solar panel confusion

[cypher007]

i recently bought some amorphous solar panels from a Maplin in the UK:

http://www.maplin.co.uk/module.aspx?moduleno=217850

as you can see there 12W. then i bought this kit:

http://www.maplin.co.uk/Module.aspx?ModuleNo=223250

these four panels are supossed to produce 60W.

hmm im confused the panels are the same size and the only difference i can see between the panels is the 12W panel seems to have approx twice as many junction lines on it. how can they get 15W out of the same size panel? now just to confuse things further, ive got two old ICP solar panels which are about the same size but look like the Maplin's 12W panels? ive got a real head scratch on here, either ICP are telling porkies on there panels or Maplins are. oh the Maplin panels are made in China by a company called Topraysolar. any help clearing up this confusion would be appreciated.

[DamonHD]

On my boxes from Maplin for the 12W panels there were tick boxes for 12W and 15W at least, ie indicating that there exist multiple different products with the same physical format that could go in the same packaging.

That could be simply different parts from the same line separated by testing, or parts with different manufacturing processes.

I see no problem!  B^>

Rgds

Damon

[hamitduk]

I have two sets, They are the same China crap, they do work I see 2.5 amps out of them (60 watts 24VDC).  Words of lack of wisdom replace all the bolts and wing nuts with some that the thread match.  I had some nuts that would fall off the bolts, lock tite them, glue the frame together, and bolt it to the roof, don't depend on the peg brace, it will break/or the wind and flip the array over and crack the panels. You can also find them at costco.com or at amazon.com

Hami

[Chuck]

It's common practice in the PV industry to sell panels with the same size and different power ratings. The theory is that they assemble them and then test the output. They then sell them as X watts or Y watts depending on the output. I've seen 120, 110 and 100 watt versions of the same panel offered for sale.

I wonder sometimes if you can actually see much difference without an MPPT controller ?

[ghurd]

I believe they test the cell output, group like cells then assemble.

I recall 70, 75, 80, 85, 90, and 95W the same size from Photowatt.  Early was 70 to 80W, progressed later to 85 to 95W.

Was easy to tell the 85W made more than the 75W.

G-