Obama Transition Team Examining Space Solar Power

DynaSoar writes "President-elect Obama's transition team has published for public comment a white paper entitled Space Solar Power (SSP) — A Solution for Energy Independence & Climate Change. The paper was prepared and submitted by the Space Frontier Foundation and other citizen space advocates, and calls for the new Administration to make development of Space Solar Power a national priority. The SSP white paper was among the first ten released by the Obama transition team. It is the first and only space-related white paper released by the team to date. With 145 comments thus far, it is already among the top five most-discussed of the 20-some white papers on Change.gov."

Comments

How?

[Tubal-Cain]

And how exactly do they plan on getting the panels/mirrors/whatever up there?

Re:How?

[Samschnooks]

Outsource to the EU, Russians, or the Chinese?

Re:How?

[east coast]

I thought Obama's plan was to keep the jobs and technology home based. After all, outsourcing doesn't do much to create jobs.

he's either going to have to do this with NASA and keep their funding up or it's just more banter from a politician.

Re:How?

[meza]

Well stuff has been put up in space before. No biggie. What I'm wondering is how they plan to get the energy back down here.

Any one have links to actual engineering proposals of how Space Solar Power would work and its benefits? Seems to me like "space" is not one of them, there is plenty of desert and whatnot to put solar cells in here on earth with much less maintenance cost and of course the possibility of running wires to get the energy to wherever it is actually needed.

Re:How?

[Socguy]

http://en.wikipedia.org/wiki/Space_solar_power

Beam the energy in the form of microwaves to rectennas on the ground.

Re:How?

[Terminal Saint]

The concept has been kicking around for years. It generally calls for getting the power back down via microwaves.
http://en.wikipedia.org/wiki/Solar_power_satellite/

Re:How?

[peragrin]

Obama doesn't want to kill NASA, Obama wanted to streamline a few of NASA's pipe dreams Like returning to the moon or manned mars missions. Things that have little practical value in the next 5 years. a return trip to the moon would only be for historical reasons and maybe to bring back a few more moon rocks.

Re:How?

[Anonymous Coward]

Landing on the Moon is not a pipe dream, we've done it. Going to Mars is not a pipe dream, it's a plausable extension of the capabilities we have today. Both of these can be done for reasonable cost, and in the process spur innovation and boost our national prestige. Given the fact that we appear to be in a national malaise, the latter should not be considered trivial.

The pipe dream here is solar space power. It's an absurd concept that will never be profitable compared to Earth-based utilities. Even the supposed "military applications" like beaming power into remote battlefields is bogus.

Re:How?

[J05H]

No cite needed. Fact: the 2000-era OSP/Orbital Space Plane project was going to provide a capsule or small spaceplane atop EELV.

the VSE said nothing about "Build a heavy lift rocket" - it did say to open the Solar System to human economic sphere. Mike Griffin took Bush's VSE and created ESAS plan from it - this became the Ares/Constellation projects. While Orion (the capsule) is an OK idea, the fact that NASA is trying to field yet another medium-lift rocket is a terrible idea. The obvious part of the problem - no payload should be designed to fly exclusively on one rocket. Even more short-sighted is fielding a giant new HLV that will also have exactly one customer - and it will still be mostly flying propellant - the actual hardware is light enough for ELVs. Instead of building the payloads and helping to build the existing market for medium-class launch while focusing on the mission (go to Moon, go to Mars, make conditions for homesteading/mining, etc) they have focused and stumbled on the first mile of the problem.

This goes back to Griffin's recent "Your not qualified" statements - he only sees the engineering aspect and is apparently blind to economic, historical and political forces. Apollo on Steroids is hide-bound not muscle-bound.

On SSP - SSP will require putting thousands of tons of hardware in orbit regardless of specific tech choices. Boeing proposed an "Ultra Heavy Lift" booster in the 1970s called LEO - 250tons to orbit. It can be done in arbitrarily large chunks but has also been proposed on the other end by Dr. Hoyt of Tethers Unlimited as a single payload of 25t flown on EELV. Beamed power can be demonstrated on an in-space scale first (w/ huge market potential) and later on Earth. The DoD has looked into an all-electric future with SSP, Gerard O'Neill proposed basing the entire space economy on beamed power as well. The basic tech has been demonstrated in the lab and recently between two Hawai'i islands.

Beamed power can be one of the most environmentally benign forms of energy production. It produces a microwave equivalent of 2X sunlight strength on the target rectennae and is tuned to be transparent to water, producing little to none atmospheric heating. Developed as GEO power plants they could provide baseline power to cities. Digital phase-array antennae may provide dynamic control and non-photovoltaics may be the better solution for generation (solar-dynamic/sterling). SSP is one technology that offers tremendous potential.

Re:How?

[roguetrick]

If the permanent colony is as useful as the ISS, I'd sooner not have it.

Re:How?

[Teancum]

Why does this have to involve NASA at all? Yes, NASA seems to be the agency with experience in dealing with spaceflight, but NASA certainly isn't the only (nor even the largest agency in the U.S. government) that is involved with spaceflight.

In terms of dollars actually spent on spaceflight, I don't know which is larger: The NSA (National Security Agency... who operate the spy satellites and hack into the internet) and the U.S. Air Force Space Directorate. Both are larger than NASA. The Air Force at one point even built their own private launch complex for the Shuttle... even though it was never actually used.

If NASA were completely eliminated as an agency, American activities in space certainly wouldn't end. It wouldn't even be the end of civilian space efforts that are done by agencies like NOAA and the U.S. Department of Agriculture.

Also, I hardly consider the Ares I rocket to be an efficient use of limited funds to build power-sats, but that is fodder for a completely separate post.

Re:How? - I'll tell you how

[Anonymous Coward]

As usual, just throw money at NASA and ignore it when it doesn't work since it's really pork.

Life imitates art

[mind21_98]

Doesn't this remind you of the microwave power plants in SimCity? To me, it does. :)

Pie in the sky

[yog]

I'm sorry to say, this SSP white paper is simply that--a piece of paper with a pie-in-the-sky proposal that is unlikely to get funded to the same extent as fusion energy by the DOE.

Since it's a space-based project, it should really be funded and organized by NASA, which after all knows something about orbital solar arrays, while the DOE is merely an umbrella bureaucracy without a clear mission. Jimmy Carter set it up, as I recall, and during the laissez-faire Republican administrations as well as the Clinton years, it has been primarily a custodian for regulating fission reactors and funding some research projects.

There is so much potential for reaping energy savings on land, without having to resort to dangerous space flights and risky, massive construction projects in orbit, that it's amazing that this proposal is even being looked at by the transition team. I suspect this is fake news.

Don't get me wrong--I'm a total space nut, and I want to see us spending a trillion a year on space, and spread our civilization out to the planets before we blow this one away.

But when we can reap significant energy savings merely by painting the rooftops white of most government buildings, when we drive cars that have half or one third the fuel efficiency they could have, when we live in uninsulated buildings--it's ridiculous to proclaim that an SSP would solve our energy problems.

We should definitely build orbital facilities that would include solar arrays, perhaps to house dangerous manufacturing operations and to do zero-grav research, but this is not the most persuasive white paper that they are going to look at, I suspect.

Re:Pie in the sky

[DynaSoar]

I'm sorry to say, this SSP white paper is simply that--a piece of paper with a pie-in-the-sky proposal that is unlikely to get funded to the same extent as fusion energy by the DOE.

I almost added some similar editorializing to the submission, but opted to leave it as it was. I'm also very skeptical of the proposal itself. However, I find the interest in it as compared to the other proposals on change.gov to be encouraging. This is especially so since Obama was at first hardly pro-space. Their interest in this proposal is another step away from that stance. And I believe Obama's team still to be capable of being influenced and directed to better things. This proposal is too far off, but it makes a good focus point for choosing a more positive direction. O'Neill's ideas were similarly distant, but they persist as well developed starting points.

Nonterrestrial materials

[Baldrson]

Interestingly it was Gerard O'Neill who argued in the 1970's for solar power satellites constructed from lunar material and, as part of that argument predicted the industrialization of China would lead to increased CO2 emissions from coal burning that would mandate radical restructuring of global energy technology. It may be too late now to pursue nonterrestrial material SPS since the baby boomer generation, raised and educated to pioneer space from childhood, was denied that opportunity by --- well that is the question of the millennium if not the epoch isn't it? There are almost as many answers to that question as there are religions.

there was an obvious direction in place subsequent to the space race (remember the Apollo program?) that would have been followed through to space industrialization had the launch service industry enjoyed the same protection from government competition that the satellite industry enjoyed:

* (c) Private enterprise; access; competition

In order to facilitate this development and to provide for the widest possible participation by private enterprise, United States participation in the global system shall be in the form of a private corporation, subject to appropriate governmental regulation. It is the intent of Congress that all authorized users shall have nondiscriminatory access to the system; that maximum competition be maintained in the provision of equipment and services utilized by the system; that the corporation created under this chapter be so organized and operated as to maintain and strengthen competition in the provision of communications services to the public; and that the activities of the corporation created under this chapter and of the persons or companies participating in the ownership of the corporation shall be consistent with the Federal antitrust laws.

http://www.presageinc.com/contents/experience/satellitereform/contents/briefingbook/technology/1962act.pdf

It wasn't until 1990, when a coalition of grassroots groups across the country lobbied hard for 3 years, that similar legislation got passed for launch services.

http://www.geocities.com/jim_bowery/testimny.htm

The fact that Malthusian paradigm didn't follow the Club of Rome model doesn't change the reality of the Malthusian paradigm given a fundamentally limited biosphere undergoing its largest extinction event in 60 million years. The Club of Rome merely added academic fashion to the urgency of the Malthusian situation still facing the biosphere. The 1970s was the right time to start the drive for space industrialization based on a private launch service industry. It didn't happen, the pioneering culture that founded the US is being replaced by government policy with less pioneering cultures and now we're all facing some increasingly obvious difficulties -- not just pioneer American stock -- and not just humans.

The cost of getting silicon into space from the lunar surface would be orders of magnitude less than launching from earth due not only to the much shallower gravity well but also due to the absence of atmosphere.

No beanstalk needed.

At worst a Dyneema Rotovator would be needed but probably not even that.

First, the bulk of the materials are manufactured in space from lunar raw material transported to orbital facilities so you don't need to land those facilities on the lunar surface, and you don't have to worry about g-loading the raw materials you are sending to the orbital facilities.

Second, you don't manufacture everything in space -- only bulky materials like solar cells, reflectors, structural members and perhaps klystrons. Only residual materials (raw and manufactured) are of terrestrial origin.

Third, the facility you do put on the lunar surface is there primarily to transport raw mater

From The Economist

[airfabio]

Recent space solar power article from The Economist

http://www.economist.com/science/tq/displaystory.cfm?story_id=12673299

Here's the full story

[purdueduck]

The link is just a one page overview and doesn't really tell you much. The idea in a nutshell: "The basic idea is very straightforward: place very large solar arrays into continuously and intensely sunlit Earth orbit (1,366 watts/m2) , collect gigawatts of electrical energy, electromagnetically beam it to Earth, and receive it on the surface for use either as baseload power via direct connection to the existing electrical grid, conversion into manufactured synthetic hydrocarbon fuels, or as lowâintensity broadcast power beamed directly to consumers." That's from National Security Space Officeâ(TM)s Advanced Concepts Office's report you can read it here: http://www.acq.osd.mil/nsso/solar/SBSPInterimAssesment0.1.pdf

Space solar but not sustainable colonization?

[macraig]

Perversely, my articulate question submitted to change.gov, asking when and whether we could expect to see sustainable off-planet colonization receive some significant priority, was virtually ignored. It was even "modded down" by some people.

If we're gonna talk about exploiting solar energy in space, we should be talking about colonizing space in the same breath. If nothing else, the technical challenges of transferring that energy from space down through a thick atmosphere to the surface of the Earth should warrant a discussion of just moving us all closer to the source in the first place.

Re:Space solar but not sustainable colonization?

[hardburn]

If nothing else, the technical challenges of transferring that energy from space down through a thick atmosphere to the surface of the Earth should warrant a discussion of just moving us all closer to the source in the first place.

This problem is the most straightforward one. There are two holes in the spectrum normally blocked by the Earth's atmosphere, one in the microwave range and the other in light (infared, I think). Both are easy to transmit and convert back into electricity.

The problem that isn't so straightforward is getting launch costs cheap enough to make it competitive with other solutions. Which ends up being exactly the same problem that colonization needs to solve, so there's no reason why research into one won't help the other.

Who needs exploration, anyway?

[hax0r_this]

Yeah, and a trip to the west coast after the Lewis and Clark expedition would only have been for historical reasons and maybe bring back a few more notes.

Re:Who needs exploration, anyway?

[Eskarel]

Exploration most certainly does have value.

That said, expensive exploration, without the means to capitalize on it, when the economy is in trouble and we're trying to cut our energy use probably doesn't have a whole lot.

Nothing wrong with sending more landers, probes, etc to mars, the moon, wherever else we can get em. It's expensive, but it's potentially valuable. Sending a person somewhere just to say you've sent them somewhere is really rather silly.

Re:Who needs exploration, anyway?

[Your.Master]

Why is this inherently a problem?

Look, I think manned space exploration is cool and all too. But if there's a reason to send humans into space, then we will have a desire. And if they don't, then this society we breed is immensely practical and correct, which is an improvement over today's society :).

Re:Who needs exploration, anyway?

[roguetrick]

Very silly logical fallacy called the slippery slope. You ignore that if there became a viable reason to send humans up there, we still would. Sending them up there to try and force us to continue sending them up there is silly.

Re:Who needs exploration, anyway?

[aliquis]

If nothing else the better we get at leaving this rock in space the higher probability of us surviving the time we fail as species on earth.

Also if we would happen to be the only life in space it makes a hell of a difference =P (but only for us :D)

Re:Who needs exploration, anyway?

[gregbot9000]

Exactly, what really needs to be known is if their is water on the moon, and how much, first. That can be done through probes a lot cheaper.

If there is an ocean at the pole than sending people up at a later date would make sense because you could then extract essentials in-sutro, saving lots on resupply missions, and with the low gravity potentially allowing longer stays than Micro G saving cost on replacing crew. Which could then possibly assemble more probes on the moon cheaper then pushing them up the gravity well or even catch a NEO. Why we haven't figured out the most important part of future space travel (what resource's are easy and cheap to get off the moon) through cheap probes yet I can't figure out.

Re:Who needs exploration, anyway?

[Waffle Iron]

Yeah, and a trip to the west coast after the Lewis and Clark expedition would only have been for historical reasons and maybe bring back a few more notes.

If Lewis and Clark had come back reporting that there was nothing on the west coast but dust, no economically extractable minerals, and that had zero atmosphere and only trace amounts of water, and that another trip would cost multiple billions of 2008 dollars, and a colony would cost hundreds of billions, then there would indeed have been no reason to go back.

Re:Who needs exploration, anyway?

[chromatic]

Ah, you've been to Las Vegas.

Re:Who needs exploration, anyway?

[nine-times]

Nothing wrong with sending more landers, probes, etc to mars, the moon, wherever else we can get em.

Especially if you suspect that these places might have resources that we can figure out a way to use. Exploration for the sake of exploration is fine and dandy, but that's not generally why human exploration has happened. The reason people sailed across dangerous uncharted areas has usually been because they expected to find something of practical/financial value on the other side.

Re:Who needs exploration, anyway?

[Teancum]

As if NASA has done much original exploration lately. How long has it been since anybody has been to the Moon?

About the only genuinely ground breaking missions currently on tap are the New Horizons mission to Pluto and the Dawn mission to the asteroids. I am excited about both, but they certainly don't need an agency the current size of NASA to support either or both missions.

The spirit to boldly go where nobody has been before seems to be lost right now with NASA. No astronauts are setting altitude (aka distance) records to explore the depths of the Solar System. Heck, it was Apollo 13... a "failed" mission... that set the all-time distance record for anybody away from the Earth. There just doesn't seem to be any fire in the policy makers to have a difference here. This isn't even a Democrat or Republican issue, as both political parties are to blame.

Re:Who needs exploration, anyway?

[Teancum]

The problem with Helium 3 is that the fusion device to be able to practically use it has yet to be invented.

This particular isotope of Helium is found in the outer-atmosphere of the Sun and has been blowing onto the surface of the Moon for billions of years. As such, it permeates the top layers of the Moon and can be extracted economically to be able to... by itself... pay for manned trips to the Moon.

The problem is that the world-wide demand for Helium-3 right now is so minuscule that a single trip to the Moon would satisfy world-wide demand for the substance over the rest of this century.

Assuming that some fusion reactors actually get built and can produce practical energy supplies, there would certainly be demand for this on an industrial scale to justify permanent mining operations on the Moon. But that is assuming technological break-throughs are going to happen here... which has at least so far proven to be quite difficult to achieve for fusion devices.

Re:Who needs exploration, anyway?

[Teancum]

You are talking about a planet-sized object that doesn't have to be lifted out of the Earth's gravity well.... and the ability to do metal fabrication on an industrial scale using techniques that can only be dreamed about on the Earth.

The Moon has the surface area of North America and has mineral deposits at least equal to anything found on the Earth. Wouldn't it be better to stip mine the Moon to extract resources there rather than to destroy major eco-systems here on the Earth for the same resources?

And don't even get started with some of the high-metal astroids, that even a small asteroid has more precious metals than everything that has ever been mined in the history of all mankind to date. Of course the problem would be on how to mine it and send that to the Earth economically, but that is a problem I'm sure somebody will eventually figure out.

Space gives us two things we seem to be hurting on here on the Earth: raw natural resources and energy. This is energy by far and away more abundant in multiple forms than all of the petroleum reserves, nuclear fuel reserves, and "alternative energy" sources combined that can be exploited over the rest of the history of this planet here on the Earth.

This is also dismissing the fact that even going somewhere else and having to apply human ingenuity to new environments almost always produces side benefits that ultimately help all of the rest of mankind as well. Explicitly because of the development of space sciences to date, mankind as a whole is better fed, lives longer, safer, and much more comfortable.... on a planet-wide basis.... than our species has ever been before.

Every single problem you think may be plaguing mankind... from war, famine, disease, and natural disasters... has been made more comfortable and less damaging due to advances in space science. Name a problem you think should be fixed, and I'll tell you explicit space projects and missions that have made life much easier.

If you want to live like people did in the 1930's before any of this happened... go ahead. Just make sure you know what life was like back then before you push the rest of us back to that sort of lifestyle. I really don't think you want to go back to living under those conditions... even if you lived in a place like the USA or Europe of the 1930's.

Re:Who needs exploration, anyway?

[sumdumass]

The problem with Helium 3 is that the fusion device to be able to practically use it has yet to be invented.

I don't think this is so much a problem seeing how out capabilities to safely return to the moon still haven't been reinvented yet. I mean it isn't like we are going tomorrow and at least an abundant supply of the stuff could make the research more availible.

The problem is that the world-wide demand for Helium-3 right now is so minuscule that a single trip to the Moon would satisfy world-wide demand for the substance over the rest of this century.

We are looking to the future right? I mean If the tesh to use it is as safe and productive as the claims say, then a future mission to the moon compiled with future uses would basically make it worth it. No one is going to ramp up a need for something we can't get. That would be like purposely forcing a shortage in a market just so it costs more. With it here and the ability to get it, then usage would increase to make it viable and probably self supporting.

Assuming that some fusion reactors actually get built and can produce practical energy supplies, there would certainly be demand for this on an industrial scale to justify permanent mining operations on the Moon. But that is assuming technological break-throughs are going to happen here... which has at least so far proven to be quite difficult to achieve for fusion devices.

I think we are at a Chicken and the egg type impasse here. Which comes first, the need for a supply of Helium3 to feed the otherwise limited reactors or feed supply to produce the capabilities of them resulting in the creation and dependency on it. Right now, we have to rely on a government to go to the moon and pick the stuff up or have it created as well as captured in rather expensive ways. One of those ways require extracting fossil fuels from the ground and isn't very productive.

Even if we had one condenses load of it, and a means to get more with the expectations of it being availible, I'm willing to bet that the need will be there.

rube would be proud.

[Anonymous Coward]

this wacky idea of harnessing solar energy seem rather rube goldberg-ish. if you read the original concept paper you would know there are flywheels and giant vacuum tubes on this thing. aside from that, the ultraprecision for positioning this monstrosity is beyond anything humans have ever done. no worries though, when a giant beam of radiation accidentally hits the wrong place, im sure the people wont mind being irradiated.

in short, this idea is insane.

Numbers?

[hax0r_this]

Well, I can't find any really great numbers, but heres what I have:

According to the article from the Economist linked below 1.3 GW of solar energy pass through every square kilometer of space (presumably this is near Earth).

According to Wikipedia, nuclear power plants on earth had a total capacity of 366 GW in late 2005.

So by some rough calculations, assuming 100% efficient panels we would need ~280 square kilometers of solar panels in space just to gather as much energy as we can currently produce with nuclear power.

Today, even highly experimental solar cells don't reach 50% efficiency. So 2 * 280 = 560.

Now I can't find any good numbers on the efficiency of this "beaming" energy back to earth, but I'm going to throw out that 10% would be generous, its probably way less. But assuming 10%, 10 * 560 = 5600 square kilometers of solar cells in space just to get as much useful power as we get from our dismal nuclear setup today.

And thats not to mention the size of antennas you would need on either end to beam that power, or the safety issues involved (you think windmills or low frequency submarine radios kill a lot of birds, how about a 3.6 TW microwave beam?)

Re:Numbers?

[StarsAreAlsoFire]

You don't use panels 'directly'. You use thin film mylar/reflective surfaces and focus a beam to ( some central generator station ). The ( ) are because there are plenty of ways to take a concentrated beam of sunlight and turn it into energy.

I agree with the paper ( as much of it as I've read ) in that 'this WILL happen someday'. But it won't be anytime soon. Worth looking into? Ehhhh. Dunno. I'd love to see it. Personally I think researching it to be a better use of NASA's bucks than a moon shot.

But I also agree with the 'Really? Beaming all this power to central locations won't be dangerous? Come again?' aspect. I read somewhere that you aren't supposed to watch your food cook in a microwave, as there is enough stray radiation ( the technical term for light, not being a kook ) to potentially increase the likelihood of cataracts. E.g. the shielding on the microwave door isn't perfect.

I speak as one that has a BS in aerospace, and really really really wants to see us move into space. But I cannot condone spending money on this as a VIABLE source of energy for the next decade. I would HIGHLY ENCOURAGE investments in space power for *research* purposes.

Re:Numbers?

[jstockdale]

Um ... not to nit-pick, but free-space losses are for isotropic radiation, and can be compensated for by a high gain antenna -- remember that lasers are also em-waves -- a perfectly focused beam, if technologically possible to generate, would travel through a vacuum indefinitely (otherwise, it'd be a violation of conservation of energy, no?). So, throw a well designed antenna system up there and although you still won't have 100% efficiency, it certainly won't be 1/150th of the power generated in geosync.

Re:Numbers?

[rbrander]

I read the Economist article and noted the name of the scientist ("Mankins") who researched it.

I typed "mankins microwave transmission efficiency loss" into Google and the second link was an IEEE article with the abstract appended below.

Your number is 45% for DC-to-
DC.

So not assuming that solar-cell efficiency can make it to 50%, but cheerfully assuming that the kind of cells that will do well in an industrial setting space for long periods can reach today's in-the-lab max of 40%, your area comes to:

560 km^2 / 40% / 45% = 3111 km^2.

And so what? There's a lot more space than that out there. (See opening paras of Hitchhiker's Guide for how much.) The question is the available money, not the available space. Those 556GW of nuclear had a total capital cost of well over a trillion. (And a land area sucked up of well over 3111 km^2 by the way, add up all the mines and waste dumps and reprocessing facilities, not just the plants. And that's area we can use for other things, down here; not a lot of other things to do with 3111 km^2 of orbit.)

The Economist article is unequivocal: SSP would cost FIFTY CENTS per kWh. That's just awful, way worse than earth-based solar or wind, even backed up with 85 watts per 100W so that they are base-load capable.

But one lives, and allocates research dollars, in hope. I'd bump the fusion budget from $300M to $500M, and match that with SSP research funds...about $400M of which would go to "cheaper lift costs", the truly key barrier.

Space solar power programs and microwave wireless power transmission technology
McSpadden, J.O.; Mankins, J.C.
Microwave Magazine, IEEE
Volume 3, Issue 4, Dec 2002 Page(s): 46 - 57
Digital Object Identifier 10.1109/MMW.2002.1145675
Summary: Future large-scale space solar power (SSP) will form a very complex integrated system of systems requiring numerous significant advances in current technology and capabilities. Ongoing technology developments have narrowed many of the gaps, but major technical, regulatory, and conceptual hurdles remain. Continuing systems concept studies and analyses will be critical to success, as will following a clear strategic R&T road map. This road map must assure both an incremental and evolutionary approach to developing needed technologies and systems is followed, with significant and broadly applicable advances with each increment. In particular, the technologies and systems needed for SPS must support highly leveraged applicability to needs in space science, robotic and human exploration, and the development of space. Considerable progress has been made in the critical area of microwave power transmission. At 5.8 GHz, DC-RF converters with efficiencies over 80% are achievable today. Rectennas developed at 5.8 GHz have also been measured with efficiencies greater than 80%. With optimized components in both the transmitter and rectenna, an SPS system has the potential of a DC-to-DC efficiency of 45%.

Re:Numbers?

[JoeMerchant]

Think: mirrors, concentrated sunlight on a generating station in the desert - or, on unruly cities, or troublesome mountain ranges with AlQueda infested caves.

Yeah, the economic math doesn't work

[IdahoEv]

There is so much potential for reaping energy savings on land, without having to resort to dangerous space flights and risky, massive construction projects in orbit, that it's amazing that this proposal is even being looked at by the transition team.

I'm also a space nut, and I agree with you completely. A simple look at cost/benefit, even back-of-the envelope, makes it entirely clear how silly orbital solar is.

1) Benefits - how much energy can an orbital solar array produce, relative to the same size solar array on Earth? About twice as much - it's lit for 24 instead of 12 hours. (plus benefit of always-perpendicular incident radiation, but minus losses in conversion & transmission.) Ultimately, ~2x power from the same array.

2) Costs - how much does it cost to put that solar array in orbit, and build the microwave transmission system, relative to the same size solar array on Earth? Answer: an awful lot more than 2x. More like 100x.

Paying 100x cost for 2x the power generation is not anyone's idea of good economics. End of story.

It's just so much cheaper to simply build twice the arrays on the ground, even if you have to build huge power storage facilities or around-the-world ultra-high-voltage power lines to funnel energy to the night side of the planet.

Maybe in 100 years we'll have a developed space industry that can build them, up there, on the cheap. But certainly not any time soon.

 

Why bother with space solar power?

[Khyber]

We haven't even come close to getting terra-based solar power up and going as a mainstream energy alternative. Let's work on the ground before we put things in the air, gentlemen.

Re:Why bother with space solar power?

[mikelieman]

WHY?

The sun NEVER SETS in GEO.

and once you build the infrastructure to build/service the constellation of satellites, you have the infrastructure to go to the Moon, Mars, Titan and anywhere else you care to go.

This technology simply is the killer-application which will drive American domination of the Universe.

And if it ain't us, it'll be the Chinese. Your choice.

Re:Why bother with space solar power?

[modestmelody]

Though this is more about pie-in-the-sky this would be cool and inspiring stuff, practically, our best options right now are solar thermal power.

Concentrated solar power uses no new materials-- glass, steel, mirrors, steam turbines, water, and occasionally fancy salts that we've already invented. It's one of the only renewable alternatives that doesn't want any money for research, just help getting some of the start up money to use materials we already have and make here in the US to build up these plants. Though they're not price-competitive yet, most research suggests that once enough capacity is built, economy of scale will kick in and it'll be competitive with fossil fuel costs within five years.

Talk about the ability to prime pump a market.

Plus, concentrated solar works naturally with usage peaks and can be used for desalinization/purification of water which is great considering regions where there is little rain/cloud coverage is ideal.

Two things need to happen-- we need to build more terrestrial solar capacity, both concentrated thermal and photovoltaic, and more importantly, we need to construct better power infrastructure so we can deliver energy from high solar density areas (which are typically desolate and therefore don't have the power pumping capacity some areas have) across far distances.

Re:Why bother with space solar power?

[GileadGreene]

Actually, the sun does set in GEO. Just not for very long, and only at certain times of the year. Eclipse seasons for a geostationary satellite occur around the vernal and autumnal equinoxes. The seasons last around 40-50 days, with maximum sun-occultation duration of about 72 minutes. A discussion of the relevant orbit geometry can be found here.

Re:Why bother with space solar power?

[Khyber]

Why? Lots of reasons, the most important being:

A. Cost of putting such a LARGE array up there.

B. Inefficiencies in power transmission (how're you going to beam it to the surface? Microwaves? Why not just harness it at ground level and store it in batteries, and cut out several points where conversion losses would be found?)

C. Maintenance costs/damage protection/prevention - just how do you plan on keeping these things safe from random space debris flying at ultrasonic speeds?

D. energy costs to build/deploy - these things would have to be MASSIVE with current solar technologies to get usable power after factoring in loss for transmission and conversion.

Need more?

Re:Why bother with space solar power?

[lotho brandybuck]

The sun never sets on earth, either.

It would seem much more effective to find 3 deserts, spaced approximately 120 degrees around the globe, then run and HVDC power transmission link connecting everything.

Or, you could combine solar power plants (either solar thermal or direct PV) with pumped storage systems. All realizable with present technology. There are many reasons we need to be in space. Solar power is not one of them. The sun shines all the way down here with only a 30% reduction in power.

Re:Two clear choices

[The Living Fractal]

That you received +5 Insightful for your post is staggering.

My favority scenario (although rather unrealistic) is people marching into gas chambers while watched over by the Eco-Troops.

This is your favorite? Seriously? How very insightful that you are able to pick your favorite way for billions of people to die!

I find it intriguing that you think these potential futures are 'choices'. As if the collective of Humanity is actually going to do anything without being forced to do it! Name one thing Humanity has done as a whole that was a 'choice'.

It's as if you think that we had a choice going from your purported 200million limit to where the population is today. What, was everyone going to just up and stop fucking? I don't think so.

BTW, you are dangerously out of touch if you think the world cannot support more than 200 million people.

Pipe dreams, in the sky

[Anonymous Coward]

I am a retired physicist/space scientist who researched this subject in the 1970s and again in the 1990s. While it is true that a huge amount of energy passes by and intercepts this planet, it was and remains too dangerous to try to get it down here for us to use.

The idea was shelved back then for the simple reason that the number of launches needed to build the orbital facilities would completely destroy the ozone layer. (EVERY launch does damage to the upper atmosphere.) Funny, but the textbook of reference material about that is "missing from shelves" as of the 1st Bush administration.

Yet another analysis showed that the reflectance of that much material up there would make the darkest night roughly equal to the full moon at mid-twilight.

Better to solve our problems right here.

Re:The problem is power control

[mikelieman]

Get caught up on the technology. They fixed that one a long time ago. Simply put, the ground station emits a pilot beam. Go study the topic, and you'll see that it's 1970's technology.

If Reagan had started the ball rolling, we'd have stations online now.

Who do you trust with a death ray?

[victim]

Whenever you read "spaced based solar power", just replace that with "municipal scale death ray". Now decide who should be in control of it.

Re:Who do you trust with a death ray?

[JoeMerchant]

The power density would probably never be high enough to turn it into a death ray.

A 1" magnifying glass can make solar death rays for ants... any multi giga watt system capable of transmitting that power to the ground in a useful form is going to be capable of frying stuff. It may be "completely harmless by design" - but with what this system is going to cost to build, I can't imagine it getting funded without a military application onboard.

Re:Who do you trust with a death ray?

[afxgrin]

That's a poor analogy.

You're putting all the light at a focal point. This would be the equivalent of having the lens too close to the ant, with it out of focus... the ant will just be rather bright.

What I'm saying with the microwave beam is that you can't focus it that finely. Instead the system would be transmitting from many point sources, and the beam just can't be that easily focused without having a huuuuuge dish.

One of the earlier proposals from the JPL was to use a phase-injected array of magnetrons to provide a steered microwave beam. That beam will still be really, really wide ... remember the wavelength of EM energy we're dealing with is on the order of centimeters in length ... the EM energy going through your magnifying glass is nanometers in length. You can easily focus that energy with a 1" magnifying glass... when it comes to microwaves, especially from GEO, it's just not going to be that focused. Even if you scale this up to multi-gigawatts ... let's say 1000 GW - the entire US demand for electricity at the end of 2007. If that power was beamed down from the sky at 100% efficiency, over an area of land of 100km x 100km, that's only 100 W/m2 ... now if we reduce that down to an area like 20km x 20km, it's 2.5 kW/m2 - that's probably not safe.

But at 100 W/m2 it should be okay ... obviously there's no single 100 km x 100 km site that's practical, so you have different sites around the country... makes sense anyhow - you don't want all the power in one spot anyhow.

Every single paper explaining this project basically cites the beam as being highly divergent and requiring - a very large field - to harvest the power.

An anonymous poster further up however provides the best response about risks -

  - the amount of rocket launches required to implement a system on the scale we'd want would basically destroy the ozone layer.

That's not acceptable by any means ... that risks killing off large portions of the biosphere. Most photosynthetic plants really don't like UV light in any higher dose than necessary. It's one thing to zap them with a single short pulse, it's another thing to provide continous wave ionization of the epidermis...

The military application has always been the ability to have a power source anywhere the forces go in the world.

Death beam from above isn't practical using this system, they'd more likely use orbital death rods, fission reaction powered gamma/x-ray beam, or good ole missiles.

I vote the idea down simply for the damage we'll do launching that many rockets into space.

Yup, but:

[John Guilt]

0.) You fill out the environmental impact statement (because this is not Soviet Russia!).
1.) Do we want to get a lot of power from something so vulnerable to easily-deniable sabotage?
2.) Any such device could also pass muster as a death-ray; this might raise objections from a Major Creditor Nation.

What about space junk?

[free2create]

If they are in low earth orbit odds of a shuttle hitting space junk http://www.foxnews.com/story/0,2933,418741,00.html are about 1-300 (I assume over a week period). This means with such a large area odds of a collision to be over 99% at low earth orbit. Now to beam power down that would be geo- which is still pretty crowded ... For low earth orbit below 600km gravity eventually cleans up the mess but not geostationary: http://www.taipeitimes.com/News/feat/archives/2003/07/16/2003059688

someone's penny wise, pound foolish

[leftie]

NASA's total budget request for FY 2009 was $17.6 billion...

http://www.nasa.gov/pdf/210020main_NASA_FY09_Budget_Estimates_Summary.pdf

Wanna bitch about wasting money, go yell at a banker or a broker.

Space Solar Power does make sense, sometimes

[DanielRavenNest]

The atmosphere absorbs around 25% of sunlight on a sunny day, and you have nighttime and clouds. So a solar collector in space produces around 5 times as much raw power as one on the ground. Space solar power makes sense if *ALL THE OTHER COSTS OF GETTING THE POWER DOWN TO THE UTILITY GRID* are less than 5 times as high. Otherwise ground based solar power is cheaper.

Right now, the cost equation says it does not make sense. Some combination of cheaper launch methods, robotic construction, and supply of 99% of the power satellite parts from space-based sources *MIGHT* change that answer.

(I am a rocket scientist, in fact I got paid to help figure out that 99% number in considerable detail. Most of a solar power satellite can be sourced from space. A small part it makes more sense to get from earth, computer parts for example)

Re:Space Solar Power does make sense, sometimes

[Teancum]

You still have to transmit the power to the Earth... and surprisingly water vapor also absorbs a great amount of the energy. A cloudy day on the Earth is therefore going to reduce the amount of power available from these satellites. So yeah, weather has an impact here.

BTW, if you thought global warming due to CO2 production was huge, just wait until you get the figures for what happens to that other 80%+ of the energy that doesn't get collected on the surface. It all gets absorbed directly into the Earth's atmosphere. Talk about anthroprgenic climate change. Has this really been thought through here?