FYI,

"Harvest the Sun — From Space"
New York Times
http://www.nytimes.com/2008/07/23/opinion/23smith.html?
ex=1374552000&en=94912ae69854b48f&ei=5124&partner=permalink&exprod=per
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: As we face $4.50 a gallon gas, we also know that alternative energy
: sources — coal, oil shale, ethanol, wind and ground-based solar
: — are either of limited potential, very expensive, require huge
: energy storage systems or harm the environment. There is, however,
: one potential future energy source that is environmentally
: friendly, has essentially unlimited potential and can be cost
: competitive with any renewable source: space solar power.

: Science fiction? Actually, no — the technology already exists. A
: space solar power system would involve building large solar energy
: collectors in orbit around the Earth. These panels would collect
: far more energy than land-based units, which are hampered by
: weather, low angles of the sun in northern climes and, of course,
: the darkness of night.

: Once collected, the solar energy would be safely beamed to Earth
: via wireless radio transmission, where it would be received by
: antennas near cities and other places where large amounts of power
: are used. The received energy would then be converted to electric
: power for distribution over the existing grid. Government
: scientists have projected that the cost of electric power
: generation from such a system could be as low as 8 to 10 cents per
: kilowatt-hour, which is within the range of what consumers pay
: now.

: In terms of cost effectiveness, the two stumbling blocks for space
: solar power have been the expense of launching the collectors and
: the efficiency of their solar cells. Fortunately, the recent
: development of thinner, lighter and much higher efficiency solar
: cells promises to make sending them into space less expensive and
: return of energy much greater.

: Much of the progress has come in the private sector. Companies like
: Space Exploration Technologies and Orbital Sciences, working in
: conjunction with NASA's public-private Commercial Orbital
: Transportation Services initiative, have been developing the
: capacity for very low cost launchings to the International Space
: Station. This same technology could be adapted to sending up a
: solar power satellite system.

: Still, because building the first operational space solar power
: system will be very costly, a practical first step would be to
: conduct a test using the International Space Station as a
: "construction shack" to house the astronauts and equipment. The
: station's existing solar panels could be used for the demonstration
: project, and its robotic manipulator arms could assemble the large
: transmitting antenna. While the station's location in orbit would
: permit only intermittent transmission of power back to Earth, a
: successful test would serve as what scientists call "proof of
: concept."

: Over the past 15 years, Americans have invested more than
: $100 billion, directly and indirectly, on the space station and
: supporting shuttle flights. With an energy crisis deepening, it's
: time to begin to develop a huge return on that investment. (And for
: those who worry that science would lose out to economics, there's
: no reason that work on space solar power couldn't go hand in hand
: with work toward a manned mission to Mars, advanced propulsion
: systems and other priorities of the space station.)

: In fact, in a time of some skepticism about the utility of our
: space program, NASA should realize that the American public would
: be inspired by our astronauts working in space to meet critical
: energy needs here on Earth.

Mark Reiff