Solar panel question

[mesa]

Some one in the area is selling a solar panel that is 4x2 and for 12 volt but thatvis all they know,is there any way to figure wattage on this by the size of the panel or would there be anything on the frame? This is the photo of it.Thanks

[mptjelgin]

There is likely a decal on the back of the panel with the manufacturers name, model number, and perhaps some amperage and voltage information. 

In that size range I would guess it to be around 100 watts. I had a couple of Kyocera panels that were 5' by 2' that were 130 watt panels, so that should be in the ballpark. 

[bigjim]

Looks a whole lot like one of mine that I can't remember the name of but are 100watt. That rings a bell. I am pretty sure they were Photowatt 100.s Bought in NM in Aug or Sep of 2001

[Yarome]

I would agree. Looks to be a monocrystalline (that's a plus) and considering relative age by it's appearance and wafer design... 2.7 watt wafers. So a 100 watt 12v panel. Those 4 brackets (?) (2 each side) are sure poorly positioned though (shading issue). If they can't be removed without damaging the frame I would take a pass.

If that is to be your only panel it might do you (don't know what your intended use/purpose is) if the price is right (~25-30 bucks(?)). If you are thinking about including it in an array then I would take a pass then too.

[mesa]

thanks all for the info, think I am going to pass on this 

[SCClockDr]

20 hours ago, mesa said:

thanks all for the info, think I am going to pass on this 

If you indeed do pass. Where are they?

[mesa]

SCClockDr ,they are in Rimrock, AZ they were on our neighborhood Facebook page.

[bigjim]

If you could get it cheap to reasonable like Yarome said it could be a good way to start playing with solar to learn. Thats the way I started. Then when I  got the new panels I sold off the used ones at got some of  my money back. If that panel has no cracks and the brackets can be removed they should be good for at least another ten years assuming  they are about the age of mine.  Probably longer.

[Lou Schneider]

First off, that's a 32 cell panel (4 columns of 9 cells each) so it will have an output voltage of about 16 volts.  Most "12 volt" solar panels have 36 cells to give about 18 volts peak voltage.

The higher peak voltage comes in handy in less than ideal conditions, particularly when the panel gets hot and it's voltage drops below the peak value.

If you put a 32 cell panel in a system using 36 cell panels, the system voltage will drop to the voltage produced by the lowest voltage panel.  In other words, putting to waste the extra cells in the other panels.

[mscans]

On ‎1‎/‎8‎/‎2018 at 7:06 PM, Lou Schneider said:

First off, that's a 32 cell panel (4 columns of 9 cells each) so it will have an output voltage of about 16 volts.  Most "12 volt" solar panels have 36 cells to give about 18 volts peak voltage.

The higher peak voltage comes in handy in less than ideal conditions, particularly when the panel gets hot and it's voltage drops below the peak value.

If you put a 32 cell panel in a system using 36 cell panels, the system voltage will drop to the voltage produced by the lowest voltage panel.  In other words, putting to waste the extra cells in the other panels.

9 X 4= 36 so they are the correct size for todays systems.  Brackets may have been removed and reinstall upside down for storage but are usually just nut and bolted on not a "hard" connection.