Santiago - 5-28-2009 at 10:26 AM
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This photo is taken from due west, setting sun would be behind the photographer. The sloping gray roof faces southwest. You can see the 3 solar
panels on the flat roof in a metal frame which I don't want to use anymore. My question is this: is it better to lay the panels on the flat roof so
they get indirect morning and afternoon sun with direct noon sun, or to put them on the sloped gray roof (40% or so) where they will get direct
afternoon/evening sun but no morning sun? The, ahem, salt cedars 
do
not shade the sloped roof.
Bob and Susan - 5-28-2009 at 12:51 PM
put them where you can clean and service them...
remember the swing of the sun from winter to summer too
Russ - 5-28-2009 at 01:14 PM
Just an idea Santiago. If the stairway I see accesses what appears to be a pila you could build a shed roof over that and shade the pila & get the
right angle for optimum solar.
El Camote - 5-28-2009 at 01:17 PM
Put them at an angle to most efficiently capture the winter sun when the days are short and you most need the electricity.
rts551 - 5-28-2009 at 01:42 PM
After a lot of playing around, I placed mine Southwest (on the roof with mounts). It gave me the best winter exposure for the shortest days, and it
was convenient for mounting. You should consider both.
arrowhead - 5-28-2009 at 02:47 PM
Assuming your place is in BOLA, the maximum solar energy will be achieved by mounting the solar panels on the flat part of the roof with the northern
edges of the panels tipped up so that the panels are at an angle of 29 degrees to the horizon, with the long axis of the solar panels aligned due
north and south. BOLA is at a latitude of 29 degrees and mounting the panels at an angle of 29 degrees places them perpendicular to the sun's rays.
No other fixed postion will generate more power.
tripledigitken - 5-28-2009 at 04:00 PM
Here is some information that may be helpful....................
Angle of Orientation for Solar Panels & photovoltaic modules,
When installing photovoltaic modules, be aware that they generate maximum power when facing the sun directly. The fixed position which approximates
this ideal over the course of the year, thus maximizing annual energy production, is facing due South (in the Northern Hemisphere) or due North (in
the Southern Hemisphere) at the angle listed in the table in the next column.Note that these orientations are true,
The table below shows the fixed angle above horizontal at which modules should be installed in order to maximize annual energy output.
At some installations, it may be cost-effective to adjust the tilt seasonally. At most latitudes, performance can be improved during the summer by
using an angle flatter than the chart’s recommendation; conversely, a steeper angle can improve winter performance.
If modules are not cleaned regularly, it is recommended that they not be mounted at an angle flatter than 15”. Flatter angles cannot take ful1
advantage of the cleansing action of rainfall.
MODULE TILT ANGLE
Solar modules produce the most power when they are pointed directly at the sun. For installations where the solar modules are mounted to a permanent
structure, the solar modules should be tilted for optimum winter performance. As a rule, if the system power production is adequate in the win ter, it
will be satisfactory during the rest of the year. The mod ule tilt angle is measured between the solar modules and the ground.
Example: A module mounted in Miami, Florida (latitude 26º should be tilted at approximately 36º from horizontal, and should be faced due South.
Latitude Site Tilt Angle
0-15° 15º
15-25° SAME AS Latitude
25-30° add 5° to local latitude
30-35° add 10° to local latitude
35-40° add 15° to local latitude
40° + add 20° to local latitude
Ken
Santiago - 5-23-2017 at 05:20 AM
This post is from the first year of the Obama administration. I would HOPE that you would realize that the cabin has CHANGED considerably since then.
Panels are on a flat roof.
ncampion - 5-23-2017 at 09:01 AM
I agree with soulpatch. When designing a solar system always start with usage and work backwards from there. In the Winter you have much fewer
daylight hours for charging but in the summer you generally have a higher electrical load (fans mostly). I optimized our system for summer as
that’s when I use the most power (we power mini-split AC units). Just make sure you have enough generating power for your winter days considering
that you will only be able to generate about half of the output as in the summer. The panels really drop output when the sun’s angle is less than
90 degrees.
Martyman - 5-24-2017 at 01:03 PM
You'll have to put them on a tall tower to get out of the shade of Ubermans new monstrosity.