Solar panel question

[HABBERDABBER]

A buddy gave me a 20 watt, nominal 48 volt solar panel today. It is 48 V output, as I checked and tested it today, in the sun. So what is this good for? Can it be used in some fashion with a 12 volt Escape system?


I never got far enough in my schooling to know if it has utility or use for me.


Got a notion?

[fudge_brownie]

Is it just the panel? A controller attached to the panel? Any other connections? I assume a rigid panel with a aluminum frame?

[HABBERDABBER]

It's a rigid glass panel and aluminum frame with a black box on back. All other items TBD. Just got it, and not studied yet. Will post a pic tomorrow.



I trust you are wearing your sunscreen, a hat, and sunglasses too, down there in Florida, Paul?

[Vermilye]

If you have an MPPT solar controller it could be used with a 12V system, although 20 watts is hardly worth it other than as a battery maintainer. The voltage is too high for most PWM controllers such as the GoPower.

[HABBERDABBER]

The panel was from an above ground hot water circulating pump system. It is 14" X 19". Here are photos of the backside info.


The black box is only a protective output junction box.


I have 200W photovoltaic capability, so I don't need this pnel, but was wondering why the 48V output.

[Mike G]

It might make a good "white elephant" gift at Christmastime...

[Brian B-P]

Originally Posted by HABBERDABBER

A buddy gave me a 20 watt, nominal 48 volt solar panel today. It is 48 V output, as I checked and tested it today, in the sun.?

Originally Posted by HABBERDABBER

The panel was from an above ground hot water circulating pump system. It is 14" X 19". Here are photos of the backside info.

... was wondering why the 48V output.

The open-circuit voltage is rated at 43.8 V (not 48 V), which - like all of the other voltage specs - is only double the voltage of panels which are intended for nominally 12-volt systems. The open-circuit voltage isn't important, and isn't the nominal voltage rating; the panel can't produce any power at that voltage. This panel is presumably designed for a nominally 24-volt system; the pump system probably has a nominally 24 V lead-acid battery.

It would be good for anyone with a nominally 24-volt system. There are lots of those, but not in RVs.

[HABBERDABBER]

I now know more, and yes, this is a "white elephant" item, or more likely, a St. Vincent de Paul charity donation, along with all the other detritus I've accumulated and need to dispose/ and downsize.

[John in Santa Cruz]

the key spec there is Vmp: 36V, which is the voltage at max power. the open circuit voltage of 43V, its making 0 amps therefore zero watts. at 36.2V, it outputs 0.55A which is where that 20A number comes from.

yeah, its for charging a 24V system . about the right size for a pair of 12V 20AH small VRLA AGM batts in series, which is what might run a gate opener or your pump thing, or whatever.

[fudge_brownie]

Tom,
With enough effort you could use the panel to drive your outdoor decorations? Here in Florida every one has an Olaf light up display at the Disney campground. How about setting up a trail camera with flood light? A theft deterrent system. Can you somehow incorporate the panel into a woodworking project, you are quite handy at that? The possibilities are endless, don’t get discouraged.