# HOT!! solar panel



## artvandaley (Jun 15, 2012)

At my cabin I have 2x120 watt 17.8 volts in circuit at 6.8 amps each Suntech solar panels on my shed that have a MC4 connectors, and I connected a 48 foot (48' from panels to battery) 8 awg wire with MC4 connectors to the panels which leads to a 20 amp fuse and then goes to a PWM 25 amp charge controller. Connected at the 20 amp fuse I have a 15 watt solar panel 21 volts in circuit at 1 amp with 12 awg wires 38' from the battery, wired to the 2x120 watt panel's 8 awg wires. I did this because in the winter the 2x120 watt panels will be covered, and the 15 watt panel is mounted Vertically so it can feed power to the 110 ah battery during the winter when nobody is at the cabin to clear the snow. From the 110 ah battery I have 6 lights totaling 24 watts with 12 awg wires and a 1000 Watt inverter with 2 awg wire (inverter to battery is 17'). Now when I connect the whole thing the wires never got warm and everything seems to work great. Can this make the solar panels so hot I can't even touch them for a split sec? I do have the panels in a wooden framed box covered by plexiglass to keep people from throwing rocks directly as the panel and branches from falling on the panels. I was wondering if this is the only reason why the panel would get hot.
I'm not sure if this can be viewed, but I have a pdf of what I have wired here, http://joeytclements.com/cabinmay2012.pdf
and the box here http://joeytclements.com/solarpanelshed.pdf


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## NaeKid (Oct 17, 2008)

The way that you describe the plexi-box around the big panels makes me think that you might have a "greenhouse" type of situation. The black of the solar-panel probably is collecting more than just the light, but also the heat from the sun and there is no place for it to go.

I would highly consider replacing the solid plexi-glass with something that is breathable like a steel mesh of some sort (chicken-wire could work as well) and see it that makes a difference. Also, I would try to re-angle the panels a little bit so that any snow that might fall on the panels will have the ability to slide / melt off of the panels. An additional 10° might be all that it needs.


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## CulexPipiens (Nov 17, 2010)

Easy test, disconnect the panels and, wtih the same "weather" check and see if they are still as hot or not. If so, then as NaeKid says, it's a greenhouse issue. If disconnected they stay cool then it's something in your system.


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## Pixelphoto (May 31, 2012)

solar panels get ho naturally but it will diminish the life if inside a plexiglass box. Like someone else stated its the greenhouse effect. You are worried about someone killing your solar panel by throwing rocks but you may be killing it by overheating it.
They are designed to allow air flow around them. Use a mesh over them so they can breath instead of something solid.


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## Tex (Oct 31, 2008)

Instead of plexiglass, would chicken wire be better? It wouldn't block the sun, but would not promote overheating. Chicken wire would protect from tree branches and large hail. Small hail shouldn't be much of a problem.

If the wiring were undersized, the wiring or electrical connections themselves would heat up. The sun is the only thing that should heat up the panels. A plexiglass box would only magnify that like in a greenhouse.


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## DKRinAK (Nov 21, 2011)

Put the vent hols on top of the box, not along the bottom.

Also, the angle of the panels should be based on your latitude.

This site (http://www.macslab.com/optsolar.html) has informaition on setting the angle.

and cool charts - like this


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## Nadja (Jan 12, 2011)

Remove the Plexiglas instantly ! You are literally baking the panels. Never never put anything over the face of the panels, unless you want a meltdown.


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