The Japan Aerospace Exploration Agency (JAXA) and Osaka University have been working together to develop a device which converts sunlight into laser-light with four times the efficiency of previous attempts. According to a report out of Tokyo, the team is working on Space-based solar power systems which can collect sunlight in space and convert it into laser light, which is then transmitted to Earth and used for electricity... or to power a massive Death-Ray. The project works by storing sunlight-based energy in plate made from a sintered powder of metals like chromium and neodymium. When weak laser light is shined onto the plate, the stored energy is transferred to the laser where its strength is amplified by a factor of four. In one test, a 0.5-watt laser was amplified to 180-watts by the plates. Scientists have thus far been able to garner 40-percent of the solar energy produced, and they hope to have a system ready for satellite mounting by the
not-too-distant year 2030. Huzzah! [Warning: read link requires subscription]
posted September 4th 2007 2:22PM
Me thinks they have heard the rumblings of Godzilla and Mothra
"In one test, a 0.5-watt laser was amplified to 180-watts by the plates"
So, it this a perpetual motion machine or am I missing something? a watt is a measure of total energy, so if something turns half a watt into 180 watts, they have just pulled 179.5 watts out of their ears. now if they meant it took half a volt or half an amp and made it 180, this would be ok.
I have a problem with this idea. I laud them for coming up with such a creative idea but it seems that there are too many flaws. First of all firing a laser beam from space to earth will have a problem with disassociation of ions as well as a host of problems dictated by Mie and Rayleigh Scattering. Also they did not mention if the wavelength this laser is visible, IR or UV. IR of course really will do nothing at all. Visible would require quite a lot of power i.e. overall wattage. UV requires even more. Also how would they correct for the beam widening? Does that mean they would have to have some sort of collimator up there orbiting as well?
Along with that there would have to be some sort of system that fixates the laser in a geosynchronous orbit that is aimed at a desert based desired capacitor-like or energy absorbing device that can accommodate power of that beam width(w/square area/ ster radian). Moreover, the overall radiation alone from that laser would completely vaporize it's target and surroundings. Think about it that target would have to be cooled with either a huge supply of water, which in the dessert is short to come by unless there is some sort of huge aquafir beneath that surface or it needs to be cooled by some sort cryogenic material. That cryogenic target would need some sort of vacuum pump system that will also require lots of energy. All in all too many little problems.
Also I agree with the comment above me about the mirror would be far more efficient if it were parabolic. Other wise you lose energy from not collecting the straylight radiation.
I don't think I have enough room in this commenting box to express how science fiction this idea is.