On Mon, 12 Apr 2004 13:52:35 -0700, "Joel Kolstad"
wrote:

Watson A.Name "Watt Sun - the Dark Remover" wrote:
Also the currewnt outputdepends somewhat on the latitude you're at. You
won't get all that current at the arctic circle.

The difference for panels perpendicular to the sun on the equator and
the arctic circle in the summer noon is about 10-15 %, due to the
atmospheric absorbtion. The difference between the equator and pole is
about 30 % in the same conditions.

If the panel is tracking the sun, the panel on the pole during the
summer will produce electricity for 24 h each day, while the other
panel on the equator will produce for less than 12 h. On the arctic
circle about 18-20 h each day will give usable electric output.
Exactly at the arctic circle, the midnight sunlight is strongly
attenuated by the atmosphere, so you can look at it even with your
naked eyes or ordinary sunglasses, thus the electric output is also
minimal.

He might actually have a better chance there during the periods when the sun
never sets than at, e.g., the equator... solar cells are noticably more
efficient when they're keep cold, which is typically a lot earier to do in
the arctic than at the equator!

The silicon cell behaves quite in the same way as a silicon diode
which has a 0,7 V threshold voltage and -2 mV/C temperature constant,
thus the cell output voltage (and hence power) drops with temperature.

However, the cells are heated by solar radiation at nearly at constant
flux on the equator and arctic circle, thus, the main issue is how
well the heat will be removed from the cell to the environment. At the
arctic summer the air temperature can be well over 20 C for longer
periods of time, so this does not help a lot in keeping the cells
cool.

Paul