FYI,

"Report Urges U.S. to Pursue Space-Based Solar Power"
SPACE.com
http://news.yahoo.com/s/space/20071012/sc_space/reporturgesustopursues
pacebasedsolarpower;_ylt=AjRNvcEazA79S7fxw5ixO7AE1vAI

: A Pentagon-chartered report urges the United States to take the
: lead in developing space platforms capable of capturing sunlight
: and beaming electrical power to Earth.

: Space-based solar power, according to the report, has the potential
: to help the United States stave off climate change and avoid future
: conflicts over oil by harnessing the Sun's power to provide an
: essentially inexhaustible supply of clean energy.

: The report, "Space-Based Solar Power as an Opportunity for
: Strategic Security," was undertaken by the Pentagon's National
: Security Space Office this spring as a collaborative effort that
: relied heavily on Internet discussions by more than 170 scientific,
: legal, and business experts around the world. The Space Frontier
: Foundation, an activist organization normally critical of
: government-led space programs, hosted the website used to collect
: input for the report.

: Speaking at a press conference held here Oct. 10 to unveil the
: report, U.S. Marine Corps Lt. Col. Paul Damphousse of the National
: Space Security Space Office said the six-month study, while "done
: on the cheap," produced some very positive findings about the
: feasibility of space-based solar power and its potential to
: strengthen U.S. national security.

: "One of the major findings was that space-based solar power does
: present strategic opportunity for us in the 21st century,"
: Damphousse said. "It can advance our U.S. and partner security
: capability and freedom of action and merits significant additional
: study and demonstration on the part of the United States so we can
: help either the United State s develop this, or allow the
: commercial sector to step up."

: Demonstrations needed

: Specifically, the report calls for the U.S. government to
: underwrite the development of space-based solar power by funding a
: progressively bigger and more expensive technology demonstrations
: that would culminate with building a platform in geosynchronous
: orbit bigger than the international space station and capable of
: beaming 5-10 megawatts of power to a receiving station on the
: ground.

: Nearer term, the U.S. government should fund in depth studies and
: some initial proof-of-concept demonstrations to show that
: space-based solar power is a technically and economically viable to
: solution to the world's growing energy needs.

: Aside from its potential to defuse future energy wars and mitigate
: global warming, Damphousse said beaming power down from space could
: also enable the U.S. military to operate forward bases in far
: flung, hostile regions such as Iraq without relying on vulnerable
: convoys to truck in fossil fuels to run the electrical generators
: needed to keep the lights on.

: As the report puts it, "beamed energy from space in quantities
: greater than 5 megawatts has the potential to be a disruptive game
: changer on the battlefield. [Space-based solar power] and its
: enabling wireless power transmission technology could facilitate
: extremely flexible 'energy on demand' for combat units and
: installations across and entire theater, while significantly
: reducing dependence on over-land fuel deliveries."

: Although the U.S. military would reap tremendous benefits from
: space-based solar power, Damphousse said the Pentagon is unlikely
: to fund development and demonstration of the technology. That role,
: he said, would be more appropriate for NASA or the Department of
: Energy, both of which have studied space-based solar power in the
: past.

: The Pentagon would, however, be a willing early adopter of the new
: technology, Damphousse said, and provide a potentially robust
: market for firms trying to build a business around space-based
: solar power.

: "While challenges do remain and the business case does not
: necessarily close at this time from a financial sense, space-based
: solar power is closer than ever," he said. "We are the day after
: next from being able to actually do this."

: Damphousse, however, cautioned that the private sector will not
: invest in space-based solar power until the United States buys down
: some of the risk through a technology development and demonstration
: effort at least on par with what the government spends on nuclear
: fusion research and perhaps as much as it is spending to construct
: and operate the international space station.

: "Demonstrations are key here," he said. "If we can demonstrate
: this, the business case will close rapidly."

: Military applications

: The Pentagon's interest is another important factor. Military
: officials involved in the report calculate that the United States
: is paying $1 per kilowatt hour or more to supply power to its
: forward operating bases in Iraq.

: NASA first studied space-based solar power in the 1970s, concluding
: then that the concept was technically feasible but not economically
: viable. Cost estimates produced at the time estimated the United
: States would have to spend $300 billion to $1 trillion to deliver
: the first kilowatt hour of space-based power to the ground, said
: John Mankins, a former NASA technologist who led the agency's
: space-based solar power research and now consults and runs the
: Space Power Association.

: Advances in computing, robotics, solar cell efficiency, and other
: technologies helped drive that estimate down by the time NASA took
: a fresh look at space-based solar power in the mid-1990s, Mankins
: said, but still not enough justify the upfront expense of such an
: undertaking at a time when oil was going for $15 a barrel.

: With oil currently trading today as high as $80 a barrel and the
: U.S. military paying dearly to keep kerosene-powered generators
: humming in an oil-rich region like Iraq, the economics have change
: significantly since NASA pulled the plug on space-based solar power
: research in around 2002.

: On the technical front, solar cell efficiency has improved faster
: than expected. Ten years ago, when solar cells were topping out
: around 15 percent efficiency, experts predicted that 25 percent
: efficiency would not be achieved until close to 2020, Mankins said,
: yet Sylmar, Calif.-based Spectrolab – a Boeing subsidiary – last
: year unveiled an advanced solar cell with a 40.7 percent conversion
: efficiency.

: One critical area that has not made many advances since the 1990s
: or even the 1970s is the cost of launch. Mankins said
: commercially-viable space-based solar power platforms will only
: become feasible with the kind of dramatically cheaper launch costs
: promised by fully reusable launch vehicles flying dozens of times a
: year.

: "If somebody tries to sell you stock in a space solar power company
: today saying we are going to start building immediately, you should
: probably call your broker and not take that at face value," Mankins
: said. "There's a lot of challenges that need to be overcome."

: Mankins said the space station could be used to host some early
: technology validation demonstrations, from testing appropriate
: materials to tapping into the station's solar-powered electrical
: grid to transmit a low level of energy back to Earth. Worthwhile
: component tests could be accomplished for "a few million" dollars,
: Mankins estimated, while a space station-based power-beaming
: experiment would cost "tens of millions" of dollars.

: Placing a free-flying space-based solar power demonstrator in
: low-Earth orbit, he said, would cost $500 million to $1 billion. A
: geosynchronous system capable of transmitting a sustained
: 5-10 megawatts of power down to the ground would cost around
: $10 billion, he said, and provide enough electricity for a military
: base. Commercial platforms, likewise, would be very expensive to
: build.

: "These things are not going to be small or cheap," Mankins said.
: "It's not like buying a jetliner. It's going to be like buying the
: Hoover Dam."

: While the upfront costs are steep, Mankins and others said
: space-based solar power's potential to meet the world's future
: energy needs is huge.

: According to the report, "a single kilometer-wide band of
: geosynchronous earth orbit experiences enough solar flux in one
: year to nearly equal the amount of energy contained within all
: known recoverable conventional oil reserves on Earth today."

Mark Reiff