Forgot your password?
typodupeerror
Space Power

PG&E Makes Deal For Solar Power From Space 392

Posted by Soulskill
from the just-watch-out-for-the-shadow-square-wire dept.
N!NJA writes "California's biggest energy utility announced a deal Monday to purchase 200 megawatts of electricity from a startup company that plans to beam the power down to Earth from outer space, beginning in 2016. Solaren would generate the power using solar panels in Earth orbit and convert it to radio-frequency transmissions that would be beamed down to a receiving station in Fresno, PG&E said. From there, the energy would be converted into electricity and fed into PG&E's power grid."
This discussion has been archived. No new comments can be posted.

PG&E Makes Deal For Solar Power From Space

Comments Filter:
  • I've seen this (Score:3, Interesting)

    by ArcherB (796902) on Tuesday April 14, 2009 @07:16AM (#27568519) Journal

    They mentioned it in the first Robocop movie.

  • by Ihlosi (895663) on Tuesday April 14, 2009 @07:23AM (#27568573)
    Or are they really saying they're going to install roughly 200000 m^2 worth of solar collectors in space? That's a square of roughly 450x450m. And "some startup" is planning a feat like that?
  • Re:Bad idea (Score:4, Interesting)

    by Rosco P. Coltrane (209368) on Tuesday April 14, 2009 @07:24AM (#27568577)

    This is a horrible idea. What happens when the beamer is hit by a micro meteor nocking out the com and pointing the sat at SF?

    Forget micrometeors. The real question is: what happens when Solaren goes the Enron way (and isn't bailed out by your tax dollar) and their satellite is allowed to go derelict and drift? Will it leave a narrow trail of roasted humans across California?

  • by tomtomtom777 (1148633) on Tuesday April 14, 2009 @07:29AM (#27568633) Homepage

    Or are they really saying they're going to install roughly 200000 m^2 worth of solar collectors in space? That's a square of roughly 450x450m. And "some startup" is planning a feat like that?

    Nope. The amount of sunlight per m2 in space is several factors higher than on earth.

  • Re:Bad idea (Score:3, Interesting)

    by Lloyd_Bryant (73136) on Tuesday April 14, 2009 @07:37AM (#27568691)

    I take it you never heard of the concept of "failsafe" systems? For instance - the ground station is transmitting a "keep alive" signal to the satellite once every 100ms. The satellite hardware is designed so that if the keep-alive isn't received after 250ms, it automatically cuts off the transmitter.

    And the ground station is set so that if it detects the power beam moving over a certain distance off-center of the receiver, it cuts the keep-alive.

    The only part of this concept that's "rocket science" is the business of getting the solar panels up there. The rest is just engineering (which engineers happen to be quite good at).

  • by CubicleView (910143) on Tuesday April 14, 2009 @07:37AM (#27568693) Journal
    Yes, I'm sure it could... in theory. I don't know the numbers/ specifics but presumably, it could mess up communications equipment etc? I'd be interested to know what effect it would have on an airport for example. Anyway, that said I don't see that it would be a particularly good weapon. It could be blown up easily enough, and it's going to be a very large target. I'd also imagine that it would require a constant radio link with a ground station or similar, before it beam down any significant energy, like a dead man switch(or the opposite of one I suppose). That's just a guess though.
  • Re:Bad idea (Score:4, Interesting)

    by Lloyd_Bryant (73136) on Tuesday April 14, 2009 @07:52AM (#27568813)

    Considering how far the beam might deviate in 250 ms, I think the reaction time should be made much, much short. Microseconds.

    True - the reaction time should be shorter. So try this: The ground station is transmitting a laser signal, which the satellite receives using a system with a VERY limited field of vision. If the signal is interrupted, the power cuts off. That way if the satellite's orientation is disturbed enough to miss the receiver, it won't be able to see the laser...

    The keep-alive idea I originally posted doesn't hold up on closer inspection - there's over 100ms of latency in a radio link from the Earth's surface to geosynchronous orbit...

  • by LabRat (8054) on Tuesday April 14, 2009 @08:01AM (#27568949)

    ...otherwise kiss radio astronomy in North America goodbye. Those guys thought they were getting interference from the Iridium constellation? Heh..wait until they get 200MW of broadband RF interference coming down on them from this monstrosity.

    Not to mention, this seems to be a complete waste of resources. I'd wager that at least as much land (if not more) will need to be dedicated to the antenna array as a 400MW (put in twice the power to make up for day-only operations) solar concentrator plant if they want any sort of chance of capturing all of the beam for conversion. Add to that the fact that the increased solar incidence in orbit will be conteracted by the losses in RF transmission (engineers were thrilled when they achieved 54% between ground towers recently...). And lets not forget the rather substantial launch costs (likely hundreds of millions of dollars). All in all...this is a concept best suited to the Sims game than real life. I'm all for alternative/renwewable energy...but this is just a waste of time and money. But hey..if some VC's like watching stacks of hundred-dollar-bills burn in the mean time...more power to them. I just hope this idiotic scheme doesn't get any federal funding. Our DOE Secretary is a pretty sharp guy...I'm sure he sees the folly in it as well and hopefully will steer well clear of it. I would think the FCC would have something to say as well..considering the MASSIVE potential for RF interference. Investment tip: I wouldn't be sinking any retirement money into this outfit ;)

  • Re:Bad idea (Score:3, Interesting)

    by Jacques Chester (151652) on Tuesday April 14, 2009 @08:05AM (#27569001)

    Will it leave a narrow trail of roasted humans across California?

    No. The microwaves are the wrong frequency, they don't interact with water and will pass straight through any living creature.

  • Re:Bad idea (Score:3, Interesting)

    by Ihlosi (895663) on Tuesday April 14, 2009 @08:16AM (#27569139)
    That's why I specified that the *receiver* have a very limited field of vision. If the satellite rotates enough to be off target, it can no longer see the laser. Thus no latency issues.

    Oh ... right. My bad. That should work as intended.

  • by dykofone (787059) on Tuesday April 14, 2009 @08:21AM (#27569223) Homepage
    Wow, yeah, just looked it up, and geostationary orbit is at about 36,000 km above sea level. If above the equator, that's in sunlight 95% of the time. Put it any farther out, or anywhere more in line with the poles, and that would rise quickly. Very cool.
  • Re:makes no sense (Score:5, Interesting)

    by Doc Ruby (173196) on Tuesday April 14, 2009 @08:33AM (#27569413) Homepage Journal

    Buying desert land isn't "astronomically expensive". It's about the cheapest land there is. There happens to be huge deserts of dirt-cheap (cheaper: sand-cheap) land all around California. Besides, this 2MW satellite probably doesn't even need more than about 25m^2 to receive its beam at 5x solar density. If they wanted to be really safe, they probably could diffuse it over 2500m^2, for 5W:m^2, which doesn't hurt anyone.

    The efficiency here is the 30% extra incoming solar power that is otherwise lost in the atmosphere (minus some small lost amount they're tuning the beam to minimize), times the 24/7 uptime instead of about 25% terrestrial due to night/weather/seasons. That's a starting point of 520%. But the other advantage is the much larger area that thin collector sheets can cover in space. Launching costs money per mass, but the collectors can unfurl across kilometers. And the maintenance costs in microgravity/femtopressure are much lower over years, despite the remoteness. After the large initial costs, the ongoing costs per watt are extremely low.

    2MW would require only about 40x40m collectors. A square kilometer collector would bring 1.3GW. The geosync satellite beaming to Fresno could receive from collectors in all kinds of other orbits pointing at the hub. This infrastructure could conceivably bring all 17TW of Earth's energy consumption into a series of ground stations from only about 114*114 Km of collectors. A few score hubs around the equator each using a few dozen GW lasers could replace all the coal currently burned for stationary power. The sky is literally the limit.

  • SPSS (Score:4, Interesting)

    by Orgasmatron (8103) on Tuesday April 14, 2009 @08:43AM (#27569535)

    This really is very safe, and all the technology is known (not at this scale maybe, but known). The only thing that has stopped us from doing it already has been a lack of willpower.

    If you are sending microwaves from a smallish antenna (small enough that you can boost it into GEO, for example) all the way back to earth, the receiver needs to be huge, like many acres. Basically you find a good pasture, put posts in the ground every few dozen feet in a grid, run wires and diodes between the poles, and you now have a high efficiency rectenna and the cows grazing underneath won't even notice.

    Even if the beam wandered, the power per square meter isn't that high, and to get through the atmosphere with minimal losses, it won't be at a frequency that is easily absorbed by water, which means that it won't be at a frequency that is easily absorbed by you or me.

  • Re:Bad idea (Score:5, Interesting)

    by Hojima (1228978) on Tuesday April 14, 2009 @10:11AM (#27570871)

    Everyone does that every day. It's called the sun. That's where this thing gets its energy from. However, there is a key difference between solar radiation, and the radiation that this machine produces. The reason that we have solar frequencies converted to this frequency, is because it interacts close to nothing with the atmosphere, or just about any organic particle/interference. A lot of matter interacts with very specific frequencies, which is why this frequency will only give power to the designated material. Think of an atom as a football at the center of the stadium. The electrons would be like flies in the bleachers. Now if you want to hit the flies with bullets, you have to aim to where they generally are, or you'll miss. It works kinda like that.

  • Re:Bad idea (Score:3, Interesting)

    by muridae (966931) on Tuesday April 14, 2009 @10:24AM (#27571073)

    Then I recommend MythBuster's Free Energy episode, where they did pull a tiny bit of electricity out of the air from radio waves.

    In general terms, it's how a crystal radio gets the power to run. You didn't think the 100 or 300 or how ever many watts the radio stations brag about broadcasting just vaporised?

  • Re:Bad idea (Score:4, Interesting)

    by rufty_tufty (888596) on Tuesday April 14, 2009 @11:02AM (#27571747) Homepage

    I was referring to this:
    http://www.atomicinsights.com/may95/plutonium_eff.html [atomicinsights.com]

Lo! Men have become the tool of their tools. -- Henry David Thoreau

Working...