[amsat-bb] HIgh efficiency solar cells for cubesats

[Edward R Cole]

Bob,

That's very interesting curve.  Guessing for most home users its more 
cost effective to purchase more cells for increased power than paying 
more for higher efficiency.

I really don't recall what I paid for remote radio site solar power 
about 15 years ago.  I believe they were 30 to 50w panels and cost 
about $400.  Our first panels were made by Arco and Solar Electric 
(something) made the last ones we installed.

This was commercial mountain-top comm sites only reachable by 
helicopter about one month/year due to weather.  Our largest site was 
shared with State of Alaska who maintained a mw link from Kenai 
Peninsula to Kodiak Island (about 70 mi over water).  We had five 
radios, most of which were 5w but two had 30w amps (all 
FM).  Originally we used a battery bank rated at 10,800 AH at 13.2v 
(were air cells) which had to be replaced every three years.  But we 
installed a two panel solar charged system using two 100 AH 
deep-cycle batteries to supplement the fixed battery bank during 
roughly 6-months of high sunlight in the arctic summer.

We thought that would extend the main battery bank life to four years 
but it did not quite do it.  Energy use analysis was complicated by 
multiple users so our guess fell short.

Helicopter cost each year for one trip to the mountain ran $5,000 for 
40min flight one-way and standby time on the mountain while we worked 
(usually four hours).  After being stuck on the mountain for seven 
days in 40F-40mph winds in rain we decided to keep the helo on the 
mountain so we could get off quickly in event of bad wx which could 
develop in 15-min socking in the mountain top for long 
duration.  Winter had the shelter covered over under 15-20 foot of 
snow with winds upward of 200 mph.  Top of the mountain had 
year-round snow cover.

Nice to be retired <smile>

73, Ed - KL7UW
http://www.kl7uw.com
     "Kits made by KL7UW"
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