DIY Solar Resources? 311
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."
Well? (Score:5, Funny)
Marine battery + panel + DC lighting. Done (Score:5, Informative)
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.
Re:Marine battery + panel + DC lighting. Done (Score:4, Informative)
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:Marine battery + panel + DC lighting. Done (Score:4, Informative)
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
Re:Marine battery + panel + DC lighting. Done (Score:5, Insightful)
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)
Everyone is missing the obvious here. Simply remove the roof, and the sun will light the interior directly.
Re:Well? (Score:5, Informative)
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? (Score:5, Informative)
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"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 [boeing.com]. 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 product
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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? (Score:5, Insightful)
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? (Score:4, Insightful)
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:4, Interesting)
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? (Score:4, Interesting)
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 [wikipedia.org]
For daytime lighting of the shed you might try to make
your own Solatube.
http://en.wikipedia.org/wiki/Light_tube [wikipedia.org]
Re:Mod grandparent down! (Score:5, Informative)
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."
Hawaii (Score:3, Informative)
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 [energy.gov] power.
FalconRe: (Score:3, Informative)
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.
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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
Re:Well? (Score:4, Informative)
Yeah, that'd work wonders at nighttime.
Because you _never_ do work in a shed at nighttime.
Re:Google shopping results (Score:3, Informative)
Re:Google shopping results for "solar powered shed light" gives a lot of good solutions. Anywhere from $30-$100, fluorescent or xenon, indoor outdoor...
No, no, no (Score:3, Insightful)
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 (Score:5, Funny)
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 (Score:5, Funny)
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Wiring is not hard. Talk of burning your house down is pure hyperbole.
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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)
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)
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)
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?
Re:No, no, no (Score:5, Insightful)
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.
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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
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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
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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 Gram
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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.
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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)
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With enough amperage even 12volt wiring can start a fire. Don't think so? Go short the terminals on your car battery sometime...
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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
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Well, he talked about starting with lighting. The end point was left pretty open, and he mentions wanting to get resources that culminate with whole-house wiring. Expansion past lighting is what requires planning, and it seems that he is at least interested in the possibility of expansion. That's the only reason I've brought up points of consideration that have very little bearing on wiring for DC-only lighting.
Were DC-only lighting his only goal, his mention of being unable to adapt other published project
Re:No, no, no (Score:5, Insightful)
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.
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)
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.
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Something that starts with basic theory and ends with the ability to wire a house would be perfect.
RTFS? :)
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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
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Good luck finding inspectors that know anything about DC wiring. And yeah, apparently DC wiring has it's own set of tricks that need to be followed that are separate from AC wiring - circuit breakers for instance act differently on DC than AC. Heck in my area two inspectors couldn't even agree on the right way to do something when asked by my contractor! We waited till post inspection to do the work as a result these two inspectors literally had an argument on the best way to solve the problem right in fro
2 words Home Power (Score:5, Informative)
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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 :-)
Car and Caravan components (Score:2)
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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?
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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.
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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
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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.
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Second this. Another option is to look around for telcos who are cycling out their backup deep cycles. Usually done every 5 years, these batteries are typically cheap, durable, and have many years of life left in them.
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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....
Re:Car and Caravan components (Score:5, Informative)
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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)
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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!
Simple, in theory (Score:2)
Doing it the wrong way (Score:2)
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Cool it down. The gas coalesces better when there's no Brownian motion to fling it everywhere.
Solar is hit and miss ... (Score:2, Insightful)
... 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
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... you've got clouds and rain and much less than 12 hours of sunshine available on any given day year round.
At the Equator: solar
At the Poles: wind
In between: combination of the two
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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
DIY hack = take apart consumer stuff. (Score:5, Interesting)
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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.
What scale? (Score:2)
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
non-grid-tied?; requirements? (Score:2)
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
Step #1: $pend money.... (Score:5, Insightful)
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.
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.
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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.
~
garden lights (Score:2)
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.
Why *IS* this so hard? (Score:2, Funny)
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
DIY Solar Resources? (Score:2)
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)
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]
Check out some good magazines (Score:5, Informative)
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.
Treat Batteries Like they are a bomb (Score:4, Informative)
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.
slashdot is a good site (Score:3, Informative)
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:Free energy (Score:5, Interesting)
Hook up the battery to an inverter (to make 115V AC)
Plug light into inverter.
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I guess you could do that. But I'm buessing he(she?) already has lights. Chasing
down low voltage lights aint no fun either. Hard to get and not as many options...
I used led's in my solar setup. Now I use a lot of candles instead. LED lighting is damn damn ugly.
I use fluorescents if I need a lot of light.
The odd thing too is, once you stop using electric lights you tend ot go to sleep at night and wake up with the sun and I'm saying this as somebody whose been a night owl, a serious one, for decades. No long
While you're at it - light tubes! (Score:5, Interesting)
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!
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I can't find any CF bulb that doesn't take a long time to light up. I've tried every brand I've seen (major brands--Toshiba, Panasonic--I live in Japan), and the best ones are slow, and the worst are already in the trash (before I knew how toxic they are!). I have decided that, like PC fan noise, my standards are just way higher than other people's (that's not bragging--I'm open to the idea that I may just be a whiny bastard).
And don't even get me started on the color.
Oh, and I have observed exactly N
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Bill said:
"Even better, just run as much stuff on dc as possible."
Edison would be proud of you!
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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.
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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
Re:Free energy (Score:4, Informative)
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
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Yes and no. it wouldn't hurt for a standard 12volt DC connector to help keep things going, the problem is in most DC system one of the leads is bonded to the car/boat/plane/train/etc to bring back the current.
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Or do we just go with the damn huge "cigarette lighter" connector?
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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 (Score:5, Informative)
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.
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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 so
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...which works wonders after 6pm. Try again.
Re:DIY? Why? (Score:4, Informative)
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.
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