Slashdot Mirror
How Space-Based Solar Power Plants Could Be Built By Robots On the Moon (blastingnews.com)
MarkWhittington writes: The concept of space based solar power has been around for decades. The late Gerard K. O'Neill proposed building them as a way to finance space colonies in the 1970s. Recently Popular Science reported on a modern approach to building space based solar energy stations. Instead of relying on massive, orbiting space colonies filled with construction workers to put the plants together, why not automate the entire process?
Where is Solaren's 2016 installation?
https://en.wikipedia.org/wiki/...
Oh, not even a single bolt in orbit yet? Oh I guess it'll just magically happen in the next nine months?
These space fantasies always follow the same pattern:
1) Uncritical support from people raised on sci-fi and proficient in software, but with no knowledge of the physical sciences and engineering
2) Failure to deliver anything
3) Upping the ante to ever more ridiculous concepts
Given that its been quite a while since someone landed anything on the moon. It would be a victory for space exploration if someone sent up a robot and dug a hole. People in the 60s would have expected a decent size lunar colony by now
I'm sure the instant someone can make more selling electrons generated from orbit than it costs to produce them (without siphoning tax dollars off of the rest of us clods), you'll see such a business materialize, the world will be a better place, oceans will stop rising, etc.
Until then, let's continue with the research but utilize what's the most cost effective now.
Fer God's sake, fusion energy is just around the corner... :)
An object in space beaming energy down to a planet. Sounds a lot like a Death Star to me.
As for self-replication, that would be a neat trick to master just on earth and is probably still a long ways off; but once we do, it works just as well on Earth. Furthermore, the moon is still a fairly deep gravity well; for any kind of orbital construction, it makes much more sense to divert an asteroid into orbit and use that as the raw material for solar panels, space stations, or whatever, rather than launching from the moon.
> "The problem with regular solar power is that the sun isn't always up." (from the article)
This problem exists on the Moon too. It makes sense to get raw materials from the Moon, but not to put your factory there. It takes about 900 MJ to produce a square meter of silicon solar panel, and their output is about 245 W/m^2 in space. So they make back the energy to copy themselves in 3.67 million seconds, or 42.5 days. Typical working life against radiation damage is 15 years, so the panel can copy itself 128 times in orbit away from the Moon, but only 64 times on the surface, where sunlight is available 50% of the time.
Space Station era space solar panels had a power output of 55W/kg, so a square meter has a mass of about 4.5 kg. Kinetic energy of escape from the Moon is 2.83 MJ/kg, so launching the materials for the solar panel require 12.75 MJ/m^2. The panel in orbit can make back that energy in 14.5 hours, so the extra energy to launch the materials is small compared to the 7.5 years of extra output you get.
Automation was nowhere near as good in the 1970's as it is today, so by all means use automated factories. But put them in high orbit so they get full-time sunlight to operate with. The Moon and Near Earth Asteroids serve as sources of raw materials to feed the factories. The reason you want both is the various asteroid types have different compositions than the Lunar surface and each other. So you get a wider range of materials to work with. In particular, some asteroid types are nearly pure iron-nickel alloy, and others have lots of carbon and water. Those are not easily obtained from the Moon, and any mining engineer will tell you to go for the highest grade ore, because it's less work to extract the product.
There was a NASA paper about the manufacture of solar cells on the moon part: http://ntrs.nasa.gov/archive/n...
--and, now that I look at the NASA site, also this one: http://ntrs.nasa.gov/archive/n...
And how exactly are we going to get this energy back to Earth? With the Simcity 2000 cityzapper?
Apparently this system receives sunlight almost 24/7 (The article mentions there will be eclipses now and then). But what they fail to take into account is that this space platform rotates with the earth in what they show to be a geostationary orbit (The video even has a ground based platform on the surface of the earth where the beam hits...) Therefore, it too will receive day/night cycles because a geostationary orbit can only occur at the equator. Full sunlight occurs in lagrangian points with respect to a system such as this. I suspect it would be necessary to have a global grid like gps and to beam from a lagrangian point to the grid then down to earth at each geostationary point. This would defeat the low density option as then fricken laserbeams would be required. Another option is a global grid of geosynchronous platforms, but that would require the space platforms directionalize its microwave energy over a small arc of movement, rather than being a straight down beam for half a second as the satellite whizzes by.
The comments of someone who knows a thing or two about the economics of space transport: "While Musk loves electric cars and spaceflight, there's one thing he hates: space solar power. "You'd have to convert photon to electron to photon back to electron. What's the conversion rate?" he says, getting riled up for the first time during his talk. "Stab that bloody thing in the heart!""
To avoid seeing this message again, always shut down your computer properly by selecting Shut Down from the Start Menu.
Another space based solar panel plan, excepting the reference to 3D printing I'd swear I read this same thing in Omni Magazine in the early 1990s.
The problem with space based solar is not technological, we have the technology, it's economics. The payback period of this power is much too long and we have more profitable alternatives. A primary one is nuclear fission. There is no shortage of uranium and thorium on Earth for fuel. This stuff is everywhere. Even if someone was unfortunate enough that the highest quality source of fission fuel was seawater they'd still be better off than space based solar. While it would be an elaborate process to get uranium from seawater that is a much easier task than building and maintaining a lunar manufacturing plant.
Building the nuclear reactor would be much easier as well. While building a nuclear reactor is not exactly trivial there are many designs to use as a starting point. The materials required to build are abundant and cheap. Just generally it's a solved problem. The radioactive waste issue is also a solved problem, the only reason it is viewed as a problem today is because we have backward laws on how to deal with radioactive material and because we have not yet built a truly modern reactor. We've been building what is basically the same backward reactors for 60 years.
If someone is serious about solving this problem of burning fossil fuels then they'd have come to the conclusion that nuclear power is the answer, or at least part of the answer. Anyone that thinks we can stop burning fossil fuels and not use nuclear power is ignorant, delusional, or has something to sell.
I am armed because I am free. I am free because I am armed.
This does sound pretty good. The most important factor in what this does is it frees up usable land for other things. The land used by solar panels and factories to make them as well.
There are problems with this idea (and other space-based systems that transmit collected energy back down to the Earth's surface).
The atmosphere diffuses all energy going through it, no matter how attenuated the energy is. The energy being transmitted from these satellites will have the same percentage of that energy diffused as the energy coming from the sun.
Why is this a problem? Solar power systems doing the transmission convert infrared and visible light energy to microwave energy. The former part of the spectrum doesn't heat things up much. How much more microwave energy heats water up is well-known. That's a very significant consideration since over 70% of the Earth's surface is covered by water as well as some of it being suspended in the air.
Solar power is better than other sources of energy by the lack of environmental impact that it causes. Transmitting that energy down from space via microwaves destroys that usefulness. Massive utilization of such a system will negate any benefit the system provides.
Remember that usable land that would be freed up by moving the solar panels off the surface. You'll lose that and more from the rising sea level that this form of energy transmission would easily exacerbate.
Um, if we manage to figure out how to 'wirelessly beam' energy over great distances with an efficiency that's anywhere near useful, and if we manage to solve the problem of what happens when a satellite or an airplane or a flock of birds or whatever flies through the beam, then maybe it'll be time to talk about automating the building of solar power plants on the Moon.
OTOH, if we manage the sci-fu and eng-fu to accomplish those things, maybe we can just efficiently generate and distribute cheap solar electric power right here on Earth, and forget about space robots and moon shots. Just a thought.
'The Economy' is a giant Ponzi scheme whose most pitiable suckers are the youngest among us and the yet-unborn.
Sure, and B.o.B says the earth is flat. I'm not buying from either the rapper or the fortune teller.
Bonus points for why "wirelessly beam[ing]" planetary scale power isn't a good idea. The article ignores the problem of how that even happens, or how a small targeting error doesn't take out Manhattan.
"National Security is the chief cause of national insecurity." - Celine's First Law
Such cannot be "automated" now or even 500 years in the future.
It's dead.
How can a carbon based biological organism compete?
Why is Snark Required?
The referenced paper says that to meet our energy needs through solar power alone we would need an area 92% of Nevada covered in solar cells. Nevada is 286,367 square kilometers in area. 92% of that is about 286,000 square kilometers. There are an estimated 1.7 billion buildings on planer Earth (see https://github.com/svendvn/sam...). If their combined area is less than the area needed for solar cells to power Earth then their average floor space area is less than 168 square metres each (about 1,700 square feet each). A 13 metre (43 foot) square building beats that. Sure, our power needs keep climbing as our population increases. So does the number of buildings required to house and service the extra people. Solar cells are too expensive to put on every roof today, but Moore's law applies. Standard roof tiles will one day come with some level of photovoltaic capability baked in.
All space-based power solutions are essentially:
1. a system that gathers solar energy and either concentrates it, or converts it to microwave energy.
2. a very-accurate tracking and targeting system to focus that energy onto a small target on the rotating surface of the Earth from the moving station in Earth orbit or the Moving and rotating moon.
This would ALSO be the world's biggest space-based super weapon with unlimited ammunition and untouchable by most nations on Earth. Nobody could put this up without a massive geopolitical blowback on Earth that might re-align international alliances, treaty organizations, etc. And all for what???? We can get cheaper energy right here on Earth from coal (which is already in the environment - it's not sitting "sequestered" in pristine titanium containment vessels somewhere)
That we don't have ....
And are very unlikely to have for the forseeable future.
And if we had replicators, we could probably pull tricks that'd make death rays in orbit unecessary anyway.
Perhaps a silly question but something that must be worked out, this base needs power but the sun sets on the moon just like it does on Earth, is this moon base solar powered too? If so then what do they propose the base do while the sun goes down for something like 400 hours?
I suppose the base could be placed on one of the poles, that would give it 24/7 daylight but I suspect this messes with the launch of the solar collecting satellites. I'd expect that a launch from the equator would take less energy than a launch from a pole. If there are three or more solar collectors on the equator, spaced somewhat evenly, and connected with long wires, then it could get 24/7 power. At that point it might be easier to have a polar power station and an equatorial launch station, again connected with long wires.
What else could power this moon base? Even if there was coal or oil on the moon there's no oxygen in the atmosphere to burn it with. There's no flowing air or water to derive energy from. What else is on the moon for energy? Uranium perhaps? Thorium even?
They'd be digging up all kinds of rock to get out things like iron, aluminum, and silicon. So what's left over? Well the processing of the rock for the solar panel material already gets you at least half way to extracting the fission fuel. Why not harvest that for energy too? Sounds more productive than building a trans-lunar power grid. It would also mean more solar panels launched instead of being used to power the base.
Another question, how much energy does it take to launch something to Earth orbit versus launching it to the Earth's surface? I'm curious since if we are extracting this fission fuel, and we have a launch system that can carry large solar arrays, there might be some left over thorium that can be dropped to Earth. Solar panels in orbit might be more efficient than those on Earth but Earth based nuclear power plants work much better than those in orbit.
Another question, aren't moon rocks a lot like Earth rocks? They'd have similar compositions as far as content of nickel, iron, silicon, and thorium, no? We'd have to build robots that can dig up rocks, extract the minerals, sort them out, and form them into parts suitable to create things like solar panels, rockets, and more (for growth or just replacement) robots. Why not just use these robots on Earth to build solar panels on Earth? The thorium and uranium they extract as byproducts could be used in nuclear reactors. We'd also be able to skip the step of building rockets and rocket fuel and simply build more robots, solar panels, and nuclear reactors.
These Earth based solar panel making robots would not need to be completely autonomous since they'd be easily accessible to us fragile humans that can't work on the moon without a habitat or cumbersome protective suits.
One last question, what do they propose these lunar robots use for rocket fuel? The stuff we use to launch rockets from Earth tend to be based on petroleum. These rocket fuels might be in the form of kerosene, derived from petroleum, or hydrogen, typically derived from natural gas. These fossil fuels do not exist in vast quantities on the moon. Even hydrogen derived from hydroxide minerals would be difficult to obtain. The rockets could be nuclear powered and use a variety of gases for the working fluid, that might cut down on the mining required for rocket fuel. Getting enough gases to use as a working fluid is likely problematic on the moon as it has no atmosphere to speak of.
I have to wonder how much actual thought was put into this proposal.
I am armed because I am free. I am free because I am armed.
I can't wait for customers, taxpayers and voters, as well as hippies, yuppies, millennialist, and jobless, homeless, crack-addicted bums, to be replaced by robots too, and we can finally eliminate the need for humans in human society altogether, once and for all!
-Nota Robot Atall!
The main issue with space solar systems is delivering the energy collected. The favored way is to send the energy as microwaves.
Deciding on a target is a problem. "Who/what shall we cook today?"
"The concept of space based solar power has been around for decades"
The IDIOTIC concept you mean. Anyone with a calculator, let alone Google, can demonstrate how RIDICULOUSLY MORONIC this idea is. Sorry for the caps, but in this case that are appropriate. Here, try it yourself:
https://matter2energy.wordpress.com/2012/03/17/the-maury-equation-redux/
https://matter2energy.wordpress.com/2014/02/25/lunacy/
I don't have anything to add to the debate other than to say that that is an awesome headline. It was awesome enough after "built", then even more awesome by the inclusion of "Robots" then to just go completely mad it added "Moon" - Robots on the Moon! My head just exploded
Sharp glassy moondust, which is electrostatically charged, and robots don't mix well. It probably killed the Chinese lander.
"How Space-Based Solar Power Plants Could Be Built By Robots On the Moon"
Best headline ever.
So they're proposing robots only? You tender little humans, let me pat your hand, sit there in the shade, and we'll take care of everything...
Screw that. Put people up there, hell, there's be plenty of jobs, including the crowd control and refreshments for those of us in line to go.
mark "what's here for us (pointing to the GOP)?"
Robots on the moon deserve a decent moon living wage of 15 Lunar Credits an hour.
Rise up! You have nothing to lose but your chains!
-- Tigger warning: This post may contain tiggers! --
If we develop practical self-replicating robots (since we can 'almost' do a proof of concept self-replicating one now)
If we develop technology to plausibly 'mine' surface material (i.e. moon regolith) that's not more involved in shipping material
Bonus if: If we can make both happen in a hard vacuum where no one has set foot in decades
Extra bonus: if we can prove out transmitting GW (much less TW) power from geo-stat orbit
Then of course let's do this. In reality this sounds like any of a dozen sci fi books I've read. Send magical self-replicating robots off to do some job and let them multiply. I'm surprised they didn't include nano-something to make it even more gooder.
Any major aspect of this project would be easily be worth many times over the $350 projected cost.
You can get rich if you own a politician, but you have to be rich to buy one in the first place.
And how does TFA propose to make self-replicating robots feasible?
The first step would be to simplify the solar panels' design as much as possible. "Instead of having 1,000 different types of screws," he says, "let's have five."
Brilliant! Don't you HATE how current-generation solar panels use 1,000 different types of screws?
That that is is that that that that is not is not.
In my lecture series, I demonstrate how the Internet, affordable space access and Telepresence combine to allow solar energy farms to be built in orbit, at L points and on the moon - by people on earth remote controlling androids and robots.
Have you done the math? Any such scheme if it is going to provide a significant amount of energy to the Earth will not be so diffuse. The more diffuse you make it, the less-efficient the transfer and the greater the requirements for the Earth-based power receiver station. The people who always push this sort of thing always offer it to the public as a panacea that will replace a great many coal/gas/nuclear facilities. The reality is more like the large Crescent Dunes Solar Energy Project near Tonopah which was intended to generate 110MW and is under-performing and likely to be shuttered. For a significant space power base station that was safe enough that it only fried thousands of birds per year as the Tonopah site does, the ground station would probably need to cover half of Nevada ;-)
The sword has two edges however: The second edge is political/PR. Do you SERIOUSLY expect a public that is so easily propagandized to fear GMO crops, cell phone radiation, and lead in the solder of their consumer goods to quietly go along with a massive "microwave oven in space" with its open door aimed at little school children on soccer fields?????
Someone get this person a copy of Stargate-SG1 to see just how bad the idea of self replicating robots is.