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Uni-solar vs Photowatt

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Posted by Over40pirate on September 28, 2003, 5:41 pm
Does anyone know of a site for comparisons of solar panel output, performance,

I have been thinking of adding another solar panel or 2 on my boat, and was
leaning toward Photowatt 75-90 watt panels.  A friend recomended Uni-solar
palels claiming better performance, and better output when partially shadded.

To me the output voltage of less than 17 volts, in the Uni-solar panel would
limit the output.

Any thoughts on this would be helpfull

Posted by Solar Guppy on September 28, 2003, 7:43 pm
They are different technologies ...

Asi (Unisolar) is flexible , shade tolerant as pros , but degrades quickly
in the Sun and need 2x the size for the same power output as Si panels

Keep in mind the VI curve (the voltage/Current output) of Asi and Si are
different and putting them in parallel with not yield the combined
name-plate rating of both panels.

If you need cheap panels have a look at

They have BP solar Asi laminate panels (no frame) for 118.88 for 82 watts
(that's only 1.44 watt). I would think a boat would be a perfect application
for these type of panels as you could just glue them onto the deck



Posted by Over40pirate on September 28, 2003, 10:45 pm
 The Unisolar panels I'm talking about, are rigid panels. It is a 64 watt panel,
that is larger in physical size than a 75 watt Siemens.

They are different technologies ...

Posted by Solar Guppy on September 29, 2003, 12:25 am
 No , there not different ... (BP vs Uni Solar)

A-Si = amorphous silicon

Si = single crystal or polycrystalline silicon

The BP's are identical in technology to the Unisolar , there both A-Si , the
64 watt one you are looking at just happens to be in a frame ...

A-Si (any manufactures) will be 2X the area of Si for the same power rating
due to the lower efficiency in converting light to electrical power.

Si is very brittle, in a moving environment like a boat it would be more
likely to be damaged over time , put a hole in Si , no power , same thing
for Asi , small drop in power. I am NOT a fan of A-Si , but your boat is
probably the single best reason I could think of to use the A-Si.

The link I gave you is for the now discontinued BP line of A-Si. Still fully
warranted , just will need a charge controller (will for any panel)

Hard to beat 1.44 watt compared to 4.78
(http://www.solar-electric.com/solar-panels-40-to-80-watts.html ) for the
same thing minus the mounting frame



Posted by Eric on September 29, 2003, 2:19 am
I suspect these are old "millenium" series, laminated between 2 layers
of glass.  Not what I would consider ideal for a boat.  They are
heavy, fragile, and inefficient.  But I could be wrong.  A search for
MSP 49 doesn't turn up anything.

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