Solar panel, Increase watts?

Thread Starter

Dvexp

Joined Dec 24, 2021
1
Is it possible to take a 100w Solar panel and increase watts of said panel say to 200w or 300w?

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MrSalts

Joined Apr 2, 2020
2,767
The OP was asking about a light panel (possible something like below) now there is a color text on the first post and title was changed. Was there some DM or other evidence that the OP meant "solar panel"?
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LowQCab

Joined Nov 6, 2012
4,023
It is possible to increase the Output quite a bit ........
but I don't think 300% is gonna happen.
A very credible YouTube Channel called "Tech-Ingredients" just recently showed how to do it.
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Externet

Joined Nov 29, 2005
2,200
Some things I find very interesting on fitting mirrors to solar panels:

1- Read somewhere that sun rays after passing trough glass, and reflected back, they do not keep the heat; just the light can travel a second time trough glass. The 'greenhouse effect' that happens is supposed to be the explanation. If sun rays are passed trough a front glass first and then bounce on a mirror behind the glass to pass trough the same front glass towards the panel; the heat buildup should not be of concern, or is it ?

What is the cost of glass + mirror + attaching to the solar panel ? Reeeeaaaally, check the figure$ !

2- For the example on the video using polished metal as hinged mirrors; what is the cost of those metal sheets + attaching them to the panel ?

I found surprisingly, that buying more panels to double or triple the generated power is cheaper than attaching contraptions ! :eek:

I wanted to add/mount a thin metal sheet under a dozen of my 400W 2m x 1m panels and found the sad reality. So for the original poster; just buy more panels ! They want to wring your wallet for thin sheet metal more expensive than solar panels ! :mad:
And tracking mechanisms are still more expensive than mirrors and panels !
 

MisterBill2

Joined Jan 23, 2018
18,167
Externet is right, at least if you deal with suppliers in the solar business. The farther away from those marketing to that sector the better. Used equipment and scrap dealers, as well as some resale shops, all have better prices for materials that may not be so directly targeted to solar power use. Building a tracking system can be done a lot cheaper if one creates the system themselves, and provides their own manual adjustments for seasonal variations.
One more thing is that a 100 watt panel is a rather small item, and the connections may not have been designed for maximum efficiency, but rather minimum production costs. So evaluating the connection arrangements and the wire sizes might reveal ways to increase the output.
 

MrSalts

Joined Apr 2, 2020
2,767
If sun rays are passed trough a front glass first and then bounce on a mirror behind the glass to pass trough the same front glass towards the panel; the heat buildup should not be of concern, or is it ?
Every time the light ray has a change in refractive index, there is a reflection loss. Most solar panels have an external surface at or under 1.4 on the exterior surface. The components below are optically bonded to avoid air gaps (refractive index = 1.0) and light at the semiconductor surface is pretty efficiently absorbed as heat or to generate photo-current.
Adding a greenhouse glass means you have an air gap at the top and bottom surface of the greenhouse glass and reflection losses of entering the mirror snd leaving the mirror (assuming a glas mirror with metallized backside) or, just reflection losses if a metal surface mirror. Finally, reflection losses of the solar panel.

for simplicity, figure a 5% loss on each glass/air interface (a bit more loss on each surface for acrylic or polycarbonate). Add another 5% loss for an aluminum/glass interface (without air gap). So, a window passes 90% of light and a mirror reflects about 85% of light.

your setup would cause about 25% reduction in solar flux hitting the semiconductor surface.
 

MisterBill2

Joined Jan 23, 2018
18,167
Adding some mirrors to direct more sunlight onto the cells will increase the output some, and if you look around you should be able to find them a lot cheaper than what the solar power sellers charge.In addition, a simple scheme to keep the array pointed more towards the sun can improve efficiency a lot. And it does not need to be a dual axis constant correction tracker, "close" is good enough, exact is overkill
 

Rich2

Joined Mar 3, 2014
254
Personally I wouldn't use mirrors, the panel will get very hot and fail early. This is why flexi panels don't last long, they are bonded onto a surface with no ventilation underneath, get very hot and fail after about 2 years.
The rigid panel on our van gets hot as it is without mirrors.
 

MisterBill2

Joined Jan 23, 2018
18,167
Certainly there is a potential trade-off, no doubt. And so arranging the position of the solar panel to allow adequate air circulation is a good choice. So there is a decision to be made in this case. And really, any time the energy density is raised the amount of heat is also increased. But if more output power is needed then that is the tradeoff.
A solar panel on a van roof will get hot at least partly because a van roof gets hot even with nothing on top of it. That is the nature of sunlight.
So for the TS to reduce the heating of the solar panel, avoid putting it on a van roof!
 
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