# solar panels project



## 88726 (May 9, 2005)

hi guys

started building my solar panels , im finding the soldering very difficult and i have years of experience in soldering, i was warned about this beforehand , does anybody know where i can buy conductive adhesive (apoxy)at a decent price , maplins want 22 quid for a small tube but it must be cheaper somewhere else .
cheers
kenny+stella


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## spykal (May 9, 2005)

Hi Kenny

I have never tried to solder photo cells and as you say that you are experienced I am a little hesitant to offer advice but here goes anyway...is the soldering iron you are using big enough...it may take a lot of heat to get the solder running well, a small capacity iron may not do the job.

Have you tried different fluxes and pure solder instead of the cored type. Modern solders are usually lead free now and do not solder as well as the old lead solder. Try to get hold of some old lead solder and try Bakers Soldering Fluid No 3 as the flux. Bakers is known to be corrosive so if it works you will have to clean up the joint carefully after soldering.

Sorry if you know all this already but I was following your threads on the building of solar cells since I fancy a go at it myself.

Mike


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## 88726 (May 9, 2005)

hi mike

the problem with the cells is the pads are a silver that is fired on to the silicone directly by specialist process , so its not really a pad its more like a picture of one if you know what i mean! its only a few microns thick and the thickness is varying , i am using a silver solder to reduce the leaching of the fired silver into the solder and a quality heat varying solder station and have tried 3 fluxes one especially for silver but its still hit or miss , theres about a 2 second heat window before the pads gone , ive done 108 joints in total but about 30 gave up , theres 6 joints per cell and its usually just one of the 6 that goes awol , if it goes wrong first time the second chance is very very slim , im happy to leave the good joints alone and bond the bad ones with conductive epoxy to finish the panel but its very expensive stuff from maplins i need a reasonabally priced source. 

i cant think of any other way to attach solder to silicone unless theres a specialist acid or my alternative which is conductive epoxy.

all advice apreciated .
cheers
kenny+stella


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## spykal (May 9, 2005)

Hi Kenny

I now understand why you thought of using a conductive epoxy!, and I was right in thinking that you had possibly explored all the avenues when it came to the actual soldering.

Thats a real pain in the Butt after all money spent and the work you have done on getting the right components. I do hope you manage to get an answer to the problem. I think I will put the self build solar panel on "Hold" for a while :lol: 

Mike


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## 88726 (May 9, 2005)

hi mike 
dont give up the idea as i think its a worth while project despite the probs , cost is a bit steep now but im still saving . if i could only find stuff at the price the manufacturers do . think i will finnish the 1st panel and shelve the rest for now as its too time consuming at the moment .
cheers
kenny+stella


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## 88726 (May 9, 2005)

hi guys

ive finally got all the cells connected and tacked to the base , will try it out and post some pics when i return after the weekend.
cheers
kenny+stella


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## 88726 (May 9, 2005)

hi guys
panel now built , next to fit it to the mh and wire up the charge controller , tried it out today in the sun at 2pm and its pushing 19.5 volts , shaded it about 1/3 and the voltage dosn't drop still 19.5 v , heres the pics as promised


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## 88726 (May 9, 2005)

the prepered baseboard .


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## 88726 (May 9, 2005)

soldering the arrays ,


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## 88726 (May 9, 2005)

panel built .


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## 88726 (May 9, 2005)

panel glazed and ready to fit


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## 88726 (May 9, 2005)

oops!

cant see my pics ? not sure why . theyre in my album if you want to see them.


any ideas why the pics didnt appear in the posts ???????????????????


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## 88726 (May 9, 2005)

anyone ????????????


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## johnsandywhite (May 9, 2005)

Yes *theflyingscot* they are in your album. Was it worth all the hassle?


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## 88726 (May 9, 2005)

hi johnsandywhite

yep i know theyre in my album i actually wanted the pics on the thread postings but cant figure out why it hasn't worked this time as ive posted pics before .

i did enjoy building them and i think it was worth the hassle as it was loads cheeper and now ive done it it would be easier second time round . i always like to see if i can make stuff for myself and i usually end up learning loads as i go . suppose its a sort of hobby :lol: :lol: 

cheers
kenny=stella


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## johnsandywhite (May 9, 2005)

That's the only way to learn. Do it yourself. What is the final cost for the completed panel?


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## 88726 (May 9, 2005)

hi johnsandy

comes in about £82 for a 60 watt panel but i had to fibreglass my baseboard as it was too flexi ,

if you could find a sheet of fibreglass for the baseboard ( maybe from a breakers yard ) van roof old boat or something you could probabaly do it for about £70.

cheers
kenny+stella


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## johnsandywhite (May 9, 2005)

I don't want to rain on your parade. But you can buy them for that price on ebay. :?


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## spykal (May 9, 2005)

Hi kenny

Well done for sticking at it, you must be well pleased with it.

A thought about the base board, I once made a very strong base board for a model by sandwiching a one inch thick polystrene foam centre between two quarter inch thick pieces of plywood. the plywood was glued to the polystrene with water based latex adhesive (like copydex). This made a really strong and light board which was torsionally strong due to the "girder" effect of the two skins of ply separated by the polystyrene. I got the idea from making model aircraft wings, these have a foam core with a thin wood veneer covering. A bit late now to come up with a suggestion I know but I bet you will be having another go now that you have "cracked" it :lol: 

How do the manufactured ones stiffen the bases?

Mike


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## spykal (May 9, 2005)

johnsandywhite said:


> I don't want to rainon your parade. But you can buy them for that price on ebay. :?


I have not seen any good 60 watt panels for sale on Ebay for that sort of money, let me know when you see one. :lol:

Mike


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## johnsandywhite (May 9, 2005)

:? You're right *spycal*. Must admit I was looking during the winter and they were much cheaper then. I suppose when the Sun shines for a minute or two poeple start to think of Solar panels and the price goes up.  Only a few weeks ago I almost bought a 110W and 150W at £100 to £150.


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## 88726 (May 9, 2005)

hi guys

i spent ages looking on ebay before i started this , current prices are about £160 for a 40w and around £ 200 for a 60w and above , i wish i could have got youre prices i would have bought dozens of 100+watt panels for 100-150 quid and so would all the retailers , check out how much they sell a 100w panel for then have a cup of tea to get over the shock.

hi mike : i thought about sandwiching but i was wary of the moisture ingress this is why i fibreglassed it though i know what youre saying ,(ive got a pack of polystyrene tiles in the loft but theyre porous ) the thickness would have meant bigger and heavier and more expensive angle framing which i also wanted to avoid.

every time i tried to compromise it caused another problem somewhere else and took more time to resolve .
cheers
kenny+stella


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## 88726 (May 9, 2005)

pics now working .

big thanks to mike ! :wink: 

cheers
kenny+stella


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## 93309 (May 1, 2005)

*solar panels*

hi kenny+stella
Geat to see some one else has had a go at self building how are they performing.
any probs let me know did you get the info off this site before the crash
regards
veralin


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## 88726 (May 9, 2005)

hi veralin
nice to see youre back .

i got the info from youre original build report before the crash and via email if you remember a while back , they are working well , ive actually built a mark 2 version using only glass as ive had problems with humidity inside the panel , i also tried perpex glazing but it warped with the intense heat inside , i will post some pics when i get a chance.


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## 93309 (May 1, 2005)

*solar panels*

Hello Kenny i agree they do tend to create a bit of heat i notice on your thread the little nut and bolts round the edge are quite spaced out i think we did our approx every 4 inches whist the plexi glass does puff up they dont warp occasionaly get a bit of condensation in one end but after about an hour this seems to disappear.
What sort of glass are you going to use on the mark version as it may crack will keep an eye on your threads for more pics
all the best for now
veralin


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## 88726 (May 9, 2005)

hi veralin
ive used glass from old double glazed window panes i got for free .

pic of mk 2 panel , more in my album .


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## 95593 (Jun 30, 2005)

*diy solar panel*

Hi, thats the first diy solar panel I have seen for battery charging, well done. Another diy solar panel for domestic water heating can be found on www.bigginhill.co.uk/solar.htm. I would guess if the wiring together of the arrays can be improved it should be a more straightforward task. The expensive adhesive you mention would seem to be the easiest way. I have used copper stick on tape for holding together glass parts which is then soldered to give a leaded light effect. I wonder if the copper tape might help give a reliable contact between panels ?

How does your unit compare with a commercial unit , I had thought of a 60 or 80watt panel and looked into prices at around £350. I note on the bigginhill site they say that it does not make a lot of difference if the glass (or plastic top) is clean or not and you show the same charge if the panel is in direct sunlight or shaded, I think. Would be very interested to a link to the people that sell the arrays.

John


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## johnsandywhite (May 9, 2005)

You could always experiment with some from ebay:-

http://tinyurl.com/d26nx

Or here:-

http://www.siliconsolar.com/


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## 93309 (May 1, 2005)

*solar panels*

Hi john check selfbuildsolar panels i think i put it under parts forum ,kenny used my info and by the look of it has made a not bad job.

kenny the only thing you will have to watch is the heat build up with double glaized glass not that we have used it on panels. 
We did have a bad experience with double glaized unit a couple of years ago, when we were going to do some painting we blacked out my daughters bedroom window with black plastic bags to stop the paint going on the glass and after a couple of days the double glasses unit exploded and the glass suppier reconed it was the heat build up caused by the black plastic bags. not reflecting the sun. solar cells attract the sun thats how they get so hot.
let us know how they perform when youve had them in the sun for a while.
all the best 
veralin


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## 88726 (May 9, 2005)

hi guys

thanks john , 2 problems with conductive adhesive , cost and higher resistance joint , soldering is allways best and the more silver in it the better for output _ , but it takes more heat to flow which the cell pads dont like , my mark 2 was easier to solder as i had changed the flux , had lots of practice and perfected my tecnique . cost of comercial units is horrendous mine were hundereds of pounds cheaper and work just the same . theres some new flexible sheets of cells on the market that look the muts nuts but i dont know how they compare . my cells are monocrystaline and still produce some power with no sun . panels are best kept clean to keep the current high . you can use diodes to stop shaded cells from sucking away youre current but diodes consume power so i didnt use them as i couldnt decide if they were worth it and i couldnt get hold of a decent diagram for configuration , i bought a hundered and never used them .

a solar panel may show the same voltage on a meter but the current you get will depend on the quality of the sun.


veralin , ive had the glass panel running for about 2 weeks and im almost happy with it except for a bit of humidity inside , i can only assume it has come from the selant during cure as the panel is water tight , i intend to fit a downward vent tube to let it breathe and see if it will dry itself out , failing that i may use the tube to fill the whole thing with baby oil . that little idea comes from an american solar forum and gets good reports . unfortunately it will have to wait as my fridge is knackered


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