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NSSO on Space Based Solar Power
apsmith writes "About a year ago some of the people at the US National Security Space Office began looking into space-based solar power (SBSP) as a technology in the near-term strategic interests of the United States. At first the participants were skeptical, and the "phase 0 study" went along with no official funding. In a rather innovative move, they organized the study as a series of internet-based (bulletin-board and email) discussions, with the wordpress site open to the public, and a closed experts-only discussion using Google Groups. Initially expecting only a dozen or so interested parties, the discussion grew to include over 170 people with past expertise and interest in the issues. The final report was released Wednesday morning; it provides an excellent broad-brush review of the status of SBSP, showing immense potential, but also a number of challenges that appear only surmountable with a strong government commitment to the project. The big question is where it goes from here — NASA? DARPA? The new ARPA-E? Or something new? I was able to attend the press conference, which included Buzz Aldrin in an announcement of a new alliance to push for implementing the recommendations of the report."
Maybe the solar satellites can double as a baseball cap for the Earth :).
Haiku for you!
How is it better to lift your solar panels into orbit, generate your electricity, then beam it to the surface at (optimistically) 50% efficiency, and then receive the beamed power at (optimistically) 50% efficiency, meanwhile creating the navigational hazards of the power beams and still requiring distribution from receiving stations rather than simply generating it via panels at the point of use?
Don't get me wrong, I'm all for finding ways to utilize space, but I don't see how this is even remotely economical, especially at our current technology levels.
Convince me.
I like the idea of a separate organisation dedicated to this technology, as it's clear none of the existing organisations can do it. Set it in motion, get it done before the bloat sets in. Also like the idea of the solar-electric HEO ferry -- anyone have a link to an artist's perception of it (a real one I mean)?
Do not mock my vision of impractical footwear
The big question is where it goes from here -- NASA? DARPA? The new ARPA-E? Or something new?
By "something new", I'm sure you mean the formation of D.O.O.P.
The theory of relativity doesn't work right in Arkansas.
What they didn't know was that one of those 170 was an Anonymous Coward... [evil grin]
I'm skeptical too, but it's not quite as crazy as it sounds.
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
Terrestrial solar power is approaching $1/peek watt, at which point it will be economic.
What are the current costs per kg to get to LEO?
Benefits: doubled power due to no atmospheric loss, approximately quadrupling average power generation as you can expect to run the cells at peek power full time.
Costs: lift cost, shorter lifetime of the cells and attitude control system of the satellite (which feeds back on lift cost), power transmission loss.
Short of building a space elevator, or making the cells on orbit or on the moon I don't see that working out to a net benefit. I can't justify any of those as reasonable assumptions.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
So inefficiency is the key to success? Right... that's why my Libertarian Manifesto says "smaller government," as in, wasting less trillions of dollars. That's opposed to not wasting any money at all - see? Even idealists are willing to compromise.
Haiku for you!
Lets build in some redundancy shall we? (Just in case.)
I think you covered the list pretty well but corrosion is also a factor that space should mitigate. Well, mostly aside from the wandering bit of space debris.
I haven't RTFA, probably won't, but I'd like to throw in the additional suggestion we look into Von Neumann devices to build most of the components on a lunar base. (Earth first, and strip-mine the moon later.)
Back in my day when we chiseled our bits into stone and sent them by mule train from village to village...
How much power do we use for outdoor night lighting? Think of all those street and parking lot lamps.
How much could this demand be reduced by simply reflecting sunlight down to the night side of the Earth?
The satellites could be nothing but big steerable mirrors. No energy conversion would be needed.
If I needed funding for my project I would say the exact same thing, especially if I had 170 other highly skilled fanboys to back up my idea..
I'm pretty sure that the plans are to build these things in geosynchronous orbit, so the satellite doesn't move relative to its receiving station - which would be some equatorial platform floating somewhere between the US and Africa.
solar cells here now aren't capable of extracting more then 35% of the light that makes it to earth now, so they won't do any better in space.
the only type of solar generation that will produce more power in space due to the more intense soalr rays will be some form of mirror heating, and that present a whole bunch of other problems.
i'm also curious as to how they will keep the solar array in a sationary orbit? if it's not, you will still end up with the problem of night time
There's more important hurdles to get over before we do anything like this. namely making exiting the earth's atmosphere cheap and safe.
If you mod me down, I will become more powerful than you can imagine....
umm... is this meant as a joke or are you being serious?? ...God, I hope it's a joke.
http://en.wikipedia.org/wiki/The_High_Frontier:_Human_Colonies_in_Space http://en.wikipedia.org/wiki/Solar_power_satellite
Don't blame me -- I voted for Roslin.
A big beam, needs a big mirror. Be it microwave, infrared or visible light it's a huge gun in orbit, untouchable by IEDs and lesser nations. It doesn't even need to work that well, just 10 x amplification from nominal and any spot on earth is unlivable. Or operate as a great psychological weapon when a given region is bathed in light 24 hours a day. It is a very bad idea, like SDI was a bad idea, like the further militarization of space is a bad idea.
From the game Alpha Centauri:
Planet's Primary, Alpha Centauri A, blasts unimaginable quantities of energy into space each instant, and virtually every joule of it is wasted entirely. Incomprehensible riches can be ours if we can but stretch our arms wide enough to dip from this eternal river of wealth.
CEO Nwabudike Morgan "The Centauri Monopoly"
We're certainly not going to rely on a very fragile orbiting setup which is a sitting duck to anyone with a decent missile/launch vehicle.
Great job identifying a troll and feeding it immediately!
You're off on several items:
...
... meanwhile creating the navigational hazards of the power beams and still requiring distribution from receiving stations rather than simply generating it via panels at the point of use?
...) rather than being strongly absorbed (like the K-band microwaves used in ovens, which are tuned to one of water's absorption bands.)
How is it better to lift your solar panels into orbit, generate your electricity, then beam it to the surface at (optimistically) 50% efficiency, and then receive the beamed power at (optimistically) 50% efficiency,
First: It isn't necessarily panels. Steam plants work just fine, and are much cheaper to build and lift.
Second: There's 7 times the power per square foot available up there due to lack of atmospheric attenuation and the 24/7 nature of sunlight in space, compared to the atmosphere-and-weather-compromised equivalent of 5 or so noontime-hours-worth you get on the ground.
Third: As of the '60s they could already do > 90% DC in at orbit to DC out on the ground, using masers and TWT amplifiers in orbit and schottky diode based rectennas on the ground, not the 25% you consider optimistic. (Vacuum tubes are EASY when you don't need to pump air out of them and can heat the cathodes with focussed sunlight...)
The power beams are not a navigational hazard. You can fly right through them - as can birds. You can also sit on the ground where they're strongest - grazing cattle under the rather lacy rectennas (assuming you put 'em up on grazing land rather than, say, some sterile hunk of rocks and sand.) This is accomplished by picking the right band for the beam - in the millimeter range - where it passes right through water (clouds, birds, people,
The distribution grid is already there and very efficient. It's eminently suitable for taking power from a few rectennas located in remote regions and distributing it to cities, towns, and rural consumers across the country. What's your gripe with it?
The L5 society investigated and was pushing this a half century ago, and this is what they came up with back then. Some things have improved since. But they didn't really NEED to improve in order to make it practical.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
There are ways to drastically reduce 'lift costs' that don't involve a space elevator.
PHEM - party like it's 1997-2003!
Even as a Randroid libertarian I found that post hilarious.
Stop modding provocative posts down. Your Orwellian sanitary impulses are spoiling the environment here.
In my part of the world we get no direct sunlight for part of the year, so we'd need some monster sized batteries.
He'll pick a bunch of SMART guys and they'll solve our ENGERNY problems and they'll do it all in ONE WEEK or he'll... uh... he'll uh... give them MORE TIME and MORE MONEY because its REALLY REALLY HARD to solve our ENGERNY problems! And then if they don't do it before they die then... uh... he'll pick some MORE SMARTER GUYS and let THEM solve our ENGERNY problems!
Nothing like incentives!
Seastead this.
First off, putting them somewhere other than Earth orbit is silly - yes, you can get more energy from the Sun, but how do you transmit it to Earth? The microwave (or whatever) beam will also fall of with the square of the distance.
Actually, no.
Light intensity from the sun drops off at the square of the distance because the sun radiates as a point source in all directions.
If you put your collector array closer to the sun, you collect significantly more sunlight. Then you use that energy to power a laser. If you can keep that beam tightly focused, you won't have much loss in the beam at all.
As china showed (and USSR, as well as America), it is easy to shoot a small sat out of the sky. Now put something of that size, and it is literally shooting at the broadside of a barn. And the brilliant pebble approach would work nicely for this.
TO be honest, years ago, I thought the same thing, but if you think about it, we can simply use a nuke power plant on the ground and beam the energy to a set of sats to send the power. Just make the main receiver be at geo over USA, and then from there beam it around. The nice advantage of that, is that does not have to be just 1 power plant in America. It can be any where on the globe.
I prefer the "u" in honour as it seems to be missing these days.
Yay, let's be cunts and mod every challenging idea as "flamebait" even when you have no fucking idea what the motiviation of the original poster is.
Let's pigeonhole every controversial idea into one of two slashdot ghettoes in order to stifle the flow of information, and let's pat ourselves on the back for our Orwellian law enforcement.
Let's be proud of our complete and total subservience to the herd mentality.
meaning mainly, lower launch to orbit costs. Doing this not only gets us power, it gives us a platform for space industrialization.
Tech Public Policy stuff
The US is proposing to put devices capable of aiming megawatt beams into orbit? And who exactly will control this?
And the justification for this seems rather dubious, too. Capturing solar power in space has no obvious overall advantage over capturing it on the ground.
I'm actually a little concerned that something like this could be used as a weapon. Beaming high amounts of energy at certain targets could cause serious damage. Fortunately these guys don't have funding. As much as I like the idea of solar power at least with nuclear the area for potential damage is quiet limited, unlike something that orbits the Earth. Kinda reminds me of the Futurama episode where the sun shade burns through the auditorium.
The way to read TFA is to use the search function to look for "$". Then you can skip all the "it would work this way" stuff (this is R&D - just give it to them that they have something that MIGHT work) and get to the real feasibility.
... the military needs megawatts in the middle of nowhere sometimes, and must truck in diesel at $1/kWh.
/lb. :
It's not about the watts per square meter, or the transmission feasibility or losses, skip to the final number: how many kilograms do you have to put into HIGH orbit to deliver a 1kW to the ground?
I didn't find that number, but by searching on "$", 56 pages in to a 75 page document (but only 1 minute into my search, see the time-saving?) we come to the important points:
- even the cheapest launch costs won't let them deliver power at even military-cost scenarios of $1/kWh (10X the best commercial
rate)
- to get down to the big market of baseload commercial power, delivered at 8-10 cents/kWh, they need launch costs to drop
to $200/lb.
Current launch costs to geosynchronous orbit are $15,000 - $20,000
( http://answers.google.com/answers/threadview?id=431680 )
Obviously, this amount can drop radically with a new launch system. An earlier post from "Dr. Manhattan" ( http://science.slashdot.org/comments.pl?sid=287435&cid=20463673 ) mentions nuclear rockets. Good luck to them.
Good luck to anybody who can drop high-orbit launch costs by two orders of magnitude. A LOT of good things depend on dropping costs that much, including large manned space stations, moon bases, 100m diameter space telescopes, and space tourism for the middle class.
So while it's certainly worth some hundreds of millions per year (if it's worth billions to research fusion) to research the engineering of power transmission, and the making of lightweight cells or zero-gee solar thermal designs...lets take the discussion up again when those launch costs drop even ONE order of magnitude, shall we?
Until then, it's not even close to a pilot plant.
Read the fucking article!
While the idea of space based solar power does present some interesting potential benefits it does not help alleviate the thermodynamic issue we are presently experiencing. Global warming is thought to be caused by two major factors: A) That existing energy (heat) is being trapped on Earth by a layer of "greenhouse gasses" (which prevent the energy from radiating back into space) and B) Potential energy stores (such as fossil fuel) are being converted into kinetic energy (heat) at a greater rate than energy dissipation can occur.
Space based solar arrays may reduce greenhouse gas emissions by supplying energy in a way that does not produce more greenhouse gases, so that might be a win. However, piping more energy into the system (Earth) from outside the system (sunlight captured in orbit which would have normally not reached the surface, and redirecting it to the surface) will only increase the issue of the Earth not being able to dissipate energy into space fast enough, and there will be an overall gain in energy within the system, continuing the global warming phenomenon.
On the other hand, using ground based solar arrays do not introduce any additional energy into the system (capturing light that would have made it to the ground already). There are vast swaths of land and water on this Earth which are bombarded by sunlight, ready to be harnessed. No matter how the captured solar energy is used, it will inevitably end up as heat (infrared radiation) so even if it is just the normal desert ground soaking it up, or a solar array converting it to electricity, there is no additional energy entering the system, thus no additional contribution to the global warming issue.
This is basic thermodynamics, and I hope people which are thinking of "alternative energy sources" will consider the impact of their ideas on the system at large.
I remember, back in 1980 or so, when all the Reagan fans were jumping for joy because the actor was more popular than a naval nuclear engineer (yes; Carter actually knew his shit), Carter had proposed a system of orbital solar power stations. It would have been more or less the same thing as they are proposing today. Those of you who have access to Time magazine's archives will find an article on it.
So, here we are today, some 27 years later, and the same proposal gets floated.
Imagine if laziness hadn't dropped the issue back then. Iran, Iraq and the whole business of 9/11 would have been less critical than they now are.
FTFA:
"Conflict prevention is of particular interest to securityproviding institutions such as the U.S. Department of Defense."
Hmmmm - not on recent evidence!
You thought you could break the laws of physics without paying the PRICE?
Sarcasm seems to go right over your head, doesn't it.
He has no idea what he is talking about
Reading this I'm thinking of that powerplant in sim city where it would sometimes screw up and scorch the city with the microwave beam.
What a total waste when a far smaller investment in deep geothermal technological development will yield a far more stable, reliable and efficient energy source. See 384 page MIT study here http://web.mit.edu/ceepr/www/mit%20geothermal%20study.html.
The basic physics appears to make sense, as obviously theres more power available from solar energy in orbit. The problem is unfortunately the lifetime of any satellite.
Lubrication (KY Jelly jokes aside!) is essential for any moving part. Without it parts often wear out quickly. This problem is why satellites have a life span. They need to continually fix the orbit and the rotation of the satellite. To achieve this, gyroscopes and fuel burns are required. Once the gyroscopes have eroded away (lubrication has been used up), the satellite will be uncontrollable with respect to its rotation.
The secondary problem is the issue of keeping the satellite in a particular orbit. Fuel is used often to make minor (but essential) corrections to the orbital trajectory. Towards the end of a satellite's lifespan, it's remaining fuel is used to push it into the graveyard beyond geosynchronous orbit.
So this leaves us with a final issue: What happens when the satellite has run out of fuel/lubrication? We dump it into the graveyard orbit like we do with all the others?
Perhaps sophisticated "MagLev" type gyroscopes could remove the lubrication problem. But then we are stuck with the problem of fuel. Solar energy could be used (for a type of photon engine), but how feasible that is I don't know.
I dont get how the size of the antenna has anything at all to do with it being near-field. Near field id the close-in region of an antenna wherein the angular field distribution is dependent upon distance from the antenna. In other words...its depending on the wavelength of the freq used..so a certain multiple of that length determines what is near field and what is far field.
http://en.wikipedia.org/wiki/Dyson_Sphere
There is *no* economic incentive to putting something like this together, and it is certainly not going to "solve our energy problems". Solutions have to be global, which means North Korea needs power, just like the USA and China and India and the Vatican City. IIRC, global power consumption is somewhere around 14 TW/y. So: take whatever power ONE of these things can make and multiply it to 14TW. Mmmmm - not gonna happen at $10,000 kg payload, or with the flaky launch vehicles that have a habit of blowing up and killing everyone on board on the way up or toasting the crew on re-entry.
Terrestrial solar power connected to comparatively low efficiency (but fairly cheap to build) mass storage batteries combined with wind power connected to same batteries, in conjunction with a massive conservation effort and shift in social definitions of happiness and and assortment of greener (if localised) technologies like geo-thermal and hydro, when combined with shorter-term interim technologies like (sorry greenies) nuclear power, is a much more sustainable and practical direction as civilisation gradually powers down to sustainability.
Orbital electric is never going to happen. It's a dumb idea, and there are terrestrial solutions that are vastly cheaper and efficient - like TURNING THE FUCKING LIGHTS OFF WHEN YOU LEAVE THE ROOM and similar simple acts of conservation.
RS
Shoes for Industry. Shoes for the Dead.
Actually you have that backwards in several respects. The report goes into this a bit.
First, the amount of energy humans use is minuscule compared to the main flows of light to the Earth and heat back out - about 1 part in 10,000. Even if we replaced all human energy sources by space solar power, that added 1 part in 10,000 incoming energy will change temperatures at most something like 0.01 or 0.02 degrees - really irrelevant.
Second, solar cells absorb essentially all the sunlight that hits them. Most of that energy goes into waste heat of the ground since the cells are only 20% or so efficient. That *increases* the albedo of the ground area they cover and increases Earth's net absorption of heat. If we replaced all Earth energy use with solar cells that were 20% efficient, we'd be adding something like 2-3 times human energy use as heat input to the planet, where the energy is being absorbed instead of just reflected back out. With satellites, the energy is captured in space so the waste heat has to be dealt with up there, not down here. Further, the ground receiver doesn't care what it's properties are in visible light, assuming we're transmitting energy at a non-visible frequency, so it can be as reflective as you like and actually decrease the ground albedo. So an SSP system could use its ground systems to completely compensate for any added energy to the planet, something that a ground solar array cannot do.
Energy: time to change the picture.
Is it just me or is collecting a bunch of energy that wouldn't have reached earth, i.e. it would have bounced off of cloud cover or shot off into space, and then bringing down to earth not going to increase the amount of energy in the biosphere and thus increase the heat of the earth?
Am I missing something?
just = (My)Opinion.toCents();
This is not either/or. Do the math. To even slow down global warming during this century, we're going to need as much new clean energy as we now use from all sources. To stop it, we'll need even more. No one source will come close. We'll need every feasible source we can imagine and it still might not be enough.
There's no physical reason getting into orbit can't cost $200/lb or even $50/lb. The energy cost isn't the driver, it's the cost of throwing away all that high tech hardware every time. Several good entrepreneurs are on the problem now, but it will take some time for most of them to work up to large orbital transport. With a little backing, they could get the cost down sooner.
I hope turning off the lights makes you feel good, Ralph. In the grand scheme of things, that's about all it will do.
What do jabs at the space shuttle have to do with this (I didn't check your links, maybe I'm assuming too much)? This is talking about deployment in geosynchronous orbit, presumably unmanned deployment. So there's (a) no crew to blow up, and (b) no reentry. Good luck on that shift in the social definition of happiness, there.
From the original post: "The big question is where it goes from here -- NASA? DARPA? The new ARPA-E? Or something new?"
My money's on Haliburton, via no-bid contract.
Never let a lack of data get in the way of a good rant.
I can't help but think the people after this stuff are more interested in grant money than in solving the world's energy problems.
Comments from someone who's worked on these problems:
http://www.energyfromthorium.com/forum/viewtopic.php?t=240#1536
As others have pointed out here, launch costs are a problem, but even barring that, you need 10 square kilometers for the receiver, and the other economic factors make it uncompetitive.
It's a shame that only "sexier" energy schemes like this get attention.
The post contains facts, but it doesn't use them fully. So, $10,000/Kg for geosynchronous orbit, eh? Does that price drop if you know you're going to send up 50 launches to the same location? What's the lowest mass you could make a panel for each Watt produced? (Remember that you don't need all of the support and protective glass you need in the atmosphere.) Honestly, I would be surprised if panels being used in an ultra large array in space has a mass 1/10th what they do in Earth, and I wouldn't be surprised at 1/100th, for a given Kilowatt rating.
What about using large sheets of reflective foil to reflect even more light at the panels? That would have an almost negligible weight.
Let's say (extremely optimistically) that you could produce 100 Watts for every Kg of material sent up. Running essentially 24 hours/day would give you 2.4 kilowatt hours each day. In a year that's 876 kilowatt hours, or $876 worth at the previously mentioned military energy rates. That means it would take about 12 years to pay off, assuming energy rates don't vary. That really isn't bad at all.
Of course, that leaves out a lot of details such an maintenance, assembly, orbit corrections, meteor showers, etc, but it certainly isn't a financial impossibility. If/when launch costs drop, and some more R&D goes into focusing on Watts per Kilogram solar power, this stuff becomes a great idea.
**Now if you could get robots up into space or on the moon that were able to refine raw materials to make more panels and put them into place, then you've just created an essentially limitless source of power. Of course, by the time those exist, cold fusion will probably be old news.