Cutting solar cells

[bcroe]

Thanks for your answer. Where can I learn more about cells collector topology? Or which is the recommended topology for a diagonal cut? I want triangular cells to assemble an artistic solar application. Not needed to last for long term. Maybe one or two years.

The collector topology is designed for an uncut rectangular cell, and you can't change it. A diagonal
cut will leave some areas over "collected", others practically cut off. The pattern on the front is one
thing, another appears on the back. Its a bad idea if you need to maintain cell efficiency. It would be
a nice problem to actually model the geometry and see what you get (as some circuit board designers
have done). good luck, Bruce Roe

[jflorey2]

Thanks for your answer. Where can I learn more about cells collector topology? Or which is the recommended topology for a diagonal cut? I want triangular cells to assemble an artistic solar application. Not needed to last for long term. Maybe one or two years.

Hard to say without a photo of the cells. A common method is to put continuous electrodes along both sides of a cell with narrow electrodes across the center. In that case, a diagonal cut will result in two cells each with a little less than half their original power output. If only one edge has the continuous electrode, then after the cut one half won't work at all and the other will give you ~50% of the original power.

[Rubenz]

Depends on the topside current collector topology.

Thanks for your answer. Where can I learn more about cells collector topology? Or which is the recommended topology for a diagonal cut? I want triangular cells to assemble an artistic solar application. Not needed to last for long term. Maybe one or two years.

[Mike90250]

Cutting cells at home, works, for a while. The stress and micro-cracks initiated with the cutting, will slowly propagate over the entire cell and eventually ruin it. Factory cut cells are annealed after cutting to prevent this. So you can expect a couple years before they go bad

[jflorey2]

I suscribed to this forum about cutting cells because I have a question: What happens if I cut the cell in diagonal just to obtain two triangular cells. Would it work?

Depends on the topside current collector topology.

[Rubenz]

I suscribed to this forum about cutting cells because I have a question: What happens if I cut the cell in diagonal just to obtain two triangular cells. Would it work? Could they be joined in series?

[thediylife]

You would usually cut a solar cell in half if you want to get more voltage out of the same area (number of original cells). If you only wanted or had 18 cells which each produce 0.5V and you wanted to produce an 18V panel to charge a 12V battery then you could cut the cells in half and connect them all in series thereby creating an 18V panel. The wattage would stay the same as the original combined 18 cells but you would now have 36 cells connected in series.

As far as cutting the cells is concerned, a craft knife works, you just have to be careful.

or diamond file apparently

Should I get specs for the Tabbing Wire also? I see you can tell this is for busbar, I wasnt to sure.

Okay so I should get the Spec sheet of the Cells now?

To test Temperature. I use a Heat Detector Tester to test how hot the cells get When Finished the panel?

Now comes the hard part yes.. Im not sure I understand what to do, and how to calculate this.

For a Guy like me Im not to great at math.
im just wondering how you calculate this

[jflorey2]

Okay I got the tabbing wire or busbar information. the 0.16x1.8mm
So just wondering about how much electrons can go through this. Without degrading the cells and such.

How much current will be allowed to go through this

1, copper: oxygen-free copper content ≥99.97%

2, copper resistivity: OFC ≤0.01724Ωmm2 / m

3, the coating composition: 60% Sn 40% Pb

4, solder melting point: 179-224 ℃

5, coating thickness: 0.01 ~ 0.04mm can be customized, double-sided uniform coating

6, ribbon elongation: soft state ≥25%, ≥15% semi-soft state

7, the width of error: ± 0.05mm thickness error: ± 0.005mm

Good data.

From the busbar dimensions you can calculate the resistance per meter of busbar. 1 amp will dissipate 1 watt when sent through a 1 ohm resistor, so now you know power dissipated given current.

Now comes the hard part. You have to calculate temperature rise per watt, or degrees C per watt. That's a common spec in electronic devices, but you won't be able to calculate it easily for your application, since things like encapsulant thermal conductivity, soldering method and glass type will influence it. You can test this to see what it actually is.

Once you have that, then determine the hottest temp the cells can tolerate. That will give you maximum amps. 1 amp is 6.241×10¹⁸ electrons per second, so now you know how many electrons can safely go through it.

Okay I got the tabbing wire or busbar information. the 0.16x1.8mm
So just wondering about how much electrons can go through this. Without degrading the cells and such.

How much current will be allowed to go through this

1, copper: oxygen-free copper content ≥99.97%

2, copper resistivity: OFC ≤0.01724Ωmm2 / m

3, the coating composition: 60% Sn 40% Pb

4, solder melting point: 179-224 ℃

5, coating thickness: 0.01 ~ 0.04mm can be customized, double-sided uniform coating

6, ribbon elongation: soft state ≥25%, ≥15% semi-soft state

7, the width of error: ± 0.05mm thickness error: ± 0.005mm

Yes thats what Ive been seeing as well.

[SunEagle]

You certainly can. But you don't get the best of both types of cells - you get the worst. In other words, you could put two poorly matched 5 watt cells together and end up with 1 watt instead of 10. If they are very well matched, you might get 10 watts.

I agree. The technology is such that you will not improve by "adding different things together" but more than likely regress due to the multiple weak components.

[jflorey2]

So you guys firm on the idea you cant mix 2 different kinds of solar cells together.

You certainly can. But you don't get the best of both types of cells - you get the worst. In other words, you could put two poorly matched 5 watt cells together and end up with 1 watt instead of 10. If they are very well matched, you might get 10 watts.