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Picture of Make a high powered solar panel from broken solar cells
In this instructable, I will give you a practical guide to building a large solar panel from broken solar cells.

Step 1: Tools needed

Picture of Tools needed
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To start making solar panels from broken solar cells you need a few things.
1. 15-25 watt soldering iron
2. Light duty 60/40 electronics rosin core solder (radio shack $5.00 for a roll). You can use a silver solder, but I think its too expensive, and the difference in resistance is minimal. So I just use regular old electronics solder.
3. Multimeter
4. Pencil eraser
5. Solar tabbing pre tinned ribbing (ebay 100 feet is like $20 bucks)
6. A good flat sturdy working surface ( I use a piece of glass, but whatever you have will do)




 
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I am new to this stuff. so I'm not being sceptical, but I am wondering how you use this if one does not have an inverter.
your can use it without and inverter unless you have DC appliances!
can't
I think many of the 15.4 inch notebooks use 19 or 20 V charger. So it could be probably used to charge/power one of those. I would recommend some voltage stabilisation.
Yes, this is the voltage that a 15.4 inch notebook would use normally, but you have to remember the current on the chargers as well. Most of them are in the excess of over 65watts. This solar panel would only be able to produce around a 10 to 12 watt max power. So yes it could probably charge a laptop but after a day or so of direct sunlight. It could never power a laptop unless it is big enough for a 65 watt which would be a very big solar panel.
mattfelice (author)  johnsocm6 years ago
is a full 35 watts, not 10 to 12
If you use it to charge a battery or other DC powered device, no inverter is necessary.
conora2b5 years ago
Hi Matt
this is a really great guide but im kind off stuck on my own project

I am running a 24V battery bank for my wind turbine and want to add solar to the same bank so far i have bought 110 3"x6" solar cells rated as follows,
0.5v x 3.5a = 1.75w each

this is what im thinking off so far please correct me if im wrong in any part of it
to get 24V i need 48 cells in series and 2 sets in parallel (94 cells in total 24V + 7a) to make the most of my cells im thinking of building a 26.5V panel (104 cells in total 26.5V+7a)

is this the right way to go about it or should i lower the volts and increase the amps going to my battery bank and if so will it still store a a 24 v charge?
let's do the math for 100 cells @ .5V x 3.5A. In series you will get, (.5V x 100 = 50V) by 3.5A and in parallel we will get .5V by (3.5A X 100). So in series we are getting 50V x 3.5A = 175W. In parallel we are getting .5V x 350A = 175W. Notice how the output is the same regardless of wiring. A good rule of thumb is to charge at least a rate that is 1.5 times the voltage of the battery bank so 24V Battery Bank x 1.5 = 36V.
Hello,...can I charge a bank of say six battries with this?.and if so how long in good sun?..I'm old and new to all this solar bussiness,and really hoping this old dog can learn a few new things,Thanks John
Depends on the voltage of your battery bank. You would want the voltage to match the input voltage of the inverter. The most readily available inverter is 12 Volts. So if your battery bank consists of 6....12 volt batteries you will need to wire your batteries in parallel (1 wire + to + and 2nd wire - to -) if you are using 6- 6V batteries, you will need to wire 2 batteries in series (+ to -) and the rest in parallel to maintain your 12 Volts. To determine how long it will take to charge depends on the amp hours. So lets say your battery bank consists of 6-12V batteries rated at 30amps. So we have a total of 180 amp (30 amps x 6 batteries = 180 amps total). Let's say our panel 75 watts @ 18V. So to find the charge rate per hour we need to amps. Panel 75W/18V = 4.17amps per hour. so to find how long it would take to charge a dead battery bank we would take total amps 180/4.17 hour charge rate = 43 hours of sunlight (but a bit more for inefficiencies). That in mind, when you buy batteries, they are usually pre-charged so you aren't starting with a dead battery bank!
johnhearty3 years ago
where can i get those materials?please because we have a project in physics
check on eBay!
snernz11 months ago

stove. HA HA

zachninme7 years ago
Wow, that's easy: thanks! How do you know positive from negative?
mattfelice (author)  zachninme7 years ago
With all mono and poly crystalline cells the bottom is positive and the top is negative. Or you could just use a multimeter.
But, how do you tell bottom from top wo/ a multimeter?
mattfelice (author)  zachninme7 years ago
When I say bottom I mean underneath or the back, the grey side, sorry about that
How many volts to amps can you expect from such an arrangement thanks Dave'

I realize this is an old thread but it still seems pertinent. If anyone is following,I am wondering if there are any current *haha threads going. And, so I don't lose the thought, could one utilize graphite as a conductor? Thanks.

Why does the tabbing need to go all the way across the top? I mean as opposed to just cleaning the end of the busbar and soldering a small tab to it? Sorry i've never seen a solar cell. Also if a shard of cell doesn't have a dark spot on the back side, is it worthless, no place to solder?
aaperkins882 years ago
About how much money did this run you? Am I crazy to consider powering a chunk of my home using broken PV's?
cheesphht6 years ago
The hardest thing for me to build is the protective encapsulator. Do you build it out of glass or poly? and how was it put together? Or just direct me to the site where instructions to build such an enclosure is available. I want it strong enough to sustain winds but also light enough to put on by telescope's tracking device during the day.
There is a clear silicon two part many home builders use; but it runs around 50.00 a can. It is mixed and poured on the panel while it is face down and a brush is used to spread it.
mattfelice (author)  cheesphht6 years ago
i just made a simple wood frame painted, caulked, with a plexi top
Thank you mattfelice for answers about broken cells and panels. For new guys this is a critical part of making your own panels. Yours is the best statement I have found on the web.... ps/ What's the minimum size (% of a broken/chipped cell) I should use in a panel? Does the size of a broken cell used in a panel matter? If so, what's the rule? Thanks in advance
There really is no minimum size, you just have to remember that a couple of solar cells wired in series is only as strong as their weakest link. So if you wired a piece that was producing 200 milliamps in series with some that produce 1.5 amps it's only going to produce 200 milliamps. So if you use small ones, make sure they're only in series with other small ones.
fat644 years ago
I just ordered some broken pieces to sweden for a first hands on experiment. Taking the time to document this is what generates real wealth, thanks for sharing matt. 35 Watts sounds impressive for that, where in the world do you live btw? :)
lampajoo5 years ago
Could I use regular copper wire instead of the ribbon?
mattfelice (author)  lampajoo5 years ago
Sure. Copper wire should work fine
blacmis6 years ago
There is a VERY informative book "build your own solar panel" by Phillip Hurley that would answer every question on this thread and more. If you really want to build a solar panel and make it easy and be confident doing it. Check the book out.
Wow, that looks kind of hard, and looks like you have to be concentrating a lot not to mess up. Nice job!
mattfelice (author)  GorillazMiko7 years ago
Yeah, what makes it hard is how thin and fragile the cells are. The first batch I got, I couldn't believe how thin they were.
hey, so the top of the cells are negative and the bottom is positive? ive seen a few being constructed and the engineer always just soldered the top two ribbons and nothing underneath. am i seeing things right? also great project, im trying to do the same but i can't believe how thin theses are. im trying to connect about 40 of theses in series but its hard to know what the best steps are to make them into one huge panel. aslo which is the best way to arrange them, parrallel or in series? thanks, Mike
How Many Volts do you need?, amps? Series gives you more volts and parallel gives you more amps. You can combine the two to make it more suited to your needs: If each panel, +{lllll]-, produces 1v and 1amp then this panel produces 5v and 4amps
solarpanel.jpg
ahh ok thanks for the reply. now i get it.
Angus066 years ago
Yeah going along with what blindsided said, how is it that you wired those all in series and managed a whopping 1.85A out of that?
mattfelice (author)  Angus066 years ago
to gain the amperage you want just wire a few in parallel to make a "single cell, then continue the series. You can see examples of this on my panel
bomberss276 years ago
What are the dimensions of the entire solar panel? Also, how do you attach this to a charge controller or alligator clips which I could use to attach to a battery?
mattfelice (author)  bomberss276 years ago
its about 4' long by 15" wide
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