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Japanese Firm Proposes Microwave-Linked Solar Plant On the Moon
littlesparkvt writes "Harnessing the sun's power is nothing new on Earth, but if a Japanese company has its way, it will build a solar strip across the 11,000 mile Lunar equator that could supply our world with clean and unlimited solar energy for generations." Some of the company's other projects look just as ambitious.
The Lunar equator is 11,000 Kilometers long.
"I do not agree with what you say, but I will defend to the death your right to say it"
Collect massive amounts of power, and beam it towards a planet. What could possibly go wrong?
In a surprise vote at the UN, the General Assembly accepted a proposal from Krasnovia to rename the planet. The new name is "Alderaan."
much of left-wing thought is a kind of playing with fire by people who don't even know that fire is hot - George Orwell
..They become Shimizu's Dream corporation staffers.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
maybe look ambitious but i'm sure they will succes with they technology. Coz japan is awsome
http://omjes.info
s/Timely/oldAsFuck/. Hilarious when Huffington Post beats Slashdot to a story by two and a half months.
I am Audience.
I remember in that game you could build a microwave power plant that got its power from something orbiting the planet or on the moon. Occasionally it would misalign and blow away a few city blocks of stuff.
We already have plenty of sunlight right here on earth. That isn't the problem. The problem is how to gather, store, and use it. Solving those problems on the earth would be better than solving them on the moon
Solar insolation on the moon is not dramatically higher than on Earth - around 1400 W/m^2 versus around 1000 W/m^2 on Earth. Granted, a Lunar solar station wouldn't be affected by weather, but Earth based receivers will suffer from efficiency loss during bad weather.
Could they achieve the same result by building a bit larger system on earth, but without the hundreds (or thousands?) of rocket launches it would take to get the materials to the moon to get the thing started?
Besides, who wants to see a big black ribbon around the moon?
So then this world will be like Transmetropolitan, only lamer, because it's on the Moon and not Mercury...
- In Soviet Korea, only old people loose all their bases to Natalie Portman's petrified hot grits overlords.
I remember having this conversation in Physics class many years ago, would be fantastic if it goes ahead but I honestly don't think that anyone would invest the huge amount of money needed to even attempt this, at least not until the oil has run out.
In a cybernetic fit of rage she pissed off to another age...
Some of the company's other projects look just as luicrous.
we're already warming, no need to pump in extra energy. we need to use the plenty we get from the sol better.
A major issue is that the moon is fairly far up Earth's gravity well. It is easy to get things to low-Earth orbit and already tough to get things to even geo-stationary. The main saving of putting anything on the moon will come if you can do a large part of your construction on-site since otherwise moving that much material up is going to be tough. If you are doing automated construction on site you also are going to need to be able to make mainly a lot of solar cells. Solar cells are primarily silicon and there's already been prior research on refining the moon's regolith for silicon to manufacture electronic components and that looks possibly doable but one does need to get over some technical chemistry issues. See e.g. http://www.asi.org/adb/02/13/02/silicon-production.html.
The other issue is distance for power transmission: most designs for microwave power involve power transmission from at most a little over geo-stat at about 35,000 km. The distance to the moon is about 10 times that, so if you don't have a really tight beam, there are going to be issues. Also, since the moon change's position you are going to need a large number of sites on Earth that can receive the beam, and if you can't switch off smoothly between them always (which would itself require massive planet-wide infrastructure), you would still need power sources on Earth (possibly just massive storage facilities?) to deal with those times.
Overall, a really cool idea with a lot of technical hurdles. I hope they can make it work but I'm not optimistic.
Are these ideas realistic anytime soon? Not really. Are they possible with today's technology? Iffy, although some probably are. Would I like to see most of them actually in existence now, if it were possible? Most definitely!
Especially the space ones, and the pyramid city. I like those ideas!
Z
"Its way"... not "It's way".
Whoops, we just microwaved the south pacific, boiling the seas creating the largest fish soup bowl in the world.
i feel that my proposal is just as likely to become a reality be it a good idea or not
Strategic Defense Initiative (Star Wars) http://en.wikipedia.org/wiki/S...
The US contractors and gov spend time and treasure looking at different forms energy over distance in space.
Something very expected happens over distance to all that power, then add in the earths weather and you have non trivial issues.
Add ever more power or lasers or wavelengths... it all drops off fast but finding out just how and by how much can be a wonderful boondoggle.
Interaction of multiple lasers, different rays, microwaves all have their power, distance issues and are known to science.
Domestic spying is now "Benign Information Gathering"
Microwave power plant on the moon?
What's next, giant energy beam cannon powered by said power plant?
Non impediti ratione cogitationus.
I would say that only the Japanese would think surface area here on Earth to be at such a premium that it would be worth it versus panels here on Earth.
I would, except for the slew of other people who have proposed lifting them into orbit.
I view all such proposals as a distraction from the real logistics issues involved in installing more of the renewables we can build now and connect to the power grid by more conventional means, with the added whimsical notion that what they really want is a death ray.
Someone had to do it.
Perhaps they should focus on one incredibly ambitions plan instead of eight separate ones. I'm also a bit curious how big the receivers would have to be earthside to collect the beamed energy. I don't know if they've invented the microwave equivalent of a laser which is probably what would be needed to to keep the receivers less than 20 miles wide.
After the oil runs out, there won't be any money. Details here. Warning -- it's a harrowing read.
Whether it's specifically THIS project, or another.
Whether it's The Japanese or someone else.
The incentive to achieve this is too unavoidable.
Why? (I hear you ask)
Because the distinction between a targetable multi-terawatt laser and an eco-friendly solar-power downlink is mythical (legal, at best).
So Japan can bypass (simultaneously, no less) their own constitutional ban on militarisation AND the internal treaty against "space weapons".
Visit CryptoGnome in his home.
I'm sure they will do this as soon as a space elevator becomes available. I probably wouldn't hold my breath.
William Atherton better have his home insurance paid up.
Yes, but it's not always the same half. :-P
The moon is tide-locked to the Earth, not to the sun. The so-called "dark side of the moon" gets just as much sunlight, but it never faces us. Moon based solar collection will have most of the problems that Earth based collection has... and a whole host of new problems.
I won't join Slashcott. OTOH, If Beta goes live, I just won't be back until it's fixed. Sorry Dice.
But with them off nukes cost less and give off more power.
Start by building the Solaren plant in orbit first you Space Nutter religious fundamentalists. You swindlers.
Guess they never played SimCity...
I've got better things to do tonight than die.
Shimizu Corporation intersects with Dr. Criswell in another way that I just discovered today after searching for his more recent patents.
We've got to attract technological civilization's population away from natural ecosystems into idealized artificial environments such as Shimizu Corporation's design for what it calls the "Green Float". You can house the entire population of civilization in beach-front property on the boundary of a tropical rain forest where people can swim, fish, hunt and gather recreationally, as well as access the height of urban lifestyle. From there space habitats are likely to emerge so that the natural propensity of these "cells" to replicate endlessly needn't destroy Earth's biosphere. Interestingly, I came up with a geometry that looks very similar to that years ago, with the Solar Updraft Tower Algae Biosphere proforma and, over the subsequent years, I found a floating photobioreactor technology that requires little more than 2 layers of polyfilm that has demonstrated production per cost figures far in excess of what I projected in that proforma. Before I ran across Shimizu Corp's Green Float I had further refined the idea based on the Atmospheric Vortex Engine, which, like Shimizu's "Green Float", is ideally sited in the equatorial doldrums and could make use of the central tower of the Green Float. I posted some preliminary thoughts over at the Seastead Institute's blog.
A key problem I attempted to address in my preliminary thoughts was the early market for energy from the Atmospheric Vortex Engines that would form the nuclei for Shimizu's Green Floats. A big problem was the fact that the electric power markets are thousands of miles away from the floating AVEs even if you could build on the order of a terawatt of oceanic power transmission lines thousands of miles long. Early markets are critical for attracting capital -- the lack of which renders such grandiose ideas "non-starters".
I had thought it would be very nice to have a microwave transmission technology that could dynamically switch the power distribution to achieve the holy grail of "dispatchable" power generation for peak loads, but wasn't aware, until just now, that Dr. Criswell's recent revision of his patent serves precisely that purpose.
Seastead this.
> I view all such proposals as a distraction...
So do I for the most part - but maybe not for Japan. After all they don't really have the land area to do much in the way of renewables themselves, are subject to tropical storms which make offshore source problematic, and they aren't exactly on the best terms with their neighbors.
Plus there's the fact that such a system could very easily be modified into a terrifying weapon, which could do a great deal for the national security of a tiny island nation off the shore of a hostile up-and-coming superpower. I doubt they want to be the US's political lapdogs forever.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
This proposal would only make sense if you planned on using the first few missions to establish the ability to turn local Lunar resources into solar panels
On the other hand, an orbital system would have to lift well... how much?
current solar panels weigh 15.8 kg/m^2, lets make life simple and imagine that they can make solar panels that are 1kg/m^2
and the moons equator is 11,000 Km (I can;t believe that the story said that it was miles...) and lets say they decide to make it a Km wide that is
11 billion kg of mass you are putting into orbit to match the generating ability of the lunar system
Ouch, that is a big win for a Lunar system right there... Even if you could get a solar film in space that was down to a gram per square meter, that is still 11 million kg... or 460 shuttle launches ouch!
Wherever You Go, There You Are
It's a grand idea, but too limited. I'm still waiting for a proposal along the lines of Transmetropolitan, covering the surface of Mercury with solar panels.
Why on the surface of the Moon? That's nonsense. In case they hadn't thought about that, the nights on the Moon are 14 days long; why go into space to achieve the same problems we have right here on Earth?
Build them in orbit. First of all, they won't need to be sturdy enough to hold up under their own weight, and can be in the sun 99% of the time. Second, beaming power back from 22,000 miles up will be easier than beaming it back from 250,000 miles.
They don't have to worry about beta software. Besides, it takes about this long to allow for our in depth analysis and witty repartes.
Faster! Faster! Faster would be better!
Yes, I don't however see any data on their website about how wide they are planning to build the ring out. If their graphical renderings are accurate, they display a 195 pixel moon with a 22 pixel ring. Given that google tells me the moon's radius is 1737 km, that means the ring should be about 200 km wide.
So considering that we have a 11,000 km ring that is 200 km width, the power generation for the light-facing half should be what you'd expect from 5500km x 200km or 1,100,000 square kilometers. I've seen estimates of 1.2 mw per square km for solar. Using that as a basis we'd expect 1,320,000 mw of constant power generation. Wikipedia says to take off 10% due to conversion inefficiencies of microwave transmission of electricity and we probably should take off another 5% or so for weather and atmospheric disruptions or inefficiencies. That leaves us with 1,122,000 mw of constant power.
As a point of comparison, all the wind power in the entire world added up to 238,351 megawatts in 2011, so it is roughly five times the capacity of that. However, in 2008 the world had an average power consumption rate of 15 terawatts . 1,122,000 mw is 1.12 terawatts, so this project could supply roughly 7% of the worlds electricity if it was operational today.
The moon has an area of 37,932,000 square km though, so if we coated the entire moon and got energy from the sunny side and do the same math we get 19.34 terrawats. So, at our current state of energy usage it could power the world if we coated the moon in solar panels.
I'm not sure about the aesthetics of it though, a racing stripe on the moon.
Big apple, new Yorik, undig it, something's unrotting in Edenmark.
Oh, yeah? Well...
rewriting history since 2109
Step 1: Come up with an idea
Step 2: Impress the public
Step 3: ?? implement
Step 4: Profit
One should not hurry up and jump past step 3.
Power loss too great!
No one to local admin!
Telemetered admin out of the question!
Somebody masturbating! Ah Ha! Now there is the answer!
The problem is oil can *never* run out. There will always be at least one hidden drop left. The price may increase exponentially as reserves run dry, but "run out" is not an accurate statement of how it would go. The impact won't be equitable, but it wouldn't immediately put us in the post-apocalyptic scenario described. The thing not mentioned in there as an immediate thing that can be done to lessen the impact is "buy as many solar panels as you can afford (and fit on your roof), and install them feeding the grid." When the collapse comes, if 10% of people have done that, there'll be enough power for light industry to continue for a few hours every day. If 100% of people have done that, then there'll be almost no impact on quality of life, presuming we also build some storage for night, but the storage won't be built until there's enough surplus to store.
With a little night storage, there's enough roof space to have 100% solar meet 100% of our power needs. Though high-use areas like the US would need to buy from lower need areas, like Mexico for zero life change.
Learn to love Alaska
Some of the company's other projects look just as unrealistic.
FTFY.
The moon isn't smooth for a reason. Do you want stuff smashing into your solar panels? better off in space where you don't attract much of anything.
Democracy Now! - uncensored, anti-establishment news
Just to be clear, they're proposing building a facility on the moon to shoot lasers and/or microwaves at the earth. WHAT COULD POSSIBLY GO WRONG. :)
Because beaming extra energy into the Earth's atmosphere won't warm the planet at all.
Although this isn't new news and has been announced last year (around September), the fact remains that the beta is horrible and people are leaving for a better site.
http://www.cnn.com/TECH/9705/2...
Oh yeah, another joke/scam that never materialized. But rest assured, Space Nutters will grow tumescent and argue passionately that the species, the entire species, even the poor and dirty people will benefit greatly from some billionaires transferring money amongst each other tax-free and when the project never, ever happens, ever, give each other bailouts with your tax money.
As people have pointed out, the surface of the moon isn't always lit. They should put the solar panels on the surface of the sun instead.
Day 935. 95% of our solar panels are working, but since we are a light year from the nearest star, they aren't doing shit.
That'd be the most unstoppable, powerful, unlimited energy weapon ever made. So no, nobody is making one of those...ever.
I definitely want to see a push towards solar power, but space based to me just isn't the way to go.
It takes ludicrous amounts of money to put anything in space. For the same price you could create a facility that is ten times as big...and its a facility where maintenance and upgrades don't require a team of astronaut engineers.
Land isn't our problem, there is leagues of land that could support a solar facility. The problem is cost...and nothing in space comes cheaply.
Any energy added to the earth contributes to global warming.
All electrical energy, when used, eventually winds up as heat. Adding energy to the earth from space (be it orbital power plants, or this scheme on the moon), or even by fusion power, will result in warming the planet.
Earth-based solar power installations use energy that is already heating the earth, so they don't contribute to the problem in the way orbital or lunar power installations would.
There is no master but the master and qt-1 is his prophet...
Anonymous has pointed out that such solar panels would only provide 7% of power required by our civilization. Then what advantage could we get by constructing lots of nuclear power plants on the Moon?
This is so incredibly dimwitted that I'm not going to try to work it out again. Like I did the first two dozen times (literally) some opportunistic bunch of dimwits came up with a 'plan' like this. NOBODY had ANY plans to send people to the moon. NOBODY has ANY plans to build anything on the moon. NONE of this is going to happen in the lifetime of ANYBODY alive today. No, STS, FH, the Chinese incessant moon landing talks - none of that count as plans. That is what is known as 'talk'.
These people have no idea what thei're talking about.
This nonsense has been going on for decades.
The ONLY people that will have the ability and, perhaps, the will to do this are Spacex (yes, I'm a fan but even I'm getting tired of dragging them out every time) and the Chinese. And NONE of them have any PLAN to do this. Just talk. At least Spacex and the Chinese haven't stooped to pretty pictures on pointless, pretty websites.
This is not going to happen.
Why would you link a solar strip to a microwave on the moon? Never mind there is currently nobody living on the moon, the second you open the door on the microwave all the air - and the hotpocket - would get sucked out into space, and I'm pretty sure you can't eat a hot pocket once it has moon dust on it.
-- A change is as good as a reboot.
Giant laser or maser (assuming someone manages to develop one) on the moon beaming gigawatts of power at us what could POSSIBLY go wrong? Anyone read The Moon Is A Harsh Mistress lately? Just substitute massively powerful energy weapons for a mass driver.
Are YOU using the TOOL, or is the TOOL using YOU? Think about it!
On ISS, they get about 0.1 mw from an acre, that is 24.7 mw from km2. It's a 20x more then what Your source says is max.
http://www.nasa.gov/mission_pages/station/main/onthestation/facts_and_figures.html
That is not saying that the idea is good, just to point a possible estimation error.
Consider that a typical top-end solar panel can get 255 Wp (Wp = Watts at Peak) for a panel. The referenced panel holds 60 156x156mm monocrystalline polysilicon cells, totaling about 1.4602m^2 , or roughly 174.6Wp/m^2
1,100,000 km^2 (from above) comes to 192 terawatts of electricity under ideal lab conditions.
All is good and all that, except for the energy input required to produce the solar cells.
Assuming we produce the solar cells here, at the bottom of the gravity well, and transport them to the moon - even if we do not include the energy required to transport that much solar cells to the moon - the energy requirement in the production of the solar cells itself would further deplete the fosiil fuels that are left on Planet Earth.
GGP talked about the possibility of coating the entire surface of the moon
... The moon has an area of 37,932,000 square km ...
, would there be sufficient power left on planet Earth to produce that many solar cells ?
Muchas Gracias, Señor Edward Snowden !
I remember seeing this five years ago in the New Scientist
Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.
The moon is great choice, compared to space, because it provides the hard supporting stuff with avoid the self crush of the project due to its own mass.
But there might be two "small" problem:
1. meteorite still falls on the moon (well, same problem if you are in space), and there is no atmosphere to burn them, so from the grain of sand to the big rock, you are exposed to them, and fixing the impacts' result on your nice array of solar cells might be a full time jobs.
2. moon so far has no magnetic field per itself (per lack of a rotating iron core in a magma mantle). With cables along the whole equator, it will be interesting to see the resulting field and its interaction with the earth-field (which protect us from solar wind and other nasty charged stuffs). With a few teraWatts to collects and move to the other side, the new moon is going to be interesting.
You got your units wrong here, I'm afraid. The source you are referring to is not speaking about 1.2 MW per square km. It is speaking about 1.2 MW per km of road. Roads are pretty thin, so installing solar panels along them does not result in many square kilometers per km.
This mistake leads to your result being off by a huge amount. The solar constant is 1.361 GW per square km. Normally this is reduced by 30% by the atmosphere, but that does not apply in space. Neither are there clouds to worry about, so we can pretty much use this number directly, after dividing by pi to account for the lunar day/night cycle, giving us about 0.45 GW per square km. High-end satellite solar cells get up to 29% efficiency. Using that, we get 0.13 GW per square km. With an area of 11,000 km by 200 km = 2.2 million square km (we have already taken the night into account in our numbers), that results in a total production of 286 TW, which is 19 times the world's current total energy use. Of course, one has to get this energy down to earth somehow too. This seems to have an efficiency of about 85% (possibly squared - unclear). That partially negates the advantage of being outside the atmosphere, but we still end up receiving 206-243 TW.
So no, the main objection to this plan isn't that there wouldn't be enough energy available. It is how much resources would be spent making it. I think one will need some sort of self-replicating solar-cell-producing robot on the moon to avoid this requiring too many launches. But I have not read the tehcnical details of their plan.
As I pointed out previously, the number isn't 1.2 MW per square km. The article that number is from talks about building solar cells along roads, and the number is 1.2 MW per km of road. A more realistic number is 130 MW per square km, and that already takes the day/night cycle into account, so you can use the whole area. Also, milli (m) and mega (M) are very different, so don't be sloppy with the case in units. In my reply to your previous, anonymous post, I arrived at 200+ TW of average power after beaming to Earth. That is different from your number by a factor of 200!
I won't silence my inner shepherd. Japan is a notoriously crackpot xenophobic country on many levels. They still think the emperor is a god and that they're a master race. And you'll spring into action to say I'm paranoid or something when it is in fact them that spool out these attitudes. It's pretty obvious that these panels could be oriented to dose specific areas with enormous concentrated amounts of EM radiation. That's all a nuke really is after all, agent the gamma radiation and pulse. It's a bright hot flash of radiation.
Good idea..in the wrong hands, worst possible hands arguably..
Pie in the sky and tall tales, why don't you try and build a moonbase with 50 people - or even 5, before trying to cover half the moon with solar panels? Just building them would require the moon to be already colonized, with millions of people living there, which is not happening any time soon.
that results in a total production of 286 TW, which is 19 times the world's current total energy use
compared to
so this project could supply roughly 7% of the worlds electricity
A pretty significant difference.
It's a good idea, except:
- the cost of getting the original materials to the moon is ... astronomic.
- the cost of getting the dependencies for building on the moon is astronomic as well (workers or enough robots to build a 11000 km solar panel strip), unless we send a Von Neumann machine; if we do, I propose we make it out of Unobtanium so it'll last.
- the system would provide good clean energy for the whole planet, except when something goes horribly wrong; Then, the cost of the project would increase by the cost of getting a crew to fix the problem all the way up there (high risk, large cost, polluting rocket and so on), and human lives (as in "the microwave beam unfortunately hit near the receiving station; cancer risk in the area increased to 90% in 10 minutes").
Tie two birds together: although they have four wings, they cannot fly. (The blind man)
If you read your source, the 1.2MW figure is for 1km length of highway, if covered with solar panel roof or some such, it has nothing to do with power produced with _square_ kilometer of solar panels.
Here's a better estimate, if ground is fully covered in solar panels:
(2*1750km*200km*1e6*1400W/m^2*.2*1e-12)TW = 196TW
Think of 2*1750km*200km as the size of rectangular shadow left behind the stripe in the moon: as it tells how much sunshine the strip absorbed, we don't have to think about the angles solar panels making the stripe actually have. 1e6 converts km^2 to m^2, 1400W/m^2 is the amount of power 1 m^2 area perpendicular to sunshine receives at earth distance to sun, .2 is typical solar panel efficiency and 1e-12 converts watts to terawatts.
If we'd lose say half while beaming and converting it to use on earth, it'd still be vastly more than humanity uses at the moment. There you go.
Yes, I don't however see any data on their website about how wide they are planning to build the ring out.
Maybe because they aren't actually planning anything. This is science fiction, not a serious endeavor. People propose all kinds of things that can't reasonably be done but sounds pretty cool. Spend about 30 seconds thinking about the economics, technical problems, logistics problems and our current level of technology and you'll appreciate how absurd this "proposal" is. This is the sort of thing people do when they want a grant to "study" some far out idea that they know damn well cannot be done.
If the microwave laser ever gets knocked out of alignment, you'll never ever have to worry about popcorn shortages.
Or anything else, I guess.
but we wouldn't get a viable space-faring capability as a side-effect if we built it on Earth.
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
The lunar surface is covered in silicon, and has plenty of iron, aluminum, and magnesium.
Great! What about oxygen? Carbon? Water? The thousands of other chemicals, materials and tools that we take for granted here on Earth which are required for production?
Ship a refinery and fab up to the Moon, and whatever trace dopants and alloys you need.
Oh is that all there is to it? We just have to ship a hypothetical refinery which can somehow process all the different materials without any supply chain of any kind. Where pray tell can we find this magic piece of technology? [/joking sarcasm]
Seriously, have you given this a moment's actual serious thought? You seem to seriously think that we can send a few rocket loads of equipment and somehow manufacturing will magically take place. It doesn't work like that. You are talking about a level of manufacturing technology that is probably two to three centuries away at minimum. We don't have ANY equipment that resembles what would be needed here on Earth much less something ready to go into space. I have been in manufacturing for the better part of three decades and I'm both an engineer and an accountant. Proposals like this are absurd on the economics alone. There is FAR more to manufacturing than just a refinery and a few robots.
They plan to use lunar materials, so no hundresds of rocket launches to get started
Right, because entire supply chains can magically materialize out of the vacuum of space. Look, even here on Earth just because there is a pile of iron ore sitting around doesn't mean you have everything you need to refine, process, form, machine, deliver and install the products you need. I think there is a general lack of appreciation here of how complicated it is to make a lot of the products we take for granted. You don't just have to deliver a few robots to the moon and let the magic happen. You have to deliver an entire supply chain. That is VERY hard to do and extremely expensive. You are BADLY underestimating the amount of equipment and manpower and technology that would be needed to make this happen.
For any technology that is likely within the next 100 years, there would be hundreds (probably thousands) of rocket launches. The parent post is quite correct on this point.
I guess the point is kind of that real estate and raw materials are "free", if you get the proper manufacturing equipment up there.
Nothing is free. The people that make that hypothetical manufacturing equipment are going to want a return on their investment. Just because the costs are not direct doesn't mean they don't exist.
Since you're talking about decades of effort to build this thing, it doesn't really matter how long it takes to get there.
Yes it does because you have to fund the project. Even ignoring the technical problems (which are legion), anyone funding this is going to want a return on their investment that is not measured in decades if not centuries. Even governments aren't usually willing to put up with that long of a payback, particularly for something as absurdly hypothetical and risky as this.
Get out the slide-rule and do the path-loss and conversion loss on converting DC on the moon to microwaves, then sending microwaves down to Earth.
Then get out the abacus and add up the cost of sending a single solar panel to the Moon.
It's gotta be a factor of 1,000 to 100,000 below break-even.
Certainly they can raise the complexity and sharply increase installation and maintenance costs - but that won't buy much effective area. The ones closer to the subsolar point will increasingly shadow those further away, By the time you reach the edge, they'll effectively be in full shadow.
It is how much resources would be spent making it.
The answer is none because this will never happen. It's just science fiction that people write when they are looking for a grant to "study" something that isn't actually feasible. I'm amazed that anyone is actually bothering to worry about the physics of the power generation. That is FAR less of an issue than how to actually build the thing.
think one will need some sort of self-replicating solar-cell-producing robot on the moon to avoid this requiring too many launches.
You'd need a LOT more than a robot. Manufacturing on this sort of scale is hugely resource intensive and requires an entire supply chain. You have to have mining equipment, refineries, production equipment, assembly equipment, fabricating equipment, chemicals, additives, etc, etc. All of this has to work in space, with minimal human intervention, somehow be repaired, have replacement parts, etc. We do NOT have the technology to do this even here on Earth in a similar manner much less millions of miles away in a harsh vacuum. And I'm not even worrying about the economics of all this which are even more absurd.
Frankly even if the physics of the power generation made sense,
Some of us have been screaming solar power satellites in geosync for decades. It's a *lot* less expensive to fly to geosync, and the environmental impact studies (US) were *done* by 1980....
mark
Can you say 'Microwave Death Ray"? I know you can...
(If at first you don't succeed, do it different next time!)
I was thinking they should build a ring around the earth. It could serve multiple purposes... The outside of it could be covered in solar panels, and there could be nodes along the ring where space stations are built - they could be launching points for interplanetary missions. The ring could also contain attachment points for space elevators - to facilitate getting cargo/fuel out of earth's gravity.
Here's the math:
http://matter2energy.wordpress.com/2011/06/21/the-maury-equation/
and:
http://matter2energy.wordpress.com/2012/03/17/the-maury-equation-redux/
The long and short of it is that any soft of SBSP loses about 1/2 of the power during transmission and grid conversion. There's no way around this, it's basic radio physics.
So to make it work in your favour, you need to generation at *least* twice as much energy. And that's assuming your shipping costs are zero.
An SPS in GEO *might* be able to do that. That's because they get about five times as much light as a panel on the earth - day/night, clouds, cosine angles, etc.
But on the moon you have the same sorts of effects as the earth, with the exception of weather. The panels will cycle under the sun as the moon rotates, and spend half their time on the night side.
There is absolutely no way such a system can make up for the losses in transmission. Period. Do the math yourself if you don't believe me.
Do this idiots have any idea how much it'd cost to transport, build and service a solar strip that long? And do they really think it will supply us "for generations"? Have they a clue to the maintenance issues that'd be created by temperatures that swing from over 100 C to -150 C? That's a 250 degree C change. And don't forget what the Apollo astronauts about lunar dust covering everything.
We've spent huge sums just keeping a modest little space station functioning in low-earth orbit. This people really are quite a few sandwiches short of a picnic.
With a Japanese power company managing the project, what could possibly go wrong?
Beam divergence is a function of wavelength. There are no efficient generator of microwaves at a high enough frequency to be received by a field of synchronously rectifying 'rectennas.
Bear in mind, and over-spray would warm water, or burn houses and people.
http://www.ehow.com/how_584952...
One of the most taut sci fi thrillers I have read in a long time. And it is entirely relavant to this subject.
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