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Astrium Hopes To Test Grabbing Solar Energy From Orbit
goldaryn writes "Word from the BBC today is that Europe's biggest space company is seeking partners to help get a satellite-based solar power trial into orbit:
'EADS Astrium says the satellite system would collect the Sun's energy and transmit it to Earth via an infrared laser, to provide electricity. Space solar power has been talked about for more than 30 years as an attractive concept because it would be 'clean, inexhaustible, and available 24 hours a day.' However, there have always been question marks over its cost, efficiency and safety. But Astrium believes the technology is close to proving its maturity.'"
...would collect the Sun's energy and transmit it to Earth via an infrared laser, to provide electricity.
Can someone give a safety analysis please? It's my understanding infrared energy can be refracted by the atmosphere or diffused when there is particulate -- and if the beam strength is high enough, there's the potential for it to scatter and hit an unintended target. You know, like your skull.
#fuckbeta #iamslashdot #dicemustdie
It may be close to proving is viability, but there's no way anyone has any business calling this not-even-prototyped tech "mature."
A slashdotter who didn't build his own computer is like a Jedi who didn't build his own lightsaber.
I don't know how so many people are able to drive in traffic, given how scared people get by the most unlikely things. Only 30% of the Earth's surface is land, and we only inhabit a fraction of that. I'll take my chances. Let's see what this tech can actually do.
I thought microwave transmission was the way to go, and they had worked out how to avoid accidentally frying non-target stuff on the ground.
I prefer rogues to imbeciles because they sometimes take a rest.
Ok, I know this would displace some fossil fuel energy use (that
is increasing the greenhouse effect and trapping heat on Earth.)
But beaming electromagnetic energy (infrared, microwaves, whatever)
from part of the Sun's radiation that was going to miss Earth in the
first place seems to be adding energy to the Earth (and thus eventually
adding heat to the Earth, as the organized EM energy degrades
(gets used and entropized).
Has anyone done the calculations to make sure that the GHG emission
replacement factor of this new energy (thus its reduction of heat trapping)
is more than the brand new heat it is adding to the Earth system?
Where are we going and why are we in a handbasket?
Just do the math, it doesn't work. The cost of launch utterly WIPES OUT any hope of income. Look, rockets are expensive, electricity isn't. That's all there is to it.
Want numbers? Fine:
http://matter2energy.wordpress.com/2009/06/12/space-power/
> Seems to me like you're going to have the same parasitic losses.
Some wavelengths get through clouds better. Microwaves are best. Given that it's warmer on cloudy nights due to IR reflection, the IR doesn't strike me as a good selection - perhaps there's a few holes in there they want to use.
Not that it makes a difference. For the price of the rocket you need to launch one panel, you can buy hundreds of panels. That will generate hundreds of times the power. It's an utterly stupid concept.
Maury
As with almost every other Gundam, the designs were cribbed from actual research. 0079 had the O'Neill Cylinders (with higher spin rates for dramatic effect), Wing had pairs of linked counter-rotating ring stations (artificially lit rather than using chevron mirrors, IIRC), Turn-A had a hypervelocity skyhook (and a linac boost up to it), 00 had the aforementioned solar power ring concept, as well as a slightly upsized Bernoulli Sphere station.
I've said it before and I'll say it again: orbital solar makes no economic sense. You get 4 times the power capacity for a given amount of solar panel surface area, compared to building in a desert somewhere, at a mere thousand times the cost! Maybe someday it will make sense, but not any time soon.
Now there is an exception to this: if you've got an efficient system for sending power down to a ground station then there is potential for power distribution to remote sites. The US military would love this, as it would eliminate much of the insatiable thirst for diesel in places like Afghanistan and simplify their logistics enormously. But even for this why would you want to build a big heavy satellite with huge solar panels? Just build a satellite that picks up power from a base station and beams it back down. Simpler, cheaper and more reliable.
It costs roughly 10,000$/kg to launch all the materials used in these orbital solar power stations. There is simply no way that it is cheaper to launch solar panels into orbit at that cost than to build a set of mirrors to focus solar energy on to solar panels or using it to crack water using one of the many thermochemical cycles that exist and using that to make fuel or run the produced Hydrogen through a fuel cell.
Sigs are too short to say anything truly profound so read the above post instead.
Well, yes and no. They are going to have SOME parasitic losses, but certainly not the same ones.
Let's assume they do this in the desert somewhere, where there are only exceptionally rare clouds in the way and parasitic losses are relatively low (both for land-based solar and orbital solar). The parasitic losses attributable to the atmosphere would be approximately the same, except that the satellite doing the actual transmission to Earth would likely be in a geosynchronous orbit exactly over the receiving target, which means you'll have minimal atmospheric interference. I'm not an atmospheric expert, but I thought there was also some benefit to having a stronger/denser beam trying to penetrate the atmosphere (tended to have lower loss than a less-coherent beam).
Add to that the fact that the actual collector (or collectors) can be in a different orbit where there is no loss of sunlight, ever, and can be positioned so that the solar panels are getting maximum solar efficiency continuously. The best of Earth-based solar arrays need some sort of motorized mechanism to keep them pointed at the Sun during the course of the day, and will get maybe 10-11 hours of decent sun and only a few hours of peak sun in a given day. You easily double, or more, your yield from such a system as opposed to building it on Earth. Solar collector arrays can be built with almost no support materials and can be made FAR larger than you could possibly do practically on Earth. And, other than a collecting station here and there, no one has to give up viable, farmable, or environmentally sensitive land.
Sure, it's going to be expensive to put the little devils in orbit, but you can build them using fewer materials, they'll run at peak capacity continuously, and no one ever complained that the Great Left-Pawed Spotted Marmaset was found only at Lagrange-2 so you'll have to stop construction.
"This post contains words, known to the State of California to cause thought. Wash brain thoroughly after reading."
The first one, and associated infrastructure, costs a fortune. However, after that, your only costs are ongoing personnel costs, O&M., and the cost of new ground stations. Because the powersat-production infrastructure remains intact in orbit.
Additionally, you don't have to use silicon or other semi-conductor photocells for power: you could set up mirror arrays to concentrate sunlight on a working fluid, to heat it, and run the resulting heated gas through turbines for power generation. Obviously, you'd need a closed-loop system for that, but with large mirror arrays, behind each would be an area completely out of sunlight, and ideal for heat sinks for cooling the gases back to fluid for re-use in the cycle. . .
The economics of payback are actually not that bad: ~20 years for capital payback, and all profit from that point on. . .
That doesn't make sense. The whole point of putting them in space is that they work better there. So if you had 1 panel in space and 100 on the ground, I don't know what the real ratio would be but it'd clearly not be 1:100.
Astrium isn't exactly a fly by night outfit. If they think they can get the numbers to where a panel in space is significantly more efficient than on the ground, it may not matter that it costs a lot to launch as the launch costs can be amortized over the lifetime of the satellite, the expected future cost of energy and so on.
Hundreds? Try tens of thousands. The cheapest launch vehicle that can put a satellite in orbit that I could find costs $12 million per launch. For that price, I can buy almost 22,000 Kyocera solar panels that produce 205 watts apiece. That's at retail with the only discount being from buying them in 20-packs. That's approximately 4.5 megawatts of power generating capacity that could be paid for just by the cost of the launch. Even if you could get 100% efficiency in your transfer (impossible), this would still mean that your bird would have to provide over 4,000 panels in orbit, for a total of almost 70,000 square feet just to provide as much power as the panels you could have put up on the ground for that amount of money, not counting the cost of the the panels in space and the satellite itself. That's roughly the total panel square footage for the entire set of ISS panels. I don't think you could launch anywhere near that much mass on the $12M launch platform.
But wait, there's more. Solar panels designed for use on Earth are rigid. This allows you to build in efficiency that probably cannot be achieved in a space-style roll-out set of panels. Instead of generating just shy of 4.5 MW, the ISS's panels only generate 120 kW. Admittedly, that's in LEO and not at a full geostationary orbit, but even factoring in 24 hours of light per day instead of about 8-10 hours of full-sun-equivalent light, and even if there were a factor of 2 or 3 difference in efficiency between LEO and geosynchronous orbit, you'd still barely break even per square foot compared with panels down on the surface. So even if the satellite were free, it would not be possible to even cover the launch costs of the cheapest, smallest delivery vehicle with a satellite that's so big that it would require the largest delivery vehicle to get it into space.
And it just keeps getting worse. Even if you could magically get launch costs down and could find a way to use deploy newer, higher-efficiency panels in space, you still have the problem of solar winds. The larger your solar panel array in true outer space, the more you are affected by solar winds. ISS gets away with having such large panels because it is in LEO and is thus protected by the amount of atmosphere present. Unfortunately, because LEO is inherently not geostationary, such an orbit would be unusable as a source for power on the ground. At geostationary orbital altitudes, that much square footage would be a serious problem. A typical satellite has mere hundreds of square feet of panels, or about three orders of magnitude less than what would be required to break even.
To put it in perspective, there have been solar sail spacecraft with proposed total sail area of high single digit thousands of square feet. Realistically speaking, we're probably talking about several hundred thousand square feet of panels (10+ football fields) to achieve any useful profit in space.
I am not a physicist, so these numbers could be completely wrong. That said, my quick back-of-the-napkin (err... Google) math says that you wouldn't even get it completely unfolded before you would be so far out of orbit that the satellite would be useless. If you had... say 80% of the ~4570 mPa of radiation pressure reflected (solar panels being 20% efficient or thereabouts), you'd be talking about almost 3700 mPa of pressure, which multiplied by a 70,000 square feet area gives me about 24,000 Newtons, or over 5,300 pounds of force. Now granted if your orbit is stable enough, this will be balanced out by pushing you closer to Earth while you're between it and the sun, but even if it's as heavy as ISS, you're talking about over .06 m/s^2 acceleration, or almost 2,800 meters per second after a 12 hour half orbit. If you could stay in orbit at all, I don't think you'd even approach being geostationary....
As they say, the difference between theory and practice is that in theory, there is no difference between theory and practice. I firmly believe that the whole "solar power in space" thing is just a giant pump-and-dump scam.
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If EADS and the others had a brain, they would skip the beaming of power down, and instead developed a means of sending power to orbit first (useful for sending power to the ISS or other sats; it will require ultra caps up there), AND develop a way to relay the energy. The relay would be useful on a plane for the DOD (sending power to forward bases) as well as for disaster areas. FOr example, think Haiti. Think Katrina. Think Ca last week. By being able to put a drone up with infrared sending power to it, and then beam it down via multiple signals, it would allow real power tools to be brought in. We have seen the walking skeletons (aka alien), and the ability to lift things. Think of how useful that concept would be in Haiti right now.
Once you get beaming of power around, THEN, it becomes useful to put solar cells into space. Personally, I would put it around mars and the moon first. Have 2 or three sats providing power, to beam down to missions with ultra-caps.
I prefer the "u" in honour as it seems to be missing these days.
All your math and reasoning is sound, this proposal makes *zero* economic sense for the general civilian electricity market (most cases). But I think, from what they are shooting for as customers eventually, that this won't matter as much, the cost part. They are defense and space contractors and what they want to build is a near-virtual instant completely mobile power plant, and sell that service to governments/militaries. ex: All of a sudden they need a megawatt or three of reliable power over here behind this sand dune in east ashcanistan, they need a lot of power. they need it *today*. Try to truck or fly in the all hardware plus fuel for the whole plant, directly through "bad guy" territory, get it set up and running, or only have to have a smaller receiver station, perhaps delivered in one fast helo load? I think that's the real target and business model.
Another use would be for disaster relief, a fast big power supply at the scene. Situations like that can justify a higher cost and being highly mobile.
I was reading last month or so ago what it costs to run fuel generators in ashcanistan out in the boonies there..man..it winds up costing them something like 400 bucks a gallon to get fuel delivered. The cost is hugemongous to run those gennies in some circumstances then. This thing might actually turn out to be cheaper for extreme niche purposes like that.
Of course, on the other hand.. I don't care what they say, a huge electricity source in space, connected to a wicked powerful laser with precise aiming abilities...they can *claim* it ain't a weapon all day long...;)