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DIY solar panel substrate (discuss.tchncs.de)

submitted 1 year ago by Rolive@discuss.tchncs.de to c/diy@slrpnk.net

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I'm interested in building my own solar panels mostly for educational purposes. The idea is to use individual solar cells and solder 36 of them in series to get about 18V open circuit voltage. It's what commercial solar panels have as well so its easier to integrate later.

The cells are bonded to the substrate using optically clear silicone or EVA. Not sure which is better. Polyurethane is not good because the mere mention of humidity will cause tons of bubbles.

As for the substrate. Optically clear tempered glass is prohibitively expensive unless bought in bulk. Normal glass is significantly cheaper but could that be a safety hazard? I seriously doubt that thermal shocks are strong enough to break glass sheets unless cold rain falls on it.

Has anyone tried plexiglass/acrylic? It's UV resistant but could bend/warp at higher temperatures breaking the cells.

Perhaps using screen protectors for obsolete phones/tablets could work as well. It's really thin and strong but I don't know it holds up in a hailstorm.

Would love to hear from your experiences in DIY solar panels.

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[–] photonic_sorcerer@lemmy.dbzer0.com 5 points 1 year ago

Any SiO2-based glass should do the trick. That's what we deposit onto solar cells in the industry. Idk about keeping polymers like that out in the sun too long, but it's possible it could work without melting too much, depending on which one you land on. Bubbles in the bonding layer shouldn't matter much, but it's good practice to try to avoid them.

[–] perestroika@slrpnk.net 4 points 1 year ago* (last edited 1 year ago)

I have tried polycarbonate, with miserable results. The clear silicone did not not adhere well, and thermal expansion ratios were in mismatch - the panel destroyed itself soon, interior components separated from the polycarbonate, the panel was mounted vertically and deformation started (tracks started curving downward).

Test thoroughly and if you have doubts about mechanical resilience, maybe use the panel horizontally.

Glass is a silicate, and may have the unique advantage of expansion ratios matching silicon wafers.