Japan eyes solar station in space as new energy source
November 8, 2009 by Karyn Poupee
This file graphic illustration released from Japan's Institute for Unmanned Space Experiment Free Flyer (USEF) shows a system of space solar power system (SSPS) which consists of a large solar power generator and transmission panel. Japan's space agency hopes to by 2030 collect solar power in space and zap it down to Earth, using laser beams or microwaves.
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.
(c) 2009 AFP
Sep 05, 2010
Like... Would it be possible for this to be used as a giant death ray?
Interesting point. I've been designing spacecraft with external power supplies like lasers for some time. Getting funded is another matter.
It's probably way more cost effective to situate 10 solar power plants on earth around the equator.
The EU is currently trying for 15% solar power to the tune of 400 billion Euros. I'm guessing that for the same amount of money you can only get a tiny fraction of that from GEO sattelite installations like the one proposed.
Think of a directional antenna broadcasting in one direction. The greater the distance the wider the wave front and the energy density will be less at any given point within the wave front.
But still a cool idea!
-Do they use a Maser to transmit the microwaves?
-How efficient would the beaming through the atmosphere be?
-Wouldn't microwaves heat up the water molecules in clouds?
-How are the microwaves received? Is it just an antenna?
-What happens in the event of an impact?
-According to the United States Office Of Technology Assessment of space solar power-beaming, the efficiency would probably be about 17%.
- This would be more than enough to disrupt satellite and radio telecommunications, and cause substantial cloud modifications in the lower atmosphere that would negatively impact weather, and heat up the atmosphere. Not to mention the possibility that aircraft passengers could get fried, as well as people too close to the receiving station.
-The microwaves are received by rectennas that contain billions of copper dipoles.
-Please read the best-selling book titled Sunstroke (like I did) and you'll find out what happens when such a satellite is involved in a nasty impact.
http://www.physor...731.html but it is expired so I found it from another online source.
http://www.sfgate...0S32.DTL
It seems like a viable source of energy and it looks as if there may be a few nations looking into this as a realistic power adgenda.
And i figure that with three or four nations doing the tests for safety the credibility will be sufficient for the public.
Who fails to do arithmetic is doomed to nonsense.
Well...as long as you don't hit the resonance frequency of other molecules that is. But these are all pretty much known and thus the problem of flocks of geese being cooked in mid-flight could be easily avoided.
Thank you for your very pertinent comment in this important matter.