2009-11-08 03:58:24
by Karyn Poupee Karyn Poupee 2 hrs 29 mins ago
TOKYO (AFP) It may sound like a sci-fi vision, but Japan's space agency is
dead serious: by 2030 it wants to collect solar power in space and zap it down
to Earth, using laser beams or microwaves.
The government has just picked a group of companies and a team of researchers
tasked with turning the ambitious, multi-billion-dollar dream of unlimited
clean energy into reality in coming decades.
With few energy resources of its own and heavily reliant on oil imports, Japan
has long been a leader in solar and other renewable energies and this year set
ambitious greenhouse gas reduction targets.
But Japan's boldest plan to date is the Space Solar Power System (SSPS), in
which arrays of photovoltaic dishes several square kilometres (square miles) in
size would hover in geostationary orbit outside the Earth's atmosphere.
"Since solar power is a clean and inexhaustible energy source, we believe that
this system will be able to help solve the problems of energy shortage and
global warming," researchers at Mitsubishi Heavy Industries, one of the project
participants, wrote in a report.
"The sun's rays abound in space."
The solar cells would capture the solar energy, which is at least five times
stronger in space than on Earth, and beam it down to the ground through
clusters of lasers or microwaves.
These would be collected by gigantic parabolic antennae, likely to be located
in restricted areas at sea or on dam reservoirs, said Tadashige Takiya, a
spokesman at the Japan Aerospace Exploration Agency (JAXA).
The researchers are targeting a one gigawatt system, equivalent to a
medium-sized atomic power plant, that would produce electricity at eight yen
(cents) per kilowatt-hour, six times cheaper than its current cost in Japan.
The challenge -- including transporting the components to space -- may appear
gigantic, but Japan has been pursuing the project since 1998, with some 130
researchers studying it under JAXA's oversight.
Last month Japan's Economy and Trade Ministry and the Science Ministry took
another step toward making the project a reality, by selecting several Japanese
high-tech giants as participants in the project.
The consortium, named the Institute for Unmanned Space Experiment Free Flyer,
also includes Mitsubishi Electric, NEC, Fujitsu and Sharp.
The project's roadmap outlined several steps that would need to be taken before
a full-blown launch in 2030.
Within several years, "a satellite designed to test the transmission by
microwave should be put into low orbit with a Japanese rocket," said Tatsuhito
Fujita, one of the JAXA researchers heading the project.
The next step, expected around 2020, would be to launch and test a large
flexible photovoltaic structure with 10 megawatt power capacity, to be followed
by a 250 megawatt prototype.
This would help evaluate the project's financial viability, say officials. The
final aim is to produce electricity cheap enough to compete with other
alternative energy sources.
JAXA says the transmission technology would be safe but concedes it would have
to convince the public, which may harbour images of laser beams shooting down
from the sky, roasting birds or slicing up aircraft in mid-air.
According to a 2004 study by JAXA, the words 'laser' and 'microwave' caused the
most concern among the 1,000 people questioned.