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Space Power

Space Based Solar Power Within a Decade? 371

Posted by samzenpus
from the start-your-water-engines dept.
Nancy Atkinson writes "A new company, Space Energy, Inc., says they have developed what they call a 'rock-solid business platform' and they should be able to provide commercially available space based solar power within a decade. 'Although it's a very grandiose vision, it makes total sense,' Space Energy's Peter Sage told Universe Today. 'We're focused on the fact that this is an inevitable technology and someone is going to do it. Right now we're the best shot. We're also focused on the fact that, according to every scenario we've analyzed, the world needs space based solar power, and it needs it soon, as well as the up-scaling of just about every other source of renewable energy that we can get our hands on.'"
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Space Based Solar Power Within a Decade?

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  • Yep (Score:4, Insightful)

    by coppro (1143801) on Friday February 20, 2009 @02:06AM (#26925857)
    This is true - space-based solar power is indeed a very good (though not nearly perfect!) solution to energy needs. It also neatly solves energy locality problems - just install a receiver wherever you want, ideally. (probably not in the first version of the technology)

    The downside is that importing energy from space upsets Earth's balance - but hopefully the new energy can be used to help remove some of the uneeded, less useful energy (atmospheric thermal energy, I'm looking at you).

    But the potential is enormous. Coating the sunny side of the moon with solar arrays would provide something like 20 TW of power if I recall correctly - several times the total energy consumption of the Earth today.
    • by Culture20 (968837)

      The downside is that importing energy from space upsets Earth's balance

      My thoughts exactly. Solar power that wouldn't normally hit Earth redirected towards Earth? Global Warming!

      • Tiny effect (Score:5, Insightful)

        by Goonie (8651) <robert.merkel@TI ... ra.org minus cat> on Friday February 20, 2009 @02:29AM (#26925987) Homepage
        Even if we got our entire energy needs from this, the effect on the Earth's energy balance will be negligible compared to the effect of the additional heat trapped by our release of greenhouse gases.
        • by Hucko (998827) on Friday February 20, 2009 @03:11AM (#26926151)

          If we position it right, we can make the earth a huge solar sail and push ourselves out to an orbit that will negate the heat trapped by greenhouse gases!

        • by Nutria (679911)

          the effect on the Earth's energy balance will be negligible compared to the effect

          Says who?

          20TW of energy is nothing to sneeze at, and it's got to heat up the air it's passing thru, causing significant (remember, 20TW of energy is a lot)) localized changes to the whole weather column, which can't help but reverberate all around the globe.

          Such an idea makes for a great Asimov short story, but is impossible when real engineers and scientists start thinking of all the real ways that things could go wrong in th

          • Re:Tiny effect (Score:5, Interesting)

            by Jane Q. Public (1010737) on Friday February 20, 2009 @04:34AM (#26926411)
            "It's got to..." ???

            Interesting. When was the last time you used your microwave to make hot air? The hot air around a hot cup of tea doesn't count... that's heat from steam.

            Having said that, I still think it's a bad idea. Who is going to aim the thing, what guarantees are there against bad aim, and who is going to be liable if 100,000 people get irradiated with low-power microwaves?

            Just wanna know. That's all.
            • maybe I could start a new insurance company, and charge them much more than I would ever have to pay out, were there ever to really be such an accident. Just like the REAL insurance companies do...
            • Re: (Score:3, Informative)

              by ultranova (717540)

              Who is going to aim the thing, what guarantees are there against bad aim, and who is going to be liable if 100,000 people get irradiated with low-power microwaves?

              You do realize that microwaves don't have any effect besides heating water (and other bipolar molecules) and causing sparks to fly off metal (which is how the energy gets collected)? They aren't scary nuclear radiation, they just make you uncomfortably hot. Make the beam wide enough and it won't hurt anyone or anything.

              • Re:Tiny effect (Score:5, Insightful)

                by Jane Q. Public (1010737) on Friday February 20, 2009 @07:34AM (#26927081)
                Right. And if they are pointed at you, they will heat YOUR water.

                But if you make the beam "wide enough", as you describe, it is also not practical because it takes up far too much area (far, far too expensive). If you want to make it practical, you will have to beam it at a concentration that you definitely don't want pointed at your kitchen.

                I understand the difference between microwave radiation and, say, ionizing radiation. But sufficient concentration of either one will kill you, albeit in much different ways. And, as I was saying before: if you want to collect energy over a given area, and make it efficient, it has to be a significant amount of energy. Nobody is going to build a single receiver the size of New Mexico.

                So I get it, okay? But even though I know my new microwave is 1200W (and I even know what that means), that doesn't mean I won't find you in your office and shoot your ass if your satellite regularly aims 50mW at my kids.

                That's clear enough, isn't it?
            • Re: (Score:3, Interesting)

              by smoker2 (750216)

              When was the last time you used your microwave to make hot air? The hot air around a hot cup of tea doesn't count... that's heat from steam.

              ... and steam is composed of what ?

              That's right, water vapour ! And what are those white fluffy things in the sky ? Ding ding ding ! Clouds made of water vapour. So heating the clouds produces a change in the local weather patterns, and as we all know, local weather is part of global weather.

              This seems like a great way to start a hurricane.

            • by lordofthechia (598872) on Friday February 20, 2009 @07:53AM (#26927189)

              who is going to be liable if 100,000 people get irradiated with low-power microwaves?

              I can see it now... A bag of microwave popcorn will be the canary of the 21st century:

              Oh my god Ellie Mae! The Bag's poppin'! Get the kids indoors and make sure they got their tin foil outfits on!

            • by VShael (62735) on Friday February 20, 2009 @08:52AM (#26927547) Journal

              who is going to be liable if 100,000 people get irradiated with low-power microwaves?

              Oh, I know! Motorola and Nokia, right?

    • Re:Yep (Score:5, Insightful)

      by TheFunk (1132987) on Friday February 20, 2009 @02:27AM (#26925975)
      It's not the power out there. It's the transport that is, well, tricky. You basically have two options: - low orbit for the energy station. This means you r station zooms by at mach 25. Aiming your death ray/energy beam is a little tricky then. - geostationary orbit. Your energy station is an absurd 36000 km away. Good luck focussing and aiming then. Oh, wait, there's also the fact that nobody has ever, ever transmitted reasonable amount (like, within 10 orders of magnitude of this endeavour) of power to a receiver. I am sure it is also a real piece of cake to boost that 1 million tons of equipment into orbit needed for the job. Especially when the US does not have a normal space-faring capability anymore. No, just opportunities. No mad dreams at all. Where can I invest? Surely this is not a scam??
      • Re:Yep (Score:4, Interesting)

        by MichaelSmith (789609) on Friday February 20, 2009 @03:12AM (#26926155) Homepage Journal
        The only type of space based power I can see happening in the next 50 years is to reflect sunlight onto ground based solar power stations with orbiting mirrors. Traditional SPS is too far away. We can't even keep the systems on the ISS working between shuttle flights.
      • Re: (Score:2, Informative)

        by Anonymous Coward

        Yeah sounds pretty hard, fuck it. Thankfully we had the smartest person in the world to indicate the error of our ways. Thanks OP!

      • I thought they were researching low-gravity manufacturing. The original idea was to construct everything with robots, on the moon?

        But maybe that was a different company... I can't remember.

    • Green (Score:2, Interesting)

      by shmlco (594907)

      The "greens" will never let it happen. They already go nuts when a wind turbine wacks the occasional eagle. Can you imagine the "environmental studies" needed to cover FLOCKS of birds flying through the microwave download beam?

      Greenpeace: Stopping progress one idea at a time.

      • Re:Green (Score:5, Insightful)

        by shmlco (594907) on Friday February 20, 2009 @04:34AM (#26926413) Homepage

        And the parent comment is NOT a troll. The environmentalists will say we don't understand the effects of transmitting concentrated high-power microwave beams from space down through the upper atmosphere to the earth's surface.

        Will it affect migrating birds? Plants and wildlife in the area? Disrupt weather patterns? Cause unforeseen chemical reactions in the upper atmosphere?

        And the sad part is that they're right. We probably don't know all of the consequences...

        • Re:Green (Score:5, Insightful)

          by EdIII (1114411) * on Friday February 20, 2009 @06:39AM (#26926855)

          And the parent comment is NOT a troll.

          The parent comment IS A TROLL . Look up the definition of trolling. I think you are getting "confused" since the troll stated something moderately insightful (if not obvious) that there would probably be demands from some environmentalists to conduct some sort of environmental impact study. Clearly you agree that environmentalists would make such demands and that the troll was merely stating an unpopular opinion/position and was moderated unfairly. However, what else did he/she say?

          The "greens" will never let it happen. They already go nuts when a wind turbine wacks the occasional eagle.

          Greenpeace: Stopping progress one idea at a time.

          Firstly, he/she is comparing all environmentalists to members of Greenpeace. Secondly, he/she makes disparaging statements about Greenpeace. That was about 2/3rds of the troll's post. Labeling all people opposed to the technology, then making a comment about the difficulty(or unreasonable nature) of the impact study, and finally accusing a specific group of shortsightedness and obstinate attitudes towards progress.

          Nothing productive was accomplished in that post and it only served to defame a particular group of people and their agenda. The only supportive comment was made in support of the derogatory comments themselves. The whole tone and purpose of the article was provocative while providing no clear positions or arguments. That is, by definition, trolling.

          For full disclosure here, I am not a member of Greenpeace or any PAC with environmentalist agendas either.

          Also, I don't understand opposition to environmental impact studies. It's shortsighted to have a manifest destiny approach to everything we do. Does it give us a little convenience and pleasure? Fine. Then "fuck all the little animals cuz i'm human and they were put here for me". Progress does not have to occur at any cost. Sure, the planet may seem big to many people. However, we are finding out rather quickly that our actions ARE changing the environments and animal and plant life that we cohabit with. I'm not talking about Global Warming either. Just making the simple statement that our actions have consequences and it would be prudent to understand them to the best of our ability before proceeding.

          That's why I like the movie Rapa Nui, which is about the events on Easter Island. They ended up killing themselves and their local environment by their actions. If they had the sophistication to conduct and environmental impact study they would have quickly found out their actions were suicidal. Which is why these environmental impact studies are conducted (in my mind at least) to assess what damage we may do the environment in order to properly weigh the benefits versus the risks to not only the environment, but us as well . If it's just too damaging to the environment and we run the risk of endangering a species than it had better be pretty damn important. I want to know that it is something that will allow us to make positive progress. The comment about the eagle getting whacked is ridiculous. I don't think anyone is opposed to the renewable energy produced because of the possibility of a bird flying into the turbine. After all, the renewable energy itself is about sustainability and pollution free energy production which only benefits the environment anyways.

          Lastly, we can never know all the consequences of anything. We are just not that sophisticated yet. Personally, I just want to know that all the little squirrels are not going to grow huge tumors on their nuts. It's not that much of a leap to conclude that tumors will grow on MY NUTS TOO.

  • by phantomfive (622387) on Friday February 20, 2009 @02:10AM (#26925875) Journal
    Seriously, they just put a smile in my heart. It is just so stinking ridiculous that you ask yourself, "how in God's green earth did they EVER get anyone to pay them money to build that thing?" Who actually believes that you can put solar panels in space to generate electricity in a cost effective manner? Someone just bought the bridge.

    It puts a smile in my heart because, at the end of the day, if we have enough extra resources in this country that we can afford to put them into such a ridiculous scheme, then the recession still isn't nearly as bad as it could be.

    Awesome. Props to those salesmen.
    • by flyingfsck (986395) on Friday February 20, 2009 @02:19AM (#26925933)
      Oh, the recession isn't nearly as bad as the one in the 1980s. Things will grow in the spring - farmers will buy fertilizer, trains and trucks will run with produce, factories will hum... An interesting thing about launch costs: If there was a band of solid gold circling the earth, at a height where the space shuttle can go and get 50 tons of it at a time and bring it back down, it won't be worth it.
      • Re: (Score:3, Informative)

        by ImYourVirus (1443523)
        Yeah cause a 3:1 ratio would suck...

        50 tons of gold would be worth approx. $1,558,720,000
        Cost of 1 shuttle launch $450,000,000
        Ok so some math here, let me see carry the 1...

        Ok that leaves us with a measly $1,108,720,000 ok your right fuck that idea, thats not worth it at all... hehe
        • Re: (Score:3, Insightful)

          by daveime (1253762)

          Gold (like any other precious commodity) is worth exactly how much people are willing to pay for it. And the reason they pay so much is precisely because it is precious i.e. there is a limited quantity of it going around.

          You start bringing back 50 tons at a time (and making a tidy 1 billion profit), and you'll see that the price of gold drops through the floor and it would quickly become as worthless as oil currently is.

          So no it probably ISN'T commercially viable, at least once the gold buyers figure out wh

      • > Things will grow in the spring - farmers will buy fertilizer...

        Errr.. Thank you Chauncey Gardiner. [wikipedia.org]
    • MODS (Score:5, Insightful)

      by TapeCutter (624760) on Friday February 20, 2009 @02:56AM (#26926089) Journal
      What is wrong with you people lately? Why the hell is the GP modded troll?

      This project is an orbiting white elephant that would take an enourmous amount of energy to build, would supply only a tiny fraction of what we need at a ridiculously high cost per watt, and could easily be percieved as a space based weapon by other nations. If I didn't know better I would have to assume TFA is a lame attempt to discredit the viability of earth bound renewables.

      Here is the sales pitch on costs: "The biggest challenge for SBSP is making it work on a commercial level in terms of bottom line," said Sage, "i.e., putting together a business case that would allow the enormous infrastructure costs to be raised, the plan implemented, and then electricity sold at a price that is reasonable. I say 'reasonable' and not just 'competitive' because we're getting into a time where selling energy only on a price basis isn't going to be the criteria for purchase.

      This is total bullshit, cost is the ONLY criteria for commercial electricity generation, the fact that the costs to the environment are not accounted for in our current economic system is the problem.
      • MOD PARENT UP!! (Score:4, Insightful)

        by Brett Buck (811747) on Friday February 20, 2009 @03:08AM (#26926135)

        100% agreed, and there's no way that the launch costs are going to drop by the 3 orders of magnitude required to make this viable. I presume that his is an effort to extract "stimulus" money while the extracting is good, then fail later out. Someone will end up a millionaire and nobody is going to get any damn space power.

                    Brett

      • From +1 to +3 insightfull and then down to 0 - troll in 10 minutes.

        *me* - checks for full moon...
  • by DerekLyons (302214) <`fairwater' `at' `gmail.com'> on Friday February 20, 2009 @02:22AM (#26925947) Homepage

    Notably they fail to mention what is expected to be the long pole in the tent - launch costs. Even if Musk and SpaceX succeed, launch costs will still be at least an order of magnitude higher than what is estimated will be required for commercial success of space based power plants.

    • by Rogerborg (306625)

      Costs, you can cover by scamming trustafarian hippies. Good luck to them.

      What matters is energy. We need to see the break-even time when the energy delivered to the ground exceeds the energy used in putting the thing up there - and yes, we're including the energy costs of the raw materials, production, and the ground based maintenance and monitoring, as well as the boom-juice to get the mass up there.

      Want to bet that the break-even is longer than the realistic lifetime of the satellites?

    • by petes_PoV (912422)
      The article says they plan a demonstrator in LEO. This is the bit I don't understand`. A LEO satellite would only be useful for a few minutes every hour-and-a-half (and would be in darkness half the time, too). So it seems to me that this is fine for playing with the tech, but no use whatsoever for a commercial operation.

      for a "grown-up" system I can't see how anything except a geostationary orbit would be practical, otherwise you have to have the power beam continually tracking your target (word used adv

  • by Nyeerrmm (940927) on Friday February 20, 2009 @02:41AM (#26926037)

    Currently, there are times in the US when electricity is sold wholesale for close to a dollar a kilowatt during peak usage or times of emergency when power needs to be shipped around the national grid. Sage said SBSP will never be cost comparable with the current going rate of 6 or 7 cents a kilowatt due to the enormous set-up costs.

    Whenever I see space-based solar power I never believe its economically viable. Based on that quote, they recognize that its not viable in the current market, and that average energy costs would have to increase by a factor of 15 to 20 times in order to make it viable. They think that the trends in energy cost are going to go that way. Somehow, I think as energy costs increase we'll get more creative on the ground, expanding ground based solar power, wind, nuclear, geo-thermal, etc., improving efficiency and developing new technologies to bring those costs back down.

    As others have pointed out, launch costs are the critical, incredibly expensive aspect. In order to make it practical, we need to drastically reduce the access cost for space, by at least an order of magnitude. None of SpaceX's most optimistic estimates, or anyone elses, make it more viable.

    However, there is a practical path for development of SBSP in military applications. A few satellites and some trucks with microwave receivers on the back are very appealing when compared with the current method for generating battlefield power: supply lines hauling in diesel fuel to power good old-fashioned generators. SBSP has great tactical advantages, and may actually be comparable in cost as well. From here, we may very well see it gain civilian applications as well.

    • Re: (Score:3, Informative)

      I noticed that too. In particular, the comment about shipping energy around the national (and, conceivably, international) grids.

      I suppose one advantage of SBSP is that the aim on the satellite transmitters could be adjusted to one of several ground receiving stations, which would allow the power to travel over smaller distances on the grid. Whether this could actually make up for inverse square losses due to longer transmission paths, I don't know. Still, it's an interesting advantage to SBSP that I hadn't

    • by tibman (623933)

      I would agree with you on how useful this would be for Military Applications... just look at what doors GPS opened up.

    • Based on that quote, they recognize that its not viable in the current market, and that average energy costs would have to increase by a factor of 15 to 20 times in order to make it viable. They think that the trends in energy cost are going to go that way.

      No matter what happens to energy costs, space based solar cannot outcompete ground based solar. Space based solar can collect roughly twice as much power as ground based. (It's lit twice as long because there's no night, gains a bit from not having atmo

    • by squoozer (730327)

      Microwave beams from space being directed to a truck in the middle of a friendly camp. Brings a whole new meaning to the term friendly fire.

  • Nuclear, please. (Score:5, Insightful)

    by greg_barton (5551) * <greg_barton@NOSpaM.yahoo.com> on Friday February 20, 2009 @02:43AM (#26926049) Homepage Journal

    This is silly. Putting solar panels in orbit? Please.

    Use the money to build nuclear plants. Don't bore me with the waste issue. There is no such thing as waste, just more fuel. [theoildrum.com]

  • Other benefits (Score:3, Insightful)

    by BenihanaX (1405543) on Friday February 20, 2009 @02:44AM (#26926053)

    Other benefits might include transmitting the power to remote locations where generation or transmittal is otherwise difficult (Antarctica for example), and more efficient power distribution on the power grid. If the power could be transmitted to different sites without significant loss, I^2xR losses in power lines across the grid could be minimized. Of note would be peak hours, and sunrise/sundown. I'm not sure what the power usage graphs look like, but I'm assuming there's enough fluctuation that it would be useful to shift power as the time of day changed.

  • by HyperMinimalism (1482375) on Friday February 20, 2009 @03:02AM (#26926111)
    Space Based Solar Power (SBSP) is an economical way of delivering power to remote locations or areas isolated by war.

    To deliver power to a certain places in Iraq and Afghanistan it costs well over $1USD/kWh, not mention the loss of human life.

    The pentagon is seriously considering SBSP as a viable way to deliver power to not only these locations, but other places of humanitarian interest.

    The technology to deliver and deploy SBSP payloads (for it will take many deployments) already exist. Improvements will undoubtedly be made, and with the hopeful completion of NASA's Ares V [nasa.gov] cargo launch vehicle SBSP will be economical for the rest of us. (under 20cents(USD)/kWh.)

    As for the microwave radiation concern, it is not as scary as commonly depicted. (Can anyone recall the tale of the discovery of microwave radiation as a cooking tool--something to do with a Snickers bar melting in a pocket? [Who the heck carries a Snickers bar in their pocket?]) If the size of the receiving antenna is increased, the power of the transmitted signal may be decreased on a W/m scale. With a transmitter that can 'dither' the signal over a rather wide swath one can abate errors associated with tracking, solar anomalies and human error.

    Military applications, however, are not quite as concerned with stray microwave beams.

    Do not forget that SBSP is exposed to the sun for 24 hours--no interruptions!

    On another note the Japanese are working on developing devices that may convert solar energy to transmittable energy in upwards of 40% efficiency by converting solar power to laser. [treehugger.com]
    • Re: (Score:3, Funny)

      by TheLink (130905)
      Yeah it'll be nice to be able to accurately and very precisely deliver 10 MW to targets in a hostile area.

      Even if it's only for a minute or so and there are no sharks involved, I'm sure the military will still find a use for it :).
  • Hey, the Delorean can make 117 trips!
  • No I don't think so. Only advances I foresee are in making more portable, cheaper, more environmentally unfriendly electronic gadgets to distract the masses from the incompetence of their leaders. That or if all goes to hell we'll see amazing advances in shotguns and can openers.
  • The renderings in the article show round or hexagonal collectors that seem to be radially divided into identical slices.

    Pie in the sky?
    • The renderings in the article show round or hexagonal collectors that seem to be radially divided into identical slices.

      Pie in the sky?

      Lies!

      • by BlueStrat (756137)

        The renderings in the article show round or hexagonal collectors that seem to be radially divided into identical slices.

        Pie in the sky?

        Lies!

        No no no!

        The cake is a lie!

        C'mon, get it right!

  • Yah, that's exactly what we need. Huge solar panels out in space sitting out there just waiting to get hit by something and end up being smashed into pieces resulting in more orbiting space trash.

    If we're going to do this, we need to re-invest in "StarWars" so we can vaporize any space trash that's out there. Or better yet create automated robots stay in orbit and clean up the orbiting trash for us and compact it and eject it towards earth to burn up (think Wall-E except in space instead of on earth).

    • Business costs? (Score:3, Insightful)

      by freedom_india (780002)

      Let's see the practicalities here:
      1) Finding funding for building solar panels in space taking into account space insurance, multiple launches, space walk fees by NASA, etc.

      2) Microwave power that can possibly fry the contents aluminium cans with wings that fly all over the world? It requires dedicated road to space. That costs money in many ways: First of all congressional critters and senators have to bought to introduce an amendment that would allow FTA and FCC to provide an exemption to existing air occ

  • Economical? How? (Score:3, Insightful)

    by bertok (226922) on Friday February 20, 2009 @04:02AM (#26926327)

    Am I the only one who doesn't quite see how they intend to make this profitable?

    I assume they're planning on geosynchronous orbit (the article mentions they are), since anything else will mean intermittent power and moving collectors. In that case, the typical launch cost is $20,000/kg, and the there are serious total weight restrictions per launch. Solar cells come in two varieties: Heavy and inefficient. Trucking and installation costs of solar cells here on Earth are what, $200/kg, if that?

    The big advantage? Something like 3x the total incident power per unit area. Even if they somehow get more power (by utilizing UV light, for example, which the atmosphere mostly absorbs), you can't ignore transmissions losses, which are going to be nontrivial from geosynchronous orbit.

    So let me get this straight... they're planning on spending about 100x the cost of a terrestrial system for 3x the power gain? Wow, what a business case! Let me sign right up, I want to buy their stock *NOW* before anyone else gets wind of this!

    Even if we're incredibly generous and let them have a 10x reduction in launch costs (wishful thinking), then they're still off by a factor of 3x from matching, let alone beating, terrestrial solar power costs.

    And no wait.. I forgot.. they still need a stupid huge ground station to collect the power! So, all that money they saved having to install ground based equipment? Still have to spend it! My back-of-the-envelope maths (probably wrong) is that if they use a 1 mm wavelength microwave beam, they're looking at a receiver over 1 km wide due to diffraction limits. Mmm... cheap.

  • by VincenzoRomano (881055) on Friday February 20, 2009 @04:04AM (#26926339) Homepage Journal
    It's clearly an impossible project announced just to leverage on the green and CO2 buzz to make money.
    Wireless power transmission? Not yet possible!
    Wired power transmission? Only in low-end comics and sci.fi.
    Ground based receiving plant? Not yet designed!
    Security? Not even taken into account!
    Money from investments and stock markets? Yeah!
  • from the original article

    Sage said SBSP will never be cost comparable with the current going rate of 6 or 7 cents a kilowatt due to the enormous set-up costs

    The proposer of this scheme also says that "there are times in the US when electricity is sold wholesale for close to a dollar a kilowatt" so it looks like this is the market they're going after.

    For it to be viable, therefore, there would have to be many occasions when this spot price was reached. If that's the case, I'd prefer to go with ground based solar for my personal electricity supply, rather than being dependent on a single[1] satellite up there beaming energy in my genera

  • ...uninhabited, and sunny some of them are too. ;-)

    Admittedly the energy harvest per square meter of solar cells won't be as much as in space, but arrays built in a literally more down-to-earth way are probably just a little more accessible :-) for construction and maintenance, and don't require the "no-small-feat" type of accomplishment to find a way of beaming down the power without creating a death ray that will fry the neighbors at the first malfunction. (<theory=conspiracy>Or wait a minute, may
  • Crazy units (Score:3, Informative)

    by paul248 (536459) on Friday February 20, 2009 @05:34AM (#26926609) Homepage

    "Almost 200 million gigawatts of solar energy is beamed towards the Earth every second, which is more energy than our civilization has used since the dawn of the electrical age."

    Let's see. 200 million gigawatts * 1 second = 0.2 exajoules. Worldwide energy consumption is on the order of hundreds of exajoules per year.

    This article must be using the wrong units somewhere, but I guess that's just the status quo nowadays.

  • Space based solar power is a useless idea. The earth's atmosphere is quite transparent to light, so you don't gain much by moving outside it. If you do everything right, you gain up to a factor of two because you can stay in sunlight much longer. But to get that modest improvement you pay many orders of magnitude more in transport and maintenance costs.

    The biggest issue with space-based solar power, however, is that you're giving someone access to megawatts of power ready to be aimed at any point on the

    • Re: (Score:3, Insightful)

      by koollman (720649)

      The earth atmosphere is quite transparent to what humans usually call light. that is, visible light. a very tiny portion of the spectrum.

      But, the sun emit much more than visible light. If you can use UV or higher frequency, or perhaps a wider spectrum, then you get a lot more energy than the equivalent setup on earth.

      And, I agree with the other parts. Once you have your nice space-based energy collector, then you have a lot of energy, in space. it would be nice to find a way to take it back to places that u

  • Well, I guess it might be OK just so long as he doesn't pitch the planet into eternal darkness because of all the shadowing solar cells. Perhaps they should set them up on a exterior ring to capture the light that hasn't landed on the planet.

    But that would be a rock solid business model: We'll capture all the suns energy and sell it back to people so they can have light and heat.

    The other concern is the debris. Aren't these things going to be pulverized by all the debris that we have up there? This is be

  • Do the math, folks (Score:3, Insightful)

    by Ancient_Hacker (751168) on Friday February 20, 2009 @09:46AM (#26928003)

    Let's do the math on this one.

    Let's say we want to put up enough PV cells to replace just one largish power plant, say 1GW.

    Using conservative estimates, and assuming everything works perfectly the first time, I get a cost per kilowatt-hour of close to $8.

    That's mighty steep, like 80 times the going wholesale rate.

    The numbers for those interested in such minutea:

            watts delivered 1,000,000,000.000

            conversion to AC 0.950

            DC needed 1,052,631,578.947

            uwave to DC 0.850

            AC needed 1,238,390,092.879

            Receiving ant. Eff 0.750

            To recv ant. 1,651,186,790.506

            Atm loss 0.900

            from sat 1,834,651,989.451

            xmt ant eff 0.900

            to xmt ant 2,038,502,210.501

            uwave gen eff 0.750

            DC to uwave gen 2,718,002,947.334

            Solar cell eff 0.150

            Watts to s cell 18,120,019,648.896

            watts per sq meter 1,400.000

            avail of light 0.600

            watts avg 840.000

            sq meters needed 21,571,451.963

            weight per sq m 5.000 lbs

            cell weight 107,857,259.815

            $/lb to geo $5,000.00

            cost to lift $539,286,299,074.30

            lbs/watt gen 0.010

            lbs gen 27,180,029.473

            cosrt cells/sq meter $1,000.00

            cost cells $21,571,451,962.97

            gen cost/watt 1.000

            gen cost 2,718,002,947.334

            tot cost 563,575,753,984.601

            time to build 5.000 yrs

            cost of money 5.00%

            int factor 0.250

            cost fin 704,469,692,480.751

            yrs runs 10.000

            cost/yr 70,446,969,248.075

            kw gen 1,000,000.000
            hrs/yr 8,766.000
            kwh/yr 8,766,000,000.000

            cost/kwh 8.036

            current cost/kwh 0.100

            overrun factor 80.364

    • by goodmanj (234846) on Friday February 20, 2009 @10:48AM (#26928977)

      Parent post is good, but it's really much simpler than that.

      Cost per kg to send something to GEO orbit: $10,000
      Cost of solar cells per kg: $400

      Space-based cells produce about twice as much energy as the same panels on the ground.

      So until launch costs drop to equal to the cost to build the panels, it'll be cheaper to just build twice as many panels on the ground.

      Space-based power is a factor of 20 away.

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