| Space Laser to Transmit Solar Power to Earth |
| Written by Hank Green | ||
| Thursday, 06 September 2007 | ||
 Up until today, I was 100% opposed to space lasers. I mean, they sound cool and everything, but I never thought there would be a good reason to have an extra-terrestrial sniper rifle sitting there waiting for commands. That's just too much power.But what if the space laser was giving us a different kind of power. Specifically, solar power. Well that's what some Japanese scientists are planning with a projected 2030 launch date. Solar power in space is constant and undiluted. Additionally, you don't have to buy land on which to place the panels, you just keep them orbiting and you're set. The device works by capturing solar energy on metal alloy plates. These plates then transfer their energy to a laser, amplifying it many times. The laser is then beamed down to earth where it is captured and converted to electricity. I'm not sure how this last step is accomplished, but possibly through a traditional boiler. The process, according the scientists, can be up to 40% efficient, which makes it comparable with the most efficient solar panels of today. The problems will arise with launch costs, weather interfering with the laser, and international outcry at the supposedly peaceful deathray. Via Engadget
Comments
(34)
How is this valuable?
written by Daniel Lunsford , September 06, 2007
Not a boiler: PV, I'm certain.
written by Joel , September 06, 2007
If it's 40% efficient overall, it can't be a boiler. Lasers are inefficient to start with, as are boilers.
One great thing about laser light, as compared to sunlight, is that it's bright and, more importantly, monochromatic. You can build photovoltaic cells with a band gap tuned to the wavelength of the laser, which have excellent efficiency. The best solar cells have a stack of cells of different band gaps, each designed to take in as broad a spectrum as possible, and these still throw away a lot of energy because the sun puts out so many different wavelengths; expect a purpose-built photovoltaic cell to have much better efficiency when converting monochromatic light, and at a much lower cost. Plus, the array only has to be as large as the diffraction-limited spot size (probably less than one meter).
less Pu in space.
written by Joel , September 06, 2007
Daniel:
The ecological benefit comes from allowing solar energy to be used on space missions that would otherwise call for radiothermal generators and/or mini nuclear reactors. You remember all the brouhaha over Cassini's plutonium cargo, and what might happen if it were scattered over a city. If they could build a network of power stations to beam laser light to far-flung probes, those probes would also have lighter power systems, and the option of heavier use of electric propulsion, which would both have knock-on effects of reducing the mass of booster rockets.
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written by jeremy , September 07, 2007
Could this be a hazard for air travel?
Perhaps, if we could build a planet wide exoskeleton of solar capturing devices and beam the power to the poles where barely anyone goes, then maybe this could be something. Says the cartoonist.
Sweet! A real evil death ray!
written by Leon , September 07, 2007
Sure. It seems benevolent now. But when the world is melting, don't say I didn't warn you
 But seriously, it's good that they're looking for alternative forms of energy.
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written by ben , September 07, 2007
how about attaching solar panels to a dolphin's back and a laser to its frickin' head?
Disco Ball of Death
written by luskrat , September 07, 2007
What if a large shiny piece of space junk flies in front of the beam and momentarily deflects the laser's energy in a different direction?
not the newest of ideas
written by Necoras , September 07, 2007
This idea has been around for decades. You put up a few hundred satelites to where the solar energy is undiluted and constant. The energy is collected 24/7 and beamed down at specific times to specific places. The energy is sent as low intensity microwaves, so low that you'd barely feel them if you walked through the beam. The beam is aimed at a field which contains an underground grid of wires where it is converted to electricty to power a nearby city. Multiple satelites keep the power coming 24/7, with extra power from non-peak times being stored for later use. In terms of economics, it is fairly unfeasable with today's space economy, but that's NASA's fault. Anything's better than the shuttle (which is why we're going back to Apollo age tech). Once launch costs come down, this is THE long term energy solution. Not ethanol (dear LORD not ethanol), not more oil, not nuclear (although used correctly it's a good stop gap for a few thousand years) but clean solar for the next 5 billion years. By then we'll be at another star and we'll use that one. Enjoy
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written by bobbyfly , September 07, 2007
I'm sure they'd employ smaller, non-lethal lasers for target locking on the earth capture array, and other safety devices to prevent this from becoming a Death Ray.
And an aviation hazard? Sure would be, but that's what FAA sectionals, NOTAM's, and airspace classifications are for. Pilots would have to follow the new rule and not fly there. No biggie.
Right...
written by koew , September 07, 2007
When that happens, if that happens, it will be the day we burn our clouds and darken the sky. We'll live in darkness forever more...
im sure
written by nick , September 07, 2007
once we get this tech, im sure we can install things on it to shut it off if it starts to stray from where it should be shooting.
well, they way things been going is we make smaller, more energy efficient tech, so maybe we wont even need the sun to power things soon. maybe a slight breeze, or atomic collisions will power all our computers in the future. it will just take energy to move my ass from a to b
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written by RJ , September 07, 2007
What about the poor birds?
Why a Laser?
written by Greg Mefford , September 07, 2007
Why don't they just use a tether with a superconducting wire in it. Would that not be much more than 40% efficient? While they're at it, build a space elevator around it!
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written by AsianDDRManiac , September 07, 2007
Cheers, Necoras!
Hmmm
written by thomas , September 07, 2007
If they did put this project in place, which they probably will if everything goes according to plans,
wouldn't cause conflicts between energy power plants currently on earth? If this would work top notch and we could get all our energy there(hypothetically speaking), wouldn't that create a "sacking" of a large amount of employee's in the energy industry?
Guess these people play Sim City when th
written by jwigum , September 07, 2007
Microwave transmitters were one of the disasters... They'd miss the receiving station, and proceed to fry part of your populace.
Why worry about accidents?
written by Corvidae , September 07, 2007
You don't put a few billion dollars worth of satellite in orbit without some serious safety protocols. I'd say the chances of an accident are pretty small.
Now the chances of someone pissing off the owner of a space based death ray...Those are a LOT higher, and something to worry about. The chances of an outside power redirecting the beam are probably low, but also not something to be ignored.
Microwaves?
written by Jason , September 07, 2007
Everyone with pacemaker's beware and stay clear!
Pew pew!
written by Me , September 07, 2007
Pewpewpewpewpewpewwwww!
Did no one watch "Die Another Day"?
written by Brian , September 07, 2007
In that Bond movie, the baddies had something like this (named Icarus) and it was most definitely turned into a weapon.
But on a serious note, the practicality of this seems way off base.
Waist of money
written by Farnsworth , September 07, 2007
some of the other comments point out other flaws in the idea as well. I was wondering how much money it will cost to research and develop said "laser" how much money it will cost to put enough of them in orbit, what the carbon footprint of all of this is and how long will it remain in orbit with out needing repair.
all of that sounds like a big waist of money if you took the money that is being given to this and apply it to wind, and solar now it would far out way any energy that the laser will create 20 years from now
That was one of the lamest posts I've ev
written by Jamie , September 07, 2007
How about a little research into what space-based solar really is and how it works. The idea has been around for a long time and has the potential to match or exceed the total national power output. The power density of the beam coming down in less than standing in the light of a full moon. Sorry for sounding like a science snob but the responses previously posted just go to demonstrate the pathetic state of general scientific knowlege and awareness in this country.
Some answers
written by spacechicken , September 07, 2007
Having actually researched this concept I can provide some answers for people.
1. What happens if the beam goes off target? Easy - it turns off. There is a relatively simple feedback circuit - if beam strays, turn off beam. Also, for added protection, you put the receiving station in the middle of a large lake. So if the beam does stray AND doesn't get cut off all it will do is heat water. 1b. Can this be turned in a weapon? Well - yes. So can just about all modern technologies (and most older ones too). Who would use it as a weapon though? The country that owns it to smite other countries? They could, but in the process they would be turning off the lights in their own country - not exactly the smartest move. 2. Why not microwaves? The wavelength of microwaves is too long meaning the rectenna (antenna for microwaves) you need to have needs an area measured in square kilometres (miles). With lasers the receiver (which would be a PV array) would only need to be a matter of a few square metres (yards). 3. Why do this instead of spending the money on earth based power sources? Simple - space based solar has the advantage of being available 24 hours a day, 365 days per year. No worries about cloud coverage (although this can effect power transmission via laser - there are solutions) or if the wind dies down. There is no need to blanket vast areas with PV arrays or wind turbines. No need to add to the carbon load by burning anything. Hope this helps.
space elevator
written by james , September 07, 2007
this is valuable not so much as an energy source, but if they've developed an efficent laster power transmittance system, thats one of the major hurdles for a space elevator (powering the crawlers). If carbon nanotube production picks up the idea comes much closer to feasibility
what about solar powered satellites?
written by jason Nolan , September 08, 2007
Man, this is lame. Back in the late 80s peter glaser was working on solar powered satellites (http://en.wikipedia.org/wiki/Solar_power_satellite). I was covering it for a canadian newspaper. The problem was in transmission. They wanted to use microwaves and tuned feedback transmission. It made sense. Lasers seem really moronic by comparison.
A different use....
written by The Profit , September 08, 2007
this could be used as a weapon, or to power our citys,
but what if it was used for another purpose? say to help terraform mars? ive heard of various methods of terraforming mars, sending a nuke to the ice cap to melt it(make good ol oxygen) why not a bunch of lasers above the poles? just an idea dont know how feasable it is....
I am against this insane train idea
written by Dagon , September 08, 2007
Trains? C'mon! How fast are these things going to ride? On oil? A few texas lunatics sell that oil but only produce some 300 gallons a year for medicinal purposes. Where would you get all that oil, mister smartpants? And how fast are those trains going to move? 50 miles an hour? That's insane, the wind forces will kill anyone standing within 30 paces. And on tracks you say? The amount of iron will bankrupt anyone who starts with such a project. The idea is balderdash and the person who came up with such a notion should be hanged. Horse and carriage will serve us fine.
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written by Darth Vasya , September 08, 2007
> with a projected 2030 launch date ... The problems will arise with launch costs
Dude, by that time they'll already have built the space elevator. Launch cost: approx. zero dollars.
This just doesn't make economic sense
written by TomR , September 08, 2007
Even if all the technology works, and your transmission system is highly efficient, I don't see these getting built.
Why? In space, sunlight gives you 1366 Watts/square meter. In the best spots on earth, like the Saraha, average sunlight is about 250 Watts/sq-meter. That includes all losses: nighttime, absorption by air, sun angle changing over the year, clouds, etc. So, one solar panel in space gathers about as much as 6 on the ground. For this to work, you've got to be able to put a solar panel and transmittion equipment out in high-earth orbit for less than the cost of putting 6 of them in a desert somewhere. Even at the very cheapest, it costs about $5000/kg to get something into low earth orbit, and 2-3x that if you want to get it into an orbit where it's not spending a lot of time in the earth's shadow. Even a space elevator isn't expected to drop this below $1000/kg. ( http://en.wikipedia.org/wiki/S..._economics ) It's a nice idea, but going to space is just too expensive for industrial scale projects.
Response to tomR's " this dosent make ec
written by mazer , April 22, 2008
What your not taking into account is area. pannels in space may be 6x as effecient ( although you're ignoring the fact that these panels are 40% effecient and most earth based are 10-15%, which compounds on the additional light recieved by not having to travel through the atmosphere) but theres plenty more space in space than on earth.
The united states alone goes through about 3.23 TW (on average), so using 15% effecient panels in the average sunlight of the sahara would require 86 thousand km², thats alot of land to panel over.
man on a mission
written by ca , June 15, 2008
I love this post I know that any such project man puts his mind to we can acomplish dragging the nay sayers along kicking and screaming! the space age basically laid the fondation for cell phone's satelite tv, communications even cable tv! and lets dont forget WD40
and please get me more info on the space elevator will it be one or many connected to gether will they use the weight of one comeing down to help power the next one up if so this could greatly increase space elevator efficientcy
they have found a way to trasmit that en
written by raju , July 10, 2008
Japanese scientists working on the project have experimented with a special laser of 1,064-nanometer-wavelength light . they chose that frequency of light because it easily cuts through Earth’s atmosphere, losing no more than 10 percent of its pop.)they expect to put a array in geo stationary orbit and thus solar energy could be collected 24 hours a day; and weather would not pose a problem..
as for coverting solar energy to lasers they are experimenting with yttrium-aluminum-garnet ceramic material containing neodymium and chromium. and most importantly they say the laser will not harm humans... and interesting aspect is that we can use this energy to separate hydrogen from water and thus run and entire hydrogen economy... target year of deployment is 2030.. and most importantly they say that a mile long solar array in geo synchronous orbit can receive enough energy in an year to equal all known oil deposits on planet earth...!!!!!!!!!!
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written by Mike Bramer , July 11, 2008
To Daniel Lunsford,
Ok, I'll give you the first one. Current launch technologies burn a lot of fuel. But who's to say we won't have improved on them by 2030? How about a rail gun type launch or just building the thing in space at the ISS? But seriously, do you know anything about lasers and computer tracking? I guess you don't know anyone who's gotten laser eye surgery. And did you read the part about it being Japanese scientists who are developing this laser? Because if you don't know anything about Japan, let me tell you; they have lots and lots of extra land on which to build solar array's. It's like Montana over there. Think about the associated cost? Of building a one time device that remains in permanent orbit and beams down endless amounts of undiluted energy??? 'Cause no solar radiation gets filtered by the ozone or the ionosphere, right? And in case you're not paying attention, current 'harvesting technology' is already pretty much at it's theoretical limit. I simply cannot see us getting to the point where we would take your uninformed bias seriously. This thing sounds awesome! Go Ecogeek! and Kudos Dagon for the train skepticism. | ||
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I simply cannot see us getting to the point where we're capturing all the wind, biomass, and solar energy that's all around us--the point when we decide that we need to go into orbit to get more juice.
Come on now, EcoGeek... you're pretty good about getting the relevant technological advances out to us, but leave the science fiction to Hollywood.
-- Daniel Lunsford