On Tue, 29 Jul 2008 16:39:56 -0400, Whata Fool wrote:

I spotted a comment in passing that with today's technology
we could have electrical power for 10 cents per KWh.
From solar cells in orbit, power beamed to the planet.


AKA, "Pie In The Sky", there has not even been a megawatt
test of transmitting power wireless.

The idea should not even be considered until transmitting
multi-megawatt power to remote locations becomes common-place.

Every time oil prices go up, this appears. I first saw it in the '70's
so-called "Crisis".
So do all the 200 MPG engines, the pill that you drop in the tank that
JC Whitney-type places sell, and stories about cranks and quacks who
crawl out into the sunlight every time energy gets expensive.

SO..allegedly people are killing themseves with a few Watts from
cellphones, and getting leukemia from "Power line waves" but we are
going to irradiate cities with gigawatts.

Since silicon PV's only last a decade on the ground, how will they
fare with vacuum UV, ion implantation with Solar Wind, and gamma rays?

This is what happens when journalists try to write about Science and
Engineering; Ignore these stories when they appear. They were stupid
thirty years ago, and even stupider now.
At least back then they were only written by kids with pimples who
played with themselves too much.
Now they have grown up and are still wriitng them.

Grunty Grogan wrote:
Since silicon PV's only last a decade on the ground, how will they
fare with vacuum UV, ion implantation with Solar Wind, and gamma rays?
Really good "space grade" cells last a bit longer, but they do
deteriorate from the hostile blast from the sun. But, they are just too
expensive for large-scale energy collection. The big comm satellites
get a few KW from their cells, and they have to spin to keep from
getting thermal differential from the bright side to the dark side.
That means some of the cells are in the dark at any time. The huge
panels on the ISS (space station) deliver some dozens of KW all
combined, and cost millions to build and almost as much (or maybe more?)
to get into orbit.

If you want REAL power, you need mirror-like concentrators and some kind
of heat engine, either Stirling cycle or steam turbines. That, of
course, requires a HUGE heat radiator to get rid of the heat at the
"back side" of the engine.

This is all so insanely expensive, especially since we (the US) just
about have no heavy-lift launch capacity now, that it doesn't make any
sense. Large thermal arrays or PV arrays on the ground are MUCH easier
to install and maintain, that EASILY pays for the land use and lower
efficiency here on the surface. Not to mention at ALL, the transmission
problem. I think the engineering has been done, it will work, but
again, at HUGE, HUGE, expense. Wires are just a lot cheaper and more
efficient.

Jon