DIY Solar Panels...What kind of glass?

[tjames]

Someone deleted my post?

[russ]

Tempered if you want panels to last past the first hail storm then yes

Thickness? Assuming tempered, would one shoot for 1/8" thick total? Too thin? too thin

Iron-Free seems universally desired. less light loss

Textured on front for less reflection / more penetration? I guess this has been independently verified hundreds of times that it's much better than flat floated glass?

textured surface? What commercial mfg uses that?

[tjames]

Thanks Russ- I guess I was just picking up from the OP question: What glass is best, or rather most reasonable?

Super-exotic glass (Ruby or something?) doesn't seem to be justifiable due to high cost

Tempered

Thickness? Assuming tempered, would one shoot for 1/8" thick total? Too thin?

Iron-Free seems universally desired.

Textured on front for less reflection / more penetration? I guess this has been independently verified hundreds of times that it's much better than flat floated glass?

[russ]

I guess I'll bump this thread. Looking to price a lotta glass

Start calling your local dealers

[tjames]

I guess I'll bump this thread. Looking to price a lotta glass

[Dellyjoe]

Plexiglas transmits 92% of visible light and over 10 years in the harshest sunlight will lose about 2% - which you can't really detect with your own eyeballs.

Sounds like a pretty big efficiency loss!

so sun just a recap you would spend more money on polycaronate glass b/c you will not lose as much power, is 10 % really that much if you are talking 100 dollars or so more for glass??

just a question i hope im not like sounding like im yelling or anything.

[dfowensby]

wonderful info!

stumbled onto this thread googling for glass info for building a drain-back waterheater system i'm researching. thanks much--life just got easier!

[themaxx69]

Well as far as ebay here, there are only 2 sellers I am looking at, and they have thousands of positive feedback, so I'm not worried about that. But like I was saying about sunelec.com prices, if I want a 5kw system that I know the panels are going to last basically forever, I'd buy from there instead of building dozens of panels using glass of thick polycarbonate and only saving a small percentage. I'll probably just build some to use recreationally and for emergency use. Probably around 1-2kw.

[russ]

The ads you see on ebay are not all that accurate - they know that you can not test the cells to prove anything other than what they claim.

Many listings on ebay are like the story I read today where a lady bought an iPad in the parking lot of a shopping mall. When she got home and opened the box she found a block of wood with the Apple logo on it.

I suggest that you start with a small panel and see how it goes - it isn't so easy as most of the rather stupid utube postings claim.

[themaxx69]

Well actually most of the cells I have looked at are advertised as grade a or no defects. I have seen ones with minor chips for a little less, but not much. Buying a thousand cells for a system, I wouldn't mess with saving a few cents per watt. Although there are lots with cells cut in half roughly for around $.33 a watt, which would be good for making maybe a small system.

[Mike90250]

When I buy my house this is one of the first things I will do.

2nd thing will be to find insurance coverage.

discover what the "coefficient of thermal expansion" is for the materials you place in the panel. (cells, glass, backing) if they dont all match, the weakest one (the thin cells) will fracture. Air pockets will capture and condense moisture. ebay cells, are not prime (A) cells, they are rejects, for any of a dozen or more reasons.

[themaxx69]

Hey, another newbie here.

After many years of wanting to get into solar panels and to land of free electricity(mostly), I am about ready to start buying and building.

One quick question about a post I just saw, why would you put a piece of glass or polycarbonate behind the cells?

Onto the glass vs PC. I have been reading a lot about this lately and based on what I found, I am 99% sure I'm going with polycarbonate. Probably the number one reason is price. All the stores I called in the Phoenix area wanted around $11 a square foot for 1/8" tempered glass! If you paid that right there, you would spend more making a solar panel than buying one from sunelec.com. And honestly, with the prices of solar panels lately, not even including tax incentives of utility rebates, it's not much cheaper to do it yourself if any at all. Sunelec.com has panels around $1.50 a watt. Grade a cells on ebay run maybe $.50-$.70 a watt depending how many you buy. Add the cost of panel material and glass or PC, and you could actually pay more, not to mention the time it take to build and quality of build vs brand new factory made with warranty.

The only way I see to really save money is to use really thin flat PC and possibly smaller panels, or even thinner(.8mm) corrugated PC. And that's using only one piece for the front, not front and back.

I'm using prices from http://www.eplastics.com/Plastic/Lex...arbonate_Sheet
and

http://www.gemplers.com/product/171499/Corrugated-Polycarbonate-Sheets-Clear

Any input would be great.

And by the way, I just found out here in arizona there is a new program where you can "lease" a grid-tie 5kw system, installed, maintained, and warrantied for around $7,000. After 25 years I think, they give you the option to buy, at supposedly next to nothing. I'm not sure if this is just SRP or both SRP and APS electric. And you don't have to deal with any rebates or anything. I think if you own a home, you'd be insane not to do this.

Complete 5kw system installed, maintained, and warrantied against damage for around $7,000 or less!!!!!!

When I buy my house this is one of the first things I will do.

It's a good thing that people here are so knowledgeable about solar panels. I would like to add some information about the angle. It should face perfectly where the sun shines the longest time so that the solar panels will receive the maximum energy.

[Swampwood]

I called the 2 glass stores in town.. One is 40% cheaper than the other for the same thing...call around.
I'm looking at 1/4'' tempered front, thinking about 1/4" plexi for the back.

[russ]

Hi Raudy - Welcome to Solar Panel Talk!

Hopefully someone has a suggestion for you.

Some have suggested old shower curtain glass - tempered so it can not be cut but the price should be right.

Otherwise call the glass suppliers in a city near you and keep on until you find an attractive price.

Russ