How can I find out how many watts my solar panels are?

[Schultztrio]

I received 4 solar panels from a co worker. They are brand new. There is no information on them other than a serial number. They measure 21" by 47". Is there a way to tell how many watts they are? I've got a pic attached.

[Ward L]

maybe ask the coworker where he got them?

[russ]

Hot, hot, hot?

[Shockah]

21x47= probably 100watts.

[GageTyler13]

300 watt panels are typically 1 meter x 2 meters in size and around 6 cm thick. They require racking (mounting system) to whatever substrate applies - roof or ground-mount. The cost for such panels may be anywhere from $0.75 per watt at utility size quantities to up to $1.50/watt in smaller quantities. You are looking at something in excess of 250 square feet of area. And the cost will approach $12,000 including racking.

[russ]

300 watt panels are typically 1 meter x 2 meters in size and around 6 cm thick. They require racking (mounting system) to whatever substrate applies - roof or ground-mount. The cost for such panels may be anywhere from $0.75 per watt at utility size quantities to up to $1.50/watt in smaller quantities. You are looking at something in excess of 250 square feet of area. And the cost will approach $12,000 including racking.

Nice bit of copy/paste - forget advertising and try to post things people are interested in - not just generic blather.

[Wy_White_Wolf]

My Guess:

The first 4 digits of the serial number (EP80) tell me they are 80 watt panels. I couldn't match EP80 up with anyones model number but the dims match an 80 watt panel I found on Amazon.

WWW

[bcroe]

I received 4 solar panels from a co worker. They are brand new. There is no information on them other than a serial number. They measure 21" by 47". Is there a way to tell how many watts they are? I've got a pic attached.

They appear to have 36 cells, so open circuit voltage Voc might be 18V. Easily confirmed
with a voltmeter. V max power would be about 80%, 14.4V. They might work with
a 12V battery.

If you can get them pointed at an intense noontime sun, measure the short circuit
current Isc. Current at max power will approach 90% of that. These may not be
exactly the original ratings, but they certainly represent what performance you
can expect. Bruce Roe

[SunEagle]

They look very much like my 80 watt panels (the 2 in the middle) made by SOPRAY. Mine have a rating of Vmp = 17.7 VDC and Imp = 4.5 amps.

The ones on the outside are 90 watt panels from the same company. Same Vmp but slightly higher Imp.

[Schultztrio]

They appear to have 36 cells, so open circuit voltage Voc might be 18V. Easily confirmed
with a voltmeter. V max power would be about 80%, 14.4V. They might work with
a 12V battery.

If you can get them pointed at an intense noontime sun, measure the short circuit
current Isc. Current at max power will approach 90% of that. These may not be
exactly the original ratings, but they certainly represent what performance you
can expect. Bruce Roe

Thank you guys very much for the info. It's very much appreciated and a good start to look for further info.