Giant space laser

[Ravashak]

EADS Astrium develops space power concept
By Jonathan Amos
Science reporter, BBC News

Europe's biggest space company is seeking partners to fly a demonstration solar power mission in 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. However, there have always been question marks over its cost, efficiency and safety.

But Astrium believes the technology is close to proving its maturity.

"Today we are not at an operational stage; it's just a test," said chief executive officer Francois Auque. "In order to implement a solution, of course, we would need to find partnerships and to invest, to develop operational systems," he told BBC News.

Those partnerships could comprise space agencies, the EU or national governments and even power companies, he said.

'Safe' system

Space solar power is an attractive concept because it would be clean, inexhaustible, and available 24 hours a day.

The amount of energy falling on photovoltaic cells placed in orbit is considerably greater than the same solar panels positioned on the Earth's surface. In space, the incidence of light is unaffected by clouds, dust or the filtering effects of atmospheric gases.
Laser test (EADS Astrium)
Power transmission by laser is being studied in the lab

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.

The company has already tested power transmission via laser in its labs, and is now working on improving the efficiencies of the end-to-end system.

Necessary efficiency

Robert Laine, Astrium's chief technology officer, acknowledges however that there are still some big challenges to be overcome.

"Today, we will be limited in power by the size of the laser we can build. That's a prime limitation," he said.
Demonstrator (EADS Astrium)
The concept would need to be proven with a demonstration mission

"On the receive side, the conversion of this infrared energy into electricity - that's something which is progressing very fast and we are working with the University of Surrey [in the UK] to develop converters.

"The principle is to get a very high efficiency of conversion of the infrared [laser light] into electricity. If we achieve 80% then it's a real winner."

Dr Laine said a small demonstration of the technology ought to be ready for launch in the coming decade.

"Like any technology, someone has to demonstrate it first before it can become an operational system," he told BBC News.

"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."
Linkage (http://news.bbc.co.uk/2/hi/science/nature/8467472.stm)

So, the biggest of Europe's space companies is planning to test the idea for electricity.

Wonder how long it'll take before NASA will try something similar, but then BIGGER xP

[Osterbaum]

NASA will try out the same thing, except scratch the infrared idea and use microwaves instead. That way it could be used as a weapon against the infidels who do not believe in liberal democracy!

[Aerozord]

Infered or microwaves are irrelavent in this case. If its focused, which it should be. It would be ALOT of energy. Of course its cost inefficient as a weapon. Though I dont think it would be cost efficient as an energy source either. Granted avoiding the filtering of the atmosphere would help, but not sure it could collect enough energy. I mean thats the problem with our ground based ones

[Hanuman]

I don't get it, if we can't get a 1:1 ENERGY RATIO on earth, how can they expect to even hit 1:1 cost//energy ratio by launching it into space?
I mean, if we were talking mirror array into some sort of molten chamber then sure, but for just cells... you gotta bake more energy into them than they produce in their entire life.

That's why you don't see every dick and tom plastering free energy on their roof.

[01d55]

I don't get it, if we can't get a 1:1 ENERGY RATIO on earth, how can they expect to even hit 1:1 cost//energy ratio by launching it into space?
I mean, if we were talking mirror array into some sort of molten chamber then sure, but for just cells... you gotta bake more energy into them than they produce in their entire life.

That's why you don't see every dick and tom plastering free energy on their roof.
Modern panels pay back their energy cost in less than 5 years of use.
Crystalline silicon PV systems presently have energy pay-back times of 1.5-2 years for South-European locations and 2.7-3.5 yr for Middle-European locations. For silicon technology clear prospects for a reduction of energy input exist, and an energy pay-back of 1 year may be possible within a few years. Thin film technologies now have energy pay-back times in the range of 1-1.5 years (S.Europe).

As for satellites, the idea is to convert the visible light into a form of radiation that dissipates less as it moves through the atmosphere.

[Sithdarth]

I mean thats the problem with our ground based ones

Yeah this would be true except for the fact there really aren't any problems with the amount of energy captured. To quote myself from another thread:

Solar
The main potential of solar power lies in intermediate size solar systems. We're talking putting solar panels mainly over parking lots. For comparison, with current solar technology if we covered 10% of the land that we have already paved (US only) in solar cells we could meet 100% of the nation's energy demand. This also translates to about 1/3 of the land currently used for military bases. Both figures count only used land area that is in the physically connected 48 states. This is land that has already been more or less destroyed in terms of Nature and can continue to be used by humans as we intended while also generating power. There is the added benefit to doing solar over parking lots in terms of Vehicle to Grid (V2G) technology when electric cars become more common. V2G technology is very promising in terms of smoothing out the power fluctuations that can sometimes happen with solar as well as improving the performance and reducing the operating cost of electric cars.

Note that there is still room for the efficiency of solar panels to double which would reduce the figure by half. Also note that no one wants to rely 100% on solar or wind. The current figures generally stated are around 20% from wind and around 30% from solar with the balance of the left over power made up for with other less mature renewable technologies (tidal, geothermal, biofuel, etc), efficiency, and conservation. There would probably still be some large solar plants put up in some places but nothing nearly as bad as what some people would have you believe. Additionally the areas will only shrink as the technology improves.

and to quote myself on wind:
Wind
Wind land use is nowhere near what people make it out to be. It used to be a problem with the older and smaller turbines that where first put up in California. The blades moved faster and so you had issues with throwing ice. They also had large truss support towers that look sort of like the Eiffel tower which take up a lot of space. (They have other draw backs which will be addressed later.) What's even worse is that they were set up basically shoulder to shoulder to the point where the blades almost overlapped and all facing into the prevailing wind. That and they are relatively short. The combination of these factors made them very inefficient uses of land. Not to mention the best wind potential is like 50 miles offshore anyway.

Modern wind turbines are giant and set on single poles with no support structure. They take maybe half an acre or so of land for the actual pole and a little more for the access road to get to it. Their size also means the blades spin much slower. Further they are designed in combination with this slower speed so that they only shed ice straight downward when a blade reaches the bottom. No more chucking dangerous pieces of ice. Not to mention the turbines are now hundreds of feet in the air. The net effect is that you can farm and graze animals all the way up to basically the pole of a modern wind turbine. When you add it all up Natural Gas plants use 3.7 acres of land per MW, Nuclear uses 2-3 acres per MW, and modern Wind power comes in at 3 acres per MW. So in reality there is no problem at all.

Bird Kill:
This is where those old support towers from the wind turbines come in. Birds tend to be rather good at avoiding moving objects and not so good at avoiding stationary ones. Generally speaking the turbine blades don't kill the birds. The problem with bird kills is basically exclusive to the California wind farms that were built with those Eiffel tower like support structures closely packed in a line. When a flock of birds try to fly through that some smack into the metal trusses and some are forced into the metal trusses by the birds next to them. This can be a big problem but has mostly been eliminated by several key changes:
1) Single pole construction greatly reduces the bird lethal bird strikes on the support structure.
2) Wind turbines are now huge and very very far apart. So far apart the squeezing effect isn't really an issue.
3) The wind potential in an area is now very accurately mapped and turbines are placed to optimize performance. They can also swivel 360 degrees and change the pitch of their blades to take full advantage of the wind to produce greater efficiency. Combined with larger size this means less turbines and giant wide open spaces between them.
4) Before anyone bothers to build a wind farm the check bird migration routes so as not to put them in the way in the first place.
5) The best wind is a good ways off the coast in basically any large body of water to begin with.

To really get a perspective on this you have to compare the number of bird kills via other human activities. Current wind farms kill about 2.6 birds per turbine per year and to get 20% of our current electricity demand we'd need 211,000 turbines which would kill about 550,000 birds a year. In contrast to that communications towers (cell, TV, radio etc) kill 4-5 million birds in a year. Pesticides and oil spills kill 67-76 million birds in a year. Vehicle collisions claim another 80 million birds every year. The buildings we live in work in are attributed with 78 million to 930 million total kills depending on various factors and who you ask. Finally, the number one undisputed champ is domestic house cats which kill about 450 million birds every year. So as you can see not only are wind farm bird kills a non-issue we could potentially cause a net decrease in the number of birds killed just by eliminating the need to ship and pipe oil.


What's specifically important is that by connecting wind farms in a North-South direction you are virtually guaranteed to always have wind blowing because there is essentially no North-South correlation in wind. Further, off shore wind basically never stops blowing for any length of time. What's even more important is that solar and wind peak at completely different times. The peak for wind actually falls nicely into the area were solar power is starting to bottom out for the night but there is still a good deal of demand. Now we can do even better by spending billions of dollars developing things like carbon (http://carbonanotubebattery.com/) nanotube (http://www.scientificamerican.com/article.cfm?id=carbon-nanotubes-turn-off) batteries (http://www.technologyreview.com/NanoTech/wtr_16326,303,p1.html?a=f) or we could just buy already proven technology. (http://www.a123systems.com/a123/technology) Not only could this be done sooner it can be done cheaper and more safely. I mean if your solar satellite breaks it's a pain in the ass to fix it, not to mention getting it up there in the first place. If you get too many up there and an accident happens you end up with a domino effect and so much space debris no one gets to leave Earth for awhile and no space power. As it is we put way to many satellites up and between them and the space junk its getting crowded up there. That's not to mention the potential harm of a misdirected beam. Even with a low powered one that kind of shift in radiant energy can have effects on ecology, ground temperature, air temperature, etc, that we cannot anticipate.

The one real thing that solar panels need to do is get away from harsh chemicals used for silicon manufacture. But between places like IBM already doing that for making microchips, and there is almost no difference in the fabrication techniques, and new semiconductors like graphene, single atomically think layers of graphite, it seems a much better bet to put the money there instead of space solar panels. Especially since you can repair and upgrade Earth bound panels pretty much on the cheap. As well as integrating them with V2G cars and such also using the new super batteries. In short, space based solar panels are best left in Gundam 00 where they belong.

[Premmy]

So what you're jibber-jabbering on about is there's no good reason not to use solar and wind power?

[Sithdarth]

Solar is still a bit more expensive than say coal or nuclear but wind is already at or below fossil fuels and fission. That is of course neglecting any and all environmental impacts. Add those in and even solar is competitive but of course no one really does that. But essentially yes at this point the switch to solar and wind has everything to do with overcoming propaganda and prevailing attitudes and nothing at all to do with technological feasibility.

[Premmy]

Premmy is always right about everything and is awesome

I thought that was what you said. Cool.

[Azisien]

As long as the space transport up wasn't too expensive (and I think those X-prize contests have shown that by now?) this could work.

PV cells are still a pretty large investment for residents, but there's really no excuse for governments not pursuing them. Oh, right, oil profits.

[Sithdarth]

As long as the space transport up wasn't too expensive (and I think those X-prize contests have shown that by now?) this could work.

Not really. For several reasons.

1) None of those X-prize flights got any where near LEO much less the ridiculously high geosynchronous orbit these things would need.

2) None of the plans had the carrying capacity to get a decent sized satellite into orbit.

3) With current launch systems building and launching the satellites would be close to the $10 million range each at their lowest. (That's actually the bare bolts absolute lowest most economical launch system by a private company no less to launch satellites.) Not to mention the inevitable launch failures.

4) Way to many conversion losses to ever be practical. I mean the ground side needs 80% efficiency. The best anyone has reasonably done is around 60% with a heat engine that was rather useless in terms of generating anything. If you are going to invent an 80% efficient radiation to electricity system anyway it might as well be able to get visible light too and then you can just use it on earth. Of course a lot of scientists aren't even sure that kind of efficiency is possible.

5) Lasers are horribly inefficient. The current laboratory record is 22%. Generally its closer to 5-10% for actual in use lasers. Assuming everything goes perfect you'd only be able to transmit about 2% of collected power assuming standard efficiency cells.

6) Once that hits the ground even in the best case scenario you're going to lose some to diffraction unless you dish is giant. Lets be generous and say you somehow manage 80% efficiency thats 1.6% of the power you captured in space making it down to earth. Essentially you'd have to have almost 20 times as much power striking a surface in space compared to on Earth just to need the same amount of panels. I know its more I don't think it's that much more.

This system might work if we had space elevators to get the panels up there and to act as conventional power lines back to Earth. Then we'd probably need to build a ring like in Gundam 00. The entire engineering behind such a feet while theoretically possible is well beyond us for the foreseeable future.

[TARDIS]

let's just hope no one turns it into a potential HADOKEN, shall we? (and yes, I do mean BM's, just with a different power source.)

[Azisien]

The entire engineering behind such a feet while theoretically possible is well beyond us for the foreseeable future.

And I guess that's why this company is trying to spearhead this? They would obviously know about the challenges you state. At the very least to try and learn from the whole ordeal.

I don't know. I say we bring all the troops back home, and put half of that budget combatting world poverty, the other half building solar/wind farms. Wash hands and done.

[Osterbaum]

What about the use of this type of solar power in powering space stations, etc.?

[Sithdarth]

What about the use of this type of solar power in powering space stations, etc.?

They already do that. The ISS is like half solar panels. It's where the idea came from in the first place. Basically every craft we've sent around the inner solar system is solar powered. It's a great way to power things in space in the inner solar system. It's a crappy way to power things on Earth, specifically panels in space solar on its own is ok.

And I guess that's why this company is trying to spearhead this? They would obviously know about the challenges you state. At the very least to try and learn from the whole ordeal.

Just because you're close to an engineering problem doesn't mean you're objective about it or have a good sense of when its going to be available. Fusion power for example. It could also be that they are unaware of the actual nature of a true comparison of costs between the two alternatives which is slanting their perspective.

[Hanuman]

Modern panels pay back their energy cost in less than 5 years of use.
Where? Death Valley?
Are they well maintained or just left to fend against the elements?


As for satellites, the idea is to convert the visible light into a form of radiation that dissipates less as it moves through the atmosphere.
Right, and how much energy//money does it take to fabricate, ship and launch all this stuff into orbit compared to what it produces back?

It would be good as a research device... see how much they can capture up there and all that observational jazz.

[01d55]

Where? Death Valley?
Are they well maintained or just left to fend against the elements?
In Europe.
Read the quote, follow the link.

[Hanuman]

In Europe.
Read the quote, follow the link.
Didn't see a link before, thanks!

[Azisien]

Just because you're close to an engineering problem doesn't mean you're objective about it or have a good sense of when its going to be available. Fusion power for example. It could also be that they are unaware of the actual nature of a true comparison of costs between the two alternatives which is slanting their perspective.

Okay, but there's a big difference in my mind between "unaware of the actual nature of a true comparison of the costs between the two alternatives" and a $40 billion PV panel that can power one house down here on Earth. I just can't imagine whole companies in this business and not noticing that. So they must have some other motive or see something I don't. At least, that is how it feels.

I mean hell at least with fusion power its like, really expensive and maybe really far away, but we're already well aware of the benefits.

[Sithdarth]

Okay, but there's a big difference in my mind between "unaware of the actual nature of a true comparison of the costs between the two alternatives" and a $40 billion PV panel that can power one house down here on Earth. I just can't imagine whole companies in this business and not noticing that. So they must have some other motive or see something I don't. At least, that is how it feels.

There are several things going on here. The first is that by and large the industry has for some reason focused on large power plants in the desert. Naturally this brings up land use issues. However, it's a much better idea to simply put panels over parking garages and parking lots in smaller batches. Putting them in space is generally seen as the only possible land use resolution by a lot of people when that is just not the case. Then there is the matter of the technology required. If you could really bring down the cost of launching things into space and somehow sort out the return of power to Earth this system wouldn't be all that bad. It does have clear advantages. However, that requires solving at least two high complex technological problems instead of just one, i.e. storage. I have no idea why some people think we'll get super cheap rockets and lasers from space before we get super batteries. Plus super batteries have a lot of other obvious uses. I'd also say there is a bit of political/scifi motivation in there somewhere. Maybe they aren't aware of it but certainly somewhere in anyone's head space laser solar panels sounds so much better than parking lot solar panels. On the political side its got the feel of the Kennedy push to the moon. On the engineering side its got the attraction of being a Great Wall of China. Certainly for the public it sounds sufficiently futuristic to solve the energy problem. I mean tell someone you can solve the energy crisis with solar panels on parking lots and they'll ask you things like "If it's that easy why hasn't anyone done it yet." Tell them you are going to do it with space laser solar panels and it sounds like the kind of difficult thing that could actually be a solution. This prejudice extends to almost everyone. When solutions sound to easy or simply we seem to instinctively distrust them.

[Azisien]

There are several things going on here. The first is that by and large the industry has for some reason focused on large power plants in the desert.

I think that's because of TTWWADI (http://acronyms.thefreedictionary.com/TTWWADI). Millions of little panels all over the place? Bah! We need HUGE GIANT power plants, and they need to go to "Away." Obviously you are aware of the benefits of a big solar farm in, say, giant desert spaces no one uses anyway, but then non-distributed solar farms amplify their own disadvantages. Cloudy/misty/hazy/eclipse/whatever, oops, the whole farm is fucked for now! In a distributed model, there will almost always be power generating somewhere.

Certainly for the public it sounds sufficiently futuristic to solve the energy problem. I mean tell someone you can solve the energy crisis with solar panels on parking lots and they'll ask you things like "If it's that easy why hasn't anyone done it yet." Tell them you are going to do it with space laser solar panels and it sounds like the kind of difficult thing that could actually be a solution. This prejudice extends to almost everyone. When solutions sound to easy or simply we seem to instinctively distrust them.

I just found a solution for global warming! We build giant balloons out of....ummm...buckyballs, that sounds really futuristic. Yeah. And then we can pump carbon dioxide into them with, uh, giant robots. This is perfect. Then we can launch them into orbit using gigantic trebuchets. Hmmm, no, too retro. Quantum trebuchets! Once they're in orbit we can equip our giant solar platforms with big mechanical spider arms that can grab the balloons and hurl them into the Sun.

[TARDIS]

I still think we should be worried in case it gets turned by some military budget into a HADOKEN

[Professor Smarmiarty]

My problem was this is that for solar panels to fully use all the light in space they would be hella expensive to make. As far as I'm aware photoefficiency of all the current designs drops pretty quickly under large light conditions and ones that don't are in the theoretical camps that cost prohibitive amounts to produce.
Far cheaper to just build more on earth/develop ones that use more wavelengths.

[GrandMasterPlanetEater]

The year is 2597. Protests world-over rage at the orbiting rings of solar satellites that are blocking 67% of the solar input, turning Earth into a snowball planet so that power-hungry establishments like the Playstation 54 Supergrid Entertainment Centers can continue to run. Frigid temperatures force people to remain in debt to the SolarTec monopoly in order to heat their homes. Small "black" power companies struggle to get a foothold in the market to use a natural, Earth-warming substance buried in the ground called "coal". Political analysts argue that such methods are an uneconomical pipe dream, and experts argue that global warming was disproved by a respected group of conservative talk show hosts just after the turn of the 21st century.

Heh. It could happen.

What always nagged at me when it comes to solar power in space is that you're basically putting up a small solar sail, which would over time push you off course. I guess it doesn't take that much fuel to compensate.