what kind of glass?

[Timbaker172]

Hi all, I'm new here. I like the forum so far, seems to be a lot of knowledgeable people around.

I just put together a little solar panel for charging NiMH AA batteries. I got the idea when I spotted some solar yard lights for sale. The whole thing was thought of and invented while standing in the exterior lighting section of Menards. I bought an 8 pack of yard lights for $10, cut the solar cells out, wired 2 sets of 4 in series and and those 2 sets in parallel and glued them to a piece of plywood. Add a battery box and voila it's a charger. After showing it off to a friend, he gave me 4 more yard light that he didn't want anymore, with a 3rd set of cells this thing really does the trick. Ironically, my camera batteries are dead at the moment or I would show pictures.

Now for my question. I want to finish this little panel up and make it look somewhat professional, my only question is what type of glass should I put over the front? I've read in some places that safety glass is better, other places say tempered glass and in a fun twist one website says that safety and tempered are the same thing! The only thing I know for sure is that I get slightly higher current and open circuit voltage when I put the panel outside Vs. in the window.

P.S. sorry for the long winded post, I'm just proud of my little panel.

[Mike90250]

Safety glass is Tempered glass. When nicked, or broken, it instantly crumbles to little pieces.
For best efficiency, you want Low-Iron glass. Iron gives glass the green tint you see on edges, it sucks a lot of power away from the cell. Low-Iron glass lets more power thru to the cell. For a little demonstrator unit, any glass you get is better than fingerprints on the cell surface.