On 4/8/2009 11:53 AM Keith Ovregaard wrote:

> Some volks like the simple approach and permanently mount the panel to
> the roof. Using a larger higher output panel will help compensate for
> off-angle alignment to the sun and shady campsites.

True that off-angle output doesn't drop panel output super fast like shade
does. But one could put a thousand watt panel up there and the shade from
a few branches would drop the output to 5W or less. BTDT.

Hook an ammeter in series with the panel and shade a portion of the panel
with your hand. The output will go down faster than Lehman Brothers.

"Orientation of the modules to the sun is critical to the successful
operation of a PV system. Ideally, the modules will be at a 90° angle to
the sun's rays at all times. In practice, this is not always practical.
Tracking mounts are available which will automatically reposition the
modules continuously throughout the day, although they are quite
expensive, and installed only on large arrays. Most systems are installed
on a fixed-azimuth mount, which is adjustable seasonally for elevation.
This means that the modules are pointed due south (Northern Hemisphere) or
north (Southern Hemisphere), and the angle to the horizon adjusted several
times a year as needed to keep the modules best aligned with the sun's
rays. The result is slightly lower output power during the morning and
evening, but results also in a much lower installed price. Even small
areas of shade on a module will decrease the output dramatically, so
location is an important consideration during installation."

http://www.mrsharkey.com/busbarn/electrics/chapt1.htm

--
Mike "Rocket J Squirrel" Elliott
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
Bend, OR
KG6RCR