Space-Based Solar Power

a public discussion sponsored by the Space Frontier Foundation

The Vision (…and probably why you’re here)

Posted by Coyote on June 13, 2007

So my boss turns to me and says, “Coyote, this is just too important to America, our Allies, and the World. I want you to lead a study to figure out if space solar power is possible, and if it is, let’s get on with it. We can’t wait for someone else to pick this up; we’re going to have to do it ourselves.”

You can read all about how this study came to be by clicking on “About The Study” in the bar above. It lays out what we’re trying to do here. The problem set is H U G E. It is too large for anyone to solve by themselves–especially me, a simple caveman space professional. But we have this little thing called the Internet that can connect us and lets us look at this problem from all sides. We all have talents. Let’s see what we can do together.

When I started this project a couple of months ago I was a skeptic, but I’ve become a cautious optimist. I sent an email to a friend yesterday and summed up my feelings about the project this way:

I can’t think of a better legacy for our generation to leave to posterity than solving Earth’s energy needs once and for all…and opening a wider highway to the heavens at the same time.

I look forward to working with all of you. Game ON!

Coyote

20 Responses to “The Vision (…and probably why you’re here)”

  1. Sam Dinkin said

    Coyote, I think you may find yourself tackling launch costs, space venture capital and several other indirect problems in order to get space solar working. Here’s some articles I wrote about space solar:

    Space Solar Support?
    Give the Lunar Solar a Rest
    Beam Power Backwards
    Rectifying the case for beaming Lunar solar power
    Reaping powerful ideas from a luminary
    Review: Out of Gas

  2. Coyote said

    Sam,

    I suspect you’re right. There are a number of problems that have to be solved along the way to make space-based solar power viable. The first, as you point out is launch. I look forward to reading your stuff! Thanks.

    Coyote

  3. Phil Mills said

    SSP Demonstration

    At the moment mankind does not have the choice of utilising SSP. There are only concepts, artists impressions and technical papers written by advocates and critics of SSP.
    To break away from this and to make the public more aware of the concept of SSP and to escape from the edges of junk science altogether what we need is a demonstration of SSP.

    A similar situation arose at the beginning of the space age with Communication Satellites. Arthur C Clarke had originally wrote a short article in Wireless World that described the concept of relays in the sky in 1945 and this was at the time dismissed as a fanciful idea. One of the first demonstrations in the space age that gripped the publics imagination was the launch of Telstar 1, I can vaguely remember it now! Since then the communication Satellite industry has been nothing but a success story generating billions of dollars annually in sales of products and services. Just consider if it was dismissed in the early “60s” as too expensive, not economically feasible, and launch costs too high, (NASA had at the time confined itself to experiments with passive communication satellites such as ECHO) would we be in the same position today with communication satellites as we are with SSP? Maybe not but who knows!

    NASA is returning to the Moon! People ask why when they have been there before. NASA sometimes don’t have an answer for that or not very clever answers. There have been many attempts outside NASA at giving a reason to return ranging from mining the Moon for Helium 3 to utilize in at the moment none existent Fusion Power Stations here on Earth to mining the Moon for Platinum Based Metals to enable the Hydrogen Based economy. While not wanting to dismiss either of these reasons NASA itself does not want to attach itself to these concepts as the reason for it returning to the Moon. However NASA has announced that it wishes to set up a base at the lunar poles possibly with a view to using the ice that is said to exist there. Will that be it? What if there is no ice there or quantities are so low as to be of no or only limited use? What then?

    One of the attractions of the lunar poles is that they receive sunlight all the time enabling Solar Power generation . Does this mean that NASA is going to just explore this twilight zone and not venture into the equatorial regions of the Moon, or if they do it will be on short two week trips. Lunar Reconnaissance Orbiter is going to map the entire lunar surface, if it finds an interesting feature such as useful minerals near the equator will not Astronauts not go there because it will get dark? Surely long duration expeditions to the equatorial regions will need to be carried out where useful work can be done even with the use of artificial light and heat?

    What is needed is a SSP system on the Moon. A demonstration of the capability of the concept of SSP could be done very early on in the return to the Moon even possibly at the initial landing site or at the polar base with a Demonstration Solar Power Satellite beaming energy to a receiver. Just think of the publicity that this would generate, NASA is beaming electricity to the guys on the Moon and this could be done here on Earth too! Maybe NASA could set up a COTS type competition for a Lunar SSP demonstration to provide electricity to the lunar base . It could also be the start of the first commercial lunar based industry building power receiving stations on the Moon. A development of this capability would also enable the whole of the lunar surface to be explored whether day or night and allow Bases and Mining Settlements to be built in the lunar equatorial regions eventually to allow the other above mentioned commercial activity to take place.
    One of the original ideas that was given in the VSE was to use the Moon to develop new technologies, techniques, and learn to live off the land so to be able to venture further onwards to Mars and beyond. Isn’t the development of a lunar SSP just what is needed to fit in with the original ideas of the VSE?
    I propose that the SFF advocate for a demonstration of a Lunar SSP with a view that this would also demonstrate that this could be used here on Earth and in the further exploration and settlement of space!
    Your comments please!

    Thanks

    Phil Mills FBIS

  4. spacepolicy said

    Sam,

    I agree that there are a number of issues to be overcome (btw, overcoming these issue is good for many other reasons than space-solar-power).

    I want to address one of the issues you mention above –which is “it is much much cheaper to build solar panels on Earth. Some opponents state that is so much cheaper to build solar power farms on Earth compared to space — even after you get cheap access to space, and even after you take advantage of the inherently larger solar flux in Earth orbit, and even after you account for transmission losses, and storage losses.

    This may all be true.

    However, in my opinion, proponents of this Earth-based solar have not thought through the total system impacts of building HUGE solar power collectors on Earth. Anybody who has looked at the world’s energy appetite soon concludes that they will be huge collectors.

    Next, consider that solar cells are extremely black (if the sunlight is reflected it can not be converted to electricity), and generate large amounts of heat per square inch. Converting a desert into solar collectors would be similar to black-topping hundreds of square miles in a relatively small region. This “black area” would increase that region’s temperature quite significantly, which would likely destroy much of the life in that area, and then in the surrounding areas. If it was not a desert, it would soon be a desert … and then a very dead desert. This desert would likely grow and expand as the heat from this region impacted the surrounding environment, including the atmosphere, just like the Sahara has been growing for a long time.

    This is a major environmental downside that I think we would all like to avoid. Solar farms of this nature will generate a major “not in my backyard” effect.

    In summary, we need to take a total systems perspective when considering the alternatives. It is not a simple as some opponents suggest.

    – Charles

  5. Coyote said

    Phil,

    Thanks. You put a lot of thought into that.

    I am big on the Moon, too, and believe we need to build Moon-Based Solar Power systems and exploit the Moon for all of the energy and other resource wealth it can produce for life here on Earth–in prudent ways consistent with all international agreements (I had to get that in!).

    Speaking of international agreements, do you think we have sufficient rights to develop the Moon for energy? I read over the entire set of space treaties today (yes, I’m a wild man!) and it seems like we need to really sit down an negotiate new treaties that allow zoning, property, mineral, water, and other rights on the Moon that have been signed away.

    Cheers!

    Coyote

  6. Sam Dinkin said

    Charles,

    Respectfully, one has to factor in the heating, real estate and environmental costs and see which is the better technology. The energy beamed down to Earth will end up as waste heat too. If it’s Earth hands down, that should be monitored because the good solar sites on Earth will fill up. Earth-based solar thermal can be made to reflect unused rays into space. In 400 years at the present growth rate of economic development, our waste heat will equal the solar flux. By that time, we will indeed need to move all new energy use off Earth. In the mean time, it’s a race. The Wall Street Journal today talked about AEP trapping methane from manure to meet its greenhouse gas goals. The estimates of the cost of abating sulphur dioxide in the 1970s were much higher than actual costs once pollution permit trading started. Cheap solutions may make the waste heat issue moot (for a time). For now, there are plenty of good deserted desert sites. If solar starts to get profitable, it will outcompete farmland for land (like subsidized ethanol is doing now) and drive up prices. Ultimately, it will drive up the prices enough to make the business case for space solar close. But what century will it be in?

  7. Edawg said

    I could see something like carbon credits done for space (i.e) space credits!? The market has to understand that yes space is risky but their is masive amounts of money to be made.And any new outer space treaty has to be designed to last more than 20yrs.We could get propety zoning for the moon down pact
    only to have have china land on titan in 2060.

    Cheers yo!

  8. Wotan said

    Lt. Col. Coyote,

    Great idea to blog this. The concept studies and illustrations I’ve seen since the ’70’s have always shown large, rigid infrastructure requirements for space solar systems. Why does that have to be the case? Could we not pair up inflatable structures with flexible solar cell technology to create a much more efficient packaging concept? Why carry metal trusses into space when the solar power systems will be operating in micro-gravity conditions? Comments and thoughts?

  9. Beefcake said

    While I am all for the idea of space-based solar energy collection and transmission, I am curious as to why the focus is on a space-based technology rather than terrestrial solar energy collection. It seems to me that with a large enough network of large ground-based solar panel arrays, you would be able to provide essentially the same “energy independence” without the inherent costs and risks associated with a space-based solution.

    There have been some great strides reported recently in solar collection and focusing research. The United States has a virtually unlimited supply of vast, wide-open, and practically uninhabited areas…not to mention Canada. Imagine if we were to cover just a small fraction of our plains and wilderness with large solar focusing farms and towers. This would provide us with a virtually unlimited supply of cheap and practically free energy, as well as distribute the production of that energy all over the country and continent, thus increasing energy security. Not to mention that such a system is much easier to fix when something breaks down than a giant space-based solar generation platform or network of solar generating satellites would be 😉

    Again, I don’t want to give the impression that I am against solar power generation in space. At some point, once the technology catches up and the cost goes down, it might be an excellent way to bolster our ever-increasing energy production needs. But wouldn’t it be wiser (and cheaper, and easier) to start a little closer to home first? As one of the other posts mentioned, we need to learn to crawl and walk before we can run, right?

  10. Paul DuBose said

    SPS are a realistic option and IMO can be synergistic with helping develop the space frontier and a cost effective source of energy in that context.

    I was the editor for a study on using lunar materials to create a cost effective SPS and think there is a lot of merit in the concept. The moon has the raw materials to produce simple but large power satellites and with a modicum of automation would seem to be a key part of the solution.

    The major obstacle is the cost of launch into space and it is pretty clear to me that NASA, working with congress, will never provide the vehicle breakthrough.

    Consider working with Burt Rutan, his concepts can get you there more quickly and at a small fraction of the cost from mainstream sources. I think that with the Virgin Airlines work, we are getting close to a cost effective reusable platform into space.

    Thanks Coyote for your personal approach to this great opportunity.
    (Edited for grammar)

  11. Phil Mills said

    Coyote,
    . Seems a good idea to launch completed PV arrays to GEO. An alternative to launching the regolith itself and manufacturing the arrays in GEO. That was the original idea in the “High Frontier” with the colonies etc housing the construction workers. Whichever, like you said it is the Moon where it will happen. Using the Moon for the raw materials either for the PV arrays themselves and for the aluminium supporting structure is the only way really to go about manufacturing the SBSP satellites. This will alleviate the problems of the space launch costs from Earth which is the main criticism of the concept of SSP. Lunar regolith contains mostly aluminium anyway. The SBSP satellites could be assembled at L5 or another Lagrange point which is nearer the Moon instead of GEO and then moved down to GEO.

    Problems with manufacturing of any sort on the Moon from a standpoint of where we are now is that when we return we have arrived at a location that is basically in the stone age. OK we can take and will need to at first basic regolith moving gear, excavators etc and basic metal smelting plant but eventually we will have to manufacture everything what we need on the Moon including the factories . It’s a bit like building Gary Indiana all from scratch. This might sound expensive but it is probably cheaper than launching the SBSP satellites from Earth and constructing them in LEO then moving them again. Launching all the SBSP satellites from Earth in kit form would take hundreds of Ares 5 launches over years in comparison. Using the same launch vehicle to deliver the original manufacturing plant to the Moon will be cheaper. And once that’s done that’s it.
    Once you get the basic manufacturing facility set up on the Moon your capabilities can grow exponentially. The first basic plant with parts delivered from Earth can make another one from local material and start as well on the PV array and so on. Eventually the manufacturing time is cut because of the duplication of new local made plant. When you get to this stage no launch from Earth is needed besides more manpower as the thing grows, so costs will stabilize. If robotic methods could carry out this work or some of it such as regolith collection this would cut down on the manpower although we no doubt will have to have people fixing the machines!
    Problems I can see basically from what I have learnt over the past few years, are Lunar Dust, and problems of living in 1/6thG. These are the sort of things that NASA will no doubt study when they return.
    It’s how we start all of this off in the first place that interests but like you said we are the simpletons at this moment in time!
    Phil

  12. Sam Dinkin said

    Wotan: It’s a great idea to contract with Bigelow to coat the outside of his inflatables with thin film flexible solar cells (at least the part that doesn’t have the advertising on it). It wouldn’t be much area, but it would make the economics of space stations better. We might as well use all the structure that’s going out there anyway before we start putting up purpose built structure.

    Phil: I think it would be cheaper to put a solar fab in Mojave than on the Moon and we would get more watts per year for less cash. We need to do R&D based on what technology and systems will need to be _after_ space solar is competitive with the most expensive terrestrial substitutes in use.

  13. Phil Mills said

    Coyote,
    I decided after last weekend when I saw all the messages from Advocates that I had to add an input. I am a big believer in SSP and have waited since the 70’s for this moment. I can remember reading all about it the first time around in the High Frontier and wondered if SSP would ever get in vogue again. Then at last years NewSpace 2006 conference in Vegas Howard Bloom sort of kick started it again. I have been waiting for the past year to see what came of that and here it is. Its going to be discussed again at NewSpace 2007.
    As for the international treaties, I agree that we will have to sit down with other space fairing nations and upcoming ones as well and re-negotiate the international agreements that were wrote years ago back in the cold war times. If we don’t other nations are just going to interpret their own rules. The Chinese a few weeks back hinted about the need to have Laws governing space for example.

    Just a few thoughts on Earth based Solar. If anyone thinks that it would be cheaper to place PV arrays across huge regions of the desert instead of in GEO, they have not lived in the desert. I have lived in Saudi Arabia for 12 years out of the past 17 and believe me leaving things outside, they just get covered in dust. The efficiency of PV arrays would go down tremendously unless they are cleaned almost daily. Then there is the problem of bird droppings, yes this is a big problem out here, its corrosive . Pigeons would make their home under the arrays and before long you get problems, say no more!

    Sam,
    I like your mention of using Bigelow Expandables. I have been considering how to use this technology with SSP. Bigelow also has plans, not released yet, for landing fully assembled “base” on the Moon . I have been toying with this idea and was in process of building a model for my display at NewSpace 2007 but awaiting more information. There must be many ways of using Bigelow technology for SSP either on the Moon and in space.

    Coyote,
    How’s this for a plan on setting up initial SSP demo on the Moon using the technology that NASA is trying to develop.
    An Ares 5 is used to place unmanned LSAM descent stage into lunar orbit. In place of the ascent stage is deployable Receiving Antenna.
    SSP satellite is placed at one of the Lagrange points to be over planned landing site for the experiment.
    Manned landing takes place at selected landing site. Area surveyed and crew select landing site for unmanned LSAM calculated distance away from manned LSAM so not to get dust damage in second landing. Landing transponder deployed at second landing site.
    Unmanned LSAM lands at selected site using transponder for accurate landing.
    SSP Receiving Antenna deployed and experiment begins receiving transmitted Microwave power from SSP satellite.
    Any ideas on this folks?

  14. Brian Wang said

    Concentrated solar power is the cheapest large scale solar for ground based systems and it would seem to be the cheapest option for space as well.

    What is the lightest mirrored surface material that we can use for solar concentration ?

    We could use the Spectrolab 40.7% multicell to convert concentrated light. Spectrolab is indicating that they expect to boost the conversion rate to 45% in about 2010. They are improving at about 2% per year.

  15. spacepolicy said

    DINKINS: Respectfully, one has to factor in the heating, real estate and environmental costs and see which is the better technology. The energy beamed down to Earth will end up as waste heat too. If it’s Earth hands down, that should be monitored because the good solar sites on Earth will fill up. Earth-based solar thermal can be made to reflect unused rays into space. In 400 years at the present growth rate of economic development, our waste heat will equal the solar flux. By that time, we will indeed need to move all new energy use off Earth. In the mean time, it’s a race.

    Sam,

    Let me clarify my position.

    I am NOT saying that SSP **will ever be** economically competitive. I am NOT saying that we should make a big national decision that we will build orbital powersats. I am saying …

    1) That under certain conditions several decades in the future, SSP MIGHT be economically competitive, and that if it does … then we have done the world a great service be beginning to invest reasonable amounts now in key technologies & capabilities.

    2) That we should invest in SSP technologies and demonstrations and capabilities at a level that is at least equal to what we invest in other high-risk/high-return alternatives, like fusion.

    3) That even if Orbit-to-Earth power beaming is never economical for baseload power, that there are very useful applications in niche markets. (Orbit to orbit beaming; Beaming to large populations on Earth hit by natural disasters).

    4) That even if SBSP never makes sense, for anything (I don’t know of anybody taking this position) that developing the technologies & capabilities that we want & need for SBSP is still justified, as they are extremely useful for other purposes.

    4A) “Cheap and Reliable Access To Space” (CRATS) will deliver a very high return on investment (ROI) in many other ways. All roads to living & working on the space frontier go through cheap access to space.

    4B) Ubiquitous commercial on-orbit space operations (Dennis Wingo’s term) will deliver a very high ROI in many other ways.

    – Charles

  16. Wotan said

    Paul DeBose is absolutely right when he says that Rutan and company are the way to go. If you want bloated project management and massive cost overruns, then Boeing and L-M are the way to go. However, if you want innovative thinking, rapid concept to prototyping expertise and a track record for successfully overcoming technical challenges on the cheap, you can’t beat Burt! He and his colleagues have an uncanny ability to see solutions to problems that leverage phyical effects instead of larding their systems with extra computing power, weight and control mechanisms. Burt’s “feathering” idea is just one example.

  17. spacepolicy said

    I just had a mental picture of Burt walking around his Mojave shop saying to himself “Be one with the air … be one with the air.”

    – C

  18. Edward Wright said

    However NASA has announced that it wishes to set up a base at the lunar poles possibly with a view to using the ice that is said to exist there. Will that be it? What if there is no ice there or quantities are so low as to be of no or only limited use? What then?

    Phil, it makes no difference. The NASA VSE architecture is so expensive that nothing they do or find there will be economical. If they ever get around to building a base, it will be ISS II on the Moon, with transportation costs 10x higher than ISS I.

    What is needed is a SSP system on the Moon. A demonstration of the capability of the concept of SSP could be done very early on in the return to the Moon even possibly at the initial landing site or at the polar base with a Demonstration Solar Power Satellite beaming energy to a receiver. Just think of the publicity that this would generate, NASA is beaming electricity to the guys on the Moon and this could be done here on Earth too!

    That could be a good way to kill off any interest in SSP for several decades. Look at previous NASA demonstrations like the Shuttle and ISS. Far from attracting private investment to new launch systems and space stations, they sent investors running for cover. Not just private investors, either — even the military is gunshy about piloted spaceflight because of the Shuttle. Demonstrating how expensive something can be is not the way to promote it.

    Isn’t the development of a lunar SSP just what is needed to fit in with the original ideas of the VSE?

    No, it isn’t. NASA’s vision of space exploration calls for replacing the expensive Space Shuttle with an even more expensive Shuttle-derived heavy lifter. A viable SSP requires major reductions in the cost of space transportation, along with the cost of living and working in space. Not a good fit at all.

    (I refuse to call NASA’s VSE “the” vision of space exploration, because that implies there are no other visions for space exploration, which is incorrect.)

  19. Christine said

    The president’s VSE calls for replacing the space shuttle with commercial alternatives, and this would have happened under O’Keefe. EELV launched boilerplate CEV test flights would have been starting next year.

  20. 5abc said

    Just logged in this date(07-25-07). SSP would be a useful
    source for powering Moon operations. I read the paperback
    novel about earth hostility towards SSP where SSP Albaquerqui
    Base Control was lost and earth based mirrors were used to beam SSP microwave radiation back toward the SSP. A form of self
    destruction. Moon operations will need large amounts of
    energy to establish a MoonBase protected from Meteor impact
    and solar wind.

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