WASHINGTON – 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."
Charles Miller, one of the Space Frontier
Foundation's directors, agreed public funding is vital to getting
space-based solar power off the ground. Miller told reporters here that the
space-based solar power industry could take off within 10 years if the White
House and Congress embrace the report's recommendations by funding a robust
demonstration program and provide the same kind of incentives it offers the
nuclear power industry.
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.
"The biggest issue with
previous studies is they were trying to get five or ten cents per kilowatt
hour, so when you have a near term customer who's potentially willing to pay
much more for power, it's much easier to close the business case," Miller
said.
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."
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