Jesses DIY panel

[garybeck]

nice work Jesse! can you share how you got the cells from Evergreen? I didn't know they sold them like that. Do you mind how sharing how much you paid for them? Is there a minimum order?

thanks
gary

[jestronix]

I suspect normal silicone would be effected by hot and cold, the Dow Corning silicone I chose has a wide temp range, hopefully it handles. Here in Australia in the northern region we probably get a low of 5c in winter and a max of 44c in summer, mostly mid to high 30s.

I bought the solar cells off ebay, they are clip tabbed (makes soldering easy), I picked mine up at around $75 AUD including post.

These cells are a pain to work with, the slightest bump and they crack, also the warp when you solder them as they are so thin, really they are designed to be soldered in a lab, with expensive soldering equip. I use an $18 soldering iron which doesnt help.

For my next panels Im thinking Ill get some 6 x 6 cells, thicker and easier to work with.

Cheers

Jess

[colinsey]

Where can I buy solar cells

I've searched eBay and various other websites and can't seem to find a place to get the solar cells that I want (.55V/3A). All I could find on eBay were broken cells.

Is there a direct source to get these from?

Thanks.

[jestronix]

http://shop.ebay.com.au/eco_iq/m.html?_nkw=&_armrs=1&_from=&_ipg=&_trksid=p3686

Im thinking of these for my next panel, already soldered together. This would remove about 3 hours of soldering work per panel.

[lile001]

I suspect normal silicone would be effected by hot and cold, the Dow Corning silicone I chose has a wide temp range, hopefully it handles. Here in Australia in the northern region we probably get a low of 5c in winter and a max of 44c in summer, mostly mid to high 30s.

I bought the solar cells off ebay, they are clip tabbed (makes soldering easy), I picked mine up at around $75 AUD including post.

These cells are a pain to work with, the slightest bump and they crack, also the warp when you solder them as they are so thin, really they are designed to be soldered in a lab, with expensive soldering equip. I use an $18 soldering iron which doesnt help.

For my next panels Im thinking Ill get some 6 x 6 cells, thicker and easier to work with.

Cheers

Jess

You're starting to realize what I did when playing around with DIY cells - GREAT fun, interesting to do, but is what I build really going to be long-lasting and good quality? After making a panel about 3'X3', I decided I wasn't going to fill my roof with solar panels that way, given the amount of free time I have and the number of cells I broke. Maybe I'll use this little panel for something (run a pump? run my christmas lights? who knows) but it won't be powering my house.

A friend has solar electric panels on his house that he installed in 1986. Still going strong. I can't imagine my DIY panels would last that long.

--Lawrence

[jestronix]

Hi Lawrence,

I guess the DIY scene hasnt been going long enough to see if the sylgard builds will last. BP used sylgard on their early panels, which are still going. So there is hope, but it gets close to the price of cheap ebay panels when you use sylgard.

I wouldnt trust cheap ebay panels or my own DIY on my roof, but if you have the space you could located them out of harms way.

I moved away from sylgard as I wanted to see if I could go really cheap and still make them last.

Its only six months in and I can see a light dullness on the gridlines of the cells, where the caulk meets the cells, it hasnt effected output yet. If they last 5 years, they have done their job, they were 5 times cheaper to make then a good BP panel.

I have two panes of glass left, and a tub of sylgard, so I guess Ill do two sylgard panels and see how they go.

[lile001]

Great looking panels, Jessie! We played around with various methods of attachment and waterproofing. Realizing that EVA film is essentially a sheet of hot glue, we played with using regular hot glue guns to attach the cells to a small sheet of glass. Worked OK, left it out on a metal roof in August without a failure, but the temperatures on a roof are near the melt temperature specs of standard dime-store hot glue. There is a high temperature hot glue available, and in bulk it is pretty cheap, but the low temperature glue captures 99% of the market, so the high temperature glue is hard to find. However, if you could make this work, it might be a lot easier than a sheet of EVA plus a big home-brewed vacuum setup.

[jestronix]

updates

hi all, a few updates, have all the panels up now, 4 x 60w DIY. 2 x 40w jaycar, 1 x 40w BP (28 years old, puts in half amp lol)

This is the make shift stand for winter, trees are getting cut down next year so can mount them up on the roof. one panel looks off color, its not, i just used some black paint behind half the panel, ran out!



The bottom center panels are the best, I got the spacing and alignment right on those.

Close up of the cells after 9 months or so.



Very impressed with the ones that I totally sealed in silicone caulk not one hint of weathering. The painted ones are fine, but slight color change around the edges of the cells, seems to have slowed down though, must have been some chemicals in the paint. The dark edges on this shot are just the silicone on the front of the cells. These cells are direct to the glass.

[charlie_ruizpr]

So how have the panels looked since then. I have a 108 cell panel in the process of making and I am confused on the way to go on sealing them.

[jestronix]

So far im happiest with sealing between and the back of cells in electrical grade caulk. The painted ones were slightly effected by chemicals in the paint.

[cby016]

jestronix what exactly did you use to make your frames? If you could post some instructions and where you got the materials that would be great.

[jestronix]

Howdy,

The frames are just aluminum edges , Ive just siliconed them to the glass. On the corners Ive just cut small bits and siliconed them on to make the corners, it all seems pretty solid and has held well.

[jestronix]

Heres a couple of shots of the cells from the weekend. All cells are fine so far, and no cracks in cells, which was my biggest worry.

I upgraded the wire from the panels to the battery, 17 meters of 10mm wire. It was only 1.8mm before, and was robbing a lot of power. Havent had a sunny day since upgrading the wire, it did hit 14amps with half sun. expecting 20amps , up from 9amps with old wire.



Also added two more trojan T105s, for a total of 440 AH.





What I have noticed is the paint on the back of the silicone is going yellow, but to be expected I guess.

Im pretty happy with the panels so far, almost a year in the weather, no moisture, no cracks in the cells, fingers crossed.

[mdmiller1]

These cells are a pain to work with, ... they crack, also the warp when you solder them as they are so thin, ...

Jess

I am having this same warp problem with some 300 micron thick cells. After soldering they seem to have a warp of a millimeter or two. Is there a solution to flattening them without ending up with a pile of broken cells ??

thanks !

[Mike90250]

I am having this same warp problem with some 300 micron thick cells. After soldering they seem to have a warp of a millimeter or two. Is there a solution to flattening them without ending up with a pile of broken cells ??

thanks !

Use less solder, and a thermal controlled iron. Regular electronics solder, not the lead free stuff, will work at lower temps, and cause less warping. Large gobs of solder will shrink as it cools, and warp the cells. The thinner the layer of solder you use, the less warpage.

Less heat = less warp too.

Maybe try a small sandbag to hold the cell flat as the solder cools ?