Up here in Alaska I had a few experiences using solar powered remote
communication systems. I worked a couple years for the BLM Wildfire
Center (Fairbanks) radio shop and we had some 5w GE repeaters
installed in big fiberglass boxes with a square solar panel attached
to the cover. We would just take them out to a location (usually a
hill or mountain top) and set them on the tundra with the panel
facing straight up. The panels never got direct sun but averaged
about 70% of peak all thru the long arctic summer (20+ hours). I'm
guessing the panel was about 20-30w.
One summer/fall I worked for a bush PBS TV station (KYUK Bethel, AK)
maintaining remote TV translators. Many ran on solar panels which
were installed vertical on the side of plywood sheds that housed the
equipment. The theory was the max solar power was needed in winter
with short daylight near the horizon;' during the summer the sun was
high but days were long so average power was much more. These were
2-3 30w panels for running 10w TV translators 100% transmitting an AM
video carrier.
My last work involved remote repeater sites only accessible by air
*helo*. They ran on huge alkaline battery banks (10,800 AH) but had
200AH batteries with 60w panels recharging them in summer. Automatic
voltage sensed switching changed over from solar to the alkaline
plant. These panel were faced south at the optimum solar angle
between noon and sunrise/sunset.
For a portable "backpack" system one will have to rely on frequent
repointing to keep the panel in optimum sun. Interestingly an
overcast summer day has 70% of the sun's power on a clear day. A
flexible solar panel can be rolled and carried in a tube.
73, Ed - KL7UW
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