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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."
I someone please shed some light on this issue.
Just hook it up to your neighbor's power cable.
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.
Home Power is what you want to look at. http://www.homepower.com/home/
http://michaelsmith.id.au
Are you absolutely positive that you want to do it yourself? Personally, I'd strongly suggest that you get someone who knows what they're doing.
--frank[at]unternet.org
expose panel to sunlight.
Step two press tonuge against panel's contacts.
Step three do not repeat step two.
Do-it-yourself solar is pretty simple, in theory. In practice, it's not easy to gather enough hydrogen in an empty area of space. Darned stuff keeps spreading out whenever you turn your back to get another batch.
... you've got clouds and rain and much less than 12 hours of sunshine available on any given day year round.
Check out the wind instead. Generators can produce power in very low winds if you've got the right windmill (the ones that look like upright cylinders seem best, not the big blades).
Don't limit yourself to 110v, think about 12v and 24v DC lighting systems and battery storage and you'll be amazed at the inexpensive, 24/7, energy producing capabilities of the wind.
I'd toss a few 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.
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.
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 couple of hours north of me here, 3 north of SF) have lots of resources: http://www.solarliving.org/
Awesome furniture, accessories and cabinetry in Santa Rosa, CA: http://humanity-home.com/
Try this... http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90599
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 battery is big, needs maintenance, doesn't have a long design lifetime, and can be dangerous as hell if you screw up.
You also don't state your requirements. How much power do you need? Do you need AC, or can you get by with DC? DC is safer, and also doesn't require an inverter. Getting rid of the inverter means your efficiency is higher, and it also cuts the cost of the system. A classic application for DC solar is a pool pump. Pool pumps use DC motors, so it's wasteful to use an inverter to convert to AC, and then rectify it back to DC for the pump again. I would imagine that if all you want is lighting, you can probably do 12 V DC without an inverter.
Find free books.
Cut a big hole in the roof and put in a sky light.
What?
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.
------
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.
~
It was easy enough in Utah.
http://michaelsmith.id.au
It's great to say hire someone, but he was asking how to do it. The person that knows how to do it learned somewhere.
just steal a bunch of those ugly little garden lights. i'm sure that with those, a roll of duct tape and some speaker wire, you could figure a way to rig something up.
Seeing this question and various responses makes me sad. I've seen this song and dance repeated time after time. Don't forget to queue the people who keep trying to cram a kitchen sink into everything. ("Why not use wind?", "Better leave this to the professionals!", "It's as easy as 1, 2, ...1536. Profit!")
Photovoltaic technology has been around for decades, and yet manufacturing a simple solar cell to trickle out a couple of watts is regarded as black magic, wrapped in ignorance, surrounded by 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!
Blessed with all the brains that God gave a duck's ass, and twice the charisma.
12VDC_Power is a very good Yahoo group that covers solar power and off-grid living based on 12 volt electrical systems, which are among the best alternatives for solar using current technologies.
This is a solar security light with motion sensor. The solar panel is attached to the light/battery/motion sensor by 4 meters of wire. Put the panel on the roof of the shed. Put the security light inside. Whenever it senses motion, it will turn the light on for a few minutes. When you leave, it turns off. No switch, no wiring, no problems.
http://solarilluminations.com/acatalog/Security_Lighting.html
This one uses a 10W halogen bulb, so it isn't very efficient. I'm sure there are others that use LEDs, or perhaps you could convert this yourself.
The first thing is to keep the solar powered lighting system separate from the regular electricity. Given that it's a shed and TihSon is thinking of going solar, I assume there is no mains power. Solar is a good idea if bringing mains power to the shed is expensive.
The second thing is to use very efficient lighting. The LEDs they use in flashlights are pretty good. This accomplishes a couple of things. I don't have my code book at hand but iirc you want to do class 3 wiring. ie. less than 32 volts and inherently current limited (I forget the current but you should be able to keep it to the tens of ma. anyway.). With class 3, you can pretty much get away with anything because there's no way it can start a fire and therefore there is no insurance problem. The other thing efficiency does is reduce the overall system cost.
So, you need efficient lights, a switch, a solar panel, battery and some kind of regulator to keep the battery from overcharging. Our local car parts supplier has everything because RVs use such systems. I assume yours does too. Make sure your battery is small. A car battery can supply way too much current to be safe if you're not confident of your wiring abilities (current not voltage starts fires).
This isn't rocket science and you shouldn't be afraid of it. Unless you want to spend a lot of time in the shed, the solar panel you want is quite small. You can probably get away with the cheapest thing they have at the aforementioned car parts supplier. My WAG is that, even if you buy everything new, you should be able to do this for less than fifty bucks. (I just googled, they have a 1.8 watt panel for thirty dollars.)
So, your goal is to get light from solar energy...
;)
May I suggest a window?
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
I discussed this exact type of project (in a farm setting) with a civil engineer who did the same thing. He found that using excess energy (also from wind power) by pumping water up an incline was more efficient than batteries. He used two dams at different parts of a hill which worked well. Also shared the power storage with a neighbour since the dams were large enough and this reduced the infrastructure cost.
Do it yourself, because no one else will do it yourself. [beta blockade 10-17 Feb]
Mod parent up - this comment needs discussion because it's very interesting indeed!
Do it yourself, because no one else will do it yourself. [beta blockade 10-17 Feb]
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.
Codifex Maximus ~ In search of... a shorter sig.
12 volt DC is the easiest for lighting w/o a doubt. The hard part is finding "affordable" panels of decent quality. There used to be a large number of surplus panels, but those days are long gone. Cheating & going for the obvious http://www.google.com/search?hl=en&q=DIY+Solar&btnG=Google+Search The 12 volt airco price is scary, an inverter setup for 115 would be cheaper. As long as you're not connecting to mains, it's a simple TabA-SlotB type of setup. If you're even thinking of going to connecting it up to commercial power, get a certified electrician who knows PV systems. Your local utility will usually REQUIRE you do that if you're going to touch their system & run PV.
I have put in $12,000 and up commercial systems. I will caution you that the correct theory and implementation is bit complicated. There is a (1) panel, a (2) battery, and a (3) load. There are complex three-way, time-dependent interactions between all three components, none of which are linear, or even consistent (often). In between the three is a "controller," a little black box that does the tricky part. They don't cost much. Make sure you have a provision to measure current with a low-cost DVM and be sure to to put fuses everywhere. You can use low-cost in-line car-type fuse holders, which you can buy at a hardware store. Unprotected overloads in solar systems are ugly.
I will create a sig when innovation restarts in the U.S.
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/
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.
Don't kluge it, Ace
Its all compil-cated. OK, actually its not. Directions: Put panel in sunlight. 2. Take electricity from panel. Rules: when there is sunlight, there will be electricity. No light, no power. Got it? OK, one more thing. The panel can't produce as much electricity as a nuclear plant, so a 1x2 inch panel from your calculator can't be used to power the fridge, stove, furnace motor and the 48 inch bigscreen TV all at once. You will have to calculate how much power the panel puts out on average, come up with some means of storing the electricity when you are not using all of it, and only reliably draw something less than the average of what the panel produces. Example: 100 watt panel, full sun, if its bright 1/3 of the time (day+night+cloudy+summer+winter), then you can reliably use 33 watts of power from that panel, assuming you don't loose any from whatever storage source you have. Got it? I would check also to see how many panels you can hook up both in series and in parallel. Going too far in one direction or the other could 'cook' the panels. Hope thats all clear.
If he hooks his solar panels to a lighting system, he'll probably be able to get the LEDs to work during the day (when there's plenty of light from the sun, pouring in through the windows of the shed.
Without some storage batteries, it'll be a pretty dark shed at night.
Mother Earth News mag ran a feature last year on exactly this topic:
Easy DIY Solar Lighting
http://www.motherearthnews.com/Do-It-Yourself/2007-04-01/Easy-DIY-Solar-Lighting.aspx
From the intro:
"Many people dream of solar-electric power for their homes, but can't afford whole-house systems. Here's an affordable, entry-level system with which you can have fun and get to know the basics of solar power. This setup, built with a small photovoltaic (PV) panel, one battery and low-power direct current (DC) lighting fixtures, can bring solar lighting into your home or remote locations. If you can turn a screwdriver, you can install it yourself."
Really does read like "Solar Power for Dummies", though the info seems US-centric.
Disclaimer: I haven't built any solar power systems yet.
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.
"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.
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.
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.
Q. What is Calvin's monster snowman called? A. The Torment Of Existence Weighed Against The Horror of Non Being
lol, well I didn't mean having like hundreds of little calculator solar panels hooked up to LEDs scattered around the shed.
Do it the same as you would for 'normal' lighting, have solar panels up on the roof.
And I didn't say you wouldn't need any batteries, but that you would need less to run the same amount of lighting.
A Single car battery could probably run your average LED light (with its 30 or so LEDs bundled together) for probably 2 or 3 nights before needing a charge, but the same battery powering a 90 watt incandescent light would drain the battery after about 4 hours, as well as some loss via the inversion which could have been used.
Hi: At least look to the people who know. Get in touch for info. http://www.ovonic.com/
Imagine you have a bucket filled with water, but it has a hole at the bottom. The bigger the hole, the faster the water will drain. You can keep water in the bucket by pouring water in the top. The trick is to keep the bucket at least 1/2 full all the time. You can either try to shrink the hole or pour water in the bucket faster. In this analogy, the bucket is the battery, the hole is the appliance you are running and the pouring water is the solar panels.
In putting together a solar system you must consider how many watt hours you are consuming. How much standby power you need (will determine the size of the battery bank) and how quickly you need to replenish the energy (will determine the wattage of the solar panels).
Not only is the paper from 2002 (6 years ago), but it is NOT about energy. The paper is about arguing that PV do not work because you do not see more of them esp. without gov. help. Yet, it ignores all the subsidies that coal, oil, etc get (which is actually more than ALL of AE put together), as well as the fact that coal,oil. In addition, its argument is circular. All in all, the parent and the paper are absolutely worthless.
Make a window or two
I would suggest HomePower Magazine as a resource.
http://www.homepower.com/
Excellent quality source for diy and complicated alternative energy projects, the website has a ton of free pdf downloads, and they're online membership is only $25 which gives access to way more information ....well worth it.
do this on the cheap, get a set of 4 of the pathway lights that charge during the day and light at night (should be $30). A little dremmel work ill yield 4 solar panels and 4 sets of rechargeable batteries. put the solar cells on the roof, run wires to the batteries, 4 of those lights will generate 12v of electricity and will run for about 8 hours form a full charge. Buy youself onee of the cheapo $10 superbright LED flashlights, again with the dremel, and you will have just the lighting portion of it. A trip to the hardware store to find a little piece of frosted plexiglass to replace the cover of the flashlight should cost you about $2-3 and will diffuse the light form the LEDs..... assuming you have the dremmel, this should take about 1 hour, and cost you about $45. If you really hate the LEDs, buy a cheap battery powered light for a closet and hook that up, in which case you wire the batteries in parallel instead of in series, and just hook up 3v to light. It will be driving an incandescent and will not last as long, but it will suffice, its just a shed, right? those lights can be had for about $5 at most discount stores, and with the $30 for the path lights, you are in for $35...
The simplest solution would be to get yourself a few good car batteries. Use a bank of 12-volt solar panels. Then install 12-volt lighting, which is commonly available today. (The batteries should be of matched type and capacity... preferably all the same brand, model, and age.)
This avoids having to mess with inverters, matching the phase with your AC power, and so on, which is quite a bit of added cost and complexity.
In addition, you can set up a 12-volt lighting system without needing an electrician's or contractor's permit, it doesn't have to be inspected, and it won't affect your insurance.
Of course, that doesn't address the issue of electrical outlets, but you said "lighting".
And when you do get your DIY kit up and running, check out this open-source project:
http://www.solarnetwork.net/dataPreview.php
thanks!
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.
Soldering together row after row of solar cells to make our own panels is trivial. What I want to know is how do I manufacture a solar cell? I don't care about volume manufacturing, and I don't care if the end result is only a quarter as efficient as ones I can buy. I can get a kiln that'll do 2600 degrees F to melt silicon. What's the recipe for making a cell that works? Surely someone's done this already.
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 were barned and rezzed ona niir dessert.
Nothing better than evaporative cooling in the desert. Refrigerated just doesn't do the job. I mean, it's quiet, and it feels nice near the A/C unit, but over by the other wall, ...
Well, anyway, what I was going to say, if I end up going back to the desert, I'll run solar water heating in the roof to get a good start on cooling things down. What I'll do with all the extra hot water in the summer, I'm not sure. Since water goes bad in the desert quickly when it isn't moving, it would not be good to just store the heated water below something. (Below what, anyway? where on earth do you want heat radiating back up from the ground?)
One problem with solar water to run a steam cycle is that the rare storm often includes hail.
Computer memory is just fancy paper, CPUs just fancy pens with fancy erasers; the 'net is just a fancy backyard fence.
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
I just bought this book and it is full of great information, covers the basics of electricity and a section on each type of renewable energy as well as batteries, lights, cables etc. It's a great resource.
"Energy from Nature" by Peter Pedals, Rainbow Power COmpany - www.rpc.com.au
Not to be a luddite about things, but how about a skylight or 2?
Stirling engine.
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.
I just took a class which covered basically exactly what you want to learn. Our text book was "Renewable and Effecient Electrical Power Systems" by Gilbert M. Masters. I would suggest you take a look.
Wiring your house is not hard, burning your house down is even easier.
-- Wondering how long until the internet becomes fully corporatist, like television.
Just wanted to stop by and say that if all you want to do is power a light in a shed you can get by doing this yourself and "on the cheap."
I currently run the three compact fluoro's in my living room (most used room in the apartment) using a 15w photovoltaic panel from northerntools.com, and a deep cycle marine battery.
I have details of the setup at http://www.solardiy.infowhere I also have bunches of links posted for people with questions just like yours.
One of the things people seem to wonder about most is how big of a panel they need. This is a question I get frequently.
Of course to determine the amount of energy you need to be able to generate and store in your battery, you need to know what you are going to be consuming the energy with, and how much energy it will consume.
I'd say though that if you are just trying to light a shed, you would be fine with a 10-15watt panel and a deep cycle marine/RV battery, depending on how much sun you get in a day. You will also want to consider how many days you can get with little direct sunlight, as this could cause you to require more stored energy for cloudy/dark periods.
You can get 12v compact fluoro's for cheaper now. Here are some on ebay:
http://cgi.ebay.com/12V-DC-compact-CFL-fluorescent-RV-light-bulb-16w-80w_W0QQitemZ360062670701QQcmdZViewItem
That eliminates the inverter, and reduces the overall cost of the system.
That said, I can run 3 CF bulbs through a power strip with my small inverter off a marine battery from dusk until 5am when I wake up on the couch, and the battery still has a good charge.
To mount my panel I just used an old satellite dish mount. Here is a link to the DIY PV Mount
Feel free to drop by the website and leave a comment or send me an email if you have any questions.
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200306871_200306871
"No wiring required, you get a solar panel, rechargeable batteries and 8 Watt light"
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
Highly unlikely that you'll have the capacity to run incandescent bulbs. Google for 12V LED lighting. It consumes roughly 2% of the power.
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."
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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:Google shopping results for "solar powered shed light" gives a lot of good solutions. Anywhere from $30-$100, fluorescent or xenon, indoor outdoor...
Figure out what your load is going to be first.
Say you are running a 12 volt DC LED lightiing system at a total of 50 watts. A single array of 25 LEDs will operate at about 5 watts, so you would have 10 of these LED arrays, for a total of 50 watts.
To operate the LED arrays for 6 hours a night:
6 hours(50 watts / 12 volts DC) = 25 Ah
So you would need at least a 25 Ah battery. You don't want to fully discharge the battery, so I would use two 25 Ah batteries in parallel. This leaves a buffer.
Now you would need to figure out how many panels you would need to recharge those batteries in a full day's worth of sun.
You would need 1 (64 watt panel), juicing in the sun for 5 hours. 64 watts x 5 hours = 320 watt/hours
A 64 watt panel costs around $356.00.
System parts:
- panel
- panel mount
- Deep Cycle Lead Acid Battery
- charge controller
- fuse block
- wiring
- terminal block
- terminal crimps
- battery box
- LED arrays
- meter
I would recommend a Morningstar charge controller that mounts right on the junction box of the panel.
Also you probably want to install a voltage and amp meter to give you some idea of what is going on.
I have implemented a couple of small scale solar systems, and they are fun to put together, and are a learning experience as well.
The use of a 10% risk free interest rate was also interesting.
Mod parent up; grandparent is so bad it's not even wrong. The EROEI (energy returned on energy invested) for PV is demonstrably quite positive.
The economic cost = energy argument is an interesting one but is simply wrong. There are multiple ways to attack this proposition; you could show that the energy intensity of economies (energy consumed per $ GDP produced) are not constant, labor costs are significant and do not pass through linearly to energy consumption, etc.
The economics of PV aren't great now, but are improving rapidly. The experience curve of solar shows a ~20% reduction in costs with every doubling of cumulative production, and the industry is currently growing at 30+% per year. Grid-parity could be as few as 5 years away (Solar is economically competitive in some markets today, like in sunny places with high electricity prices, e.g. Hawaii).
Simple Unexpected Concrete Credible Emotional Stories
If you decide you eventually want to actually do this the basic pricipal/theory/rig is this. 1. Get a solar panel, DC charge controller, large watt DC to AC inverter, and a few high amp hour deep cycle battery 2. Attach solar panel to charge controller, charge controller to the batteries, batteries to inverter 3. Plug you appliance in to the inverter and enjoy Realize this is a fairly large simplification and you should definately do some calculation involving the amount of watts hours you need to use versus the amount of watt hours the batteries can hold. Also you should do the calculations and shop around to find out how big of a panel you want, eseentially the bigger, the more expensive, the faster the batteries charge. And once again, THIS IS A SIMPLICATION OF THE WHOLE PROCESS not a definative description
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.
FalconShould there be a Law?
Mod parent up!
I've always tried to appreciate the technology I interact with in my everyday life. It gives me the insight to understand what we are capable of in the future. And how soon that future may be.
Mediocrity knows nothing higher than itself; but talent instantly recognizes genius. -- Sir Arthur Conan Doyle
Light tubes like the Solatube would come in handy here. However with a battery bank work could be done when it's dark. Last year or the year before IEEE's "Spectrum" had an article on how people in South Asia have been able to increase their income by buying a solar panel and batteries which allows them to do some work when dark. And the panels generate more income because they are made locally creating jobs. Ump, I just searched the site but didn't find anything, maybe it's only in the print edition.
Honda also makes some super quiet generators that are less of a pita than solar.
I'd only use generators as a backup, even when converted to run on alcohol or methane.
FalconShould there be a Law?
The guy wants solar-powered lights in a shed. We've debated everything but that, and we haven't asked basic questions: How much light does he need, and when? Is this to let him find the snow shovel in the dark, or is it to let him see what he's doing when he comes in from the sunlight? The latter will require much more power than the former.
Anyway, the best suggestion, IMO, is to adapt some ready-made solar lighting solutions. These generally turn the lights on at night with a photocell, but you might be able to replace it with a switch and put the light at the end of a cord while keeping the thing weatherproof. You should probably put a fuse in so a short in the cord doesn't blow the battery; apart from that the power and potentials (voltages) should be low enough to be safe. Here are a few products from a mail-order oufit:
http://heartlandamerica.com/browse/item.asp?product=wall--railing-mount-solar-light&PIN=46317&GUID=C9145FCD-C0AC-4D10-9C58-3EAA82C1CEB4&BC=60006005&DL=SCH6
http://heartlandamerica.com/browse/item.asp?product=4-pack-stainless-steel-solar-lights&PIN=23310&GUID=C9145FCD-C0AC-4D10-9C58-3EAA82C1CEB4&BC=60006005&DL=SCH7
http://heartlandamerica.com/browse/item.asp?product=2-pack-solar-accent-lights&PIN=38412&GUID=C9145FCD-C0AC-4D10-9C58-3EAA82C1CEB4&BC=60006005&DL=SCH4
Yes, they puff their descriptions, and some of their stuff is junk. I've bought a couple of things from them. If you read the ads critically you'll cut through the puffery; the stuff is rarely first-rate but it generally does what it says.
If you're trying to do this for environmental (or even economic) reasons then the most effective thing is to give your surplus panel to someone who needs it.
I'm assuming you have normal 110/240V power available and you want to do the solar thing to save the planet.
It will be cheaper to just use grid power for your lighting rather than spending money on batteries, chargers, inverters etc.
If you give the panel to someone who already has a remote power setup then you increase the benefit for them significantly.
After slogging through this thread, I figured that I've earned the right to throw in my two cents, so here it goes... Get a "solar generator". I'm a HAM and will be using one this weekend for field day. There are many to choose from, and for the record, the one we are using is a Solar Stik (solarstik.com). Expensive system, but extremely well built, no permits required for use, can handle the elements, etc. They have a fairly informative website, and they also have links to other solar generators for comparison shopping. Good luck!
A full-scale home lighting system is going to use vast amounts of electricity.
Maybe I missed it but I don't see where the person asking about DIY solar says anything about lighting a whole house, all I see is a "large shed", now what that means I don't know. And depending on what lights are used vast amounts of electricity may or may not be needed. CFLs use 1/4 the electricity of incandescent lights while providing the same amount of light.
Because it's a DIY project, requested by someone without basic electrical knowledge.
I have a problem with this too, I don't see where the person says how much electrical knowledge they have, or what type. Someone who knows AC may not know much about DC. A good example of this is with High Voltage DC transmission, I've heard licensed electricians admit they don't know much about it. That is a person may be able to design an AC system but not one that's DC. Where knowledge of both is needed is where there's an intertie.
FalconShould there be a Law?
Sorry, this is a duplicate post, but I am new here and accidently posted a reply to another individual's response. Here's my two cents: Some companies make "solar generators". You can do a google search to find them. They are... 1. 'self contained' & ready to operate right out of the box! 2. not required to have 'permits' for use 3. not 'application specific' and can be used for other purposes I'll be using one this coming weekend for Field Day (I'm a HAM operator). The one we are using is called a Solar Stik, and it's probably more than the average person can afford, but they have several other manufacturers of solar generators listed on their website. The solar stik website is actually a decent resource for information regarding solar power in general as well. Good luck!
I do wish they would bring back their guerrilla power features though :-)
Ah, I miss those guerrilla power articles, it's been several years or so.
FalconShould there be a Law?
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=95573
Amen to that. In fact the charging voltage on a car battery is only 1.5 to 2 volts over its current voltage to a maximum of 14.6 volts. (They have 2.1 volts per cell design max, for a nominal voltage of 12.6 volts. It is not unusual to find a car battery holding over 13 volts. blah blah blah) Putting 18V into a car battery for extended periods is not good for it. This is the other reason we use charge controllers...
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
I've heard of technophilia but... wow.
-- Programming with boost is like building a house with lego. It's a cool but I wouldn't want to live in it
I used Farrington Daniels' book Direct Use of the Sun's Energy as a starting point for several solar energy projects.
He lays out the physics in their elegant simplicity and shows Direct Uses of it as the title says.
Some writers suggest there are fire hazards, especially if you use batteries in your project. Those warnings also indicate that as an advanced amateur you really do need access to the design and installation and safety information used by the professionals.
For solar projects, the Code Check plastic guides at least cover solar electric inverter and wiring in outline.
It irritates me that Building Codes are copyright and building permit texts generally not available online.
It is too bad that example building permits and guides to drafting and writing a project are not available online. As an advanced amateur, what I need is a couple of well thought out example projects.
Even the Building Code used by San Mateo County is copyright and can not be reproduced on the Internet, which would be very helpful for people who want to build a solar energy project.
The vertical angle of the panel needs to change periodically to take advantage of maximum gain if this is to be a low buck simple easy first solar PV install. Ya, he can use one angle, probably a midwinter angle and get a lot of juice, but it isn't all that optimal either. Really, there is a reason they make adjustable mounts (and even active x and y trackers), it is a lot cheaper to add some cheap framing than to add more solar panels for the same amount of amps to the batteries. You really will notice it with just one panel. Active east west tracking along with it is even spiffier for efficiency gains, but that is still costly and usually only done on real high end installs, but manually adjusted vertical frameworks are by far the most common, because it just works and adds not that much to the total cost. I mean it's a little aluminum L or square bracket action and some bolts and wingnuts usually and a few minutes work once in awhile. And it really depends on where you live, too, how important this is, the further north the more critical (and it-geolocation- was not specified in original topic by submitter so I made a generic reply)
Uh... No. Batteries charge by drawing current. This will naturally cause a voltage drop on your supply. The voltage of the battery will be a compromize between the battery's (uncharged) voltage and the voltage rise due to the amount of current the panel is able to supply. The diode prevents the battery reverse "charging" the solar panel in the dark. This system works well in practise. The company that makes the systems here is Zimbabwean (so no URL - just take my word for it) uses relays to "regulate" the charging. The actually problem is with overcharging (and thus damaging) the battery by forcing the voltage above 14V if the system is left unused and charging for too long.
Your second point is probably correct though.
I have determined that my sig is indeterminate.
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.
This is a common trap by newbies to solar power who have not bothered to do the math. For the shed, the math works. For my home, it doesn't.
The assumption is wire will transport power from one place to another effeciently regardless of the source voltage. Low voltage is OK for very low power applications and very short runs, such as in an automobile and less than 100 watts.
For the shed, 12 volts may be OK as all the runs are very short and the application is for low power and short durations. The power miser looks at an inverter with 90% effeciency and go Oh! No!, that power waster has to go!
Let's make the shed a little larger, like a small shop. In the shed you want to work on the lawnmower and the LEDs are not bright enough and you would like to use the drill press. A single solar panel is about 60 watts. figure an average production of about 5-8 hours/day depending on location. In a week, you will have collected 60 Watts X 5 to 8 X 7 or about 2-3 KWH. For the weekend, you can run 2 42 Watt CF lamps for 4 hours each evening and still use the drill press on an inverter. The cost of converting the drill press and using 12 volt CF lamps would far exceed the cost of a 1KW inverter. 2 evenings of light is 42 X 2 X 4 = 2/3 KWH. Running a 500 Watt 1/2 hp Drill press for an hour won't kill the battery as it uses another 1/4 KWH. If we lost 10% of our power to the inverter, so what?
With the inverter we can run more than basic stumble in the dark flashlight brightness and get work done.
Now the math. The drill press uses 3X it's full run power for start-up. For grins try it on 12 volts. 1500 Watts at 12 volts draws 125 Amps. How long is your power cord? At 120 volts the draw is 12.5 Amps. Now for power loss. 10% of 1500 watts is 150 Watts to the inverter. How about a power cord to the battery 30 feet long?
1 It must handle 125 Amps safely
2 It must not drop the voltage to the motor by more than 1%.
For 120 volts the permitted drop is 1.2 volts. 1.2 Volts X 12.5 Amps is 15 Watts lost in the cord. (why vac cords get warm) At 10X the wire size permitted for 120 Volts (think 10 power cords in parallel) the 1.2 volt drop from 12 volts would be a very serious brown-out of 10%. Even worse is the power lost in the 10X larger cord. Instead of 15 watts, you now lost 150 Watts in the cord. You need someting much bigger than 10 X the wire size you needed for 120 Volts. Care to hit the wire tables to calculate the wire size needed to start the drill press with only a 1% voltage drop from the 12 volt system? Don't forget, a 30 foot power cord has 2 condutors, it's a 60 foot total length.
So what is the better way to get power to the drill press and lights? Mine runs fine on a 12AWG extension cord. The Xantrex pro-watt inverter was on sale at Costco for under $50. A 30 foot cord and 1/2 HP 12 volt motor would cost way more than that. On sunny days, I lug out the drill press and use it outside. A standard extension cord works fine.
In short, an inverter permits the use of high power short runtime tools at distances more than 5 feet from the battery. Without it, these uses are impractical.
The above is not based on a shed installation, but a motorhome with 8 panels and a pair of deep cycle batteries. The fridge, microwave, computer, monitor, and printer are all solar powered. Electric power tools are used from time to time and are the basis for the calculations.
Do you want just a few lights, or do you want to do more?
The truth shall set you free!
OMG, all my expensive solar panels blocked the light from my skylights! Oh, it's the Greener's Lament...
Uh, you DID plan skylights, didn't you?
Say, assuming here that your large workshop will be filled with high-current electric motors on all that woodworking equipment you have, and that you'll need a significant electric panel to power the place (loaded with 30-amp circuits). Why isn't high-efficiency fluorescent lighting and skylights the solution you seek?
If it is just a storage shed, why do you need more than battery-powered LED lights or an LED flashlight or lantern? It's not like you are going out there each day to fondle your possessions.
Which brings up the final point--why build a shed for storage? Just get rid of that junk and live frugally.
I would add couple things (that will out cost AC, currently):
1) DC has the advantage of a simple capacitor can handle startup surges, they can be spread around easily (don't need the wire sized for the surge then.)
2) You can run higher voltages of DC, split up your battery banks/solar cells to stack appropriately. 85% efficient 96Volt to 12 Volt @ 30 amp are available. They waste no energy during no/low load situations (AC inverters that shut off are becoming available, but can be a pain) If 96Volt DC devices became high volume, all the arguments you post disappear (except I am back to needing a permit for "high voltage" wiring.)
I would add, that although their efficiency is horrible, using air powered drills is the convenient way to go. IE my 3/4 Hp 1/2" air drill, weighs less than any 1/2 HP AC drill, has more torque, and the hose is not that much different than the AC extension cord. The expanding air, cools the drill keeping it much cooler. Except that it takes a 5HP motor at the compressor to run a 3/4 HP motor. (If I can just figure out how to solar power enough stored air, then their will be little need for AC in the shop.)
How are you supposed to learn unless you try?
Heard from a guy juggling flaming stuff on 15' up a free standing ladder "I'd say 'don't try this at home' but where do you think I learned it"
Sounds daemonic to me. I now believe that Edison didn't invent the light bulb but G~d thought him a shabby prometheus and tossed him a bone.
(AC inverters that shut off are becoming available, but can be a pain)
Inverters with low standby (full voltage output) are also common. My 1KW inverter has a 4 Watt idle. In a day it wastes 42 Watt hours, or 0.042 KWH. Since I collect about 1.5 KWH/day, I leave the thing on 24/7 and don't worry about resetting clocks, starting the inverter to turn on lights, etc. For a loss of .35% is isn't worth saving.
Look for inverters with less than 50 mA no load current. (not the sine wave units). Most stuff runs fine on modified sine wave inverters. Some stuff runs better as the peak currents on power supply recifiers is greatly reduced. Computers, monitors, and printers fall into this catagory, and these items are the first salesmen try to sell sine wave inverters to. Other items to run off sine wave include induction motors and lighg dimmers. Refrigerators run more effeciently off sine waves. I haven't yet bought a sine wave unit to run the freezer as most of the time it runs off the utility and the inverter is just back-up power for outages. For extended outages, I plug into the hybrid car.
Stuff that works fine on modified sine wave is basicaly anything that has a switching power supply.
Save the sine wave stuff for high end audio where a little buzz is a problem. For the rest of the stuff, a quality stepped modified sine wave is very effecient.
The truth shall set you free!
Be sure to get enough mirrors.
Slashdot "libertarians": Small government for me, big government for those I disagree with. -1, I disagree with you
Short question, short answer:
http://knowledgepublications.com/
They have a substantial collection of books covering everything from alternative fuel sources to solar.
ja