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Astrium Hopes To Test Grabbing Solar Energy From Orbit

timothy posted more than 4 years ago | from the don't-stand-underneath-when-they-fly-by dept.

Power 144

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.'"

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144 comments

uhh... (2, Interesting)

girlintraining (1395911) | more than 4 years ago | (#30849130)

...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.

Re:uhh... (5, Funny)

Anonymous Coward | more than 4 years ago | (#30849374)

They are completely unsafe. Even a slight failure to focus the beam would destroy a huge area of land, kill thousands of people, and cause millions in damage. This analysis is based on my highly technical computer simulation [wikipedia.org] .

Re:uhh... (1, Informative)

Anonymous Coward | more than 4 years ago | (#30849602)

No no, that was using microwaves, not infrared rays!

Re:uhh... (0)

Anonymous Coward | more than 4 years ago | (#30849644)

Well-played, sir.

Re:uhh... (1)

Un pobre guey (593801) | more than 4 years ago | (#30849766)

A multi-megawatt infrared laser beam aimed at a small location on earth from a free-falling object a couple hundred miles away. All together now:
What could possibly go wrong?

Re:uhh... (1)

LehiNephi (695428) | more than 4 years ago | (#30849898)

Then why not put the collector somewhere offshore, and run a high-voltage cable to the onshore grid? Oil platforms already do this.

Re:uhh... (1)

TheKidWho (705796) | more than 4 years ago | (#30849936)

Everything and anything could go wrong if an idiot like you designed it, thankfully or at least hopefully the guys at EADS Astrium aren't idiots.

Re:uhh... (1)

asdf7890 (1518587) | more than 4 years ago | (#30850122)

The project will be compose of the lowest bidders for each constituent part. I find you *abundance* of faith disturbing!

Re:uhh... (5, Insightful)

ZorbaTHut (126196) | more than 4 years ago | (#30850786)

You know what I always think is kind of weird?

People have this view of big-business as being this lumbering creature trying to save a cent everywhere they possibly can. Remove safety here, cut corners there, as long as it works for five minutes after it's sold, it's good enough. And, yes, in some ways this is justified. But on the other hand, this same technique is used everywhere - everywhere - in skyscrapers, in cargo ships, in the ridiculously complicated personal computer that you are using right now to read this.

We know how to manage risk, and we know how to manage safety. We can make things exactly as safe as we want to, assuming we're willing to pay the money.

We live in a world where we combust petrochemicals inside high-precision aluminum devices to fling multi-ton metal boxes around many times faster than we can run. When we get to our destination we purchase mass-produced foodstuffs, many of which have never been inspected by humans. We go to work in megaton cages of steel and concrete, sometimes in areas where the ground itself is known to shake with deadly force, and we sit there eating our food while sitting mere feet from copper cables carrying enough electricity to kill us a hundred times over, protected only by drywall and rubber insulation.

All of these things were provided by the lowest bidder.

And then we go home and complain about the scary new lasers and how people don't make things like they used to, damn them, they'll destroy us all, if only they didn't cut corners.

I dunno. Somehow I'm just not all that worried.

Re:uhh... (1)

Firedog (230345) | more than 4 years ago | (#30851844)

Sometimes things do manage to work out for the best.

But then, you discover that your child's toys are full of lead (or worse, cadmium [cbsnews.com] ), that practically all canned foods contain BPA [consumerreports.org] , and that building codes are sometimes ignored, especially in countries like Haiti [tulsabeacon.com] .

You definitely want to make sure that the multi-ton metal box you ride around in is not provided by the lowest bidder [youtube.com] .

And maybe those mass-produced foodstuffs are truly scary [nytimes.com] , and really shouldn't be called foodstuffs.

I, for one, am worried.

Safety (1)

DanielRavenNest (107550) | more than 4 years ago | (#30849542)

Its about as dangerous as the inside of a coal fired plant boiler - ie not a good place to stand, if they used a high intensity beam. They probably wont though. Although some solar cells on the ground receiving end can take 400 suns intensity, they require active cooling or they melt (very much the same as CPUs in computers, and roughly the same energy per area). If your cooling failed, you would damage your reciever, so it would be an expensive repair.

The point of solar from space is that you get around 5x as much sunlight to work with up there (less nighttime, clouds, and atmosphere absorption). So if the extra costs of putting it up there are less than 5x as high, you are ahead by putting it in space. If not, you are better off putting it on the ground.

For certain uses like the military, even an expensive, but *steerable* power source is a big win over using trucks carrying fuel.

And since power in space is currently a lot more valuble than on the ground, a first experiment should be to beam power *up*, for example to add extra power to the Space Station, or to test out that nifty VASIMR plasma thruster, they eat lots of power. Power on board the Space station runs $140/kWh, around 1000x what it sells for on the ground, so sending it *up* makes economic sense.

Re:Safety (1)

LehiNephi (695428) | more than 4 years ago | (#30849870)

Current satellites use solar panels for power. If you beam power up from earth, you're going to need....solar panels to collect it. If the solar panels can handle more light than they currently get from direct solar radiation, you might be onto something. Considering that most of the diffraction/refraction/scattering of light happens in the first few miles of atmosphere, it seems to me that light beamed up from earth would be scattered far more than light beamed to earth from space.

Re:Safety (1)

TheKidWho (705796) | more than 4 years ago | (#30850022)

Except for the fact that it's rather difficult to send power to a satellite that is orbiting at LEO... You know, orbital mechanics and all.

Space Station Power (1)

DanielRavenNest (107550) | more than 4 years ago | (#30851680)

You would use the same solar panels they have there now, but since the Station is in the earth's shadow 40% of the time, they don't generate power currently during part of the orbit. And by bypassing the batteries on the truss, you also gain from not having the battery conversion losses, so its possible to get around a 2x total power increase.

@LehiNephi - The Space Station is a big enough target that atmospheric distortion is not a problem. At that altitude you would be able to see a target about 1.5m across without adaptive optics, and the station is a lot larger than that.

@TheKidWho - yes, a single ground station does not provide coverage of much of the Station's ground track. But remember that each of the 4 solar arrays on the station cost $300million, even a small increase in power would pay for a lot of overgrown searchlights. Because the target is so large, your optics on the ground does not have to be as good as a telescope, somewhat better than those big searchlights they use for store openings will work.

The space station is typically 1 arc minute across when seen from the ground, which is about the same resolution as the human eye, or about 1/30 the width of the moon, its a big target.

Ring around the Earth!!!! (0, Offtopic)

jameskojiro (705701) | more than 4 years ago | (#30849134)

I would like a Ring around the earth like they had in the series Gundam 00. With three main towers to beyond Geo sync, and fricking huge!!! Of course if one of the towers should fail.... LOOK OUT BELOW!!!!

Don't build cities in the orbital direction of the towers on the ground, cause it sucks to be them.....

Re:Ring around the Earth!!!! (3, Interesting)

EdZ (755139) | more than 4 years ago | (#30849328)

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.

maturity? (4, Insightful)

Lord Ender (156273) | more than 4 years ago | (#30849158)

It may be close to proving is viability, but there's no way anyone has any business calling this not-even-prototyped tech "mature."

Re:maturity? (1)

shabtai87 (1715592) | more than 4 years ago | (#30849268)

Agreed. That term definitely not applicable here. maturity for a technology implies quite a few working revisions, ending in a better performance (by whatever metric is applicable) and a certain integration into society.

Umm.... (1, Offtopic)

ExE122 (954104) | more than 4 years ago | (#30849162)

system would collect the Sun's energy and transmit it to Earth via an infrared laser, to provide electricity

To "provide electricity" or to "discuss the location of the hidden rebel base"?

Is anyone else scared?

Ooh, scary (2, Interesting)

Deosyne (92713) | more than 4 years ago | (#30849188)

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.

Re:Ooh, scary (1)

GiveBenADollar (1722738) | more than 4 years ago | (#30849564)

Well considering the satellites need to beam the power down to earth based generation stations and these earth based stations will need to be close to population centers to avoid transmission losses, there is a reason to be afraid of this technology.

"Astrium says the latter can be addressed by using infrared lasers which, if misdirected, would not risk "cooking" anyone in their path."

So a 20kw microwave beam can cook you, but a 20kw infrared beam will feel like getting hit by fluffy bunnies? If you are transmitting large amounts of power it will be dangerous. If it's a wide beam then it is inefficient but less dangerous, if it is a narrow beam then it is more efficient but more dangerous. I can only imagine the public outcry the first time an aircraft runs into one of these beams.

We still have nothing showing that this technology has the potential to be cheaper than earth based solar.

I don't see how this can be efficient ... (1)

BitZtream (692029) | more than 4 years ago | (#30849192)

Why is it that we can put something in orbit to avoid the atmosphere losses, but then beam it down through the same atmosphere they are avoiding in order to use it on the ground.

Seems to me like you're going to have the same parasitic losses.

Re:I don't see how this can be efficient ... (3, Interesting)

Maury Markowitz (452832) | more than 4 years ago | (#30849326)

> 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

Re:I don't see how this can be efficient ... (4, Interesting)

Salgak1 (20136) | more than 4 years ago | (#30849806)

Actually, the efficiency comes if you build in-orbit from indigenous materials. The classic powersat concept generally involves lunar regolith mining, launch to low Lunar orbit via magnetic mass-driver, and solar smelting in orbit.

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. . .

Re:I don't see how this can be efficient ... (2, Informative)

IamTheRealMike (537420) | more than 4 years ago | (#30849838)

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.

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.

Re:I don't see how this can be efficient ... (2, Interesting)

dgatwood (11270) | more than 4 years ago | (#30850902)

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.

Re:I don't see how this can be efficient ... (0)

Anonymous Coward | more than 4 years ago | (#30849474)

Part of the reasoning is that if you place it in the right orbit you can get on your panels for 24 hours a day.

Re:I don't see how this can be efficient ... (1)

Maury Markowitz (452832) | more than 4 years ago | (#30849684)

> Part of the reasoning is that if you place it in the right orbit you can get on your panels for 24 hours a day

Which is twice what you get on Earth (think about it, night, day). Now factor in that the panels last about 1/2 the lifetime that they do on Earth. The math isn't looking good, is it?

So maybe you don't know much about the real world of power supplies, and think that the arguments about "base load" aren't the total load of rubbish that they are. In that case, I 100% guarantee you that you can built two panels and the wire all the way across the ocean for less money than it costs to launch one set into space.

Maury

Re:I don't see how this can be efficient ... (1)

ppanon (16583) | more than 4 years ago | (#30850426)

I 100% guarantee you that you can built two panels and the wire all the way across the ocean for less money than it costs to launch one set into space.

Looks like you forgot to take into account transmission loss [wikipedia.org] through wires. Now, you're going to get conversion loss in your IR laser beaming at the source and destination, as well well as some transmission loss through the atmosphere, but that number is going to be fixed no matter what the orbit. Conversely 20,000 kilometers of wire leads to some pretty hefty power loss if it's not superconducting wire, and some pretty significant construction and ongoing cooling costs, particularly underwater, if you're planning on using superconducting cable. This isn't a fiber optic telco cable you're talking about.

Re:I don't see how this can be efficient ... (1)

ppanon (16583) | more than 4 years ago | (#30850514)

Oops, a better article [wikipedia.org] on transmission loss. With a 3% transmission loss per 1000km, that's about a 46% loss over 20,000km. So you're going to need 4 panels on the other side of the planet, not 2.

Re:I don't see how this can be efficient ... (1)

Maury Markowitz (452832) | more than 4 years ago | (#30851562)

If you start off roughly equal, things aren't going well. Everything else is the small end of the stick.

> Looks like you forgot to take into account transmission loss

Transmission losses on 768 kVDC lines are about 2% per 1000 km. About 10% losses across the Atlantic. Transmission losses from space are 20% in the best case, and 50% in the common case.

So no, I didn't forget to take this into account. I deliberately ignored it, because it makes things worse for space power.

Any other things you think I've forgot to mention? I'm sure they make the economics worse as well.

Maury

Re:I don't see how this can be efficient ... (3, Interesting)

natehoy (1608657) | more than 4 years ago | (#30849620)

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.

Why use lasers? (3, Interesting)

NotBornYesterday (1093817) | more than 4 years ago | (#30849194)

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.

Re:Why use lasers? (1)

wizardforce (1005805) | more than 4 years ago | (#30849300)

That is precisely what I was thinking. Converting solar energy to electrical energy and then back into infrared and finally converting that infrared light back into electricity sounds to me to be extremely inefficient. Secondly, the infrared laser would probably need to be pretty powerful to transmit the power to the surface of the Earth which seems dangerous as well. It only takes a laser that has a power of a few watts/cm^2 to set fire to things and here we're talking about much much more power being spread over a presumably small area. Microwave beaming is more efficient and safer as you can use a microwave band that isn't terribly absorbed by the atmosphere or the water that is in living things.

Re:Why use lasers? (2, Informative)

bughunter (10093) | more than 4 years ago | (#30850456)

There are large windows in the atmospheric infrared absorption spectrum [wikipedia.org] suitable for transmitting IR signals and power.

It's not transmission efficiency so much as conversion efficiency, and overall system cost. IR is about equivalent to microwave, and getting better, whereas microwave is essentially mature.

Microwave comes to mind first because back in the 1950's and 60's when these ideas were first proposed, microwave was the best tech, but not any longer.

Re:Why use lasers? (1)

Lord Ender (156273) | more than 4 years ago | (#30849364)

It is easier to get bonus grant money from the War industry if you have the possibility of repurposing your power plant into a ship-sinking, building-burning space laser.

Re:Why use lasers? (1, Funny)

NotBornYesterday (1093817) | more than 4 years ago | (#30849468)

That's all well and good, but where the hell are they going to get a shark big enough to mount such a large laser?

Re:Why use lasers? (1)

jbezorg (1263978) | more than 4 years ago | (#30849746)

Then get the huge shark into orbit.

No! It could be a robotic shark built in space!....

( thus laying the groundwork to "Tinfins 2" the sea-quel )

Re:Why use lasers? (1)

Salgak1 (20136) | more than 4 years ago | (#30849846)

Who says you need light to do it ? A sufficiently-focused microwave beam would do the trick, AND be invisible. All you have to do is package it as the Orbital Death-Ray, and . . . Profit!!!

Re:Why use lasers? (1)

Hurricane78 (562437) | more than 4 years ago | (#30849882)

Wouldn’t it be better, to just shoot a huge parabolic mirror into space? Weighs less, easily replaced, and if properly focused (perhaps with a lightweight fresnel lens at the right position, it could e.g. heat a large bulb of water on earth, or something like that.

But, yes, I don’t know how much the athmosphere would filter them.
But I also don’t know it the sun actually emits other types of waves too, that are strong enough to be used. Because it doesn’t have to be a mirror for light, does it? :)

Re:Why use lasers? (0)

Anonymous Coward | more than 4 years ago | (#30850052)

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.

You are looking at it the wrong way. You want to work out a way to purposefully fry things on the ground, and then get the military to fund it. Anything accurate enough to fry things is accurate enough to keep away from them, with several orders of magnitude of safety built in.

Re:Why use lasers? (3, Informative)

bughunter (10093) | more than 4 years ago | (#30850284)

Why use lasers?

Conversion efficiency. Lifetime. Environmental suitability. Potential for technology insertion and incremental improvements.

The magnetron, while efficient at converting electrical power to microwave, is being surpassed by the VECSEL solid-state IR laser in efficiency. Both are about 70-75% efficient, but magnetrons are a rather old, very mature technology whereas solid state lasers are still maturing. Magnetrons are at their limit; solid-state lasers still have room for improvement.

And solid state devices can more easily be made to have a long service lifetime and to tolerate being shaken nearly to death on top of a rocket than magnetrons can. These are satellite applications, so reliability, service life and ruggedness are very important requirements.

For conversion back to electrons, I'm not so sure of that trade, but I trust they factored that in. IR is quite suitable mainly because a microwave transducers have some fundamental drawbacks. A microwave receiver is a bolometer, or bolometer array, which works best when incident power is focused on a nonlinear element, so some sort of refractive "lens" element will be needed, most likely an array of refractive concentrators. In the infrared, however, photovoltaic cells can be distributed over a wide area - and again, they are a maturing technology that is getting cheaper and more efficient with time... all in all I'm not surprised they chose IR.

Isn't this loading more heat onto Earth? (3, Interesting)

presidenteloco (659168) | more than 4 years ago | (#30849218)

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?

Re:Isn't this loading more heat onto Earth? (1)

Monkeedude1212 (1560403) | more than 4 years ago | (#30849310)

Not if that heat is being turned into energy. Depends on how much waste heat is produced by this, but since we haven't tried it, we don't know.

Re:Isn't this loading more heat onto Earth? (1)

natehoy (1608657) | more than 4 years ago | (#30849948)

And when you use that energy, what do you get? Heat. All energy eventually becomes heat. This will be a net heat increase on Earth.

Fortunately, it's a net heat increase that doesn't also release heat-trapping pollutants or heat-absorbing particulates like fossil fuels do, so the excess heat will have the opportunity to radiate out of the atmosphere.

Re:Isn't this loading more heat onto Earth? (1)

newcastlejon (1483695) | more than 4 years ago | (#30850212)

Heat is Energy. In fact every bit of waste energy ends up as heat.

The OP point stands: we are directing energy at the Earth that wouldn't have otherwise got there.

While the question of whether this will be offset by a reduction in greenhouse gas emissions remains, we are still adding energy to the ecosystem.

Re:Isn't this loading more heat onto Earth? (1)

sznupi (719324) | more than 4 years ago | (#30849360)

It will certainly add much less "heat" to Earth then the majority of ways in which we are obtaining energy, for given energy amount.

The reason is that in case of such satellite system (or pretty much any "renewable" energy source), the added energy comes only from losses or the final work done with the energy.

Whereas in the case of fossil fuels the most significant, by far, addition of energy to Earth comes not from losses or work output, but from changing the atmosphere, in a way that it captures more heat from the Sun.

Re:Isn't this loading more heat onto Earth? (2, Insightful)

pixelpusher220 (529617) | more than 4 years ago | (#30849434)

As you say, the problem is not extra energy being added to Earth, but the reduction in the amount of heat energy being allowed to leave earth.

If by adding the energy in the proposed manner we can stop the extra CO2 from being added to the atmosphere, then likely the extra energy would just radiate into space.

And since you're wondering, the amount of extra energy being grabbed pales in comparison to the amount of energy already hitting the earth. These panels aren't going to be even a tiny fraction of the size of the earth.

Re:Isn't this loading more heat onto Earth? (1)

tagno25 (1518033) | more than 4 years ago | (#30849582)

And since you're wondering, the amount of extra energy being grabbed pales in comparison to the amount of energy already hitting the earth. These panels aren't going to be even a tiny fraction of the size of the earth.

Why not have two panels, one at ~.5AU and one near one of the poles of earth, both orbiting the sun. Panel one sends a large amount of energy to panel two which then transmits it to a station in a relatively unpopulated location.

Re:Isn't this loading more heat onto Earth? (1)

pixelpusher220 (529617) | more than 4 years ago | (#30849770)

not quite sure what you're responding too but here goes:

The power needs to be beamed to a location reasonably close to where it will be used. The transmission from the ground station out to the end-users still has the same loss rates as current power plants.

My point was that unless the solar panels are the size of a continent they aren't going to be adding significantly more energy to the earth than is already being added right now.

Re:Isn't this loading more heat onto Earth? (1)

CrimsonAvenger (580665) | more than 4 years ago | (#30849908)

Why not have two panels, one at ~.5AU and one near one of the poles of earth, both orbiting the sun. Panel one sends a large amount of energy to panel two which then transmits it to a station in a relatively unpopulated location.

Because the panel at 0.5AU would be moving relative to Earth?

Because sometimes it would be behind the sun, and sometimes it would be 1.5 AU from the Earth? And most of the time it would be ~1 AU from Earth?

Because maintenance on something that far away would be anightmare?

And because it's completely unnecessary?

Re:Isn't this loading more heat onto Earth? (1)

Muros (1167213) | more than 4 years ago | (#30849646)

I don't imagine it would be a problem. Humans use a very small portion of the energy that we get from the sun, thus even replacing all current power requirements with a scheme like this is only slightly increasing the earths total energy input. And, the more energy there is sloshing around, the more the earth radiates back into space. The problem with greenhouse gasses, as you said, is that they trap radiation, and they are merely a byproduct of fossil fuel consumption. We will have the same amount of energy entering the atmosphere either way, as the energy stored chemically in fossil fuels doesn't affect climate in any way when it's buried underground.

Re:Isn't this loading more heat onto Earth? (1)

jhfry (829244) | more than 4 years ago | (#30849950)

I started to do the calculations, and the numbers became so huge that I decided just to put it this way...

Such an enormous amount of solar energy strikes the earth already, that you could beam our entire energy supply in and it would be absorbed by a rounding error when calculating the increase in solar energy caused by the technology. And it would be easily offset by the reduction in energy released by fossil fuel use.

What will they do at night? (0)

Anonymous Coward | more than 4 years ago | (#30849222)

When their line of sight is obscured by the polish air force landing on the sun?

Working out the bugs (1)

Nebulious (1241096) | more than 4 years ago | (#30849270)

"Critics, though, have always pointed to multiple hurdles - to the cost of launching and assembling large solar stations in orbit, to the losses in efficiency in conversion, and to the safety issues surrounding some wireless transmission methods, particularly those that use microwaves.

Astrium says the latter can be addressed by using infrared lasers which, if misdirected, would not risk "cooking" anyone in their path."

I got a great laugh out of that one. A+ journalism!

This DOES NOT COMPUTE (3, Insightful)

Maury Markowitz (452832) | more than 4 years ago | (#30849282)

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/

Re:This DOES NOT COMPUTE (2, Interesting)

Darth Sdlavrot (1614139) | more than 4 years ago | (#30849394)

At $5000 per pound maybe. How about at $250 per pound?

http://science.slashdot.org/story/10/01/16/0015238/A-Space-Cannon-That-Might-Actually-Work?from=rss [slashdot.org]

Re:This DOES NOT COMPUTE (1)

wizardforce (1005805) | more than 4 years ago | (#30849544)

I'm sure you could build some really cool mirrors to focus solar power on to some soalr panels for less than that.

Re:This DOES NOT COMPUTE (2, Interesting)

Maury Markowitz (452832) | more than 4 years ago | (#30849624)

> How about at $250 per pound?

DO THE MATH. Sheesh.

The panels I use are 20 kg for 200 to 220 watts. That's 10 watts per kg, or 5 watts per pound.

In Toronto, you get 1250 kWh per year 1000 kW installed. So about 1.2 wh per w.

So that's about 6 wh per pound.

I get paid the utterly ridiculous price of 80 cents a kWh for this power. That's 0.08 cents per wh.

So that's just under 50 cents a year per pound.

With me so far? Ok, let's keep going...

On Earth I have an expected lifetime of at least 20 years, and 25 is more common. So each pound of panel will generate 10 dollars over its lifetime.

In space I get about 5 times the power, but losses are higher, and panel lifetime is about 12 years. I use 4 times as much power as an Earth based panel as a good estimate. So that means that same pound of panels will generate a whopping 25 dollars over its lifetime.

Sooo, does 25 dollars pay off the 250 dollar launch costs?

Does that answer your question?

Maury

Re:This DOES NOT COMPUTE (0)

Anonymous Coward | more than 4 years ago | (#30852042)

Your calculation left out the cost difference of leasing a small plot of land for the microwave receiver vs. leasing a much larger plot of land for the equivalent number of solar panels. Your example is based on your house which you already own or rent so no additional land was needed, unlike a commercial solar installation.

Why don't we just sit back and wait to see if they manage to turn a profit? Neither you or I will pay the price if the venture fails.

Re:This DOES NOT COMPUTE (2, Insightful)

pixelpusher220 (529617) | more than 4 years ago | (#30849534)

well electricity is only 'not expensive' if you don't account for the 'cost' of the CO2 (and other pollutants) being released. Just like if I dump my waste into the river, the 'cost' isn't borne by me, but by anyone downstream. To me it's cheap.

What is the cost of global warming? How much do you amortize against the fossil fuels? We frankly don't know yet, but many indications are that it's going to be a massively significant amount. If 400 million people need to relocate because of sea-level rise, you want to put a cost estimate on that? Or just take Florida if that's easier to understand, how much to relocate 1/2 the state?

Re:This DOES NOT COMPUTE (2, Insightful)

Maury Markowitz (452832) | more than 4 years ago | (#30849730)

> don't account for the 'cost' of the CO2

Which might be a good argument (but isn't) if you're comparing a solar panel in space with a coal plant on Earth. But I'm comparing a solar panel in space with a solar panel on Earth. There's no hidden cost to hide behind.

Besides, have you ever seen a rocket? Not exactly green power!

Maury

Re:This DOES NOT COMPUTE (1)

tagno25 (1518033) | more than 4 years ago | (#30849790)

Besides, have you ever seen a rocket? Not exactly green power!

Maury

Maybe if it is a solid state rocket, but aren't most rockets liquid fuel now a days and isn't the liquid hydrogen and oxygen?

Re:This DOES NOT COMPUTE (1)

Maury Markowitz (452832) | more than 4 years ago | (#30849872)

> isn't the liquid hydrogen and oxygen

At huge PSI's and temperatures. The exhaust will rot out your lungs. Besides, every major launch platform also uses solids.

Maury

Re:This DOES NOT COMPUTE (1)

CrimsonAvenger (580665) | more than 4 years ago | (#30849990)

Maybe if it is a solid state rocket, but aren't most rockets liquid fuel now a days and isn't the liquid hydrogen and oxygen?

Yes and no, in that order. Most rockets are liquid fuel (but most of them have solid boosters in one form or another), but most don't use H2/O2. Try kerosene/O2.

Re:This DOES NOT COMPUTE (0)

Anonymous Coward | more than 4 years ago | (#30851686)

Just because the fuel is hydrogen and oxygen doesn't mean the rocket is carbon neutral. Pure hydrogen and oxygen have to be generated somehow. That means large plants running on fossil fuels with a large workforce commuting by fossil fuel burning vehicles, shipments arriving and leaving by fossil fuel burning trucks and trains and ships, etc.

Hydrogen is not an energy source, it's an energy carrier. The source of the energy might be solar or wind or geothermal or nuclear, or it might just be coal or gas or oil.

Re:This DOES NOT COMPUTE (1)

pixelpusher220 (529617) | more than 4 years ago | (#30850092)

I'm comparing a solar panel in space with a solar panel on Earth

Fair enough. But then you also need to factor in the cost of either a night time power supply or energy storage capabilities.

Plus, since northern latitudes don't really get great sun a good percent of the year, you'll need a way to provide them with the added power they'll need.

and cloudy places, power during dust storms, or anything else that might obstruct the terrestrial panels.

I agree it's a *very* ambitious plan that may or may not be feasible, but you do need to make sure the results are the same (full 24/hr power) before making a true comparison.

Besides, have you ever seen a rocket? Not exactly green power!

you mean like the H2+O2=H2O rocket that powers the space shuttle and Delta IVs? Obviously the Shuttle SRB's aren't exactly green but quite a bit of the Shuttle's thrust is actually quite green. (or at least could be assuming solar power to produce the H2 & O2)

Re:This DOES NOT COMPUTE (0)

Anonymous Coward | more than 4 years ago | (#30850134)

But I'm comparing a solar panel in space with a solar panel on Earth. There's no hidden cost to hide behind.

How green is solar panel on Earth really? Once the Sun's energy enter into the atmosphere, does it not belong to the Earth Eco system? Where ever you place the panel, even in desert, you are taking it away from the Earth. And as stated in the summary, those panel will be operating 24 hours a day, instead of variable depending on the weather.

Tsk, tsk. (0)

Anonymous Coward | more than 4 years ago | (#30850272)

You really think it's about energy?

Maybe I buy a new tin-foil hat... this time with a mirror-like finishing...

Re:This DOES NOT COMPUTE (2, Insightful)

BJ_Covert_Action (1499847) | more than 4 years ago | (#30850376)

Launch costs are dropping and will continue to do so as SpaceX, Orbital Sciences, and other commercial vendors start to compete in the industry. I don't know that the savings will be enough. But it is worth keeping in mind that space is going to become quite a bit more accessible in the next five to ten years. Also, if you took the time to assemble the orbital solar panels in a modular manner, the way it was done with the ISS (but using more robotic construction techniques in place of human ones), you could piggy back your component launch costs with other payloads thus further reducing launch costs. It may not be affordable right now, but again, never rule out the future.

Also, doing this type of thing at least once or twice would be interesting from an R&D and proof of concept standpoint alone. Perhaps the conclusion would be, "Right now it costs too much, we will need future technology to make something like this work." But, trying it out will give you much more hard data on what that future technology is and, possibly, how to develop it later. It will also force you to take those kinds of requirements into your mission design from the get go, thus providing valuable experience, knowledge, and science.

In short, the concept is not a total waste of time.

weapon (0)

Anonymous Coward | more than 4 years ago | (#30849294)

Sounds to me like the EU's attempt to get a weapon in space.

http://en.wikipedia.org/wiki/Die_Another_Day: The North Koreans already did it!

What's to test? (1)

Darth Sdlavrot (1614139) | more than 4 years ago | (#30849320)

We know we can collect/generate electricity from the Sun -- PV or steam driven turbine.

And we know we can transmit it (electricity) across long distances using microwave and/or infrared.

Isn't this just adding "from space" to the equation?

Not unlike adding "with a computer" or "over the internet" to a patent?

Re:What's to test? (1)

Maury Markowitz (452832) | more than 4 years ago | (#30849776)

Well let's see:

1) 100% of our efforts to build large lightweight structures in space have failed. We have no idea how to do this successfully.

2) we have nowhere near the launch capacity needed to put one of these up in a time frame less than decades.

3) what capacity we do have is FOUR ORDERS OF MAGNITUDE too expensive.

Other than that though... yeah, it's nothing more than adding "from space" to the equation...

Maury

Re:What's to test? (1)

Lithdren (605362) | more than 4 years ago | (#30850814)

Yeah! Same deal with going to 'Mars' or whatever that red blight in the sky is called. I mean, we've landed on the moon, its not like we got anything else to prove at this point, right?

Global Warming (1)

Ogive17 (691899) | more than 4 years ago | (#30849340)

Assuming this can be done efficiently enough to take large scale, wouldn't this actually contribute to global warming? We're taking energy that normally would not hit the planet, beaming it down to use as a cheap source of electricity, which then gets turn into heat.

Right? Or would we radiate enough heat out of the atmosphere if we could stop using fossil fuels to negate it?

Re:Global Warming (1)

sznupi (719324) | more than 4 years ago | (#30849478)

Global warming doesn't come from the energy we use. It comes from the massive amounts of energy from the Sun that doesn't escape back, because the composition of the atmosphere has changed; while conceptually this system would do something similar, it would have insanely higher ratio of the energy we use to the energy that simply gets trapped in the atmosphere due to its operation.

Re:Global Warming (1)

wizardforce (1005805) | more than 4 years ago | (#30849526)

Assuming this can be done efficiently enough to take large scale, wouldn't this actually contribute to global warming?

It's better than burning billions of tons of dirty coal to produce the same amount of power. Any extra warming from making use of this energy is completely dwarfed by several orders of magnitude by the warming caused by the CO2 produced by burning an amount of coal to replace the power from the solar power station.

Makes no sense (4, Insightful)

jpmorgan (517966) | more than 4 years ago | (#30849346)

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.

Re:Makes no sense (1)

MozeeToby (1163751) | more than 4 years ago | (#30849490)

Not that I'm really disagreeing with you, but you'll actually get around 8+ times the power capacity. 4 times for being above the atmosphere, 2 times for not having night to worry about (depending on your orbit). Throw in a bit more for cloudy days (assuming their transfer mechanism goes through with minimal losses. And combine that with the the kinds of super-efficient panels that are used for space technology, and you'll get a pretty significant increase.

Two things stand in the way as I see it. 1) Launch costs are just plain too high. Cut them to a 20th of what they are now and this idea might work. 2) Except for the day/night part, it should be possible to use the high efficiency solar panels on the ground, using mirrors to concentrate the light down to be just as, if not more intense, than in orbit. I can't imagine mirrors and a tracking mechanism are more expensive than a launch.

Re:Makes no sense (2, Interesting)

Maury Markowitz (452832) | more than 4 years ago | (#30849848)

> Not that I'm really disagreeing with you, but you'll actually get around 8+ times the power capacity

Bzzzt, wrong. Power density is about 15% greater in space. You get 2 times the hours of sunlight (day, night). You get about 20% more "clear sky" (Sites in Nevada have over 80% clear weather).

So it's more like 4 times, ignoring the 50% conversion and shipping costs, and the fact that the panels last only 12 years instead of 20+. If you consider those alone, a panel on the ground will generate some significant fraction of the power of the same panel in space.

Maury

Re:Makes no sense (0)

Anonymous Coward | more than 4 years ago | (#30850468)

What if you have no available land area for a massive solar farm? Like, say, Japan.

Re:Makes no sense (1)

noidentity (188756) | more than 4 years ago | (#30851566)

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.

Wait, you're suggesting that it's simpler to generate the power on Earth, beam it up to a satellite, then beam it back down to Earth? How are you going to have a small satellite that picks up this beamed power without losing alignment?

Trusting a municpal power generator to space?? (1)

filesiteguy (695431) | more than 4 years ago | (#30849358)

Though it seems like a cool idea, I cannot see how getting a power source in an unregulated (no laws) area like space would be beneficial.

Who's gonna be the first bean counter to get fired because he/she signed up for this new service then was unable to perform normal duties when the system was accidentally hit by a rock and there's no backup.

space power (2, Informative)

wizardforce (1005805) | more than 4 years ago | (#30849420)

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.

This idea seems really dumb for many reasons (1, Redundant)

rcb1974 (654474) | more than 4 years ago | (#30849584)

Why this is still a dumb idea:
  1. Cost/kWh: From the article "We have reached a point where, in the next five years, we could build something which is in the order of 10-20 kW to transmit useful energy to the ground." Are you kidding me? 10-20kW? Pfft. That is very little power -- thats like powering 3 or 4 houses. The cost of the energy, materials, and time to design, build, launch, maintain (ground based monitoring, ground based photodiodes used to capture the laser light), a system like this would probably all cost at least 150 million dollars. I doubt a satellite like this would last more than 50 years. 150 million bucks for 10-20kW? What kind of a joke is that. Ground based solar/wind would me much more cost effective and just as clean.
  2. Space Garbage: Do we really need more junk in geosynchronous orbit? Launching satellites may create space junk.
  3. Safety: Do we really want a high powered laser beam (10-20kW) continuously aimed at earth? What happens if the devices on the satellite that control orientation fail? Then the beam might hit something else if it wasn't immediately powered off. I don't care what wavelength of light is used -- microwaves, infrared, UV, whatever -- if it is sufficiently concentrated by the time it reaches the Earth's surface, it can be harmful/unsafe. This technology has military applications.
  4. Venture Capitalists, don't let yourselves be fooled...

Re:This idea seems really dumb for many reasons (1)

zaq1xsw2cde9 (608119) | more than 4 years ago | (#30849732)

  1. the 10-20kW satellite, is not the production satellite, that is the proof of concept satellite.
  2. Geosyncronous orbit would not really be good for this concept, as it would have darkness for some hours per day. perhaps a Lagrange point would be better? (I'm don't know anything about how hard it would be to put stuff in a Lagrange point)
  3. You could probably find frequencies that would minimize saftey problems, but it could ba a concern
  4. Venture Capitalist should always be careful.

Re:This idea seems really dumb for many reasons (1)

marcosdumay (620877) | more than 4 years ago | (#30850050)

Putting those things on a lagrange point is way (a few orders of magnitude) more expensive, way riskier, and would make it way harder to keep a laser colimated until it reaches Earth.

Re:This idea seems really dumb for many reasons (1)

Maury Markowitz (452832) | more than 4 years ago | (#30849856)

Space Garbage: Do we really need more junk in geosynchronous orbit? Launching satellites may create space junk.

I did this calculation too. For every 100 kWp you launch, you have a 40% chance of causing a Kessler Syndrome.

Maury

Popcorn (0)

Anonymous Coward | more than 4 years ago | (#30850996)

Do you have any idea how much popcorn the world's armed forces eat each year!

And why not nuclear? (1)

damasterwc (1247688) | more than 4 years ago | (#30850494)

There is a high-tech way to have clean, cheap energy. Everything was going great until hysteria set in in the 70s. Explain to me why a 1GW plant (with a 92% uptime unlike solar or wind) running on 7 lbs of thorium per day is not a universally accepted bipartisan plan? Why aren't we mass producing LFTRs [google.com] globally?? The LFTR, breeders, and other types of 4th generation reactors ARE the solution. Mass producing them and getting the technology ready is a lot more likely to happen than a "renewable" future or orbit solar energy. If the billions wasted in "alternative energy" research and subsidies were wisely invested into 4th gen nuclear technology things would look a lot better today.

Kind of a waste (2, Interesting)

WindBourne (631190) | more than 4 years ago | (#30851206)

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.

Free energy or Solar powered weapon ? (1)

Latinhypercube (935707) | more than 4 years ago | (#30851492)

Seriously is this Free energy or a Solar powered weapon ? How about transmitting the energy to Earth via powerful radio transmission ? So only a receiver at the correct frequency will absorb power, Tesla style...

Sacrificial Light (0)

Anonymous Coward | more than 4 years ago | (#30852094)

I can see some hundred or two hundred years in the future, bands of nomadic mutants push a captured maiden from the Vault into the "beam of light" to be purified....

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