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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."
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.
... 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.
Generally speaking, if you already have on-site utility power, that's going to be cheaper over the long run than solar cells.
...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).
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.
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.
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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.
That analysis isn't too clear. It sounds like some economics student got ahold of some numbers and a calculator, and this is what he spewed in a late night drunken bull session at the dorm, and no one called him on his bullshit.
It is probably true that the economic unviability of varous energy schemes generally points to the fact that they may use up more energy than they create. It is probably a good first-order attempt at evaluating the "carbon footprint" of a Prius, for example, to see if it saves enough gas to pay for the expensive technology in it, as expensive components usually cost more in terms of carbon released to make.
However, this guy takes it too far. He observes that it is possible to swap dollars and energy in both directions; he uses the $10 word "fungible" which seems to have the effect of short-circuiting much of his gray matter; and then he asserts that money-losing PV schemes are actually consuming energy. Does this "educated stupid" egghead believe that an interest bearing account violates the laws of thermodynamics ?
I think more carefully researched guesses are that PV panels started breaking even around 2000 or so, and they produce more energy over their lifetimes than they took up to produce, now. (This is ignoring the fact that PV panels produced with cheap hydroelectric power in the Northwest can act as sort of batteries to export that cheap power to sunny places.)
This is the best link I know of that analyzes the PV payback issue (in terms of energy, not dollars):
http://www.ecotopia.com/apollo2/pvpayback.htm
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.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.
~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
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
Blessed with all the brains that God gave a duck's ass, and twice the charisma.
Not to be a luddite about things, but how about a skylight or 2?
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.
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.
testing out my trending skills
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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