Acrylic/Perspex v Glass

[Apollo1972]

I have been doing a lot of research of the diffs between Glass and Acrylic/Perspex. However my research has not fielded a definitive "NO" for acrylic/Perspex. If the glass is iron free and toughened, this is the panel front. But I have seen perspex that is said to be 7 times the strenth of glass, that is also UV Protected (not yellowing) and some sheets @ 5 or even 6mm thick I would think would not lose shape and warp.

So has anyone actually built a panel with acrylic/perspex??? does it "weather" well???

[Mike90250]

It's soft and will scratch easier than glass. It also burns when a cell in a panel overheats.

[solarchris]

I've Used Acrylic Instead of Glass In A Solar Panel Before

So has anyone actually built a panel with acrylic/perspex??? does it "weather" well???

I've built a solar panel using Acrylic instead of glass. I wrote up a guide on thesolarpowerexpert.com using this technique.

The pros are as follows:

• Did not yellow or discollor. The brand I used is truely UV stable.
• *Was* much stronger and rugged than glass

The cons are as follows:

• Does appear to attenuate solar power more than glass
• Even at 1/4" thick, the material wated to flex from the heat. I suggest very sturdy mounting, possibly using plywood as a backing

[Apollo1972]

It's soft and will scratch easier than glass. It also burns when a cell in a panel overheats.

This is an interesting statement, as what impact does Acrylic have on the heat transfer to a well ventilated panel? As typical Glass slows down heat transfer, i.e is a good insulator.....

Acrylic is a bad insulator, so if a cell in a panel starts to overheat, then surley having acrylic would be a benefit as it would transfer the heat away faster from the cell/panel than glass??

[Mike90250]

This is an interesting statement, as what impact does Acrylic have on the heat transfer to a well ventilated panel? As typical Glass slows down heat transfer, i.e is a good insulator.....

Acrylic is a bad insulator, so if a cell in a panel starts to overheat, then surley having acrylic would be a benefit as it would transfer the heat away faster from the cell/panel than glass??

Actually - glass is a pretty good thermal conductor, and spreads the heat from a bad cell. Plastics are better thermal insulators, and so the heat stays trapped at the bad cell. And if you use plywood.........

[Apollo1972]

Actually - glass is a pretty good thermal conductor, and spreads the heat from a bad cell. Plastics are better thermal insulators, and so the heat stays trapped at the bad cell. And if you use plywood.........

Thanks for the clarification - I got turned around a bit, when I was looking @ http://www.engineeringtoolbox.com/th...ity-d_429.html

So I think that if all the cells are ok, with no bad wiring connections/shorts. And the panel is a min 50mm away from the mounting surface, with adequate air flow for the temperature to be controlled, then a perspex/acrylic front should be OK?

[badley]

heat plays a fairly large role in performance of a cell. my design being thin glass front and back and totally sealed heatsinks heat out really well and keeps performance acceptable, i can actually watch a voltmeter fluctuate in real time with gusts of breeze with a panel hooked in and under load so its a real factor. That said, i think any kind of plastic is going to hold heat in and wont be near as good as glass in that respect. You talk of air circulation but unless this is a project that is transportable, having cells/tab/solder connections exposed to air will cause rapid deterioration in my opinion. What would be a viable option is using thin glass for cost effectiveness, having the cells sealed in, in a way that promoted heat sinking both front and rear, and using acrylic/plexi sheet on the front held off the actual glass by standoffs if you have cheap access to that material, strictly as a protective shield against hail ect .. another consideration with thin window-type glass in a large panel is flexibilty of the whole unit so it has to be used in conjunction with a strong frame or rear mounting system .. but i would choose thin cheap window glass over any type of acrylic or plastic myself as an actual panel construction material for a front and either sylgard type sealer or more glass for the rear supported well with a frame ..

[Apollo1972]

Thanks for your comment and insight, much appreciated.