Several years ago I built a 60 Watt solar panel. It's a great panel. I still use it a lot. However, it is big, and heavy, and I don't always need 60 Watts of power. Sometimes I just need a little power for a portable device or two. I'd like to be able to charge up my cell phone, or MP3 player without having to lug around the big solar panel. I'd also like the panel to be more compact and easier to pack when I am traveling light. So I decided to build a 15 Watt Solar panel that folds up to be more compact. Some people may complain that it is too much effort, and doesn't save enough money to make it worth the trouble of building their own 15 Watt panel. For me though, it is all about the joy of building. Anybody can buy a solar panel. How many people build their own? Plus it folds up, which most commercially made panels don't do.

I experimented with putting plexiglass covers over both halves of the panel, but in the end decided not to use them, so those steps are omitted from this Instructable. You can see the mistakes I made, and the omitted steps, and lots more about constructing this solar panel on my web site. See also my home-built wind turbine and home-built biomass gasifier alternative energy projects while you are at my web site.

Here is a video walk-around of the finished solar panel. This Instructable will explain how I built it.

Step 1: Getting the Solar Cells

The main stumbling block to building solar panels is acquiring solar cells at a reasonable price. New solar cells are very expensive, and can even sometimes be hard to find in quantity at any price. Blemished and damaged solar cells are available on Ebay and other places at a fraction of the cost of new perfect cells. These second rate solar cells can be used to make a solar panel that will work just fine.

My first solar panel used 3 X 6 inch monocrystalline silicon solar cells. They are highly efficient and produce a lot of current. But they are also big and delicate and difficult to work with. For this project I decided to use a different kind of solar cells. I used 40 thin-film Copper Indium di Selenide (CIS) solar cells. Each cell is actually a miniature solar panel 60mm x 60mm x 2mm thick, that will produce a little over 4.5 Volts and 80 mA in bright sunlight, that only comes out to about 0.375 Watts per cell, but 40 of them together produce the 15 Watts I was targeting. I would wire them together in groups of 4 cells in series to get about 18 Volts, and then wire the groups of 4 cells in parallel. I would divide the 40 cells into two groups of 20 and build a folding box to mount them in. I bought 40 of the (CIS) solar cells off of Ebay and got to work.
This is really a great project.<br> But I learn a lot how to make it own at cheap rate<br> from a blog, and engineer explain everything on his website<br> Please look at his Solar Panels Website <a href="http://topdiysolarpanels.com/" rel="nofollow">http://topdiysolarpanels.com/</a>
Since I'm not keen on this stuff, could comeone please tell me what type of things I would be able to use this panel for?? like fans.. Joe forman grill... or what?? Thanks -M
it can power a 15 watt 12 volt light bulb ;)
12V AM Radio
Looks great! I designed a similar panel a few years back, but never got around to building it. Mine had an extra hinged panel and folded up like a 'Z'.
Hi, some PDF files on this subject you to send me an email
Excellent project, ideal for camping.
Hi, some PDF files on this subject you to send me an email
Hi,<br><br>You've posted a comment on my question and it seems to me that you have the answer to what I am looking for, but I would want to know if my Panel is rated at 10.4v max .223A and 2Watt Peak, what particular diode should I use to be connected in my system should I intend to charge 4 NiMH batteries rated each at 1000mA and 1.5v. <br>I believed you could help me with this since it seems that your experiment is relative to what I am doing and the difference is that its a smaller system.<br>I just want to make sure so that I wont risk of wasting everything that I have started, Thanks and it really feels good to have someone to advise me in this kind of field since I was only new.<br><br>Thanks and Best Regards<br>
Any Schottky diode rated for 1 Amp or more would suit you. <br><br>Also I think you need a controller to charge NiMH batteries
After reading your website I had the thought of adding washers under the plexiglass at the screws securing it. This would allow for venting heat but still protect the cells. Good work and I enjoyed the information.<br><br>
Good project but Im working on a smaller 5W,Solar Charge 12VDC 4.5AH Portable Power Supply as 15 it a bit too big to fit my camera bag &amp; mini Net book .<br>I can now charge Hand phone,Laptops &amp; a convenient 66W 12 DC Supply! in place without Electricity. Woohoo!.wooitimothy@gmail.com, facebook: Timothy Wooi Malaysia
Nice work!<br><br>Sometimes I do this with thin-film panels. They are really strong because they are flexible and won't break when dropped. Also they can be rolled up. <br><br>It would be super cool if the thing could be partially shaded and still work. I think most arrays won't work unless they have full exposure to sunlight. There are some foldable military-spec ones that work under a variety of conditions including shade and fold up very small. <br><br>
nice project, maybe you should try building it into a suit case, that way it cuts out the cardboard box <br>
What devices can this project charge (5 volts dc?)? Can I charge cell phones? How long should I leave my devices on the panel wire connection? If I leave some devise on the charger will it burn out? Can it put out 12 volts? I have a lot of twelve volt devices. Thanks.
Remember, 5V is what comes out of USB sockets. Most devices that use this only draw 500mA (2.5W). Therefore this panel could charge 6+ devices at once in full sun, or 1-2 reliably on a dull day.
I found these cells on electric goldmine.com for 1.69 USD a couple years ago. I totally should have bought up about 40 of them. Great idea though, I personally like these glass cells better than the silicone wafers because they are more durable.
hi! cool solar panel! i might have a possible fix for the voltage drop you mentioned on you web site. ive bought these cis cells before and have read from several web sites about stableizing the cells before puting load on them or building panels. These cells should be placed in full sun for several hours with no load, unbuilt, before you do anything with them. This lets the cell become chemicaly stable and repairs imperfections in the cell. ive only bought four of these cells, but did the sitting out in the sun thing first, and have never seen too much of a voltage drop at high tempetures (the cells can get almost too hot to pick up). each of the four cells never get below about 4.2 to 4.3 once they are hot. hope this might help.
Awesoem project!

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