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Space Power

How Space-Based Solar Power Plants Could Be Built By Robots On the Moon (blastingnews.com) 159

MarkWhittington writes: The concept of space based solar power has been around for decades. The late Gerard K. O'Neill proposed building them as a way to finance space colonies in the 1970s. Recently Popular Science reported on a modern approach to building space based solar energy stations. Instead of relying on massive, orbiting space colonies filled with construction workers to put the plants together, why not automate the entire process?
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How Space-Based Solar Power Plants Could Be Built By Robots On the Moon

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  • Bahahahaha (Score:2, Insightful)

    by Anonymous Coward

    Where is Solaren's 2016 installation?

    https://en.wikipedia.org/wiki/... [wikipedia.org]

    Oh, not even a single bolt in orbit yet? Oh I guess it'll just magically happen in the next nine months?

    These space fantasies always follow the same pattern:

    1) Uncritical support from people raised on sci-fi and proficient in software, but with no knowledge of the physical sciences and engineering
    2) Failure to deliver anything
    3) Upping the ante to ever more ridiculous concepts

    • Who are you going to believe, actual working engineers, or some guy who has seen "Empire" 47 times? Those guys in ID4 engineered a virus including a mocking graphic in about an hour and a half, and that was 15 years ago? Damn negative nellies!

      • There was a NASA paper about the manufacture of solar cells on the moon part: http://ntrs.nasa.gov/archive/n... [nasa.gov]
        --and, now that I look at the NASA site, also this one: http://ntrs.nasa.gov/archive/n... [nasa.gov]
        • by dbIII ( 701233 )
          One thing most people miss is with less gravity the zone refining of silicon to make cells of that type would be a bit easier than on Earth.
          Also there are other processes that require less infrastructure than you need to make great big ingots of pure silicon, but those ingots are very useful to make electronics etc.


          A final thing is that it makes less sense to export energy than to export things made using that energy. Getting things back down to Earth is not going to cost a vast amount in energy, it's al
  • by ickleberry ( 864871 ) <web@pineapple.vg> on Sunday March 20, 2016 @08:46PM (#51740173) Homepage
    Given that its been quite a while since someone landed anything on the moon. It would be a victory for space exploration if someone sent up a robot and dug a hole. People in the 60s would have expected a decent size lunar colony by now
    • Given that its been quite a while since someone landed anything on the moon. It would be a victory for space exploration if someone sent up a robot and dug a hole.

      It would be, but the next robots [xprize.org] on the moon won't be digging holes. Just rolling around. (Unless one of the teams gets really ambitious while trying to win the bonus $4 million available for discovering water.) The prize availability terminates at the end of next year, so the teams competing had better hurry up.

    • by AmiMoJo ( 196126 )

      A much simpler, easier option is to send up some really big mirrors. No electronics beyond what is required for unfolding and station-keeping, no issues with head dissipation, no need to develop new receivers on the ground. Just bounce some sunlight at the ground, and either use it for lighting or throw up some solar panels/thermal collectors.

      The mirrors can be huge because their mass is relatively low. You only need thin sheet metal. In fact thinner is better because micro-meteorites will punch holes and p

      • In a pinch you might even be able to use such a system to deflect asteroids, if it were large enough. Or clean up space debris by deorbiting it.

        Or torch enemy capital. Or just kill their crops with drought. Or spark forest fires.

        You're talking about a weapon of mass destruction.

        • by AmiMoJo ( 196126 )

          The ability to launch pretty much anything of significant mass into orbit can be turned into a weapon of mass destruction.

  • capitalism filter (Score:5, Insightful)

    by Ritz_Just_Ritz ( 883997 ) on Sunday March 20, 2016 @08:57PM (#51740219)

    I'm sure the instant someone can make more selling electrons generated from orbit than it costs to produce them (without siphoning tax dollars off of the rest of us clods), you'll see such a business materialize, the world will be a better place, oceans will stop rising, etc.

    Until then, let's continue with the research but utilize what's the most cost effective now.

    Fer God's sake, fusion energy is just around the corner... :)

    • I'm sure the instant someone can make more selling electrons generated from orbit than it costs to produce them (without siphoning tax dollars off of the rest of us clods), you'll see such a business materialize, the world will be a better place, oceans will stop rising, etc.

      Until then, let's continue with the research but utilize what's the most cost effective now.

      Fer God's sake, fusion energy is just around the corner... :)

      Yes, there's a Latin-Asian fusion place around the corner that helps produce methane...
      Refried beans and Kimchi...
      No candles allowed!

      • Refried beans and Kimchi...

        And here i was thinking I was the only person who mixed shit like that together...

        • Refried beans and Kimchi...

          And here i was thinking I was the only person who mixed shit like that together...

          Try avocado chunks and diced green chili in oatmeal, one of my breakfast favs...
          no sugar needed and it's actually healthy, it just sounds terrible.

          • by dbIII ( 701233 )
            There's an Indian breakfast similar to that called "poha" - one variant is green chilli and onion with rice flakes, lemon juice and coconut. Nice hot or cold.
        • When I was young, I went to war with a cube farm neighbor. Started innocently enough, a few rubber bands bounced off the ceiling.

          The nuclear option: Kimchi, taco bell, hard-boiled, slightly old, eggs and cheep can beer. Got us half a day off. 'Collateral damage' thought there was a gas leak...there was, no gas service in the area though.

          Felt kind of bad for the poor bastards who sat nearby, got to wounder if they ever figured out why we had fans pointing at each other's cube. It more or less ended afte

    • by dbIII ( 701233 )
      You sell those electrons as ingots of titanium or whatever. Or better still use that stuff to do other things offplanet and avoid having to drag so much mass up from Earth.

      As a single piece it makes almost zero sense but as one of many projects it does.

      One thing "Space 1999" actually got right (passing comment in ep1) was assembling large spacecraft on the moon to avoid dragging structural parts up from Earth.
    • by dbIII ( 701233 )

      Fer God's sake, fusion energy is just around the corner... :)

      Fusion energy was seen as 20 years off decades ago, but since then barely five years of the sort of effort anticipated has happened.

    • Re: (Score:2, Informative)

      by delt0r ( 999393 )
      Even if humans never burnt a single kg of carbon based fuels. Ocean levels would still rise. They rise for quite a while after a glaciation.
    • "Fer God's sake, fusion energy is just around the corner... :)"

      And nuclear fission is here now.

      A good measure of the quality of an energy source is the energy return on energy investment (EROEI). Oil, natural gas, wind, and nuclear fission all can get 10:1 or better. Hydro and coal can get near 100:1 or better. We see ground based solar getting less than 10:1 with 2:1 being common. For space based solar to work it'd have to compete with what we have now and whatever else might come along in the time it'

      • by MrKaos ( 858439 )

        "Fer God's sake, fusion energy is just around the corner... :)"

        And nuclear fission is here now.

        A good measure of the quality of an energy source is the energy return on energy investment (EROEI).

        I see a future that is driven by nuclear fission, nothing else can compare.

        Work studying the EROEI of nuclear power has already been done [stormsmith.nl] with input from a host of universities. They included the technologies you speak of and found that nuclear power has a *negative* EROEI.

        • "They included the technologies you speak of and found that nuclear power has a *negative* EROEI."

          What you linked to did not show a negative EROEI for nuclear power for current technologies, it showed rather pathetic returns but not negative. These numbers are based on old technologies and the assumption that nuclear fuel will be harder to obtain in the future.

          With breeder reactors fuel will become easier to find, because instead of the exceedingly rare U-235 we can use the much more plentiful U-238 and th

      • > We see ground based solar getting less than 10:1 with 2:1 being common

        No it's not. The *worst* panels, the normal poly-Si ones you see on the market, have an EROI of 4 years, and an expected lifetime of 40 years. Actually all evidence to date suggests the lifetime is 60 to 100 years, but we can't say for sure because modern panels only started being built in the 1970s. That's the *worst* case, the other technologies like thin-film are better.

        Please, stop spreading FUD. You're hurting the world.

        http://w

      • by AmiMoJo ( 196126 )

        A good measure of the quality of an energy source is the energy return on energy investment (EROEI).

        Not really, because as you point out:

        If we rule out coal because coal is bad

        You have to take a holistic approach. Even if EROEI isn't that great, if the technology avoids lots of other problems it's still worth doing. The only time EROEI is of much use is in comparing similar technologies or ruling some that are below some reasonable threshold out.

        Other technologies like bio-diesel, ethanol (corn or sugar beets), geothermal, and such get EROEI that barely exceed 1:1

        What? Geothermal is around 30:1 if you include hot water supply, or around 10:1 without. The other have their own attractions, particularly if they can be gathered from waste. Bio waste generation is c

        • Geothermal varies widely.

          It's great in Iceland. But that's relatively unique geology.

          In CA (Calaveras) there are geothermal fields that are exhausted after about 30 years. They cooled the earth enough that they can't make steam economically anymore. Lost money, but still a worthwhile experiment. Just don't do it again. Don't try to fix with scale.

          • by AmiMoJo ( 196126 )

            Sounds like bad planning, or maybe they just didn't have the survey equipment back then. In any case, these days all the new plants are doing well. African nations are finding that they are cheap and scale well, as well as being very clean.

          • by suutar ( 1860506 )

            but the Yellowstone caldera is just sitting there! :)

    • by KGIII ( 973947 )

      > Fer God's sake, fusion energy is just around the corner...

      You laugh and it's a rather traditional joke around here but it *does* look like they're getting closer and closer. Of course, I'm old and fusion power has been anywhere from five to thirty five and even fifty years away. The funky looking machine the Germans are building is claimed to have some potential - they've had it spun up and run it at some pretty high temperatures - if I understand their last press release properly.

      Hmm... I'm 58. It was

      • > You laugh and it's a rather traditional joke around here but it *does* look like they're getting closer and closer

        No, they are not. If you apply the "capitalism filter", they are further from success than ever. Much further.

        The problem isn't fusion, which continues to develop. The problem is that *so did everything else*. During the last 40 years, fusion devices got WAY more expensive and harder to keep running. Meanwhile, the price of a PV panel dropped over 100 times.

        Basically, even if fusion were to

        • If you apply the "capitalism filter", they are further from success than ever.

          The problem with applying "capitalism filter" to energy production is that keeping industrial civilization going is a good enough cause to pay taxes for subsidizing. Also, our eventual starships are going to need power sources capable of working in interstellar space, and in practice that likely means either fission or fusion reactors, at least in early gens.

      • by HiThere ( 15173 )

        Well, this time some major corporations are tying their names to it. Lockheed, e.g. It could be just PR fluff, but they could be serious. (Of course, they say "apartment building", but the mean "military base", but that's still fusion power.)

    • I'm not really sure that beaming energy from the moon, or just earth orbit, would be that much better for reducing our global warming contributions. All that energy that we'd be beaming down is radiation that would have passed our planet by, except we're redirecting it. That means we'd actually be increasing the amount of energy in our habitat. Transmitting energy in the form of radiation to receive it elsewhere and convert into electricity is extremely inefficient, especially as the distance increases, and

      • by HiThere ( 15173 )

        It would give us *different* problems. It would allow the carbon dioxide level in the air to return to lower levels, which would make the radiation of heat more effective, but it would add increased heat to they system. But how much? You'd want to choose your frequencies for optimal transmission effectiveness, which means water is transparent, and so are rain drops and fog, but you'd also want efficient absorption at the receiver. Something just longer than microwaves is probably about right, but I'm no

  • by beatle11 ( 1086123 ) on Sunday March 20, 2016 @08:58PM (#51740225)
    An object in space beaming energy down to a planet. Sounds a lot like a Death Star to me.
  • by ooloorie ( 4394035 ) on Sunday March 20, 2016 @09:00PM (#51740233)
    The economics of space based solar power make little sense. You gain maybe a factor of three in terms of energy captured, but at the cost of massive launch costs, expensive maintenance, expensive transmission systems and large ground based stations, and the risk of having what amounts to energy beam weapons in space. If you think solar energy is cost effective, just put three times as many solar panels on the ground (in the Sahara and Mojave) and you still come out ahead.

    As for self-replication, that would be a neat trick to master just on earth and is probably still a long ways off; but once we do, it works just as well on Earth. Furthermore, the moon is still a fairly deep gravity well; for any kind of orbital construction, it makes much more sense to divert an asteroid into orbit and use that as the raw material for solar panels, space stations, or whatever, rather than launching from the moon.

    • by DanielRavenNest ( 107550 ) on Sunday March 20, 2016 @09:47PM (#51740469)

      Actually, the ratio is 7:1 in space vs an average location on Earth. 24 vs 4-5 hours/day of usable sunlight, and 36% brighter Sun above the atmosphere. The economics of space power then boil down to if you can provide power from space for less than 7 times as much as the same solar system on the ground, space makes sense. Otherwise it doesn't. Per your arguments against:

      * Launch costs - The point of using local energy and materials in space is to avoid those massive launch costs. Orbital mining has mass return ratios of hundreds to thousands to 1 (depends on where you mine, and how), so the amount you need to launch from Earth is greatly reduced.

      * Expensive maintenance - Communications satellites typically last 15 years with zero maintenance (though they do carry spare hardware). They consist of solar panels, and microwave transmitters. Solar power satellites have the same parts, just way way bigger. So maintenance should be minimal, and what there is can be automated, since the SPS has lots of copies of the same items.

      * Expensive transmission systems - Klystrons and Gyrotrons are pretty simple devices. If you can make solar panels in space, you can make those too. You will need thousands, so you would automate the production.

      * Large ground-based stations - Solar farms on the ground need that too, so that cost is a wash.

      * Beam weapons - The power beam can't be focused smaller than a few km, so the beam intensity is less than or equal to sunlight. The focusing is determined by the wavelength, size of the transmitter antenna, and distance from space to ground. I wouldn't recommend standing in the beam, but I wouldn't recommend being inside a coal plant furnace or a nuclear reactor either.

      * Putting 7 times as many panels on the ground - This is the correct answer today. Launch costs would have to come down a lot, or mining and production in space would have to be well developed and efficient for space power to make economic sense. Those don't exist yet, but that is not an argument to stop research. It's just an argument to not build space power plants *today*.

      * Self-replication - this is very difficult, but not required. Automated machine tools today can make parts for more automated machine tools. They don't make *all* the parts, just the metal ones. Mostly automated machinery that can make most of the parts in space is sufficient. The remainder of the hard-to-make parts are sent from Earth, and humans on-site or by remote control do the tasks that automation can't handle. You are correct that this works just as well on Earth. A starter set of machines that can mostly copy itself and make parts for other machines is called a "Seed Factory". Working on that concept is my day job. See https://en.wikibooks.org/wiki/... [wikibooks.org] for a path that starts on Earth and uses the seed factory idea to expand into space.

      * Moon vs asteroids - The various types of asteroids (metallic, carbonaceous, etc.) are different compositions from each other and from the Moon. Depending what raw materials you need, you will likely want to mine both. Asteroids don't stand still. Even if they have an easy to reach orbit, they are not always in the right place in that orbit. So your departure windows are limited. The Moon has a more limited range of elements available, but it's always nearby, and has a low enough orbit velocity you can mechanically throw cargo into orbit. The right answer will depend on a detailed assessment of actual needs, which as far as I know, nobody has done using up-to-date information.

      • Your math is off. There are no geosynchronous orbits that don't pass through the earth's shadow.
        • My math is only off by 1%. The Earth's equator is tilted with respect to our orbit around the Sun, and so are the orbits of synchronous satellites. They only cross the Earth's shadow during "eclipse seasons" around the equinoxes. The rest of the time they miss the shadow.

      • > Actually, the ratio is 7:1 in space

        Not it's not. The average CF on the ground is between 15 and 30%, which means the advantage in space is less than 7 even for poor-efficiency installs like the 15% CF on my garage roof in Toronto.

        > Launch costs - The point of using local energy

        Oh come on, you think you can launch an entire industry to the moon for less money than just building the panels here on Earth?

        > Communications satellites typically last 15 years

        Gradually dying all the time. That goes direc

        • > the advantage in space is less than 7 even for poor-efficiency installs like the 15% CF on my garage roof in Toronto.

          You are neglecting that sunlight in space is 36% more intense than at standard sea-level conditions. In cities like Beijing, the ratio is higher due to local pollution.

          > you think you can launch an entire industry to the moon for less money

          Well, near-lunar orbit, where you get full-time sunlight, but not an entire industry. What you launch is a starter set of automated machines (a "

      • The power beam can't be focused smaller than a few km, so the beam intensity is less than or equal to sunlight.

        Then... what's the point?

        • Night, weather, and atmospheric absorption at low sun angles means the *average* output of a panel on the ground is much lower than the reference output (clear sky and Sun directly overhead). Weather also makes the output unpredictable.

          Space solar power would be available at full intensity 24 hours a day (except for 1% of the time the satellite is in the Earth's shadow). It would supply "baseload power" (always on) rather than "peaking power".

    • by dbIII ( 701233 )

      The economics of space based solar power make little sense

      Used to make stuff on the other hand (eg. titanium) is a different story, especially if it's to use offplanet.

    • by Hentes ( 2461350 )

      Yep, this blog post [ucsd.edu] sums it up pretty nicely.

    • by KGIII ( 973947 )

      Did you not notice the headline? It's about making stuff (for better or worse) on the moon. Beaming the gathered energy back up to the moon probably isn't realistic, now is it? FFS, it's got "on the moon" right in the title. How do you figure that building robots on the moon can be done cheaper by gathering the energy here? If that were the case, they'd just build the robots here.

    • by ceoyoyo ( 59147 )

      Space-based solar panels wouldn't be in the dark much. Not only would they produce power all the time, you could use them to supply base load without any other equipment. Plus you don't occupy any land or harm any ecosystems, either with the installation or, if you build them in space, with the manufacturing.

      There are a lot of advantages, but the whole thing hinges on building a solar panel manufacturing system in space, on the moon or a captured asteroid (it doesn't have to be self-replicating). We'll c

      • Space-based solar panels wouldn't be in the dark much.

        That's where the factor of 3 comes from.

        There are a lot of advantages,

        I don't think there are "a lot of advantages". Land, silicon, and sun are cheap on earth. If we can cheaply turn lunar regolith or asteroids into solar panels, we can do it even more cheaply in the Mojave or Sahara deserts. Geostationary orbits, on the other hand, are probably more valuable than land on the ground.

        I think capturing an asteroid and building stuff from it is great,

        • by ceoyoyo ( 59147 )

          Do you work at a PR firm? Let me re-quote the sentence you included AND the one following (with emphasis):

          Space-based solar panels wouldn't be in the dark much. Not only would they produce power all the time, you could use them to supply base load without any other equipment.

          • Yes, I ignored that point because it's mostly irrelevant. I also ignored other of your incorrect points ("Plus you don't occupy any land or harm any ecosystems, either with the installation or, if you build them in space, with the manufacturing."). Amazing, huh?
    • It is actually worse.

      How do you make silicon? On earth, we reduce silicon dioxide at high temperatures in the presence of carbon and produce more or less pure silicon and carbon monoxide. Additional processes are required to purify the silicon enough to make PV cells.

      Ref: http://www.madehow.com/Volume-... [madehow.com]

      So you need quite a bit of carbon to make pure silicon metal from silicon dioxide. Very little carbon is available on the moon. So you either need to import a lot of carbon to the moon (there go your c

      • There are many problems, but I don't see that in particular as one. There are many ways of reducing silicon dioxide besides using carbon. Even if you want to use carbon, you can use it in a circular process (that is, reduce the CO/CO2 back to carbon). The situation becomes even easier in orbit, since you can use carbonaceous asteroids (about 20% water, 5% carbon, which seems like a good ratio).
        • Carbonaceous type Near Earth Asteroids are *up to* 20% water or carbon compounds, but not 20% water plus 20% carbon. This has to do with where they originally formed, and their thermal environment since then. The water is in the form of "hydrated minerals" such as Serpentine. Water as a liquid or ice can't survive in a vacuum this near the Sun. The carbon compounds (which are similar to asphalt or oil tars) break down at about 200-300C, which is the same range as the hydrated minerals give off their wat

          • The numbers i have were correct. I didn't say it was 20% carbon. The rest of your response seems to be rooted in numerous misconceptions about how such processes would work.
  • Flaw in the idea (Score:4, Interesting)

    by DanielRavenNest ( 107550 ) on Sunday March 20, 2016 @09:01PM (#51740239)

    > "The problem with regular solar power is that the sun isn't always up." (from the article)

    This problem exists on the Moon too. It makes sense to get raw materials from the Moon, but not to put your factory there. It takes about 900 MJ to produce a square meter of silicon solar panel, and their output is about 245 W/m^2 in space. So they make back the energy to copy themselves in 3.67 million seconds, or 42.5 days. Typical working life against radiation damage is 15 years, so the panel can copy itself 128 times in orbit away from the Moon, but only 64 times on the surface, where sunlight is available 50% of the time.

    Space Station era space solar panels had a power output of 55W/kg, so a square meter has a mass of about 4.5 kg. Kinetic energy of escape from the Moon is 2.83 MJ/kg, so launching the materials for the solar panel require 12.75 MJ/m^2. The panel in orbit can make back that energy in 14.5 hours, so the extra energy to launch the materials is small compared to the 7.5 years of extra output you get.

    Automation was nowhere near as good in the 1970's as it is today, so by all means use automated factories. But put them in high orbit so they get full-time sunlight to operate with. The Moon and Near Earth Asteroids serve as sources of raw materials to feed the factories. The reason you want both is the various asteroid types have different compositions than the Lunar surface and each other. So you get a wider range of materials to work with. In particular, some asteroid types are nearly pure iron-nickel alloy, and others have lots of carbon and water. Those are not easily obtained from the Moon, and any mining engineer will tell you to go for the highest grade ore, because it's less work to extract the product.

    • This problem exists on the Moon too.

      Not if you build 'em at the poles.

      • There are very limited locations at the poles that have 24-hour sunlight, and because of the low sun angle (1.5 degrees or less), each panel casts a long shadow, which means your area fill is low. You can't produce enough power that way to satisfy Earth's needs.

    • by Kjella ( 173770 )

      Space Station era space solar panels had a power output of 55W/kg, so a square meter has a mass of about 4.5 kg. Kinetic energy of escape from the Moon is 2.83 MJ/kg, so launching the materials for the solar panel require 12.75 MJ/m^2. The panel in orbit can make back that energy in 14.5 hours, so the extra energy to launch the materials is small compared to the 7.5 years of extra output you get.

      Only if you can shoot it out of a railgun with zero construction/maintenance costs and 100% efficiency. You don't have atmosphere on the moon but a rocket has hundreds of kilometers to accelerate, we have experimental railguns like that but they accelerate at 40000 g. To get it down to manageable levels you probably need a rail hundreds of meter or even kilometers deep in the moon's surface. Or you could use rockets but by the time you've manufactured and spend the fuel, hull and engines you're probably dee

      • To get it down to manageable levels you probably need a rail hundreds of meter or even kilometers deep in the moon's surface.

        "Deep", like you're firing it up off the surface? Why do that when you can build along the surface? It's not like you need to get above an atmosphere.

        The designs I've seen are more like a Halbach array levitated train on a gentle slope than a 'gun'. To make lunar orbit roughly 50 km of track would only require 1G of acceleration, and 5 km for 10G.

        You would need to maneuver into position after that, but if you're making solar-thermal generators (and that might be simpler than trying to make doped-silicon

        • Solar sails won't directly give the Gs to make orbit on the moon. But solar sails on a cartwheeling tether might. Fuck it, just get escape velocity from the launcher, it just takes an 'arm wave'.

          If your in pure scifi, what you really want is a far side/L2 orbital tether. Use it for free delta-V on deep space probes, tricky to use to bomb the earth 'Moon is a Harsh Mistress' style. I'd be against giving the 'lunatics' linear accelerator launchers for military reasons.

      • To start with you would fling raw materials into orbit with an electric centrifuge. This is a rotating arm made of high strength materials like carbon or basalt fiber, and an electric motor and solar array to power it. Since there is no air drag on the Moon, you can bring the centrifuge up to speed gradually. A linear accelerator would be a better option for larger mass throughput (million tons per year), but using a series of coils rather than rails. They have no mechanical contact, so more durable. A

    • How about putting the factory on the Moon, and powering it 24/7 from orbital powersats? The powersats would be the first building stage before moving on to manufacture spaceship and colony parts. That way, you can save yourself the effort of launching the tailings, which remain on the moon instead of whirling around causing navigation hazards.

      Anyway the plentiful tailings could be used to build colonies in orbit. Sintered into a sort of concrete, we'd have material for millions of them before running out of

  • by hooiberg ( 1789158 ) on Sunday March 20, 2016 @09:32PM (#51740375)
    And how exactly are we going to get this energy back to Earth? With the Simcity 2000 cityzapper?
    • The standard method is a microwave beam aimed at a large ground receiver. Antenna elements and diodes convert the beam to DC electricity. It's about 75% efficient, and the beam is always on, so you collect more energy per day than the same area covered with solar panels.

      • by delt0r ( 999393 )
        So yes, a simcity 2000 cityzapper.
        • So yes, a simcity 2000 cityzapper.

          In exactly the same way that the laser in my DVD player is like the death star.

          • by delt0r ( 999393 )
            No nothing like that at all. Unless you want a receiving area many times bigger than what a solar farm would be anyway, its 100s of watts per m2. More than enough to be a problem if there are beam control issues.
  • The comments of someone who knows a thing or two about the economics of space transport: "While Musk loves electric cars and spaceflight, there's one thing he hates: space solar power. "You'd have to convert photon to electron to photon back to electron. What's the conversion rate?" he says, getting riled up for the first time during his talk. "Stab that bloody thing in the heart!""
    • Musk knows about rockets, but I know way more about solar power satellites than he does, because I have worked on the concept off and on since 1980, much of it at Boeing, who did the original studies way back then. He's also involved with Solar City, which makes ground-mounted solar panels. Space solar power is a competing concept, so he has an economic incentive to bad-mouth it.

      Of course we looked at the energy conversion chain. You have to remember that the same panel in space starts out with 7 times a

  • by jenningsthecat ( 1525947 ) on Sunday March 20, 2016 @10:39PM (#51740745)

    Um, if we manage to figure out how to 'wirelessly beam' energy over great distances with an efficiency that's anywhere near useful, and if we manage to solve the problem of what happens when a satellite or an airplane or a flock of birds or whatever flies through the beam, then maybe it'll be time to talk about automating the building of solar power plants on the Moon.

    OTOH, if we manage the sci-fu and eng-fu to accomplish those things, maybe we can just efficiently generate and distribute cheap solar electric power right here on Earth, and forget about space robots and moon shots. Just a thought.

    • if we manage to solve the problem of what happens when a satellite or an airplane or a flock of birds or whatever flies through the beam

      Nothing happens. We're talking about multi-kilometer-wide beams of a wavelength we've chosen to be as harmless as possible. Plus planes are designed to handle lightning strikes, and satellites are hardened to handle exposure to radiation and solar wind so I don't see why a Faraday cage on the really sensitive parts would be so difficult (if that isn't already part of the design).

      Well, I guess a radio telescope that was pointed right at it might get fried ... but come on.

      • if we manage to solve the problem of what happens when a satellite or an airplane or a flock of birds or whatever flies through the beam

        Nothing happens. We're talking about multi-kilometer-wide beams of a wavelength we've chosen to be as harmless as possible. Plus planes are designed to handle lightning strikes, and satellites are hardened to handle exposure to radiation and solar wind so I don't see why a Faraday cage on the really sensitive parts would be so difficult (if that isn't already part of the design).

        Well, I guess a radio telescope that was pointed right at it might get fried ... but come on.

        Thanks - I didn't realize the beam would cover such a large area. Guess I wasn't thinking... Do you also have any insight into what the ultimate efficiency would be, or what the optimal frequencies are?

  • by msauve ( 701917 ) on Sunday March 20, 2016 @10:48PM (#51740781)

    "Global warming is the greatest challenge our species will face in the next 100 years," says Justin Lewis-Weber. Currently a high school senior in California...

    Sure, and B.o.B says the earth is flat. I'm not buying from either the rapper or the fortune teller.

    Bonus points for why "wirelessly beam[ing]" planetary scale power isn't a good idea. The article ignores the problem of how that even happens, or how a small targeting error doesn't take out Manhattan.

  • by Required Snark ( 1702878 ) on Monday March 21, 2016 @12:25AM (#51741141)
    So will that mean there will be hoards of robot H1B visa applicants from the moon taking jobs away from Earthlings? They'll work 24/7 for electricity and get paid using bulk shipments of raw materials to space that are easier to get from a inhabited planet with infrastructure.

    How can a carbon based biological organism compete?

  • The referenced paper says that to meet our energy needs through solar power alone we would need an area 92% of Nevada covered in solar cells. Nevada is 286,367 square kilometers in area. 92% of that is about 286,000 square kilometers. There are an estimated 1.7 billion buildings on planer Earth (see https://github.com/svendvn/sam... [github.com]). If their combined area is less than the area needed for solar cells to power Earth then their average floor space area is less than 168 square metres each (about 1,700 squ
    • Solar cells have their own law, it's name escapes me. The historical drop in $/watt is slower than $/CPUgrunt.

      There is no guarantee that Moore's law will continue to apply in the future. Only huge piles of cash, generated by the computer industry, has kept it going as long as it has.

      Smaller feature size vs solar efficiency are basically different things. Good thing $/watt is the more important than pure efficiency, so there is hope.

  • Perhaps a silly question but something that must be worked out, this base needs power but the sun sets on the moon just like it does on Earth, is this moon base solar powered too? If so then what do they propose the base do while the sun goes down for something like 400 hours?

    I suppose the base could be placed on one of the poles, that would give it 24/7 daylight but I suspect this messes with the launch of the solar collecting satellites. I'd expect that a launch from the equator would take less energy t

    • by ceoyoyo ( 59147 )

      It's a lot easier to beam power down to the moon than down to the earth. Just leave a few of your solar power satellites in orbit of the moon.

      • I can see that as a solution. I'll even go a step further. Have a rotation of orbiting satellites. Build the pieces on the moon, launch them into lunar orbit for assembly, after it is assembled keep it in orbit for a while for powering the moon base and for testing. When the next satellite is complete the previous one can be taken from lunar orbit and placed in Earth orbit. Keep doing this at a pace to keep up with demand for new and replacement solar power satellites.

        I also have a possible solution to

  • "The concept of space based solar power has been around for decades"

    The IDIOTIC concept you mean. Anyone with a calculator, let alone Google, can demonstrate how RIDICULOUSLY MORONIC this idea is. Sorry for the caps, but in this case that are appropriate. Here, try it yourself:

    https://matter2energy.wordpress.com/2012/03/17/the-maury-equation-redux/
    https://matter2energy.wordpress.com/2014/02/25/lunacy/

  • So they're proposing robots only? You tender little humans, let me pat your hand, sit there in the shade, and we'll take care of everything...

    Screw that. Put people up there, hell, there's be plenty of jobs, including the crowd control and refreshments for those of us in line to go.

                      mark "what's here for us (pointing to the GOP)?"

  • If we develop practical self-replicating robots (since we can 'almost' do a proof of concept self-replicating one now)
    If we develop technology to plausibly 'mine' surface material (i.e. moon regolith) that's not more involved in shipping material

    Bonus if: If we can make both happen in a hard vacuum where no one has set foot in decades
    Extra bonus: if we can prove out transmitting GW (much less TW) power from geo-stat orbit

    Then of course let's do this. In reality this sounds like any of a dozen sci fi books

  • And how does TFA propose to make self-replicating robots feasible?

    The first step would be to simplify the solar panels' design as much as possible. "Instead of having 1,000 different types of screws," he says, "let's have five."

    Brilliant! Don't you HATE how current-generation solar panels use 1,000 different types of screws?

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