Gallery: New JAXA Technology Captures Solar Energy in Space


Instead of doing the old-fashioned solar power thing, and capturing the sun’s rays as they hit the Earth’s surface, the Japan Aerospace Exploration Agency (JAXA) and Osaka University Institute of Laser Engineering is bolding going where no space station has ever gone before – in terms of solar power. Pioneering scientists at Jaxa have found a way to harness solar power even closer to the source- from outer space! The Space Solar Power System (SSPS) technology would capture solar rays in space and transport the energy to be used here on the ground. A single unit placed in space would generate enough energy to power 500,000 homes!

Sound like a green version of Star Trek? It’s actually quite simple: the space solar ray capturing system consists of a solar power satellite (SPS) and ground facilities to exploit power from the SPS via laser beam. The SPS orbits the Earth and gathers solar energy; it is then transmitted to a terrestrial power station. The satellite would be launched into stationary orbit 22,400 miles above the equator that would collect solar energy and convert it to a laser beam and send it to the earth-based station.

Specialized plates mounted on the satellite would be made from a ceramic material containing chromium and neodymium- the former absorbs the sunlight and the latter translates sunlight to laser light with a very high efficiency. The new technology promises 42% solar-to-laser energy conversion efficiency.

The major advantage of this system is that it would use solar energy 24 hours a day, and would not depend only on sunny days as is the case with earth-based solar power systems. Testing would start this week, on February 20th, and the project is scheduled to be completed in 2030.

Via Pink Tentacle

+ Japan Aerospace Exploration Agency


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  1. Gary7 December 7, 2009 at 12:13 pm

    What fascinates me is the direct conversion of random wavelengths of sunlight to coherent radiation. I’d really like a followup on that tech.

    Dr. Gerard K. O’Neille proposed Solar Power Sats in the 1970s AND laid out a viable approach in his book The High Frontier.

    Launch costs/kg(and the total mass for a power sat) has always been the main limiting factor to these devices.

    Gary 7

  2. Mekhong Kurt March 4, 2008 at 2:22 am

    I believe this will be a viable option, despite the safety concerns many address. The primary concern of a laser beam straying off course could be avoided rather easily, in fact, using decades-old solutions.

    A low-tech example will suffice. When I was a teenager back in the 1960’s, I flew countless model rockets, the kind with plastic and/or cardboard bodies, balsa wood fins and nose cones, and solid-fuel engines. Then I discovered an outfit that had a three-stage, liquid-fueled rocket, the upper stage of which could achieve an altitude of around 22,000-23,000 feet, in good weather.

    I convinced my Father to fund it, including building a proper concrete launch pad and a cinder block bunker — but his consent was conditional on IF I could figure out a way to handle the safety concerns. The ranch on which I grew up is smack dab in the middle of a whole bunch of general aviation, commercial, and military airports, in all directions, even today. (There were even more back then.) Furthermore, the ranch was just inside an FAA controlled airspace area, meaning that I needed to obtain formal permission from the FAA to launch.

    Got the permission, and we were set to go, when a worry struck us: what if the rocket veered off course? Sure, the FAA would clear the airspace for a five-mile radius during the four-minute launch window — but could it veer off course enough to maybe strike an airplane outside the safety zone? You can bet a six-foot rocket loaded with liquid fuel conceivably could down even a commercial airliner.

    My highschool science teacher came up with a simple solution. He worked out how steep an angle the rocket could veer before straying beyond the safety zone at max altitude. Once he had that, he designed a simple mercury switch that would close a switch to activate a self-destruct system if the rocket tilted more than 4 degrees (or something like that — that was a long time ago). He also worked out a way I could use radio-control device used in RC model airplan flying as a manual backup.

    While for a space solar power satellite would require technology considerably more precise than a crude mercury switch, it’s not difficult, with what we have available today, to build a space age parallel. If the beam strays X amount off course, either the beam could be automatically turned off, the satellit destroyed, or some two-step sequence of the two. Plus automated signals from the ground as backup to either turn the laser off or destroy the satellite.

    Besides, JAXA is talking about 22 years up the road, not next week. Compare our abilities in 1986 to today’s. Who knows what leaps and bound our scientists and technologists will make in what is, in research terms, often multiple generations???

  3. Raja Roux February 20, 2008 at 7:57 pm

    During liftoff, each of the three space shuttle engines consumes 132,000 gallons of liquid hydrogen and 49,000 gallons of liquid oxygen fuel. That’s more than half a million gallons of fuel during an eight-and-one-half-minute launch. At full power, the three engines generate as much energy as 23 Hoover Dams. The power required to lift the solar collectors could power 500,000 for a year. Consider also the wasted energy to create the Hydrogen and Oxygen in the first place. The Space shuttle platform and ground systems alone use 161,248 MWH per launch – that’s 10,000 homes for a year!
    As for ‘a totally non-polluting energy generating system’
    The current estimate is that there are over a million bits of debris orbiting the Earth.
    If it works it could pay for itself eventually, but resources could be better spent on terra firma.
    (note: my figures are gleaned from skimming the net and may be bonkers.)

  4. Marvin February 20, 2008 at 6:42 pm

    Might also be interesting for the army in the way that it can provide power for troops globally. With multiple satellites….

    Sounds like a good initiative though.

  5. Richie February 20, 2008 at 10:58 am

    Space Solar Power (SSP) has been around for a while. This ‘laser’ idea seems troubling though. In the book, ” Designs on Space” (ISBN: 068485676X) (published in 2000), author Richard Wagner addresses ‘Space Solar Power’ between pages, 127-130. He refers to 2 systems on the shelf at NASA, that essentially have been ready to go for a while. They are ‘Solar Disc’ and ‘Sun Tower’. Both of these systems convert solar energy into electricity, then they convert the electricity into ultra low power microwaves which are beamed to Earth, via rectennas. These microwaves are only 1/4 the power of natural sunlight. So, in essence the danger to Life from these ultra low power microwaves is non-existent. The point being is that we are exposed to microwave radiation in excess of this magnitude daily, simply by living… as the Universe is naturally awash with microwave radiation that exceeds this concentration. The fascinating part is that the technology exists to convert the ultra-low power microwaves back into electricity at the collecting points here on Earth. SO the possibility of having a totally non-polluting energy generating system has been in our grasp since at least 2000.

    The lasers are a bad idea. Ultra low power microwaves are better… and are probably the way to go. Maybe this Japanese venture will embarrass the USA/NASA folks enough so that it finally implements the microwave system ? I hope so. A few years ago it was projected to cost about $80 Billion to get a system up and running. That’s a fraction of what the Iraq war cost !

  6. Piriya February 20, 2008 at 5:22 am

    “Hopefully, with the energy emergency solved, countries would be less worried about war.”

    I don’t know about that, people are silly beings, we’re always waging wars.

    I was thinking about sth like this since I was a kid. Well, I was inspired by many Japanese anime, with Space Elevator and solar power collector in space. See Gundam00 , 3 solar tower has been built to power the whole planet, and nations sought to control them, thus, leading to war among factions.

  7. Aristotle February 20, 2008 at 2:48 am

    This is one of the things we could have already done by now but didn’t do. For 60 years the lowest common denominator has pushed us into the wrong decisions. Check out the space solar power here:

  8. Kanon February 19, 2008 at 12:36 pm

    Space will be used for solar energy eventually. From my point of view, the space elevator must be put in place to make this happen. I know this system could get materials to space more efficiently than we currently can. Picture a solar panel, assembled in space, that would possibly be 3 miles long, by 3 miles wide.

    Hopefully, with the energy emergency solved, countries would be less worried about war.

  9. Will February 19, 2008 at 7:48 am

    Is the laser light they are proposing to use not affected by the level of cloud cover? If it were, then the amount of energy extracted would still be beholden to the weather.

  10. Hugo February 19, 2008 at 4:25 am

    I think the army is happy enough with a laserbeam that can power 500.000 homes. The same laserbeam is most likely able to cut the same 500.000 houses in half. I am also concerned about the damage this laser can do to the atmosphere.

  11. TT February 18, 2008 at 11:54 pm

    I can see the military backing this one, for sure. It’s a pave way to that ol’ weapons in space program. They’d put the two on the same satellite, even. It would maximize effienciency.

  12. Brandon February 18, 2008 at 6:00 pm

    This is not a new idea, just a new attempt.

  13. Don February 18, 2008 at 2:33 pm

    Most interesting, sunlight to LASER conversion. “Possibly providing power to 500,000 homes in Japan”, – again, most interesting.

    Been proposed before – microwave vs lasers. I wonder what the power levels would be at ground level to provide well over 5 MW (500,000 homes @ 1KW each) after re-conversion to AC or DC?

    Also, what size would the beams ‘footprint’ wind up being, after passing through the atmosphere? My limited experience is a 6 CM (visible ruby red) beam spreads to 1 km – earth to LEO, so GEO might be problematic.

    Good for them, at least they are willing to do the science, build the hardware and give it a go…..

    In the end, I doubt they will ever build the full power system – too much downside.

  14. Dave February 18, 2008 at 1:00 pm

    I’m glad I’m not the one responsible for making sure that a laser beam from space is always pointing at a 100 sq ft area on earth. Sounds like an accident waiting to happen. Seems to me that floating solar islands are a much better idea, when dealing with how to install large solar farms without consuming arable land.

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