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PG&E Makes Deal For Solar Power From Space

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."

38 of 392 comments (clear)

  1. Not a problem, don't be such worrywarts by BadAnalogyGuy · · Score: 5, Funny

    As long as you turn off disasters, beamed solar energy is actually a fairly cost effective power solution.

    1. Re:Not a problem, don't be such worrywarts by Jacques+Chester · · Score: 5, Insightful

      I sometimes wonder if SimCity has done more damage to the progress of orbital solar than all other causes combined.

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    2. Re:Not a problem, don't be such worrywarts by drinkypoo · · Score: 3, Informative

      I mean, what's the worst that can happen when you're beaming 200 Megawatts of energy into my town?

      Right now a fusion reactor is beaming sunlight (@ 1366W per square meter, on average) * 271.4 square km of energy at luminal frequencies alone which if I do the math right (even at this level it is by no means sure, I could be off by three orders of magnitude or something, yes I am that dyslexic about numbers) works out to about 370 gigawatts.

      The amount of energy is pretty irrelevant by itself, aside from what it can add to the grid.

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  2. Re:In all seriousness... by Jamu · · Score: 4, Funny

    That's just a bonus.

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  3. Re:Bad idea by xTantrum · · Score: 3, Funny

    yeah this should make it way easier for the aliens to knock out our power systems and take over the earth. *sigh*

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  4. Re:In all seriousness... by mrv00t · · Score: 5, Funny

    Just disable HAVE_WEAPON_SUPPORT flag in configure.in before building the sw for the space power station.

  5. It think they've been duped. by Ihlosi · · Score: 3, Interesting

    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?

    1. Re:It think they've been duped. by Jacques+Chester · · Score: 3, Informative

      Plus in space solar power is available constantly, rather than being affected by night time, winter hours and weather. As they point out you don't have to pay for the real estate, just the trip to get there.

      And it gives more consistent power because you don't get dust settling on the panels. I realise that sounds stupid, but dust can reduce efficiency by a lot in a few years; your costs go up because you have to pay people to be cleaning acres and acres of solar panels.

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      Classical Liberalism: All your base are belong to you.

    2. Re:It think they've been duped. by Ihlosi · · Score: 4, Insightful
      Nope. The amount of sunlight per m2 in space is several factors higher than on earth.

      The solar constant is about 1.4 kW/m^2 in Earths orbit. I fail to see how they want to produce 200 MW with significantly less than 0.2 km^2 of collector area. Care to explain it to me?

    3. Re:It think they've been duped. by Jacques+Chester · · Score: 3, Informative

      There are a number of points you can choose that are geostationary and in shadow less than 2% of the time (as I recall the 1970s proposal). Other schemes call for having multiple satellites that hand off to each other. This proposal is I think of the former variety.

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      Classical Liberalism: All your base are belong to you.

    4. Re:It think they've been duped. by Jacques+Chester · · Score: 3, Informative

      The trick to remember is that the Earth is actually quite a small part of the sky when seen from a satellite in geostationary orbit. It seems big to us, but it's just a pale blue dot after all.

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      Classical Liberalism: All your base are belong to you.

    5. Re:It think they've been duped. by Doc+Ruby · · Score: 3, Informative

      How about I convince you they're planning to deliver only 2MW, not 200MW.

      They say they'll reach a 17GWh:y delivery once the platform is stable. There's 8765.81277 hours in a year, so that's 17 billionWh / 8765.81277h = 1.9393524 million watts.

      The solar "constant" in geosync Earth orbit (about 35Km elevation) is 1366W:m^2. That's 1419.73089m^2, or 0.00141973089Km^2, significantly less (0.709865445%) than 0.2Km^2.

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    6. Re:It think they've been duped. by Doc+Ruby · · Score: 3, Informative

      TFA's math is wrong. TFA says specifically

      [Solaren corporate spokesperson Marshall] said the agreement called for 800 gigawatt-hours of electricity to be provided during the first year of operation, and 1,700 gigawatt-hours for subsequent years.

      1700 GWh in an 8700 hour year is just under 2MW. 200MW is enough power for 100,000 homes at 2KW each (a low average), so even their math that 1700GWh is "the annual consumption of 250,000 average homes" is wrong. I think their quoting the numbers in the contract is more reliable than their arithmetic.

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      make install -not war

  6. Re:Bad idea by Rosco+P.+Coltrane · · Score: 3, Interesting

    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?

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  7. Re:In all seriousness... by Ihlosi · · Score: 4, Insightful
    couldn't this also be used as a weapon?

    Yes. But as the Russians found out - any energy source can be used as a weapon. The more people are dependent on it, the better. And such usage doesn't even involve violence - just mention that there might be some service disruptions, outages, etc, if you don't get your way.

  8. Excellent headline by Big+Nothing · · Score: 5, Funny

    "PG&E Makes Deal For Solar Power From Space"

    Is there any other kind?

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  9. Re:Bad idea by TheRaven64 · · Score: 5, Funny

    I'm sorry, maybe it's too early in the morning for my brain to be working, but could you be a little more specific about what you consider the downside to be?

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  10. Re:Bad idea by Antique+Geekmeister · · Score: 3, Funny

    A lot of folks in SF find a sudden need to head to the bathroom, preferably with wire cutters, to get those genital piercings _off_?

  11. Re:Bad idea by JamesP · · Score: 4, Funny

    The effects of microwave radiation on high density airborne smug are still unknown

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  12. Re:In all seriousness... by Thanshin · · Score: 4, Funny

    couldn't this also be used as a weapon?

    "Tonight we had a most unfortunate accident. A micrometeor hit the satellite, changing it's orientation. The accident, unfortunately, destroyed a coal plant. Again.

    Oh, by the way. We're raising the prices 25%."

  13. Re:In all seriousness... by Farmer+Tim · · Score: 4, Funny

    I'd be interested to know what effect it would have on an airport for example.

    The in-flight meals would be warm for once. Now, if only someone could work out a way of beaming flavour from a satellite...

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  14. Re:Bad idea by Lloyd_Bryant · · Score: 3, Interesting

    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...

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  15. Interlock by Doc+Ruby · · Score: 4, Informative

    These beaming systems have interlocks pointed back from the ground receiver to the satellite. If the two get out of alignment, the satellite immediately loses the ground signal, and immediately stops transmitting.

    Besides, the beamed power density doesn't have to be very high per square meter. If it's just concentrated 5x from its density in space, it's 6.5KW:m^2. At this system's 2MW transmission rate, is only 308m^2, or a square 17.5m on a side. If it's really RF, even if the interlock failsafe failed, the beam wouldn't do much except fry some unshielded electronics in the way until something else shut it down. I'm sure the multiple layers of government regulators will ensure a lot of "deadman switches" to stop the only thing that everyone guesses could go wrong.

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  16. Re:In all seriousness... by TapeCutter · · Score: 4, Insightful

    "couldn't this also be used as a weapon?"

    No, it will never get off the ground.

    Having said that, Solaren's web site is all about down to earth renewable projects. The 200MW of power the power company has pledged to buy is the equivalent of 40 commercial windmills. My guess is this is a "foot in the door" deal that cost neither party a cent but Solaren now know what the power company are willing to pay. Using this knowledge they can go back at a later date and convert the pie-in-the-sky pledge into a purchase from a normal wind/solar farm that will do the same thing for the same predetermined price.

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  17. Re:Bad idea by jamesh · · Score: 3, Funny

    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?

    It turns everyone gay?

    That's not a horrible idea... that's a fabulous idea :)

  18. Re:Bad idea by Lloyd_Bryant · · Score: 5, Insightful

    The problem is that a laser beam doesn't go any faster than light speed, either.

    The satellite would have to determine on its own whether it's still pointing the right way.

    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.

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  19. Re:I've seen this by cthulu_mt · · Score: 4, Funny

    They also thought Detriot would be a wastekand of crime and poverty and everyone would drive oversized cars.

    Fools...

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  20. Re:Bad idea by Jacques+Chester · · Score: 3, Informative

    Again, no. The microwaves don't interact with organic matter, they pass through. You're not getting cancer from TV broadcasts or mobile phone towers either.

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    Classical Liberalism: All your base are belong to you.

  21. Re:makes no sense by Doc+Ruby · · Score: 4, Interesting

    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.

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  22. SPSS by Orgasmatron · · Score: 3, Interesting

    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.

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  23. Re:Bad idea by blueskies · · Score: 3, Insightful

    Why don't you stand in front of a 200 Megawatt transmission and get back to us on that one?

  24. Re:makes no sense by icebrain · · Score: 5, Informative

    During most of the year, geostationary satellites spend 100% of the time in sunlight. During "eclipse season" (which happens around the spring/fall equinoxes), they get eclipsed, for a few minutes up to about 70 (at the peak of the season). A discussion of this can be found here: http://celestrak.com/columns/v04n09/

    During those times, you could redirect from another satellite, use an alternative power source (batteries, capacitors, fueled generators, etc), and/or have a "brownout". Power outages suck, but if you're in a place where conventional power sources are unavailable/impractical/infeasable, it's better than nothing.

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  25. Re:Bad idea by afidel · · Score: 3, Informative

    I see you aren't an electronics geek, it's simple to make a crystal radio that's powered by nothing more than the radio waves floating around you =) Oh and the solution is simple, you use a feedback loop. You have a continue signal on the ground that tells the satellite to send power, if the beam gets misaligned the ground station loses power and the continue signal stops and the satellite shuts down transmission.

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  26. Re:In all seriousness... by Farmer+Tim · · Score: 3, Funny

    They're a device designed to prevent passengers becoming bored and restless on longer flights. Originally they were cheap cardboard construction kits, but the airlines found that by serving them with gravy mix they had greater entertainment value.

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  27. Re:Bad idea by Hojima · · Score: 5, Interesting

    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.

  28. Re:Bad idea by rufty_tufty · · Score: 3, Interesting
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  29. Re:Bad idea by Raenex · · Score: 3, Insightful

    I *GAVE* them a damned idea that would save MILLIONS and cost very little to implement. I even did the research myself. And THIS is what they're getting? My idea would've generated ten times the amount of power, at FAR LESS COST.

    Then publish your research and promote it.

  30. Re:Bad idea by Brandon30X · · Score: 3, Informative

    You answered your own question. It cant produce a narrow beam, which is the same reason why it cant cook anybody. You have a large diameter beam (kilometers in diameter) at a low power density (similar to the energy density of sunlight) and a huge rectenna array (say, covering many farmers fields by being upheld on stilts). Yes, this works. I have studied it. Smarter people than you or I have studied it. I swear to god NOBODY on slashdot understands power density. Every frikin time this subject comes up its always "its a weapon!"

    Now economic viability and possible electronic interference you can go and argue all you want.

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