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-   -   Polished solar panel versus higher output (http://www.cruisersforum.com/forums/f14/polished-solar-panel-versus-higher-output-172833.html)

bobs 18-09-2016 01:10

Polished solar panel versus higher output
 
I hope you people don't mind me pasting a link to an another board , that way I don't have to post all the photo's again.
The topic is about a polished solar and a consequential higher output due to it.
But ............. please read it , maybe on this board I could find the answer to the riddle.

Freaks of nature , solar panels behaving strange | Jeanneau Owners Network Forum

Thanks

StuM 18-09-2016 01:44

Re: Polished solar panel versus higher output
 
Justa a WAG, but this:
" I then turned to the ' fine ' paste which is a bit more abrasive than the finishing type"
would suggest you may have actually covered the surface with very fine scratches which are reflecting some of the light.

Try redoing it with the finishing paste and see if you get an improvement.

noelex 77 18-09-2016 02:21

Re: Polished solar panel versus higher output
 
As others have said, it is hard to know if there was not a problem with the panel before it was treated. Some flexible solar panels are prone to problems so a defective panel is not unlikely.

If we assume for the moment that the panel was identical to others and speculate why your treatment has decreased the output. I would be concerned that the mechanical vibration from the polishing machine directly on the coating could have damaged some of cells. Microcracks in solar cells are a common mode of failure and the combination of vibration and pressure, even if done carefully was something the cells were not designed for.

I think it is more likely to blame than the change in the optical surface. Your treatment should only have improved the transmission and hence the output.

Measuring the Voltage would be helpful. If the optical surface is poor the current will drop but the voltage will remain near normal. If the cells have suffered damage such as microcracking (from the polishing process of from normal wear and tear) the voltage and current will both drop significantly.

bobs 18-09-2016 04:47

Re: Polished solar panel versus higher output
 
Thanks for the replies already.

@ Stum ,
As you can read in topic it did crossed my mind to re-polisch the panel as an additional experiment , trial.
Will do that asap.

@ Noelex ,

Not knowing what was going on here I did measure the voltage of all the panels after afterwards . Strangely enough , panel 1 , the polished and underperforming one gave a slightly higher voltage reading.
These are the facts.

Regards

stevec195 18-09-2016 05:40

Re: Polished solar panel versus higher output
 
Other than a good wash, I for one will not generally be seen polishing my solar panels. It does sound like a theoretically good idea.


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zboss 18-09-2016 07:12

Re: Polished solar panel versus higher output
 
Quote:

Originally Posted by stevec195 (Post 2215599)
Other than a good wash, I for one will not generally be seen polishing my solar panels. It does sound like a theoretically good idea.


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Its recommended by certain manufacturers to polish flexible panels if they haze. For example... here is one from Solbian:

http://www.y-tronics.com/assets/file...6Polishing.pdf

newhaul 18-09-2016 07:16

Re: Polished solar panel versus higher output
 
Seems to me that the power polish likely as others have stated caused physical damage to the panel. As far as washing them that is a given and applying a wax to the surface by hand and polishing thereafter will help the panels not so much with output but rather with easier cleaning throughout the season. This hand waxing is even recommended by several manufacturers. For just that reason.
Edit:
Dang Z you beat me to the punch.

Captain Bill 18-09-2016 07:24

Re: Polished solar panel versus higher output
 
Many solar panels are actually wired internally as two parallel panels. You did not state the brand of panel so I could not check to see if yours were wired this way. The output from the polished panel seems to be a bit over half of that of the non-polished panels. If your polishing effort did improve the output but 1/2 of your panel has failed one might expect to see a bit over half of the output of the non-polished panels.

a64pilot 18-09-2016 07:51

Re: Polished solar panel versus higher output
 
If you want to polish these things, you may look into polishes meant to polish plastic, like aircraft or motorcycle windshields


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foufou 18-09-2016 13:28

Re: Polished solar panel versus higher output
 
You have to check each panel before and after polishing. Not one panel polished compared to another un-polished as Noelex noted. Polish your remaining panels and post the new set of data. Dying to know the outcome of the next tests. f

bobs 18-09-2016 20:21

Re: Polished solar panel versus higher output
 
Thanks for the comments.
But polishing another panel to verify the theory of created scratches that prevent light getting to the cells will also mean I would probable have two crippled panels instead of one.
Not such a good deal no ?
Is hard for me to believe I've picked a previously bad panel for the first polish experiment.
But maybe I should just unpack my solars and give panel 1 ( the polished one ) a extra run with the finishing paste .
If you can turn gelcoat into a mirror with it , I might get the unvisible scratches on the panels surface off too.
It's worth a try.

Strange though , a dirty , foggy/hazy panel has more output than the (apparently ) shine panel 1.

Regards

HankOnthewater 18-09-2016 21:33

Re: Polished solar panel versus higher output
 
And up to now I always I thought solar power was maintenance free......:smile:

FSMike 18-09-2016 21:40

Re: Polished solar panel versus higher output
 
I don't know a thing about the "mechanics" of solar panels, but, for some sideways thinking -

Polished panels are shinier.
If they are shinier, it's because they reflect more light?
If they reflect more light, that means less light is getting in to the solar cells?
Which means less power being generated?

Since some manufacturers recommend polishing, I'm doubtless completely wrong about all this.
All I ever do with my panels is rinse with fresh water, and occasionally wash them when I wash the boat.

thinwater 18-09-2016 21:44

Re: Polished solar panel versus higher output
 
Quote:

Originally Posted by bobs (Post 2216133)
Thanks for the comments.
But polishing another panel to verify the theory of created scratches that prevent light getting to the cells will also mean I would probable have two crippled panels instead of one.
Not such a good deal no ?
Is hard for me to believe I've picked a previously bad panel for the first polish experiment.
But maybe I should just unpack my solars and give panel 1 ( the polished one ) a extra run with the finishing paste .
If you can turn gelcoat into a mirror with it , I might get the unvisible scratches on the panels surface off too.
It's worth a try.

Strange though , a dirty , foggy/hazy panel has more output than the (apparently ) shine panel 1.

Regards

Personally, I think Nollex has it right; the vibration and pressure did it. Even supported, these are fragile.

A simpler expereiment would be to lay a fresh sheet of acrylic over a good panel, and then take the sheet and make it hazy with some coarse compound. I think you will find the difference is trivial. There is simply no way the state of polish explains the dramatic drop off.

The take away is very gentle hand cleaning only.

StuM 18-09-2016 21:46

Re: Polished solar panel versus higher output
 
Quote:

Originally Posted by bobs (Post 2216133)
Strange though , a dirty , foggy/hazy panel has more output than the (apparently ) shine panel 1.

Regards

If it's shiny, that suggests that it is reflecting rather than absorbing the light :)


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