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Planned Constuction of Orbiting Microwave Power Station
Fith writes "A small news item tells of a research project to build robots that will assemble and repair a gigantic orbiting solar collector. You'll have to scroll down a bit to find the section. Basically, power collected will be beamed back to earth using 'safe levels' of microwave energy. " This is a proposal that's been floating around for quite some time-vast LEO or HEO solar panel arrays, beaming the power down to earth. For those of you who played, Simcity2000, this was one of the power options as well. NASA hopes to part of this operational by 2015.
Solar cells pull 75W/m^2 and harness the proven energy of the sun. Side effects include sunburn.
Also, while a single power plant may not have a big impact, with global warming being a concern, collecting more solar energy and focussing it on earth is the wrong direction to go in.
The solution to energy problems on earth seems to me not to beam in more energy from space but to conserve more energy at home. The US in particular is so wasteful of energy that the kind of money spent on those projects would be better spent on some simple, down-to-earth conservation programs.
(I also wonder why this particular avenue is being pursued. Technically, it would seem that simple mylar reflectors in space for night time lighting of urban areas would be a much more logical first step. They could help conserve a lot of energy, would be technically much simpler, and couldn't be easily repurposed for military use. To me, that alternative makes the microwave-based approach suspiciously look like dual-use technology and a boondoggle for certain kinds of research.)
Microwave energy would be cheap and clean to harvest from space. I'm sure we all remember the Simcity 2000 disaster where the microwave beam went "off-target" and traced a path of destruction across the city, however. :)
In real life, I don't believe we have to worry about such things.
æeee!
But what if the beam misses the power station here on earth? What if it blows up all the surrounding arcologies??
These answers are not actual answers. I'd have to check my 'propaganda machine' in order to provide sources, references and hard numbers, but...
1) How much fissionable fuel do we really have given _current_ technology?
Essencially limitless. I say this because I've seen projections of consumption and demand (granted, from pro-nukes). These guys feel that nuclear power could supply all of the worlds power needs for thousands of years. Sans fossil, at linearly increasing demand.
Also, I've heard that the fission power would provide enough juice to get fusion off the ground. There's enough hydrogen in them there oceans...
2) Do you have a good waste disposal solution?
I'd said in other posts that the only reason there even is a high-level waste problem, is the regulations imposed on nuclear facilities. The same tech that reburns waste down to an inert state can be used for making weapons, and the Fed doesn't like that being publically available. After all, if the TVA decided to sell Plutonium to the Contras, all hell would break loose.
As for disposing of low-level waste, well, that's equivalently radioactive to the coal ash that comes out of a traditional fossil plant, if not less so. We use that crud to pave highways and fertilize fields.
3) given that wind power is cheaper per kWh (yes, true go research it!), how can you justify the cost?
Actually, here I agree with you. Renewable, 99.44% pure enrgy sources are preferable. There's no risk of accident - no matter how small. Sure, the tower might collapse and kill someone, but it won't render the landscape useless for millenia.
But the wind dies down, the clouds roll in, rivers dry up now and again, and Greenland is so far away. Fission is much more... predictable.
I think that the key to successful power management is the same as for financial investments. Diversification.
Use fossil as the first level, hit-and-run power source to get new infrastructure established. Then put in the nuke plant to serve as rock bottom supply and take the fossils offline. Then, based on the geography and weather conditions of a region, install an enviromentally passive system.
I grant you, a 'natural' system would suffice if there were a single entity responsible for transmission and distribution of thus generated power over an immense area, but you have to accept that it would be a government monopoly. Can't make it work in a deregulated industry.
The other option is to have smaller, cooperating entities, that can supply their rock bottom need (nuclear) and provide their own spinning reserve for nominal use. Then deal with the T&D issues with their peers.
-- What you do today will cost you a day of your life.
Just think of the benefits that could be realized with microwave irradiation.
We could maintain a comfortable minimum temperature in some of the world's coldest areas. Imagine, Fargo in the middle of winter, at a balmy 75 degF. Weather forecasters could actually guarantee tomorrow's highs. Swimming pools and car engines would always be warm, as would be the toilet seats across the nation.
If we can tighten the beam enough, and develop super-precise satellite navigation systems, we could use one of these puppies for snow removal on the nation's highways. We could even melt a few hundred thousand acres of the Sahara for use as the world's biggest mirror for the world's biggest telescope..
Now everyone, from L.A. to Bangor Maine can have a nice tan. Just go out during the designated irradiation period (day or night) and stare up into the sky. Oh, and all the stylish tinfoil hats we'd all have to wear. And clothes would stay 'fresh-from-the-dryer' warm, all day.
Remember how grandma would cool off freshly baked pies by setting them on the window sill? Well, now we'll be able to thaw the Thanksgiving turkey that way..
Just think, no more mosquitoes! At 6:30 each night, get off the patio. Then ZAP! 30 seconds later, not a 'skeeter in a 500 mile radius. Just be sure to bring in the pets.
We could aim the thing at the Antarctic, and make the world's biggest ice sculpture... Seriously though, maybe carve off a big iceberg and haul it to where there's a drought? Well, maybe not.
On the down side, leaving a dog in a closed car on a hot summer day would be kinder than leaving him out on the lawn. Hot dogs anyone?
-- What you do today will cost you a day of your life.
There's no need to spend money on this kind of science fiction for a while.
Fusion research has been languishing for years, obtaining only small slices of the funding pie. Despite this fact, researchers have already developed fusion reactors that generate a controlled energy profit. Granted, there are cheaper ways to boil water today, but the price tag is shrinking.
Fusion power plants would create no radioactive waste whatsoever. They take in deuterium (a Hydrogen isotope found in so-called "heavy water", which is easily mined right from the oceans), and put out energy, Helium, and other harmless by-products.
As an aside, note that Helium is a "perishable" resource; the Earth was only born with so much, and it's light enough to escape into space. People laughed a few years back at the "waste" of money in maintaining a national Helium repository, but they shouldn't have. It's a very valuable element for research, and it's disappearing.
Fusion power would utilize a plentiful resource, and provide energy at enormous efficiency (*much* greater than current fission-based nuclear power), without harming the environment. Yet, it continues to get scanty funding.
Write your Congressman and encourage spending on a power supply that has already been developed and has no bad side effects. This microwave stuff might be quite helpful for supplying the moon with electricity (of course, so might simple aluminum foil reflectors that simply concentrate sunlight on lunar power cells), but we're still a ways off from needing it there. Perhaps the money that would be saved by replacing our current power plants with fusion-based counterparts could help pay for the next leap ahead in the space program.
The article that you cite does mention that there has to be a return path; this would mean either a loop or other more exotic methods (such as the plasma gun suggested in the article).
The setup described is fundamentally different from what the original poster was suggesting, though - the sky hook generates power from the motion of the shuttle through the Earth's magnetic field. The original poster suggested stringing wires from the surface of the Earth upwards, which are stationary with respect to the Earth's magnetic field.
Any method of power generation that taps motion with respect to a magnetic field is actually just drawing power from the kinetic energy implicit in that motion - i.e., as you generate power, you slow down with respect to that field. For something in low earth orbit, like the shuttle using a sky hook as described, this will eventually degrade your orbit and bring you back to earth. The kinetic energy that you're tapping is also just the kinetic energy that you gave the shuttle during liftoff - so using this kind of scheme for power generating satellites is not useful, as you are just getting back the energy that you put into the satellite in the first place to put it in orbit.
There are other neat ways that you can use sky hooks, other neat things that you can do with extremely strong tethers, and ways of using tall towers to generate power on Earth, but these are beyond the scope of this discussion.
There were experiements which showed that we could actually construct nuclear power plants which burned off all of the excess radioactive waste except for a very small amount which isn't even harmful.
There were experiements which showed that we could have actually constructed nuclear power plants which used HALF as much water as current ones and STILL cool effectively.
Of course, we can no longer construct new nuclear power plants, so they may end up going down in history as bad just because the older ones produce tons of harmful radioactive waste and we cannot build newer ones which wouldn't.
Hopefully we can get the kind of power from microwave power plants that would could in SimCity 2000 and 3000. If not, we can always turn back to safe nuclear (The problem is convincing the rest of the world that this is possible.)
Julian
--
eMail: x-virge@shafe.com
icq: 1521358
http://www.delanet.com/~jkmissig/
First, bomb-grade plutonium was only made in Hanford, WA in a facility called the "N reactor", if memory serves. This was a special unit, which irradiated uranium very briefly before reprocessing it to extract the plutonium. Spent fuel from commercial nuclear plants has never been used to make bombs; most of it is still sitting in cooling pools at the plants where it was used. Conclusion 1: Commercial US nuclear power was never associated with bombs.
Second: The requirement for bombs is that plutonium have very little of the troublesome 238, 240 and 241 isotopes. If you have very much, the bomb is far more likely to "fizzle" than explode. As soon as plutonium is created it begins to transmute from the neutron bombardment, so making bomb-grade Pu requires removing and reprocessing very frequently, on a schedule of weeks. Fuel in commercial US nuclear plants is left in the core, running at far higher power levels than the N reactor, for years. By the time it comes out, it's so chock-full of higher isotopes that no bomb designer would even think about using it. The rate of spontaneous fissions is so high that you can't get a supercritical mass assembled before it takes itself apart (without producing any significant bang). Conclusion 2: Commercial US nuclear power reactors cannot be used to make bomb materials (and still make power). Soviet RMBK's are another matter, but we don't use them.
Now go, and FUD no more.
Washington D.C.: (AP)
Hackers [yeah, I know, but it's a news story] took over the Eastern Seabord Microwave Generation Satellite earlier today, and threatened to redirect the beam at downtown D.C. if Kevin Mitnick was not released immediately.
Al Gore, the inventor of microwave energy, who singlehandedly placed the aforementioned satellite in orbit, declined, to the dismay of the hackers.
Officials at the Pentagon were heard to scream in agony as the installation was turned into a smoldering heap of molten slag.
The hackers, subsequently, threaten to defrost Hillary Clinton; but assure that the Antarctic penguin habitat is not threatened in any way.
-- What you do today will cost you a day of your life.
L. Ron (and NASA for that matter) stole the idea from Issac Asimov. One of the stories in "I, Robot" was about a station that collected solar energy and fed it back to earth in a tight beam. It even mentioned the effect it would have if the beam went off even by a fraction of an inch.
This was written in the mid/late '40's, I believe.
Not all radiation is the same. Unlike radiation from nuclear reactions, RF radiation is not annodizing radiation.
If you put a frog in a microwave, you're less likely to get a mutant frog than French cuisinne.
RF basically just bakes things; not much different than getting burned. The nasty thing is that, unlike a good 'ol fire-induced burn, RF heats tissue up from the inside out. So if you're subjected to a high degree of RF radiation, you're likely to be damaged by it before you begin to notice warnings. The amount of damage is deturmined by the power of the RF source, the distance from that source, and how long it took you to notice you're being radiated (length of time exposed to the source).
The Arthur D. Little (consulting) Company first championed this idea back in the 1970s, long before Sim City.
Probably the best place to prototype microwave power transmision would be at the Straight of Belle Ilse, in Canada, between the Island of Newfoundland and Labrador. Vast quantities of hydro-electric power are going undeveloped in Labrador because there is no way to transfer it across the 20 miles of the Straight. Undersea cables won't work because icebergs drag across the bottom of the Straight in winter. Tunneling is prohibitavely expensive due to the hard rock.
The biggest problem, however, relates to concentrating the power, from whatever source, just before creating the microwave beam. You have lots of megawatts all going through a single point. Any resistance at all -- and you quickly heat your concentrator and vaporize it.
Eliminate the Price-Anderson Act, and the civilian Nuclear Energy system would be shut down by the beancounters.
I'd blame it more on the lawyers and public hysteria. Just as Dow-Corning has been bankrupted by breast implant suits despite the latest scientific evidence claiming no link between implants, the threat of lawsuits is enough to cripple development of further plants. Yet the ones that exist in the U.S. work cleanly and safely, as opposed to coal plants which result in coal miner deaths, hydroelectric plants which disrupt the whole water ecosphere, fuel-burning plants which lead to spills, etc. Maybe solar plants (using mirrors to concentrate the light, so the environmental impact of the collectors is low), wind-powered ones, or salinity or thermal-gradient plants could do better, but not by much.
Ooh, a sarcasm detector. Oh, that's a real useful invention.
(Imagine, what is the likelyhood that smacking my computer with a hammer will make it work **better**?)
Accually in fact Microsoft and Intel are setting up a new test lab where they provide and infinate amount of monkeys and infinate amount of hammers and let them hammer out the bugs in computers. Microsoft was quoted as saying "Hey if they wrote Shakespear I bet they can create W2K." While Intel was quoted as saying, "Hey we've already surpassed the laws of physics getting computers to compute a instruction faster than light can travel across your motherboard."
Oh btw.. I thought ball lighting was real and not just a myth?
The cause and effect are probably reversed there. I wonder how many intellectual people choose to use cell phones..
fellow came into the plant (the Nuclear Power Plant) a few years back and set off the alarms on the way in
Amen! Due to the very vocal and hugely ignorant opposition to nuclear power, most people don't know the facts. FUD is rampant against nukes, and when people hear the word 'nuclear' they think Hiroshima and Chernobyl.
The facts are:
Nuclear can be very dangerous, when it goes bad. It's quite spectacular. But, it is so regulated, and the people involved are highly aware of the dangers, that the likelyhood of accidents is miniscule.
I would think that the ignorance level about this field of science would be pretty low here on
-- What you do today will cost you a day of your life.
Remember when nuclear power was being deployed, the hype that surrounded it? The "killer app" of power turned out to be more of a killer than anybody had bargained for. Even if Simcity 2k style things don't happen, are there other things that might? For instance: It stated in the article that the levels of radiation will be "safe." I presume that means safe for humans, i.e. non-lethal dosages. But remember that radiation has a tendancy to mutate things, and that humans are not the only thing that can mutate. So can birds, frogs, and airborne bacteria. While it may seem farfetched, it is entirely possible that these moderately high-powered beams of radiation could create such a high level of mutation in airborne bacteria as to create a "super bacteria," resistant against antibiotics and, most importantly, already airborne. Just some food for thought.... Russell P.
See you, space cowboy...
the NASA will be sued for patent infringment really soon by the makers of SimCity2000.
There was an article in the Pittsburgh Post-Gazette earlier this week. Here is an online version:
7 12solar1.asp
http://www.post-gazette.com/healthscience/19990
It's much longer and more informative than the one on the CMU site...
Um, hot water gets deposited back into the environment with all kinds of power plants, not just Nuclear ones. Coal burning, Gas burning, Geothermal, they all dump hot water back into the environment (or let it turn to steam, depending on the design). The only ones that don't are Windmills (which have very limited usefulness), Hydroelectric (which also mess up spawning patterns of fish), Solar (dang near useless unless you live in the desert), and Hydrodynamic (which havn't been built yet AFAIK). There might be some other types that don't dump hot water, but they're not practical (or at least not in use).
I read the internet for the articles.
The whole thing has to be a joke! "Safe power levels?" You need a few megawatts to power a small manufacturing plant. A whole city requires thousands of times that. How is billions or trillions of watts going to be safe? Will it ionize the air on the way down? Safe power levels should be less than the intensity of our sun, otherwise imagine bugs under a magnifying glass. So, why not use solar cells? They are proven, yet still costly at about $20,000 to really do a house good.
The thing would make a wonderful weapon to control the population that is so naughty with that internet porn, encryption, and terrorism. We can't have citizens get out of hand...
Actually, many types of rocks are radioactive (though something like, say, a spent fuel rod is a few orders of magnitude _more_ radioactive). There is actually a significant health hazard if the bricks and concrete in your basement are made from stone that is high in Thorium. As a part of its decay chain, Thorium becomes Radon, which is a radioactive gas (the heaviest of the inert gasses). This tends to collect in basements, giving you dangerous radiation exposure if you are exposed to it for years.
This has been happening for as long as rocks have existed on Earth.
Now, I'm not saying that nuclear power is without its dangers; I'm just pointing out that many rocks are indeed radioactive
Only as clarification, for the benefit of the under-informed: not directed at the original poster.
Old plants produce highly radioactive waste due to regulations, not inefficieny. The result of fission on U238 can be enriched, and reburned, repeatedly, until what remains is less readioactive than the granite under our feet.
However, the process that does this, can also be used for producing weapons-grade fissionable materials, and the NRC/DoE/DoD don't want that tech to be in the public sector.
It is NRC regulations that require that high level redioactive waste be burried in mountains, at significant cost, rather than used for fuel.
Consider the analogy of pig farming. You grow corn to feed your pigs. Your pigs make waste.
You can use the waste to fertilize your corn, and to produce methane. You can use the methane to power generators to make electricity. You can use the electricity to run lights, ventilators, water pumps and the like. You can deliver the water to the pigs, and to irrigate your corn crop. You can then sell excess corn to buy more pigs.
But, the waste smells bad, so the government makes you bury it.
-- What you do today will cost you a day of your life.
The site is slashdotted already, seconds after being posted here. That has left me with a ton of questions.
I wonder how they are going to focus a beam with hundreds of megawatts of power in it down through the atmosphere. There are all kinds of engineering problems to overcome, such as dispersion of the beam in the atmosphere, reflections and deflections of parts of the beam by atmospheric winds, compensation for changes in the temperature and humidity of the air.
How large a target will the beam be aimed at? Presumably a field several miles across full of receiving antennas. The antennas near the center of the beam will receive full power, while antennas at the edge would receive only a few percent.
How do you keep birds from flying into the beam area, and what happens to people living near the receiver? Do you move all the citizens out of the area, and declare it a danger zone? How do you shield the operation engineers working near the site?
I think NASA is hoping to get a small pilot program up and testing in the next 20 years or so. There is a lot of research left to be done.
And the SimCity beam was one of the best. Bzzzzzzzzzzzzzzzzzzzzzzz.
the AC
Hemos is like...sci-fi fans;he thinks technology is cool, but he hasn't bothered to understand the science it's based on
That's somewhat interesting, but I've never seen the case study myself, and wonder what kind of control group they used -- maybe people who use cellular phones are simply more intelligent and imaginative and use phones because of that. My interpretation of what I was told (by an MD) was that the cellular radiation stimulates activity in regions of the brain where without the cell phones there would be none.
However, the nice conclusion exists, given this premise, that microwave radiation that misses the target and haphazardly strikes people will benefit the overall IQ level of the country. Maybe we should target some high schools and examine the effects.
Note: It has never been conclusively shown that cellular radiation increases the chances of brain tumours. I worked in a nuclear power plant -- the fear of radiation is greatly exaggerated, I assure you. Live in the average Ukranian basement for 8 months and you'll exceed legal Canadian doses of radiation (legal, not lethal :P).
Radiation becomes a problem when it is in the form is acute doses -- high exposures in a short period of time. Just for the sake of a story: a fellow came into the plant (the Nuclear Power Plant) a few years back and set off the alarms on the way in. It was surprising to discover that the source of the radiation that set off the alarms was in his belly -- a result of him eating Caribou meat over the weekend when he went hunting. The Caribou were eating lichen off rocks, and rocks are radioactive, and hence the Caribou meat was releasing enough radioactivity to set off the alarms at our wonderful Nuclear Power Plant.
Um, no.
Firstly, in order for your weight to pull the wire outward, it has to be at or above the altitude at which geosynchronous orbits are normally found - about 40,000 km (about 25,000 miles). That's more than 100 or 200 km. The _wieght_ of this wire will be very substantial - enough that the tensile strength on the wire is far greater than any material currently in use can sustain. Find materials that can take these kinds of stresses, and we will be able to do far more interesting things than generating power.
Secondly, I think you mean the sun's magnetic field (carried outwards by the solar wind). The earth's magnetic field rotates with the earth - your wire will not be moving with respect to it, and so will generate no power from it. The sun's magnetic field will give you power, but it's open to question how much (could someone with the required numbers and background provide an estimate, please?).
Thirdly, you need a loop of wire to generate power from a magnetic field in this manner, not just a single wire. If you had magical cable that could withstand the required stresses, this could be built in the manner you describe, but that's a pretty big "if".
In summary, there are a lot of other methods that can be implemented _now_ that are more practical.
A minor quibble here - the amounts of waste produced are actually quite small. The energy density in nuclear fuels, even when burned in conventional, inefficient fission plants, is between four and five orders of magnitude higher than the energy density of fossil fuels. Correspondingly _less_ fuel is needed, and so you wind up with between 10,000 and 100,000 times less waste material than with fossil fuel plants.
Instead of a billion tonnes of coal burned to produce three billion tonnes of CO2, for instance, you'd get ten thousand tonnes of uranium oxide producing ten thousand tonnes of plutonium oxide and mixed nasty isotopes.
This is still not negligeable, but you could store this in a gymnasium with room to spare. Compared to a _billion_ tonnes of coal.
What we actually need is a reliable way of storing _small_ amounts of waste for very long periods of time. That, or transmuting it all into something with a shorter half-life (expensive).
>Just put the energy in a really big Tesla Coil.
Cool! Now we're at C&C Red Alert! I REALLY liked the Tesla Coils's. ZAP!
jf
Actually, there's more information about this at NASA, in an article entitled Integrated thin-film solar power satellite. It goes into more detail about the part we care about -- the satellite and its uses -- instead of the robot being developed at CMU to help construct the darn thing. It even has a couple of MacPaint-like pictures of what this thing might look like.
What about (as someone else mentioned) flying objects which end up in the path of the beam? Even if it would pass through us, it would get absorbed by rain clouds (making it just as effective as those solar panels we were all promised in the late '70s), or worse yet, by birds, airplanes, and other flying objects... Certainly, the danger of the solar collector crashing to the ground is less than that of an orbiting nuclear reactor or black hole...but it still seems a bit unsafe. For this thing to be useful at all, it's got to transmit multi-megawatts of energy from point A to point B, and that energy will inevitably get absorbed by SOMETHING in the area. And if the levels are low enough to be "human-safe," then they're barely going to be able to light a bulb, let alone run something useful (like a section of a power grid).
That's why NASA is looking at using these things more to transmit power to lunar bases, Mars missions, and the like. In these controlled environments, something like a giant orbiting solar panel make a heck of a lot of sense:
P.S. Anyone reading this remember when parts of your 'Net link were transmitted by microwave? Our link in college used to go down regularly, and a call to MIT confirmed that their microwave link to BU (or was it BC? I can never remember) was down due to rain. Sure adds another dimension to the concept of "Internet Weather Forecasting!" :)
"But always she's the spectre of uncertainty I first endured, then faded, then embraced..."
There are different kinds of radiation. Just
because people call microwave ovens "nukes"
does not mean that they actually use nuclear
radiation.
Quick science review: There are two main types
of "radiation" in this context: that caused by
acclerated particles (alpha and beta radiation,
produced by fission and to a lesser degree
fusion) and electromagnetic radiation.
Hopefully you know that all electromagnetic
radiation is essentially the same thing. It's
a vibrating electromagnetic wave, the only
important things are the frequency and the
intensity. High-frequency stuff (like gamma and
x rays) are "ionizing"; even a little of it can
knock an electron free of an atom. If this
happens to DNA, presto, you have a mutation.
Visible light and microwave radiation are "non-
ionizing". Unless you have a lot of it,
it won't do damage to individual molecules. You
don't want to stand in front of a powerful
antenna, but that's not because it's actually
ionizing atoms in your body. It's just dumping
energy into it, which shows up as heat. You can
get cooked that way.
Now, cells put under stress do spontaneously mutate from time to time. As I
understand it, this is why sunburn can cause
skin cancer; I don't think that ultraviolet light
is considered ionizing.
Bacteria might proliferate in a warm area (such
as a proposed microwave power receiever would
be) but that's no different from fish accumulating
near nuclear power plants because they like the
heat from the cooling water.
PHEM - party like it's 1997-2003!