Our love for solar projects continues on with this method to make your own solar panels. [Mike] built a 60 watt solar panel from individual solar cells he purchased off eBay. Procuring parts off of eBay normally causes others hardship when they try to duplicate the project, however in this case there are so many types of cells people can use to produce their own unique solar panel. Even cells that are extremely damaged my still be used, as in this example. To charge a 12 volt battery the number of cells in series just needs to be 16-18 volts, and the rest in parallel will supply more current. Charging a battery without a charge controller is not recommended, but commercial ones are easily had. Those not interested in jumping all the way in with solar may want to test the waters by building their own panel and putting it to use as a charging station for your portable gadgets.
Be careful, the cells need to be isolated by diodes otherwise there is a possibility of fire. If one cell becones obscured by a shadow current will flow into that cell like a shorted battery(a 600mV battery) and heat up.
I’ve been digging around the net as much as possible for info on DIY panels and nowhere have I seen anyone mention even the possibility of solar panel catching fire!
I am in the process of building a single 130 watt solar panel from 72 3″x6″ cells (which turned out to be 3.2″x6″ so have had to re-adjust my plans slightly), it will be just over 1 meter square, using acrylic instead of glass and will be held rigid with L-shaped aluminium angle bolted to it & sealed with a silicon substance as it will be permanently outside (and here in the UK the weather is often very wet).
One thing to note about the cells used in the panel pictured (the same as the ones I’ve got) are that they are fragile as hell & as brittle as glass, I measured one to be 0.33mm thick. One of the batch I bought arrived broken (it did travel halfway across the globe) so it gave me the chance to see just how brittle it is, it’s now in several pieces and I’ve learnt to treat them with the utmost respect, thankfully the eBay seller sent me 80 instead of the 72 I ordered, which leaves me with 7 ‘error margin’ cells.
Still waiting for the tab ribbon to solder the cells together though :(
BTW if you’re wondering how the professionals put their panels together with these types of cell: http://www.youtube.com/watch?v=qYeynLy6pj8
I have a small 30watt Kyocera brand solar panel which is 25 years old, it still works fine giving out 24watts peak so the commercial ones are definitely built to last.
this is a good point, here is a PDF that discusses this.
http://scholar.lib.vt.edu/theses/available/etd-11698-16389/unrestricted/Chapt_4.pdf
Jason Rollette
I don’t keep up on solar technology, but I thought BG Micro had an interesting deal: http://www.bgmicro.com/index.asp?PageAction=VIEWPROD&ProdID=12269
Copper Indium Diselenide, 4.5V at 90ma from a 2×2 inch cell, for 2.50 if you buy 50 of them. So that’s about 48 watts for $125, $2.60 per watt. I’ve seen some interesting auctions on eBay for the same type of cell, might even be cheaper.
Also: please fix the comment box. Just try using it, you’ll see what we mean.
Individual cells don’t need blocking (usually schottky) diodes but panels do when put in parallel to stop them trying to feed power into each other, and you can use a schottky diode on small panels to avoid having to use a charge controller. Larger panels require a charge controller to stop the battery from being over-charged.
macegr, those 2*2 inch cells are 0.405 watts (4.5v * 0.09A), 50 of them would make a 20.25watt panel for $124.50, $6.18 per watt. Not a complete bargain and not a terrible price either, but they look great for someone wanting to make a panel without having to deal with ultra-fragile cells.
Um I think the both of you are wrong on your calculations.
If you need lets say about 18 volts for charging a battery,
so if you ran 4 of these cells in series (4×4.5v gives you
18v @ 360ma) now if you ran 12 of those in parallel that gives
you (12 x 360ma) 4.32 AMPs or a panel that produces (18v x 4.32AMP)
77.76 watts with 2 cells to spare. because your not going to run 50 cells in
series, while your calculations are right haku, you dont want
a 220v solar panel.
Thanks Olly I was researching that because what haku said
did not make sence to me. By the way that come out to about
137.45 with shipping thats 1.76 a watt. A 80 watt panel runs
about 400-500$ and for a 500$ 80 Watt panel thats about 6.25$
a watt. So its about a 3rd of the price. I need a beer!
olly,
Identical cells (or batteries) in series you add up the voltage. The ampage stays the same.
Identical cells (or batteries) in parallel you add up the ampage. The voltage stays the same.
4 of those cells in series gives you 18v @ 90ma. 18 * 0.09 = 1.62 watts.
4 of those cells in parallel gives you 4.5v @ 360ma. 4.5 * 0.36 = 1.62 watts.
The total wattage always stays the same no matter how the cells are joined.
If you wanted to make a panel with those cells you’d do better with getting 52 & putting them in a 13×4 grid array, wire up 13 sets of 4 cells in series, and put those 13 sets in parallel (all the pluses together & all the negatives together).
In that 52-cell configuration you’d end up with 18v @ 1.17A, 13 x 0.09A (90ma), 21.06 watts.
where did you get the cells from
and how much
The cells I have were bought from http://search.ebay.com/_W0QQfgtpZ1QQfrppZ25QQsassZlifestylephoto but they’ve not got any listed at the time of posting this, they were $4/cell + postage (and annoyingly + import duty, that’s rip-off Britain for ya). They must still have literally bucket loads because if you look at their completed listings you’ll see they didn’t sell all the cells listed.
just goes to prove that solar power needn’t cost a fortune
does anyone know of how to make a 130 watt panel
what size cells amps and volts what is the formula
for figureing this out first experience in solar in series or parallel tell me more live in USA GA.
yea i found some good cells on ebay and put together a simple panel. hasn’t caught on fire yet..knock on wood
I am building panels, you only need blocking diodes in series with your panel to stop the current flow in the dark!
Individual cells will not heat up enough to burst into flame, unless the supporting medium is tinder dry tissue, and even then I doubt that even here in Aussie where the sun is somewhat hotter/longer than the uk :-)
Mike
Where did you get the Frame from?
Nice information. Here is a link with information about building your own solar panel (DIY) with information about diodes and how to use them:
http://www.xs4all.nl/~hante/zonnepaneel.html
In short: a blocking diode is only needed when the panel is connected to a battery or when panels are in serie and not protected by bypass diodes. A bypass diode is needed to protect individual cells, but the protection is done over a series of cells, otherwise costs would be to high. A bypass diode is to prevent cell(s) from breaking when they are in the shade while others are not. They break because they will basically burn up, they wont burst into flame, but do break and in that case your panel will be useless.
Sunny
The solar panel prices have drop a lot the last year…I am not sure if economically has any value building a solar panel by yourself. However if someone enjoy diy things there is a point doing it.
Just goes to show you DIY Solar power is posible with very little up front cost.
This year should bring us a lot of new tech on building you own home made solar power.