Gerald,
Dunno if you've observed the new highway signs that are solar-powered.
These things have a BUNCH of golf-cart batteries, not a whole lot of
solar collection, and LED "bulbs". Those things must be very, very
energy efficient; they're quite bright, yet run on a really minimal
solar system, I think it's MAYBE 300 watts, just twice what I have on my
trailer.
Interestingly, those signs can be controlled/programmed via cell phone,
and the LEDs are available in either 17 or 23 degrees of viewing angle.
(from the one company that I checked out) It must be very good technolgy
because they replaced the old Diesel-powered signs almost overnight.
<<Jim>>
"Dr. Gerald N. Johnson, electrical engineer" wrote:
>
>
> The cost of energy, when you are dragging a battery back and forth, is a
> whole heap higher than the cost of buying it from the local power
> company. It kind of looks as if the LED lamps might be as much as ten
> times more efficient as fluorescent lamps (I'm getting cautious with my
> numbers now as I study them more), which could mean a 90 ampere hour
> battery could run them a long time between charges. For example, if I
> turned on all three ceiling fixtures in my Caravel, the battery load
> would be 17.28 amps (in theory at least) and the 90 ampere hour battery
> would last 5.2 hours. With fluorescents it would last at least three
> times as long. With LEDs maybe 250 hours, maybe more. That could mean
> charging the battery with a 5 watt solar panel for $30 or 40 instead of
> a 75 watt solar panel for ten times that.
>
>
--
<<http://www.oldengine.org/members/jdunmyer>>
<<[EMAIL PROTECTED]>>
<<lower SE Michigan, USA>>
<<mailto:[EMAIL PROTECTED]>>
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