dlkf writes: "There is an article on Space.com that talks about some of the benefits, costs and current research relevant to using satellites to generate and store power. This surplus of power could then be beamed via laser or microwave to earth or other satellites."
let's all pray that Nasa's aiming is a darn site better than the military or we'll all be fried:)... time to get those anti-laser suits for my cats i think
will we be reading this again 25 years from now
by
hagbard5235
·
· Score: 3, Insightful
This was first seriously proposed by
Gerald K. Oneill of Princeton University in
1975! It was feasable ( and even profitable )
then, but the capitalization was to high for
any organization on earth but the US Government
to undertake. The only reason we haven't done
it already is because of a defect of will, a
myopy of purpose, and inability to look further
ahead than the next election.
When will we, the citizens of the United States,
have the vision to demand these sorts of
projects from our government? Oneill's initial
proposal had an estimated 20 year pay back time, for
the first powersat. Subsequent powersats would
have been much cheaper. If the proposal Oneill
made had been taken up seriously in 1976, and taken
say 2 years to get it's political legs so that
actual work began in 1978, and it took ten
years to build, we would have had cheap abundant
energy by 1988.
Given cheap abundant energy it would be feasible to
produce, for example, metal hydride or fuel cell
powered cars. Given a 10 year ramp up and phase in
for those technologies we would have in 1998
been largely petroleum free ( at least for
power ).
Does anyone question that this would be a better
place to be... and we could be there by now, if
only we had the vision, and the will.
I remember this...
by
Rob.Mathers
·
· Score: 5, Funny
from SimCity2000. I based my entire city's power grid on 4 of these things. Then the microwave beam missed, and blew up two of the other power plants.
Wonder why the bots from the Matrix never thought of doing this?
They have probably never seen Highlander 2. Not that many people have.
Why not use the acres of urban tarpaper?
by
SgtChaireBourne
·
· Score: 5, Interesting
There must be millions of square kilometers of flat rooves in the world's cities. Since most are neither generally accessable nor designed for regular activties, they'd make
an idea place for solar arrays. You could even use DC instead of AC due to the proximity, but that would be a bother. In hot areas, the shade would help lower the temperature of the upper floors.
-- Beta is broken and the link to classic doesn't work. Stop wasting our time or there won't be anybody left here.
Re:Why not use the acres of urban tarpaper?
by
markmoss
·
· Score: 3, Informative
If we _are_ going to solar power collected on Earth, then covering rooftops is definitely the way to go. It's been a long time since I did the calculations, but the way I figured it (1) we'd need less than 50% of the total roof area in the US, and (2) blocking the sun from that much undeveloped land would be a massive ecological disaster... (There is life even in the Nevada desert.)
But it's very expensive. Solar cells cost over $1/watt the last time I looked. And 1KW of solar cells gives you far less than 1KW of delivered power most of the time -- they are rated for peak power, which is aimed directly at the sun at noon on a clear day on a mountaintop in the tropics. I did some datalogging with a small solar panel where I live this summer; in a Michigan summer, clear days give you the equivalent of 2 hrs/day at full power. Many days aren't clear, some are so cloudy that I never got enough current to measure. Overage, I think a 1KW panel around here will collect 1KW-hour per day in the summer. Winter is going to be a lot worse. I'm also testing a small windcharger -- it didn't collect enough energy to notice in September, October is shaping up a little better, and maybe it will give a decent power output when the winter storms start hitting...
California would be better, and Tucson AZ might get 5KW-hour/day. Most American homes use considerably more than that, so you need several KW of collector. Then you also have to store the energy for night-time use. In a house-sized system, that storage is batteries, so you also need a batter charger and inverter to convert from and to AC. I'm told that the overall cost of a solar power system (panels, batteries, electronics, and wiring) for one house is $20K to $60K, and that is if you cut your power usage well below average and use either a back-up generator or a connection to the power grid for prolonged storms. (In northern Michigan, we'd probably be on back-up power Oct-March, unless another $20K into windchargers would give us winter power.) Or you can pay the power company about $100/month. It only makes sense if (1) you are an eco-freak, or (2) your house is so far back in the woods you have to pay $10K or more to get a power line hooked up. But then you also have to buy the massive inverter needed to power a well. (You can't run a 4 inch submerged pump from 24 or 48VDC -- the wiring needed would be too thick. You need 240V to bring the current down.)
If you are putting solar panels on city/suburban rooftops and connecting them to the grid, then the costs are probably lower. Each place needs an inverter that will sync to AC already on the lines -- in mass production that's not much more expensive than the inverter needed for stand-alone operation. There has to be one big energy storage system, but on a large scale there are cheaper options than batteries. For instance two ponds, one on top of a hill, one at the bottom. Pump water to the top in the daytime, and let it flow back through a turbine at night. Or convert excess electricity to hydrogen, and store it or pipe it to someplace less blessed with sunlight, then burn it in gas turbines, fuel cells, or even a converted coal plant.
But notice that in any of these cases, the final stage is still as costly to build as a conventional (fossil-fuel or hydro) electric system, plus someone has to pay for all those solar collectors, and inverters. The economics isn't there until either fuel gets more expensive or solar cells get much cheaper.
So how is a solar power satellite going to beat this? It will stay at peak power 24 hours a day, so you get 6-12 times as much energy as from the same solar panel in L.A. and reduce the requirement for night-time storage and backup power, but that's not nearly enough to make up for the launch costs.
However, an SPS does not have to use expensive semiconductors for energy conversion. Use a big mirror (e.g. a balloon with one half clear, the other half aluminized) to focus the sun on a boiler. The mirror stays pointed just by pointing the power plant at the sun and then spinning it around the mirror axis. (Pointing the microwave antenna at a fixed spot on Earth could be a problem -- maybe use phased arrays?) The only heavy parts of this system are the boiler, turbine, and condenser. Big steam plants get well over 30% efficiency, and this is better than any solar cell I have heard of. You could do this on earth too, but you've got to turn that big mirror to follow the sun, brace it against winds, etc., so it's pretty costly, although at this time it would be definitely cheaper than launching a much lighter SPS into space...
What would really make it economical would be to mine the materials and build the SPS in space. And the enthusiast's real goal is to get that mfg capacity up there -- because then they could build pretty much anything needed to colonize space. And if some earth-based gov't thinks they have to pay taxes...oops, lost control of that beam for a few minutes, sorry.
Re:Why not use the acres of urban tarpaper?
by
markmoss
·
· Score: 3, Informative
Actually, the best orbit for beaming to one spot on the ground is not just geosynchronous but geostationary: above the equator & 24 hour period. Because the Earth's axis is tilted, the orbit is at 40,000 miles radius, and Earth is only 8,000 miles in diameter, the satellite rarely passes into the Earth's shadow. At the equinoxes, it will be shadowed when it goes around the far side of the Earth, but that's only a couple of hours a day or less for a few days. So for that couple of hours (which would probably be around midnight), you have to draw power from some other satellite in a slightly different orbit, turn on your hydrogen-burning back-up power turbines, or simply declare a "blackout holiday". The rest of the year, the satellite is "above" or "below" the poles while transiting the far side.
Re:Radiations would kill us all
by
Faulder
·
· Score: 3, Informative
The wavelength (frequency) of the microwaves is what makes it excite water. I'm sure they would not be using the same wavelength to transmit energy from space to earth. Clouds and water vapor in the air would affect it.
Re:Bad Idea... Perhaps not
by
conan_albrecht
·
· Score: 5, Informative
I recently discussed this idea with a planetary scientist. We did a little research and here's what we came up with:
The microwave beam does not disrupt any planes, etc. because they are made of metal. Even a small amount of metal shields microwaves in the frequency that would be used -- same reason that metal won't heat in your home microwave -- it just reflects the light waves.
Organic beings that come into the focused beam cone are not affected much by the beam. Microwave s only sink into your skin about 1-2 inches. At most it raises your body temperature one or two degrees. Of course, people won't normally be inside of these beam cones anyway.
Earth-based solar stations have to put up with night. Orbital solar arrays only have a few hours of blackout each year. Most of the year they can beam the microwave down 24 hours per day, even in geosynchronous orbit over a country like Japan.
It may not be the best alternative for countries such as the U.S., but it makes more sense for smaller countries such as Japan that have almost no natural energy resources.
My $0.02.
Sounds Like A Maxis Idea To Me!
by
Self+Bias+Resistor
·
· Score: 3, Funny
Kind of reminds me of SimCity 2000, where Microwave power allowed you to beam energy from space into the satellite dish of the power plant. My question is, what happens if they miss? Ooops, there goes half a residential district!
--
----------
When the pin is pulled, Mr. Grenade is no longer our friend.
Problems with solar power
by
wiredog
·
· Score: 5, Informative
OK, several posters have said "Why not just use solar cells?". Here's why:
Solar power is not quite ready yet. If you live in an area, such as the desert southwest of the USA, that gets lots of sun, then solar can work. The initial cost is higher than other power sources, but people do it. The maintenance factor is a problem as well, since most solar power systems require batteries for storage. My previous employer looked at solar quite seriously because the line power, in Cedar City Utah, sucked. Brownouts were common. It turned out to be cheaper to replace equipment on a yearly basis than to put solar cells and a battery bank in.
If you live in an area such as the northwest of the USA then you can forget about solar. There are too many cloudy days.
Putting a bank of solar cells in the Nevada desert would work for Nevada, but distributing it beyond Nevada would be difficult.
The cloudy days and the distribution problems apply to SPS as well. The price of solar is going down, and in the desert areas it will probably be a better solution than SPS. In a few years.
It's a common misconception that the Nevada desert is a wasteland. Guess what: It's not. There is a rather intricate ecosystem. Covering the desert wipes out this system.
On top of that, we'll probably fight you on it. We're already getting a recklessly designed dump. No, it's not the dump we object to; it's the slipshod way it's being handled. A nuclear depository 100 miles from my house doesn't bother me. A repository run by that band of chuckleheads does.
The law for the the dump ordered the DOEto study a list of sites (provided in the law) and to build a dump at the safest site. Guess how many sites are on the list? If you said "1" you were correct.
So yes, we are suspicious of *anything* pushed by the feds. If Nevada is in charge of the plants, maybe. If it's a federal project, prepare for a very long fight.
hawk, displaced Nevadan
Re:Radiations would kill us all
by
Telek
·
· Score: 4, Informative
2.45GHz and 10GHz would be common wavelengths based on past studies. Your microwave operates at... oh 2.5GHz!
But fear not! There's more to the microwave science than meets the eye.
You see, in order for microwaves to do anything, they have to be absorbed into something and not re-emitted
This only happens when you have something in a liquid state... Otherwise, for example, when microwaves pass through steam they will excite the water molucules by causing them to vibrate madly, but as soon as the microwaves have finished passing through them the molecules stop vibrating, and nothing changes. The only way that you will get it to heat up a lot is if, in the process of causing those molecules to vibrate, those molecules rub against other molecules and transfer some kinetic energy. This can only happen effectively in liquid states.
If it's in a gaseous state and you have a constant beam that will continue to excite the water molecules in it's path, but due to winds and the fact that once you heat up a gas it will expand and move around on it's own you won't have a very large problem. If it's raining or you have a very dense cloud that's about to cause a storm, then you might have a problem, but under normal circumstances you'd be fine.
I remember reading somewhere that a good analogy was to think of them like this: imagine an object floating on water as waves pass by. The object will bob up and down but once the waves have passed there is no appreciable net change in energy to the object. However now imagine that this object was sitting right next to a fixed object, like a boat and a dock. As the boat bobs up and down it will rub up against the dock and friction will cause the dock to warm up. Same deal here.
--
If God gave us curiosity
Re:Space Solar Power: A Fresh Look
by
Antaeus+Feldspar
·
· Score: 3, Informative
Where the worthwhile portion of the parent comment was plagiarized from.
-- If people are to respect the law, perhaps the law should begin by respecting the people.
Lunar Materials for Construction
by
Baldrson
·
· Score: 3, Interesting
Satellite Solar Power has been studied since the 1970s. The NRC among others rejected it then primarily due to the launch costs, which have not declined appreciably during the intervening years.
This study by government or government-selected authorities ignored the radical option of lunar construction materials that, if properly used, could comprise almost all the mass of the satellites for a fraction of the transportation costs due to low lunar gravitation and absence of atmosphere on the lunar surface to interfere with techniques for lofting materials that would be impractical through atmospheric drag.
Space Studies Institute was the early leader in these studies of SSP-from-nonterrestrial-materials, and its founder, the late Gerard K. O'Neill had this to say about the option:
Space Studies Institute
The World's Energy Future Belongs in Orbit
by Dr. Gerard K. O'Neill
Trilogy January/February 1992
...
To make solar power satellites (SPS) practical and economical, we do not need any new science; we only need to apply what we are already doing in the more advanced industries: robotic production, computer control, and the replication by robotic machines of some of their heavier, simpler components. We do need one more thing: materials. It is neither practical, nor economical, nor environmentally acceptable to lift from the Earth by rockets the thousands of tons of materials needed to build an SPS that would supply Earth electricity equal to the output of ten nuclear power plants.
Let the Moon Pitch In
Fortunately, we do not have to. We were given something unique in our solar system: an enormous moon, orbiting tantalizingly nearby, and containing on its surface just the materials we need. Lunar soils contain 20 percent silicon for solar cells, and about 20 percent metals. Much of the rest, surprisingly enough, is oxygen. The moon has two other great advantages as a source of materials: its gravitational pull is only one-sixth of the Earth's, and because of its small diameter, the moon's gravitational grip is less than a twentieth of the Earth's.
The moon's second advantage is it has no atmosphere. The combination of the moon's weak gravitational grip and its vacuum environment makes it practical to locate electric mass accelerators on its surface which would be capable of lofting a steady stream of small payloads to a precise collection point high in space.
Such machines, called "mass-drivers," were tested nearly a decade ago under the sponsorship of our small, quiet, nonprofit foundation, the Space Studies Institute (SSI). Mass-drivers were shown to obey their computer design programs within one percent - no new science there - just straightforward engineering. Since then SSI has sponsored laboratory research on making useful products from ores similar to lunar soils.
Can SPS Technology Deliver?
As people concerned about our environment and about the world we leave to our children we should question proposed solutions to major physical problems. As fossil fuels, nuclear energy, ground-based solar, and other conventional sources of energy all fail to make sense in the world.
First of all, there is plenty of energy in space. Even in a narrow band 25,000 miles above the equator, where a satellite can maintain a fixed orbit, plenty of solar energy streams by constantly to supply far more than enough energy for the Earth of 2050.
What of the conversion on Earth? It was demonstrated years ago. The antennas convert the radio waves with an efficiency so high that less than 100 watts of waste heat goes into the environment for every 1,000 watts that goes into power lines. For coal or nuclear the numbers are: 1,500 watts waste, 2,500 watts total; for ground-based solar they are several thousand watts waste plus another thousand to make up the total - different from an Earth without solar cells - because solar cells absorb more heat than the ground they cover.
Transmission is the question that deserves continuing research: How to send the low-density radio waves from an SPS to antennas on the Earth. I have satisfied myself that transmission does not involve significant risks. But I invite you to do your own research. One of the best sources on the subject is The Microwave Debate by N.H. Steneck (MIT Press).
The points that seem to me most important about radio transmission of energy are that people would not be in the beams; that for fundamental physical reasons the beams could not be intentionally or accidentally redirected; that their intensity would be comparable to sunlight; that unlike the massive shielding around a nuclear reactor, the only shielding necessary would be a layer of household aluminum foil; and that, unlike the present irreversible dumping of 5,000 megatons per year of fossil-fuel carbon dioxide into the atmosphere, or the generation of long-lived nuclear wastes, the SPS system would leave no chemicals or radioactives behind if our descendants decided to turn it off.
SPS Stuck in Bureaucratic Morass
You and I know that satellite power aided by the use of construction materials from the lunar surface is an idea that is still almost unheard of, much less the subject of national debate, as it should be. Indeed, those most seriously studying SPS are Japan and Europe. Why does this conspiracy of silence exist? The reasons are partly unfamiliarity: three-dimensional thinking is often unwelcome in a two-dimensional world. Oddly enough, it is often more unwelcome to people who think of themselves as experts than to people who have a general, rather than a specialized education.
Institutional barriers and the normal behavior patterns of bureaucracies explain the rest of the "why". Since shortly after World War II the generation of scientists who contributed so greatly to winning that war have championed nuclear power. Though that generation is well into retirement now, it remains a powerful force in advising the government. It is joined by the heavy industries which see (or used to see) nuclear power as a market opportunity.
Fusion power research has gone on in large part because governmental science agencies like the National Aeronautics and Space Administration, the Department of Energy, and the National Science Foundation are extremely responsive to the scientific establishment. That establishment is led by such organizations as the National Academy of Sciences. The academy is made up of intelligent and highly qualified scientists, but as a body it is very conservative. Indeed, one of my colleagues high in its councils once described it as an "Old Men's Club." Fusion power research has been supported for some 40 years because, literally, generations of scientists have worked on it as graduate students, then gone on to positions of authority, and finally risen to positions where their recommendations arc heard with respect by government agencies.
In the bureaucratic format, satellite power has no natural home and no built-in constituency. NASA, now a timid, fearful NASA made up of aging pre-retirees rather than the young tigers who made Apollo work in just eight years, would be frightened out of its skin by a tough, make-it-work assignment with a tight budget and a tighter time scale. And NASA's charter doesn't cover energy. The DOE? Its charter doesn't include space. The NSF? Satellite power isn't science, it's engineering.
That's why research support toward satellite power has been left largely to the Space Studies Institute, a small foundation supported by thousands of private citizens -much as the organizations of the environmental movement are supported. Environmentally concerned citizens and groups, and SSI, should be talking. Their concerns are the same and their goals are the same. Since the governmental-scientific establishment in the United States is making no useful move toward a serious review of satellite power as a practical alternative, it may well be that concerned citizens are the only force that can bring about the necessary action. We as citizens have often succeeded in "Stop!" actions. Let us review, carefully and with open minds, whether SPS is something that we may want to "Start!"
Slashdot Mirror
in Sim City 2000? Microwave power plants!
let's all pray that Nasa's aiming is a darn site better than the military or we'll all be fried :) ... time to get those anti-laser suits for my cats i think
This was first seriously proposed by
Gerald K. Oneill of Princeton University in
1975! It was feasable ( and even profitable )
then, but the capitalization was to high for
any organization on earth but the US Government
to undertake. The only reason we haven't done
it already is because of a defect of will, a
myopy of purpose, and inability to look further
ahead than the next election.
When will we, the citizens of the United States,
have the vision to demand these sorts of
projects from our government? Oneill's initial
proposal had an estimated 20 year pay back time, for
the first powersat. Subsequent powersats would
have been much cheaper. If the proposal Oneill
made had been taken up seriously in 1976, and taken
say 2 years to get it's political legs so that
actual work began in 1978, and it took ten
years to build, we would have had cheap abundant
energy by 1988.
Given cheap abundant energy it would be feasible to
produce, for example, metal hydride or fuel cell
powered cars. Given a 10 year ramp up and phase in
for those technologies we would have in 1998
been largely petroleum free ( at least for
power ).
Does anyone question that this would be a better
place to be... and we could be there by now, if
only we had the vision, and the will.
from SimCity2000. I based my entire city's power grid on 4 of these things. Then the microwave beam missed, and blew up two of the other power plants.
My other sig is funny!
There must be millions of square kilometers of flat rooves in the world's cities. Since most are neither generally accessable nor designed for regular activties, they'd make an idea place for solar arrays. You could even use DC instead of AC due to the proximity, but that would be a bother. In hot areas, the shade would help lower the temperature of the upper floors.
Beta is broken and the link to classic doesn't work. Stop wasting our time or there won't be anybody left here.
The wavelength (frequency) of the microwaves is what makes it excite water. I'm sure they would not be using the same wavelength to transmit energy from space to earth. Clouds and water vapor in the air would affect it.
- The microwave beam does not disrupt any planes, etc. because they are made of metal. Even a small amount of metal shields microwaves in the frequency that would be used -- same reason that metal won't heat in your home microwave -- it just reflects the light waves.
- Organic beings that come into the focused beam cone are not affected much by the beam. Microwave s only sink into your skin about 1-2 inches. At most it raises your body temperature one or two degrees. Of course, people won't normally be inside of these beam cones anyway.
- Earth-based solar stations have to put up with night. Orbital solar arrays only have a few hours of blackout each year. Most of the year they can beam the microwave down 24 hours per day, even in geosynchronous orbit over a country like Japan.
It may not be the best alternative for countries such as the U.S., but it makes more sense for smaller countries such as Japan that have almost no natural energy resources.My $0.02.
Kind of reminds me of SimCity 2000, where Microwave power allowed you to beam energy from space into the satellite dish of the power plant. My question is, what happens if they miss? Ooops, there goes half a residential district!
----------
When the pin is pulled, Mr. Grenade is no longer our friend.
Solar power is not quite ready yet. If you live in an area, such as the desert southwest of the USA, that gets lots of sun, then solar can work. The initial cost is higher than other power sources, but people do it. The maintenance factor is a problem as well, since most solar power systems require batteries for storage. My previous employer looked at solar quite seriously because the line power, in Cedar City Utah, sucked. Brownouts were common. It turned out to be cheaper to replace equipment on a yearly basis than to put solar cells and a battery bank in.
If you live in an area such as the northwest of the USA then you can forget about solar. There are too many cloudy days.
Putting a bank of solar cells in the Nevada desert would work for Nevada, but distributing it beyond Nevada would be difficult.
The cloudy days and the distribution problems apply to SPS as well. The price of solar is going down, and in the desert areas it will probably be a better solution than SPS. In a few years.
Best Slashdot Co
On top of that, we'll probably fight you on it. We're already getting a recklessly designed dump. No, it's not the dump we object to; it's the slipshod way it's being handled. A nuclear depository 100 miles from my house doesn't bother me. A repository run by that band of chuckleheads does.
The law for the the dump ordered the DOEto study a list of sites (provided in the law) and to build a dump at the safest site. Guess how many sites are on the list? If you said "1" you were correct.
So yes, we are suspicious of *anything* pushed by the feds. If Nevada is in charge of the plants, maybe. If it's a federal project, prepare for a very long fight.
hawk, displaced Nevadan
2.45GHz and 10GHz would be common wavelengths based on past studies. Your microwave operates at ... oh 2.5GHz!
But fear not! There's more to the microwave science than meets the eye.
You see, in order for microwaves to do anything, they have to be absorbed into something and not re-emitted
This only happens when you have something in a liquid state... Otherwise, for example, when microwaves pass through steam they will excite the water molucules by causing them to vibrate madly, but as soon as the microwaves have finished passing through them the molecules stop vibrating, and nothing changes. The only way that you will get it to heat up a lot is if, in the process of causing those molecules to vibrate, those molecules rub against other molecules and transfer some kinetic energy. This can only happen effectively in liquid states.
If it's in a gaseous state and you have a constant beam that will continue to excite the water molecules in it's path, but due to winds and the fact that once you heat up a gas it will expand and move around on it's own you won't have a very large problem. If it's raining or you have a very dense cloud that's about to cause a storm, then you might have a problem, but under normal circumstances you'd be fine.
I remember reading somewhere that a good analogy was to think of them like this: imagine an object floating on water as waves pass by. The object will bob up and down but once the waves have passed there is no appreciable net change in energy to the object. However now imagine that this object was sitting right next to a fixed object, like a boat and a dock. As the boat bobs up and down it will rub up against the dock and friction will cause the dock to warm up. Same deal here.
If God gave us curiosity
Where the worthwhile portion of the parent comment was plagiarized from.
If people are to respect the law, perhaps the law should begin by respecting the people.
This study by government or government-selected authorities ignored the radical option of lunar construction materials that, if properly used, could comprise almost all the mass of the satellites for a fraction of the transportation costs due to low lunar gravitation and absence of atmosphere on the lunar surface to interfere with techniques for lofting materials that would be impractical through atmospheric drag.
Space Studies Institute was the early leader in these studies of SSP-from-nonterrestrial-materials, and its founder, the late Gerard K. O'Neill had this to say about the option:
Space Studies Institute
The World's Energy Future Belongs in Orbit
by Dr. Gerard K. O'Neill
Trilogy January/February 1992
To make solar power satellites (SPS) practical and economical, we do not need any new science; we only need to apply what we are already doing in the more advanced industries: robotic production, computer control, and the replication by robotic machines of some of their heavier, simpler components. We do need one more thing: materials. It is neither practical, nor economical, nor environmentally acceptable to lift from the Earth by rockets the thousands of tons of materials needed to build an SPS that would supply Earth electricity equal to the output of ten nuclear power plants.
Let the Moon Pitch In
Fortunately, we do not have to. We were given something unique in our solar system: an enormous moon, orbiting tantalizingly nearby, and containing on its surface just the materials we need. Lunar soils contain 20 percent silicon for solar cells, and about 20 percent metals. Much of the rest, surprisingly enough, is oxygen. The moon has two other great advantages as a source of materials: its gravitational pull is only one-sixth of the Earth's, and because of its small diameter, the moon's gravitational grip is less than a twentieth of the Earth's.
The moon's second advantage is it has no atmosphere. The combination of the moon's weak gravitational grip and its vacuum environment makes it practical to locate electric mass accelerators on its surface which would be capable of lofting a steady stream of small payloads to a precise collection point high in space.
Such machines, called "mass-drivers," were tested nearly a decade ago under the sponsorship of our small, quiet, nonprofit foundation, the Space Studies Institute (SSI). Mass-drivers were shown to obey their computer design programs within one percent - no new science there - just straightforward engineering. Since then SSI has sponsored laboratory research on making useful products from ores similar to lunar soils.
Can SPS Technology Deliver?
As people concerned about our environment and about the world we leave to our children we should question proposed solutions to major physical problems. As fossil fuels, nuclear energy, ground-based solar, and other conventional sources of energy all fail to make sense in the world.
First of all, there is plenty of energy in space. Even in a narrow band 25,000 miles above the equator, where a satellite can maintain a fixed orbit, plenty of solar energy streams by constantly to supply far more than enough energy for the Earth of 2050.
What of the conversion on Earth? It was demonstrated years ago. The antennas convert the radio waves with an efficiency so high that less than 100 watts of waste heat goes into the environment for every 1,000 watts that goes into power lines. For coal or nuclear the numbers are: 1,500 watts waste, 2,500 watts total; for ground-based solar they are several thousand watts waste plus another thousand to make up the total - different from an Earth without solar cells - because solar cells absorb more heat than the ground they cover.
Transmission is the question that deserves continuing research: How to send the low-density radio waves from an SPS to antennas on the Earth. I have satisfied myself that transmission does not involve significant risks. But I invite you to do your own research. One of the best sources on the subject is The Microwave Debate by N.H. Steneck (MIT Press).
The points that seem to me most important about radio transmission of energy are that people would not be in the beams; that for fundamental physical reasons the beams could not be intentionally or accidentally redirected; that their intensity would be comparable to sunlight; that unlike the massive shielding around a nuclear reactor, the only shielding necessary would be a layer of household aluminum foil; and that, unlike the present irreversible dumping of 5,000 megatons per year of fossil-fuel carbon dioxide into the atmosphere, or the generation of long-lived nuclear wastes, the SPS system would leave no chemicals or radioactives behind if our descendants decided to turn it off.
SPS Stuck in Bureaucratic Morass
You and I know that satellite power aided by the use of construction materials from the lunar surface is an idea that is still almost unheard of, much less the subject of national debate, as it should be. Indeed, those most seriously studying SPS are Japan and Europe. Why does this conspiracy of silence exist? The reasons are partly unfamiliarity: three-dimensional thinking is often unwelcome in a two-dimensional world. Oddly enough, it is often more unwelcome to people who think of themselves as experts than to people who have a general, rather than a specialized education.
Institutional barriers and the normal behavior patterns of bureaucracies explain the rest of the "why". Since shortly after World War II the generation of scientists who contributed so greatly to winning that war have championed nuclear power. Though that generation is well into retirement now, it remains a powerful force in advising the government. It is joined by the heavy industries which see (or used to see) nuclear power as a market opportunity.
Fusion power research has gone on in large part because governmental science agencies like the National Aeronautics and Space Administration, the Department of Energy, and the National Science Foundation are extremely responsive to the scientific establishment. That establishment is led by such organizations as the National Academy of Sciences. The academy is made up of intelligent and highly qualified scientists, but as a body it is very conservative. Indeed, one of my colleagues high in its councils once described it as an "Old Men's Club." Fusion power research has been supported for some 40 years because, literally, generations of scientists have worked on it as graduate students, then gone on to positions of authority, and finally risen to positions where their recommendations arc heard with respect by government agencies.
In the bureaucratic format, satellite power has no natural home and no built-in constituency. NASA, now a timid, fearful NASA made up of aging pre-retirees rather than the young tigers who made Apollo work in just eight years, would be frightened out of its skin by a tough, make-it-work assignment with a tight budget and a tighter time scale. And NASA's charter doesn't cover energy. The DOE? Its charter doesn't include space. The NSF? Satellite power isn't science, it's engineering.
That's why research support toward satellite power has been left largely to the Space Studies Institute, a small foundation supported by thousands of private citizens -much as the organizations of the environmental movement are supported. Environmentally concerned citizens and groups, and SSI, should be talking. Their concerns are the same and their goals are the same. Since the governmental-scientific establishment in the United States is making no useful move toward a serious review of satellite power as a practical alternative, it may well be that concerned citizens are the only force that can bring about the necessary action. We as citizens have often succeeded in "Stop!" actions. Let us review, carefully and with open minds, whether SPS is something that we may want to "Start!"
Seastead this.