Make a High Powered Solar Panel From Broken Solar Cells

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Introduction: 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

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)




Step 2: Overview

First get some solar sells.
Solar Cell Grab Bag
Electronics goldmine Solar cellsEbay
Thats just a few examples of where you can get solar cells, but it gives you a start.

First lest discuss parallel and series wiring

Parallel wiring increases amperage and voltage stays the same. Each cell in a parallel circuit is wired positive to positive and negative to negative.

Series wiring (mostly what you will use for solar cells} increases voltage and amperage stay the same. Each cell in a series circuit is wired positive to negative, the remaining positive and negative are you leads. You'll notice batteries in flashlights installed in series.

Now that you have your batch of solar cells we can get started!
First separate the cells in approximate similar sizes.
Remember if your wiring a group of cells together in series, the smallest cell in the circuit will dictate your panels amperage. Regardless of the size of your cells, each will produce about .5 volts. The bigger the cell typically the more ampreage you will get. So you wouldn't want five 6" cells with one 1" cell in series, because you would loose the amperage of the bigger cells and only output the amperage of the 1" cell. Basically try to keep the cells around the same size.

Most solar cells ( poly and mono crystalline) the positive side is the back of the cell and the negative is the front of the cell.

Step 3: Getting Started

Now that you have your batch of solar cells you must determine if each cell has tabbing on the busbar. If if does continue to the next step.

If your cell has no tabbing you must first use a pencil eraser to clean the surface of the busbar. Use a gentle hand as poly and monocrystalline cells are extremely fragile. Rubbing too hard will break the cell. Some of the dark spots on the busbar will hinder the solder from sticking so try to get these off. Don't go crazy if you can't, as long as a descent amount of solder sticks you are OK. The more you use the eraser the better.

Next you must tin your soldering iron with a nice blob of solder, and wait a few seconds until it stops smoking(some of the rosin burns off), then run it down the busbar. Don't beat yourself if you can't get every spot to stick as long as you can get a few spots you're good.

Now cut a piece of tabbing and use your soldering iron to melt the tabbing into the tinned busbar. Don't press down too hard let the soldering iron do the job. Thats why I suggest using a 25 watt minimum soldering iron so that you don't feel the need to press down on the cell so much.

Now that you tinned and tabbed your first cell continue and do the rest.

Now you must solder a lead to the back of the cell. Most polycrystalline cells have a dark area on the back, this is where you solder to. MonoCrystalline cells usually have small squares where you need to solder to. Just like before start by tinning your soldering iron with a good blob of solder and apply it to the underside of the cell directly under the busbar (makes it easier to line up the cells later). Then cut a small 1.5 inch of tabbing and melt it into the solder.

now that you have your leads soldered to the cell you are ready to move on to the next step.

Step 4: Wiring the Cells in Series

Now we can start wiring the cells in series. Using the tab we soldered to the back of each cell will now be used to connect to the front of the next cell.

Line them up and melt the tabbing from the underside tab on one cell to the top of the next cell. Keep doing this and you can get as many volts as you want. Remember if you don't plan on using a charge controller you will need to install a reverse flow diode on the positive side to prevent the batteries from draining during the night. You can get them at radioshack, or ebay or where ever you choose.

Thats basically all there is to it. Then all you have to do is make an enclosure of your liking, seal it all up and you have yourself a solar panel. I used a piece of painted plywood some pine peices for a frame and a piece of plexyglass all sealed together with silicone.

Step 5: You're Done

Put that bad boy in the sun and have pride when you tell people you made it yourself for pennies on the dollar.

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70 Discussions

Where did you get the broken solar cell pieces? Is there anywhere cheap to buy, or maybe pickup from a dump somewhere near a solar panel factory? I'm in LA...

2 replies

We have an office in
LA , We have lots of broken panels and they are much cheaper than the new panels but they work really well. Look up and check out my post with the pics .

Shoot an email to me or call me Doug@FortuneEnergy.net

916-492-2797x807 9-5 im in Sacramento but we have another warehouse in Chatsworth. I could sell you the panels from that location .

You can buy broken cells for cheap at ebay, look for it. What's more, look up a video of Cody's Lab youtube channel explaining further how he made his own solar panels with an old window and some stacks of broken cells he bought on ebay. You're lucky in that sense to live in the USA, there are always those kind of things there, unlike here in Spain :P

Guess that was ur first one cause i think ur wasting alot of space there looks like lol.

Hello My name is Doug and I work for Fortune Energy . We are a wholesale supplier of Solar materials. We have panels, inverters, racking, and even a design team here to answer questions or make your designs come to life. But i also have broken solar panels . I included pics. I have many panels that are just shattered . The glass is shattered and we cannot sell them with the warranty anymore, so i am going to offer them online to all of you DIY's. I have 255 watts and up Solar World, Canadian Solar, Q-Cell all the top brands. I have inverters and racking as well. Give me a call 916-870-4209x807 or email me Doug@FortuneEnergy.net and we can talk about your needs.

Thank you,

IMAG0209.jpgIMAG0210.jpg

Hi, I had a question about the panel. Do you connect the columns together? ty

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.

6 replies

your can use it without and inverter unless you have DC appliances!

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.

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?

1 reply

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

1 reply

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!