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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."
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.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?
We are all just people.
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.
Do it yourself, because no one else will do it yourself. [beta blockade 10-17 Feb]
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.
The higher the technology, the sharper that two-edged sword.
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!
Build it, Drive it, Improve it! Hybridz.org
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/
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
google "32 trillion offshore needs IRS attention"
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.