Glass and encapsulation....

[Nefariis]

I was panning on using glass and resin to finish off my solar panel, but then I got to thinking - is the glass even necessary?

Hear me out.

say you have your backing, then you put a layer or resin down, let that dry (or almost dry) then put down the solar cells, frame it, and then fill with resin. Wouldn't that be the same maybe even possibly better then using glass? - No moisture could form behind it, its water proof, and it would never break like glass.

Just wanted to hear some thoughts for or against.

[FunGas]

Glass is stiffer than resin.

When you pour the resin, it gets between the glass and the cells, totally sealing off that nasty oxygen...

[Mike90250]

When you pour the resin, it gets between the glass and the cells, totally sealing off that nasty oxygen.

And then there is:

Glass is UV resistant. resin is not, it will turn yellow and crack in 2-3 years

Resin is not Oxygen or water vapor proof. Water vapor will get inside and find voids and start to condense. Then the cells die.

[Nefariis]

This might be a noob question - but I couldnt find any links anywhere on the net of people actually trying it.

6-8 coats outdoor water based polyurethane.

It will never yellow or crack, should hold up for years, can always sand it down a little and reapply coats.

It seems like a much better solution than epoxies or resins.

[russ]

This might be a noob question - but I couldnt find any links anywhere on the net of people actually trying it.

6-8 coats outdoor water based polyurethane.

It will never yellow or crack, should hold up for years, can always sand it down a little and reapply coats.

It seems like a much better solution than epoxies or resins.

Please do - just don't complain when it all goes to hell in a hand cart.

[Nefariis]

well that's not helpful.

In what way? and what are the drawbacks?

And please don't read the above to be confrontational, it's not intended to be - I was just hoping you could elaborate more than "hell in a hand cart."

I just called a sealant specialist store and his only concern was the ability of polyurethane to adhere to silicon based solar cells - but it looks like most people uses some sort of polyurethane to encapsulate their solar cells.... so Im not sure what to make of it.

Also I did find one person that did it: http://www.homesteadingtoday.com/cou...lar-panel.html

Thanks

[Mike90250]

There has, over the years, been developed a very simple "sandwich" to seal PV cells, and not have thermal expansion tear them apart.
Glass (top)
EVA (heat melted so it turns into glue)
PV cells
EVA
Tedlar back sheet.

The glass and tedlar provide moisture protection, and the EVA is compliant enough to not stress and crack the cells for 20+ years.

Variations are less successful after 3 years.

Water Vapor in the air, is what migrates through most paint, epoxy and silicone sealers and gets trapped at the cell as water, which corrodes it at a microscopic level. Since the metal plate layer that conducts the electricity is only a couple atoms thick and see through so that the cells work, only a little corrosion is needed to kill the cell completely.