polycarbonate vs. acrylic glass vs. glass panel - Page 1
Forum section: electronics / general

author: Dellyjoe
author_rank: Regular Contributor
timestamp: June 04, 2013, 06:09:48 pm
content: hello everyone this might be a silly question, but it is what is stopping me from buying my glass for my solar panels so i would like a answer so i can get to work.i first just wanted to say that i know this forum is really not the home for this question but maybe someone out here could help me out.Just to let to know where this question came from im making my own solar panels.I went out to look for glass for my solar penal and i came across that polycarbonate blocks out UV rays from the sun which idk if that means less sun light that will hit the solar cells.if this is so then i will not buy polycarbonate but if not then i really think i should.i will go with acrylic as a back up unless someone else has a better idea.And last quesion if you made your own solar panels what glass did you use, and where did you get it from.Thanks,Joe

author: metalphreak
author_rank: Frequent Contributor
timestamp: June 05, 2013, 07:26:59 am
content: You don't want to use polycarbonate or acrylic since it blocks UV. In fact most glass is designed to block some UV as well. You don't want to block any light for a solar panel.There is a particular kind of high transmission glass you need for solar panels.Martin mentions it in this video:

author: westfw
author_rank: Super Contributor
timestamp: June 05, 2013, 08:57:45 am
content: QuoteI call snake-oil. This resource says that by the time you get through the atmosphere, only about 1% of solar irradiation energy is in the UV:http://www.powerfromthesun.net/Book/chapter02/chapter02.htmlSee alsohttp://rredc.nrel.gov/solar/spectra/am1.5/if you want to calculate the energy percentages at arbitrary cutoff frequencies.Your first day's worth of dust would probably have more effect than the choice of glass/plastic/etc, as far as initial transmission.Of more concern is whether continued exposure to (everything) will degrade the material over time. I've seen a lot of cheap solar "garden lights" cloud or yellow pretty rapidly.

author: G7PSK
author_rank: Super Contributor
timestamp: June 05, 2013, 05:32:28 pm
content: Glass also blocks UV which is why Richard Feynman sat in a truck to observe the first A bomb test.

author: dfmischler
author_rank: Frequent Contributor
timestamp: June 05, 2013, 06:59:07 pm
content: Read this about polycarbonate.Read this about acrylic.

author: Dellyjoe
author_rank: Regular Contributor
timestamp: June 05, 2013, 09:53:00 pm
content: so like if it doesn't block that much uv rays should i just stick with plastic. it would be the cheapest

author: Marco
author_rank: Super Contributor
timestamp: June 05, 2013, 10:44:38 pm
content: Plexiglass is actually more expensive than safety glass and a lot more expensive than float glass.

author: Dellyjoe
author_rank: Regular Contributor
timestamp: June 06, 2013, 01:12:42 am
content: Quote from: Marco on June 05, 2013, 10:44:38 pmmarco i have not been able to find glass for cheap i need three 63inch x 42 inches and it says that it will cost 130 dollars for one glass. Does this look right?

author: metalphreak
author_rank: Frequent Contributor
timestamp: June 06, 2013, 11:56:41 am
content: Quote from: westfw on June 05, 2013, 08:57:45 amYou can be my guest and grab some of the heat absorbing glass with 60% transmissivity and throw away 40% of your solar output from the get go. It's not just UV that it blocks. You can't just go and grab any regular glass used for windows etc. If you are going to use glass, at least get the right stuff. It's not snake oil, and it's not some impossible to find speciality glass. Low iron or iron free tempered glass is usually the go.Polycarbonate/Acrylic/Plexiglass can deteriorate in direct sunlight depending on what exact type you get. In the long run, it's not a good choice. There's a bloody good reason why all of the solar panel manufacturers use glass.