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Solar Power Satellites by 2020?
soulfuct writes: "Finally, a national space agency has budgeted funds for a test project to convert solar energy in space to microwaves and beam them down to Earth. They plan to deploy this for use by 2020. Kudos go to the National Space Development Agency of Japan (NASDA) and Kyoto University for being the first to realistically act on the idea of solar power satellites promoted decades ago by Gerard K O'Neill in his book The High Frontier. With all of Bush's rhetoric about an energy crisis, why doesn't NASA latch onto this idea to secure more funding?"
Just what *did* you think that cloudy sky that shows up on the startup screen was supposed to mean?
hawk
The aircraft thing isn't actually a big deal.
... but not very many! Any violation would probably be by private pilots.
...)
... in order to have a commercial flight wander into a beam you would probably have to have both a ground controller and the pilot mess up. And all of the computers involved on both sides get messed up too (or ignored). Not very likely.
... this is nothing new. Controlled access airspace has been around a long time.
... they are on their own ...
...
....
Go out and find (I would bet you could get some example off the net) an aviation sectional chart. You would be amazed at all of the areas marked off as restricted or off limit airspace. (Controlled airspace of all types, military training areas, missile ranges, etc.) Yes there are violations of these areas, and yes there probably would be some violations of uwave transmission beams
(Private pilots in general are pretty good at following the rules. In my exerience anyway. Mostly because the rules tend to make sense. However after spending some time with a few in Yuba county CA, I no longer believe that all of them even try to follow the rules. Or even get a license. Glad I don't live out there
Any incident with a IFR (read as: commercial traffic) aircraft running into a beam would be even more unlikely. Commercial pilots (the ones I've met anyway) are unbelievably paranoid about running into things. These are people who think of inter-aircraft clearance distances in terms of miles! They are very aware of where they are and where they are going. Soooo
The other worry you expressed about uwave interferance is not an issue. We would be talking about a direct beam here. The scatter would probably be quite small, and the restricted airspace around the beam would most likely be large enough to avoid that problem entirely.
So in conclusion to the aircraft issue
As far as birds go
I have a feeling that powersats would hurt far fewer birds than wind generators though.
I think it could be fun trying to design orbits to avoid running any other sattelite with a lower orbit through the beam though
In any case it would be good to work all of this stuff out now, with solar power. This paves the way for moving nuke plants (and hopefully fusion plants someday) off the surface and into orbit.
wow, this is getting quite long
OUT
"There's no secret. You just press the accelerator to the floor and keep turning left." -- Bill Vukovich
Surely the oil companies and their presidential puppet will not stand for this blasphemy.
I know I'm going to get marked as a troll or flamebait for this, but here it comes anyway: Clinton had two terms in office, and Mr. "I Invented The Internet" Gore did what for the California energy crisis? The power problems in California didn't suddenly begin in January when Bush took office - they've been brewing for years. Never heard of Gore doing anything about it, did you? Hmm, don't hear Gore speaking up too much about that energy crisis, do you? Wonder why that is? I don't.
What's your damage, Heather?
Slow down cowboy. The rhetoric is coming from the media, not the President. The media-mantra for the past three months has been that the energy crisis will bring down the presidency. Meanwhile gas prices are still cheaper than in 1999 under Clinton and considerably cheaper than in 1978 under Carter. As for the power crisis in California and the potential for a future shortage nationwide, I dont see any rehtoric at all. Clearly there is a short term crisis in California, and a long term problem for the rest of the country. While I am all for science R&D, statements like yours are rediculous. Commercial orbiting solar power stations are many years from becoming a reality along with fusion and mid-ocean tidal power plants. These technologies are exciting and certainly deserve funding and our interests. However, penciling in preposterous "unproven tech" in a national policy has already gotten Bush in trouble with Missile Defense. Do you suggest that he do the same will all of his policies?
There is no world conspiracy to drive up gas prices in the United States other than OPEC. Outside of the OPEC nations, the U.S. consumers enjoy the cheapest gas prices in the world. The energy crisis is one of refineries and a lack power plants.
Conservation is important, but what is more efficient, spending resources to become more efficient or spending resources to generate more power. Look at software engineering. Is /. authored with a custom C-solution. It would be alot faster than perl and appache. Why bother with an OS. Why not write an embedded system, it would be more efficient. Why use a generic relational database and not write something spesifically for your needs. Efficiency does not always translate into better (look at Java, Perl, Python, etc).
Someone you trust is one of us.
The atomspheric energy absorption is not high enough to make this inefficient and does not really contribute to making this *mostly harmless*. The reason it becomes *mostly harmless* is due to dispersion of the beam over a large area. So, a larger antenna is used to pick it up.
People need to check out the solar power satellites link cited in the post. The safety details have been addressed long ago.
Even in circumstances where it is "aiming" properly, wouldn't this be a problem for bird and airplanes? If I can't even use my cellphone for fear of interferance in the plane, what about giant beams of microwave radiation??
Well, the world isn't the United States. For one thing, the U.S. is home to the world's largest oil companies, which aren't all that interested in anything not coming out of the ground. Another, LAND. Solar farms don't work in Japan, which is, to put it gently, overpopulated. Countries like Japan or England or Germany can't unroll miles of mylar on the ground. Solarsats take all the infrastructure and move it into space, where's there's room.
They are also permanent. Besides the beaming equipment, which I assume burns out after time, the solar cells last for a long, long, time.
And a solarsat isn't fragile -- there is no wind, no rain, no earthquakes, no gekkos. It just works, year after year.
As for cheap, after the initial construction, whatevcer it costs, the sat just keeps paying for itself, without stopping. The well doesn't run dry, there are no spills. And we don't have to pave over the deserts, either.
Not that your idea isn't good! It is pretty cheap to panel desert areas.
What a load of old rubbish
List of large man made objects in space:
- International space station
- Ummm
List of large man made objects on earth:
- Empire state building
- Super-tankers
- Pyramids
- etc etc etc
It's not difficult to find large areas of land for collecting solar energy. What do you imagine is in the sahara desert? Well, basically there is a great heap of nothing and lots of sunlight. Yes, there's no people, but running electricty through some cables to europe would still be heaps cheaper than this stupid space idea. And you need lots of room for the receiving antenna anyway.
Three that come to mind:
- Giant circular greenhouse with a huge tower in the middle. Air in the greenhouse gets hot and rushes up the tower which contains a turbine. Cool air enters round the edge. This works and there is a great big prototype somewhere in spain (anyone got any links?). You can grow crops in the green house except for the bit right in the middle where it gets a bit drafty.
- Mirrors like hugs bits if guttering which focus sunlight onto metal pipes with oil in. Oil gets very very hot, boils water, turbine etc. I believe that there are a number of plants like this working in the USA.
- Windmill. Sunlight heats ground, air rises, cold air rushes in and turns blades on great big fan up a tower. Quite a popular solution in many parts of the world.
I predict that all of these solutions will be substantially cheaper than this stupid space power idea until long after all of us are dead.
And what about maintaining.. they gonna send electritions up to the moon when things break... sounds rather costly :)
Probable impossibilities are to be preferred to improbable possibilities.
Aristotele
This has been one of those Real Soon Now (tm) projects for years, for a simple reason - assuming your solar cells are made of silicon or something of similar density, the mass of an SPS (solar power satellite) big enough to generate useful amounts of power is prohibitive.
Here's my calculations:
Assuming a solar cell 1m to a side and 1mm thick, we get: 0.001m^3/cell * 2330 kg/m^3 (the density of silicon from Webelements ) = 2.33 kg per cell.
The solar irradiance at Earth's orbit is 1367.6 W/m^2 (from NASA National Space Science Data Center ). We currently have solar cells that can convert solar energy to electrical energy at about 30% efficiency in the labs. So, we'll assume that these can be made in bulk sometime in the near future. That yields 1367.6 * 0.3 = 410.28 W/m^2.
That seems like a lot, but consider - it four 100 watt light bulbs, or your computer (no monitor), if you have a system like mine. Lets say we aim for a generating capacity nearer to your average nuclear plant - 2 megawatts. Then we need 2,000,000 / 410.28 = 4,875 panels. At 2.33 kg each that's 11.4 metric tonnes. Not a huge amount, but then you have to add about that much in support structures, repair equipment, and the microwave emmitter, of course.
You will note that I have ignored losses in transmission, etc after the power is converted from solar to electrical. That is because these conversions are all very efficient, compared to the solar/electrical conversion, so they don't change any mass calculations by that much.
So how many SPS units would we need to power the world? From the CIA World FactBook , the US in 1998 used 3.365 trillion kWh, equivalent to a continous 384 million kW. We would therefore need about 200 thousand of the 2 megawatt stations considered above, for the US alone. If we wanted to be generous and extend this technology to the rest of the globe, we need over 2 million stations of this size.
Now, this is clearly not economical, not with launch costs in the neighborhood of $500/kg for the Shuttle (some dumb boosters can haul more for only $100/kg), but there is still hope. John S. Lewis, in his book Mining The Sky shows that building SPS units is economical, if you don't have to launch the mass of the solar cells. Instead, you bootstrap - launch a processing facility to a target Near Earth Object, set down and start making solar cells. The facility would have to be unmanned, but it would in a few years time produce enough cells to build a SPS.
One thing's for sure: You sure won't see any of this from NASA. They'd like it if you gave them the trillions of dollars it would take to build one of these, so they could fail miserably and call the whole idea impossible.
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Vpered na Mars!
I think you're right about the transmit and receive angles.. that throws a wrench into my theory. :)
But about my "all men are great before declaring war on humanity," it's actually something that I uttered on IRC while I was talking to my brother. I kind of snapped one night while reading something (I can't remember exactly what it was, but it was something about a person who was imprisoned for something that I don't consider to be wrong). I'm one of those liberal anarchist apologists. :)
Anyway I always considered myself to be a good person.. but every time I read something about a grevious misjustice (guy thrown in jail for 5 years for smoking weed.. 15 year old thrown in jail for "abusing" 16 year old girlfriend (because consent is not possible when you're only 16. Ahem.) or intellectuals threatened or jailed for speaking their mind) I would feel this hate for the perpetrators (read: conservative/religious folks in a position of power). Anyway this one night I was talking casually (on IRC) to my bro about this article I was reading, and it eventually degenerated into a heated argument (only for the sake of argument; he agreed completely) and I started to imagine myself killing the judge.. the police officers.. and anyone involved with removing this person from society. I was totally convinced that I was right, and that the only way to stop the world from destroying itself was to kill all the people who aggressively hunt people they disagree with (whether or not the "criminals" were hurting anyone). This article really fucked me up at the time.
I was in this sort of quiet rage for about half an hour.. when suddenly I realized.. what the hell makes me so damned special? What differentiates me from the people I'm fantasizing about killing (while yelling fuck you agressor - you incarcerate innocent people, you die). It was like.. bam.. everything that I believed I was.. was.. not right.
I kinda dropped a level of conciousness at this point. I think this is what happens before people go insane. :) I don't remember what happened, but apparently I starting saying weird shit for like 15 minutes (that quotation is one of the things I said). When I came to, I was crying. Wierd night, to say the least. :)
I thought.. so this is how it happens.. If you're strong, when you go insane like this, you throw yourself out the window. If you're weak, you grab a shotgun and maul 100 innocent bystandards. If you're lucky like me, you realize that it's time to relax. The world is a fucked up place, and the best you can hope to do is talk.. tolerate.. and try to understand.
All people who declare war on humanity (as I did that night) are great. We all have good intentions. But we're always wrong. There is no way to win the war on humanity. Anyway. That's the story behind my quotation.
--
All men are great
before declaring war
A government is a body of people notably ungoverned - AC
There is no possibility a city will get fried by microwave energy. First of all, any system beaming energy from orbit would use a laser based targetting system. There would be an electrical cutoff if the laser failed to reach the satellite along the return path (which would presumably not be software controllable). So, if the microwave emitter lost the laser "signal" from earth (which would presumably only be receivable on a perpendicular to the ground) by drifting off course or because of a mechanical failure, the microwave emitter would shut down.
Second of all - the microwave beam would not be wide enough to cause mass destruction anyway. The waves would be directed so that it bathes a small target on the ground (less than 10 feet in diameter). So even if the guidance cutoff failed and the satellite were to hit a city with microwaves, the damage would be fairly localized (imagine a disaster the scale of a 747 crashing into a neighborhood - not a nuclear or biological weapon event).
All in all I think this will be an interesting project. Best of luck to them.
--
All men are great
before declaring war
A government is a body of people notably ungoverned - AC
For all of Bush's rhetoric, his budget has already slashed funding for alternative energy research. I think this particular idea would fall under the same axe. I'm not going to draw the obvious conclusion as to what his priorities really are.
Now, if we could bill these solar satellites as some sort of missile-defense...
But then again, so are oil, coal, and nuclear power. Everytime there's a new tech advance posted here on Slashdot, 50 people reply to the story pointing out how deadly the new tech is. Imagine the replies to the post about Ford releasing the Model T: "So we're just going to let anyone that has $500 drive around some thousand pound chunk of metal powered by EXPLODING GASOLINE! No thanks, I'm sticking to horses!" All technology is dangerous. If you discount a new idea because it's possible to accidentally kill people with it, well, enjoy your cave.
Today is a good day to die. They all are, though.
It wouldn't have to be especially efficient, just cheap. Unroll acres of the stuff directly onto the desert floor, or float it on the ocean. Maybe put it in the diamond-shape gaps between those circular irrigated crop fields out west.
My math estimates a few thousand square miles of 5% efficient (at 1% overall system efficiency) collectors would satisfy all our energy needs. (If you think that's too much area, imagine explaining how much area would be paved over in 2001 to a guy from the 19th century. It can be done.)
If this was treated like the Manhatten project, I'd bet they could get production started in 7 years or so. By contrast, in 7 years, NASA would still only be doing feasiblity studies on a space-based solution.