I am trying to choose a solar panel for my Catalina 25.
The two main types available locally are monocrystalline
rigid panels by Siemens and Solarex, and Thin Film panels
from UniSolar, which are flexible.
The Siemens panels run about $8-$10 per watt and the UniSolar
are $12-$15 per watt.
The UniSolar panels are also much larger for a given wattage
than the Siemens, due to the lower conversion efficiency
of the amorphous silicon as compared to the monocrystalline
silicon in the Siemens panels.
I would appreciate any comments you might send about panels
you have in service.  Would you buy the same one again?
I had a Solarex 30 watt panel on my old boat and although
it did perform as advertised, after 3 years the clear plastic
overlay started to delaminate and peel off, allowing salt and
moisture to attack the cells directly.  This panel was a sandwich
of three layers consisting of an aluminum backing plate, 
the photovoltaic cells, and a clear plastic film on top.
I am leaning toward the Siemens solar panel, because it's cover
is made of glass, not plastic.  However, I am worried that the
glass plate would not stand up to the impact of objects like
blocks and snap shackles striking it occasionally.  The UniSolar
panels are covered with a material called "Tefzel" which I assume
is a plastic of some kind, but would this delaminate like on my
Solarex panel?
The electrical loads on my boat are minimal, consisting of
4 navigation and 5 cabin lights, VHF radio, stereo cassette player,
and 4 small vent fans I rig in hatchways to keep air circulating
when the boat is not in use.  These fans are 1/4 amp computer
cooling fans, same as the one installed in the PC I am typing
this message on.  I will be adding a depth sounder and Navico
TP-300 autopilot next year, but no other electrical equipment
after that is anticipated at this time.  The boat is used for
weekend day sailing and one or two night local cruises, with
one or two week cruises every couple of years.  I estimate
a panel of 30-50 watts should keep the battery topped off.
So, what brand/model of solar panel do you prefer?
Thanks, all.
By the way, the boat is still unnamed, any suggestions?
L. Charlot- Catalina 25, hull #1205
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