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Old July 21st 08, 07:55 PM posted to rec.aviation.soaring
Bob Kuykendall
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Default Clearly Outside the Box

On Jul 20, 2:22*am, ContestID67 wrote:
I agree that this is "out of the box" thinking...


Don Lancaster has written that ideas are not a dime a dozen--rather
more like a dime a bale in hundred-bale lots.

As for structural uses of polycarbonate, that can be made to work fine
just so long as you understand the fundamental difference between
strength and stiffness.

The general rule of thumb for PV solar cells is that you can expect
1KW/m^2 of area, but only if the sun is high (less atmosphere to
penetrate) and the cells are oriented normal to the sun. So the
exposed area of a typical 15m ship of S=10m^2 might yield 10KW (just
over 13 horsepower) under once-in-a-turn conditions, and maybe average
40% of that, around 5 horsepower, over a sunlit day. I can see that
working for a highly-optimized single-seater. Heck, I've been to the
ESA Western Workshop enough times to actually see it work for a
specific highly-optimized single-seater. But for a less finely-
optimized 2-seater, probably not so much.

BTW and somewhat off-topic, in the latest update of his Energy
Fundamentals paper, Lancaster suggests that PV solar might actually
not be a net energy sink, and proposes a figure of $1/installed watt
as the break-even threshold. Heck, that might even be doable.

Thanks, Bob K.