find a whole new set of proprietary fixtures since the "Walmartian" gnomes only live for about a year.

Good luck with your project, and be sure to purchase futures in petroleum based technologies. That bubble won't burst without your support!

Re:Why *IS* this so hard?

[f2x]

I know it's generally not in good form to post a reply to your own comments, but after I posted "Why *IS* this so hard?", 3 people thought I was being a troll (I wasn't), 2 people thought it was insightful (perhaps), and 2 thought I was funny (hurray!).

It was my intent to place my frustration in a humorous light since I saw so many posts that cited the impracticality of the proposed DIY project. No one seems to get it when it comes to solving the energy problem. There is always some trollop out there who wants to make it harder than it has to be. Let's face it; the bottom line is always politics.

I'm going to take something seemingly unrelated and use it to demonstrate my argument. I will use textile manufacturing as an example. People need to wear clothes because it is unacceptable to publicly walk around in the nude. You have climate conditions, hygiene issues, and modesty concerns as your major arguments, but I digress.

How hard would it be to make a standard western style outfit? How do you obtain the raw materials? What kind of machinery would you need to process these materials? How much labor is involved? How much energy will be required? What is the environmental impact? And let's not forget about the cost. Let's start with a laundry list... (literally.)

T-shirt
Underpants
Blouse
Trousers
Socks
Shoes

We'll leave out headgear for this discussion, but just think for a moment what a single outfit costs in terms of its production. Think about the amount of thread you need to adequately cover the human figure. Think of the complexity of what it takes to weave thread into fabric. Think about the process of dying or printing the material. Think about the source of the molding compound for the soles of the footwear, and the acquisition, tanning, and shaping of the leather. Don't forget about zippers, ties, and buttons to hold it all in place. Keep in mind it has to be transported over vast distances. Just a simple outfit that you'll likely wear maybe once a week, and you can pick it up at K-mart today!

Some of us wear more or less depending on various factors, but just look at the fabric around you. An ordinary cotton T-shirt for under $10.00 is incredible to look at under magnification. Do any of us worry so much about its environmental impact to produce such a thing?

Now let's look at the photo-voltaic solar cell. Simple ones can be produced from copper foil subjected to a high temperature on one side until an oxide layer is created on the opposite side. Unfortunately this method also produces an unwanted layer of black carbon which must carefully removed to expose the pinkish layer underneath. The pink surface is then covered by either a transparent or translucent conductor. Fine wires closely laid in parallel would work nicely. Cover with glass or plastic to protect from the cell from the elements and connect leads from the back of the foil and the surface conductors. Is this any harder than gathering cotton, spinning it into thread, then weaving it into fabric?

Granted, copper foil isn't exactly an off the shelf item, but when you look at how much aluminum foil we have laying around, it's not too much to believe the same principles couldn't be used to adapt the process from a poor metal to a transitional one. It's not that big of a problem for engineers to adapt. It's a problem of supply and demand to dictate.

So who creates the demand? Do you still harbor the illusion that "We the people" have any real grass roots control over demand? The saddest truth is that demand is created by the most successful suppliers these days. You demand things they tell you to demand. e.g.: Cheap shirts, fast-food, heavier cars, hi-def TV, more absorbent paper towels, prescription drugs, cell phones that can surf the web, and longer lasting deodorants. A glance at the Sunday ads in the paper are all too telling when it comes to realizing just how much of our society is powered by hype.

And yet the idea of covering a r

While you're at it - light tubes!

[BLKMGK]

I have three light tubes aka light pipes in my home. They consist of an acrylic dome on the roof, a mirrored rigid pipe, and a diffuser at the end facing the inside. I often do not need to turn on lights with these suckers - very nice! Some tips - do NOT put them anywhere near a ceiling fan unless you want a disco and do NOT put them in your bedroom lest a full moon have you howling all night - yes moonlight is strong enough to light the room!

Other than that yeah go compact fluorescent or MAYBE LED. I have both and find that the LED is pretty directional and very stark white with a tinge of blue. The CF stuff lasts a good while but be careful not to get the crappy ones that take forever to light up :-( I have one of these and it pisses me off but it fits the fixture, the LED lights I bought wouldn't fit in the "can" fixture.

BTW notice that many holiday lights and tube lights are LED. These actually work pretty good for lighting some areas!

Re:Free energy

[BLKMGK]

Actually this is a pretty big problem! One of the things I have consistently read in magazines like Home Power is that 12volt devices can be a problem with regard to sockets and plugs. Lighter sockets do not carry current very well and are flimsy for one thing. Using standard 120 sockets is simply asking for it because as soon as you turn your back a guest or baby sitter is going to make a mistake. Lots of things have been tried but so far I've seen nothing really good.

I DID just read the other day about some new power standard being adopted by some companies to help get rid of wall warts. You'd have some sort of power strip that could power multiple devices using a standard power and it would completely shut the device down when not being used. I didn't pay much attention to that but perhaps that is a ray of hope? Whatever plugs they use might be useful for this. Best part of it is that hopefully all of those devices will use the SAME power instead of one being 9volts, another 13, yet another 12, and so on. It's crazy to have to have an entire BOX of chargers and wall warts (seriously)...

Re:Free energy

[orangesquid]

DC power transmission over short distances is feasible. Over long distances, it isn't. Look up the Current Wars and AC power distribution. For DC, P=I^2*R=V^2/R. For AC, Prms=Irms^2*Z=Vrms^2/Z. Ignoring phase shift and comparing RMS AC quantities with DC quantities, the equations look the same. The longer the lines, the larger R, so the larger your power lost to heat. DC-DC power conversion is a modern solid-state technology (using charge pumps?) and still tends to be expensive, intolerant of transients (without proper filtering), and limited to small voltages and/or currents. AC-AC power conversion is simple, cheap, and can handle huge currents and voltages. Also, it's much harder to go from DC to AC than the other way around. Until modern solid state, in fact, there was no reliable, efficient way to convert DC to AC in any significant quantity.

If you had a shed and a house on two sides of a large property, and you wanted to put solar panels on one and bring some power to the other (perhaps it is in the shade), inverter + step-up transformer + step-down transformer + AC-to-DC is going to have a noticeable improvement in efficiency over trying to carry DC long distances. If you're generating any serious amount of power, you're also going to need some thick, thick cables to carry lo-volt hi-amp DC around in order to safely dissipate the heat, especially for wires running indoors. Even if you don't care about losses, converting to/from AC is much cheaper than replacing everything in a burned-down house.

Me too

[HeyLaughingBoy]

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/

Check out some good magazines

[dnight]

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.

I have a solar power setup and it not all that.

[joecamelman123]

Ok here is my 2 cents worth. Not to discourage anyone but solar panels are incredibly complicated and hugely expensive. I have a very large 2Kw array on my house. I ended up spending over $28,000 on it. And I don't have a single battery to store power with. I use net metering. I am still tied in to the electrical grid. My array only makes power when there is enough sunlight and that is about 8-10 hours a day. I live in Florida so I get a fairly decent amount of sunlight throughout the year. Of course I also work a 9-5 job so I am not home most of the time the panels are making power but with the net metering it just spins the power meter backwards and credits me. I have electric bills anywhere between $0 - $35 dollars now. In the cooler months I have actually had a credit from not running the a/c so my bill is balancing out to $0. From start to finish it took about 3 months to design, plan, order, and have it all installed. You have to have a licensed installer install everything or you will not get the rebate here in Florida. But I was told the state rebate fund ran out of money and so I am still waiting for my refund! I still have a seperate backup generator for when the power goes out which tends to be frequently around here.

Hyperbole?

[chuckjuhl]

"During a typical year, home electrical problems account for 67,800 fires, 485 deaths, and $868 million in property losses. Home electrical wiring causes twice as many fires as electrical appliances. In urban areas, faulty wiring accounts for 33% of residential electrical fires." http://www.usfa.dhs.gov/citizens/all_citizens/home_fire_prev/electrical.shtm Hardly seems like hyperbole.

Re:Hyperbole?

[hedwards]

And how many of those fires were from obsolete, should have been replaced decades ago, wiring?

I'm not saying that it can't go really bad, but considering the numbers of houses which have outdated wiring that are being used for all the modern gear, it seems a bit of a stretch to assume that's evenly distributed or is primarily caused by incompetent installation.

Re:How did the person that knows learn?

[Bill, Shooter of Bul]

The person that knows learned by burning down two houses, a third burned down, then sank into the swamp, but the fourth worked.

Marine battery + panel + DC lighting. Done

[seanadams.com]

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.

Treat Batteries Like they are a bomb

[o1d5ch001]

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.

• All electrical should be 12V dc if you don't have to run 120V AC for anything. (no conversions!! yeah!)
• Use a good quality deep cycle or marine battery. Car batteries are intended to give lots of amps for a short period of time.
• You will need a charger manager that can reduce the charge to nothing from the solar panels so you don't boil you battery. Well, just go to Battery University and learn all about batteries.
• http://www.batteryuniversity.com/
• Look at using 12volt lights
• 12v side of life: http://www.ccis.com/home/mnemeth/12volt/12volt.htm
• Battery FAQ http://www.windsun.com/Batteries/Battery_FAQ.htm
• 12v CFL http://www.unlimited-power.co.uk/low-voltage-lights-12v-dc-CFL.html
• Very good inverters from Astron http://www.astroncorp.com/dc2ac.shtml with modified sine, not square sine if you want to run more than just lights.

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.

Re:Free energy

[NimbleSquirrel]

Hook up the battery to an inverter (to make 115V AC)

Plug light into inverter.

Why not skip this bit, and use a lower-voltage bulb? An LED array might be best, for the very low power needed. Because DC requires much thicker copper cabling, and the losses are greater over longer distances. If you don't mind paying extra for the thicker copper (and given the international price of copper this may be quite alot), then DC is a good choice. You will need better switchgear too, since the AC voltage and current ratings for switches will always be higher than the DC voltage and current ratings. DC wiring is hugely different to AC for house wiring, and DC presents more hazards than AC does. One of the reasons AC won over DC.

Re:Marine battery + panel + DC lighting. Done

[cnaumann]

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.

Re:Simplest Solar Powered Lighting

[mrbluze]

Is a skylight in the roof. Next simplest is a marketed gadget called, I think, "SolaTube". That's for when you have a ceiling as well as a roof.

I would certainly take that approach. The fewer steps of energy conversion, the better.

If I ever get prosperous enough to afford it, I will be converting our home to renewable (off the paid electricity grid). Probably a gradual process but I have to say investing in simple things like skylights, insulation, solar hot water heating has the best long term pay-off, since there is practically zero maintenance involved.

Re:Marine battery + panel + DC lighting. Done

[burni]

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

different solar lighting

[hayagriva]

Not to be a luddite about things, but how about a skylight or 2?

Re:Marine battery + panel + DC lighting. Done

[expatriot]

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.

slashdot is a good site

[zogger]

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

Re:Car and Caravan components

[o1d5ch001]

For those not from the UK, a caravan battery is probably one type of deep cycle battery. These are mostly wet batteries that use acid and water as an electrolyte. There are a number of lead acid batteries called by different names: marine, locomotive (big!!), golf cart etc. The primary difference between a car battery and a deep cycle battery is the size and perforations of the electrodes. Car batteries have lots of perforations to produce lots of amps quickly. In the deep cycle battery world, you need larger batteries to get more amps. How big? Well, 1000lb batteries for large solar installations. The leading manufacturer with a neat interactive website is Surrette Battery http://www.surrette.com/.

Golf cart batteries are very interesting for these projects. They are 6v batteries that are relatively cheap ($60-$200) each, connect them in series and you have quite a bit of energy storage.

Other types of lead acid battery uses absorbent glass mat or gel (not the same thing)to reduce the chances of an acid spill.

Lead Acid Batteries http://en.wikipedia.org/wiki/Lead-acid_battery

Absorbed Glass Mat http://en.wikipedia.org/wiki/Absorbed_Glass_Mat

CAUTION: Lead Acid batteries contain allot of stored energy. Equivalent to a stick of dynamite, and all you need to do is short it and they WILL explode. Please treat lead acid batteries with extreme care. Nothing like an exploding bomb of sulfuric acid to fuck up your day. Do not use lead acid batteries in your house, or near kids. Yes, I know people who have had batteries explode while working on their cars..

And for those who want batteries, but just use mains power to charge the batteries, here is an excellent charger that many hams use. http://www.a-aengineering.com/5smartcharger.htm

Re:Mod grandparent down!

[SETIGuy]

Mod grandparent down - that article is what we in the real world call a "pile of crap." Others could call it a "political treatise." It is based upon three greatly flawed assumptions. The first assumption is that what we pay in energy cost is somehow related to the true (monetary and environmental) cost of the energy. This is demonstrably false.

The second assumption is that the only thing that effects cost of an item is the energy used to produce the item. Also demonstrably false.

The third is the assumption that energy costs are uniform across the planet and that they do not change with time. Has he ever looked at his power bill?

Don Lancaster needs to take an Introductory Economics course. From this article I gather that the term "informally peer reviewed" means "read by people who agree with me and guess what, they still agree with me."

Re:Marine battery + panel + DC lighting. Done

[EdwinFreed]

My son and I built a very similar setup for a school project: A solar-powered kiosk for recharging portable electronic devices. It's been operating for over a year now without incident.

We used a deep-discharge AGM battery purchased locally. The panel we bought online from www.solardepot.com. We considered just using a series diode, but eventually opted for an inexpensive SCN-2 charge controller from www.allelectronics.com. We also picked up the AC inverter there. (Checking, I see the price for the controller has gone up, so you might want to shop around for one that's a little cheaper.) The various other parts, like the mechanical dial timer, fuses, outlets, conduit, and assorted mounting hardware were all purchased locally.

Frankly, the hardest part of the project was coordinating the installation (which involved getting up on the roof) with the school. The electronics went together effortlessly.

Our main worry wasn't that the setup wouldn't work, but rather that it would be vandalized. But for whatever reason that hasn't happened.

Re:Free energy

[mstrcat]

While the parent is technically true, it's pretty much hogwash for the current discussion. The amount of current even a large shed roof can produce from solar cells is too small to worry about I^2*R loses. Use standard 10 gage wire, and you won't even have to use solid copper (most is copper coated aluminum). The only place you should worry about cable thickness is between battery and first fuse/circuit breaker.

Re:Google shopping results

[reezle]

Re:Google shopping results for "solar powered shed light" gives a lot of good solutions. Anywhere from $30-$100, fluorescent or xenon, indoor outdoor...

Hawaii

[falconwolf]

Solar is economically competitive in some markets today, like in sunny places with high electricity prices, e.g. Hawaii

The big island of Puna in Hawaii gets 30% of it's energy from geothermal power.

Falcon

Re:Free energy

[BLKMGK]

AC won out over DC because it could be transmitted over long distances with less loss. Using DC meant there had to be power generation stations all over the place. Not so unlike what we'll have if everyone puts up solar panels actually. DC makes some sense with local generation.