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[MetalSlimeHunt]

I suggest that you read said article.

I did read the article. I wouldn't have posted it otherwise.

You said, and I quote, that solar power satellites were "pure science fiction and largely impossible", which obviously isn't the case even by your own admission no matter how long they'll take to get operational.

[LordBucket]

Well, I'm going to do a case study. Let's take Belgium(because I happen to live there) as an example.

...uhh, ok. What exactly is the problem? What you're doing is working, and you have a population density over TEN TIMES that of the US, and in 2010, Belgium was ranked as having in the top 10 best quality of life in the world.

If you want to keep using nuclear power, go right ahead. Radioactive materials aren't in particularly short supply. What's stopping Belgium from simply continuing to do what it's doing already?

Or were you just complaining about money?

[MetalSlimeHunt]

Radioactive materials aren't in particularly short supply.

Peak Uranium will happen before 2100.

It isn't actually that common on Earth at all.

[LordBucket]

Peak Uranium will happen before 2100.

It isn't actually that common on Earth at all.

http://www.world-nuclear.org/info/inf75.html

"Uranium is a relatively common metal, found in rocks and seawater. Economic concentrations of it are not uncommon.

Its availability to supply world energy needs is great both geologically and because of the technology for its use.

Quantities of mineral resources are greater than commonly perceived.

Uranium is a relatively common element in the crust of the Earth (very much more than in the mantle). It is a metal approximately as common as tin or zinc, and it is a constituent of most rocks and even of the sea."

[MetalSlimeHunt]

My mistake, usable uranium is not very common and is going to peak. (The seawater uranium, for example, is completely unusable and has only been extracted in small amounts.)

[mainiac]

Transmission frequencies aren't remotely a problem for microwave power transmission.  We are talking about frequencies that AFAIK aren't even used for communication outside a few black ops military applications (maybe) and the benefits far, far outweigh what we are using them for now (if anything).

And the degradation is more then outweighed by the increase in efficiency from the space location.  The increase in efficiency is as follows:
-x3 from constantly being at max output compared to earth applications which get 1/3rd max output over the day
-x1.5 from no weather conservatively
-x1.4 from no atmospheric interference even on a clear day
-x1.2 from reductions in the excess capacity needed as a safety factor
-x1.4 from reductions in power transmission losses

So that means that even after losing 17% of your capacity in the first 7 year you still are running 878% efficiency compared to earth.  Btw, a 17% reduction in 7 years does not mean a reduction in lifetime by 10%, solar panels do not take 70 years to have a 17% reduction in output.

Add onto this the fact that you can send this power to anywhere on the surface of the earth that it's needed.  So you can either chose to go the extravagant route and put that towards excess capacity so no one ever has a blackout ever again or you can bank the efficiencies and bump your economic efficiency up by another x1.5 or x2.0.

If you think that cluttering is a problem then you really, really, really, really, really have no sense of perspective about how big space is.

[10ebbor10]

Well, I'm going to do a case study. Let's take Belgium(because I happen to live there) as an example.

...uhh, ok. What exactly is the problem? What you're doing is working, and you have a population density over TEN TIMES that of the US, and in 2010, Belgium was ranked as having in the top 10 best quality of life in the world.

If you want to keep using nuclear power, go right ahead. Radioactive materials aren't in particularly short supply. What's stopping Belgium from simply continuing to do what it's doing already?

Or were you just complaining about money?

Our nuclear reactors are falling apart(often quite litteraly), and most political parties want to stop using it all toghether. This will most likely lead to a massive increase in the use of fossil fuels, as happened in Germany. But the problem mostly lies with money shortages, as it does in quite a lot of countries.

Transmission frequencies aren't remotely a problem for microwave power transmission.  We are talking about frequencies that AFAIK aren't even used for communication outside a few black ops military applications (maybe) and the benefits far, far outweigh what we are using them for now (if anything).

And the degradation is more then outweighed by the increase in efficiency from the space location.  The increase in efficiency is as follows:
-x3 from constantly being at max output compared to earth applications which get 1/3rd max output over the day
-x1.5 from no weather conservatively
-x1.4 from no atmospheric interference even on a clear day
-x1.2 from reductions in the excess capacity needed as a safety factor
-x1.4 from reductions in power transmission losses

So that means that even after losing 17% of your capacity in the first 7 year you still are running 878% efficiency compared to earth.  Btw, a 17% reduction in 7 years does not mean a reduction in lifetime by 10%, solar panels do not take 70 years to have a 17% reduction in output.

Add onto this the fact that you can send this power to anywhere on the surface of the earth that it's needed.  So you can either chose to go the extravagant route and put that towards excess capacity so no one ever has a blackout ever again or you can bank the efficiencies and bump your economic efficiency up by another x1.5 or x2.0.

If you think that cluttering is a problem then you really, really, really, really, really have no sense of perspective about how big space is.

There's a serious garbage problem in space. One small impact might render your entire system useless.
Btw, you seem to understate several issues. Depending on the frequencies, the signal might be blocked by rain/clouds(Statements from the wiki), and you are certainly going to lose some power due to transmission inefficiencies, as well as needing enormous transmitters/recievers.
Complication with different frequencies will also be a problem. I'm going to do the math on cost some time later today, but I doubt it'll be viable.
Also it's not a lifetime reduction by 10% , but to 10%. (As in, from 30 to 3 years lifetime.)

Radioactive materials aren't in particularly short supply.

Peak Uranium will happen before 2100.

It isn't actually that common on Earth at all.

Thorium, MOX, and other new reactor types. The main problem with nuclear power is a huge PR issue, and the fact that most existing reactors are way to old.

Anyway, the calculations.

Power beaming from geostationary orbit by microwaves carries the difficulty that the required 'optical aperture' sizes are very large. For example, the 1978 NASA SPS study required a 1-km diameter transmitting antenna, and a 10 km diameter receiving rectenna, for a microwave beam at 2.45 GHz. These sizes can be somewhat decreased by using shorter wavelengths, although they have increased atmospheric absorption and even potential beam blockage by rain or water droplets. Because of the thinned array curse, it is not possible to make a narrower beam by combining the beams of several smaller satellites. The large size of the transmitting and receiving antennas means that the minimum practical power level for an SPS will necessarily be high; small SPS systems will be possible, but uneconomic.

To give an idea of the scale of the problem, assuming a solar panel mass of 20 kg per kilowatt (without considering the mass of the supporting structure, antenna, or any significant mass reduction of any focusing mirrors) a 4 GW power station would weigh about 80,000 metric tons, all of which would, in current circumstances, be launched from the Earth

Now, the wiki article plans to go to LEO first, and then use ion engines to get into GEO. Sadly there doesn't seem to be much progress on those, so we're forced to go the GEO in one trip.
The most likely candidate for the trip seems to be the Delta IV-H, being the largest launch vessel in commision. This thing can carry 6,275 kg  in one trip, for a cost 300 million dollars.

80 000/ 6.275 tonnes= 12749 flights 

Now the amount of flights that this results in makes me pray I made a mistake, though I doubt it.

Now assuming we can use lightweight solar pannels

Very lightweight designs could likely achieve 1 kg/kW,[47] meaning 4,000 metric tons for the solar panels for the same 4 GW capacity station

This still means 638 flights at least, and that's just for the pannels, not counting the antennae or something.

Fake edit: Apparently the wiki comparison is incomplete, and the Ariana V can take a slightly larger payload into space. The Falcon Heavy (indevelopment) might also help, but both have a cargo capacity lower then 10.000 kg.

Note: One should take care not to confuse GTO (Geostationary transfer orbit), with GEO (Geostationary orbit.) There's a serious difference.

[LordBucket]

The seawater uranium, for example, is completely unusable
and has only been extracted in small amounts.

Your facts are wrong.

http://en.wikipedia.org/wiki/Uranium_mining#Recovery_from_seawater
http://peakoildebunked.blogspot.com/2006/01/207-uranium-from-seawater-part-1.html

It's already been done. There's just not any reason to go out of our way to develop the technology to make it cheaper because uranium is so common elsewhere. Either way, focusing on this is silly because we have 80-100 years worth of uranium already located in ground-based sources. That's a long time. Commercial nuclear power has only even existed since 1954. 100 years from now it's likely to be be archaic.

[MetalSlimeHunt]

The seawater uranium, for example, is completely unusable
and has only been extracted in small amounts.

Your facts are wrong.

http://en.wikipedia.org/wiki/Uranium_mining#Recovery_from_seawater

My facts are right.

http://en.wikipedia.org/wiki/Peak_uranium#Seawater

Although in reality it looks like Wikipedia is contradicting itself.

[LordBucket]

the problem mostly lies with money shortages

Not sure how that's relevant to this thread.

Any any case, Belgium is a good example to support my position here. You have over ten times the population density of the US and a higher quality of living than the vast majority of the world. If the rest of the planet were populated as densely as your country, we'd have room for...

Area of north america: 24,709,000 km2
Area of south america: 17,840,000 km2
Area of europe: 10,180,000 km2
Area of asia: 44,579,000 km2
Area of australia: 7,617,930 km2
Area of africa: 30,221,532 km2

Total: 135,147,462 square kilometers

Population density of Belgium: 354.7/km2

354 * 135,147,462 = 47,842,201,548

47 billion people

[10ebbor10]

Sadly, the entire world can't be populated as densily as Belgium. You don't want that. It tends to give serious problems. (Also, Belgium imports a lot of stuff, like a lot).

Secondly, the reason for the High Quality of living is the enormous amount of social security we have here. (You might have though Obama care was bad/good, but that'd probably considered conservative here) It's also the reason for the high governement debt.


Btw, I added some statistics to my post above. My calculations estimate a cost of  191 billion dollars launch costs in a best case scenario. (Launch cost only include solar pannels, and not the transmitter, structure, maintenance, assembly, any failures, development, the cost of the solar pannels, ....)

[Heron TSG]

Now tell me how you're going to replace 50%-75% of our energy supply without increasing reliance on fossil fuels, bankrupting the country or anything else.

Nuclear fission, unless you 'forget' to inspect and maintain the plants. Uranium isn't very common, but Thorium is. And you can make more Thorium and other fissile materials - get this - in a reactor. Neat, huh? Nuclear fusion, in a couple years.

As for public transit in small towns: My town has 4800-5000 people in it. There is a railway in the middle of town that goes through at least twice a day. We live 65 miles from the nearest large city, and there are several other smaller towns along the same highway. (Populations 800, 3000, and 4000 respectively.) Most people had to drive all the way to this large city in order to buy things they couldn't at home. Suddenly, someone got the idea to start a bus line that goes from the furthest town (the town of 800) and stops in each of the other towns thrice a day, before linking up with the large city's bus system by dropping you off at a major bus hub. People used it a lot, and they needed more buses. Then they decided to replace the buses with hybrid buses, and put solar panels on the roofs. Suddenly, it costs the public transport network a whole lot less to run the buses, it costs everyone making the trip (which some people do weekly) a lot less in gas, and there is less pollution from gas-burning cars, too. But no, it would never work to use public transit to replace cars.

@10ebbor10 - $191 billion at the least? Are you serious? Curiosity was gigantic and had to be sent to Mars with some of the most advanced technologies we have, and that cost $2.5 billion. I think your numbers are wildly off.

[LordBucket]

The seawater uranium, for example, is completely unusable
and has only been extracted in small amounts.

Your facts are wrong.

http://en.wikipedia.org/wiki/Uranium_mining#Recovery_from_seawater

My facts are right.

http://en.wikipedia.org/wiki/Peak_uranium#Seawater

Although in reality it looks like Wikipedia is contradicting itself.

...I think you're trying a bit too hard to interpret things so you get to feel good about being right.

It has been done. It is usable. It's not commercially viable solely because there are cheaper, easier alternatives.

The spirit of your original statements, that uranium is "rare" and that there's only enough to last us 80 more years...is silly. Just like it was silly in 1956 when it was originally estimated that we'd use up the usable uranium in about 20 years.

In 1956, we only had 20 years worth of usable uranium, now in 2012 we only have 85 years worth, and we've developed processing technology to make use of less pure sources in quantities estimated to be over 300 times that of what we're using now.

I don't think we need to be worrying about this.

[10ebbor10]

I don't think we need to be worrying about this.

What we might need to worry is what we're going to do with the waste. Sure we have enough storage space, and can reuse it in reactors. It can however also be used to produce nuclear warheads quite easily.

Now tell me how you're going to replace 50%-75% of our energy supply without increasing reliance on fossil fuels, bankrupting the country or anything else.

Nuclear fission, unless you 'forget' to inspect and maintain the plants. Uranium isn't very common, but Thorium is. And you can make more Thorium and other fissile materials - get this - in a reactor. Neat, huh? Nuclear fusion, in a couple years.

As for public transit in small towns: My town has 4800-5000 people in it. There is a railway in the middle of town that goes through at least twice a day. We live 65 miles from the nearest large city, and there are several other smaller towns along the same highway. (Populations 800, 3000, and 4000 respectively.) Most people had to drive all the way to this large city in order to buy things they couldn't at home. Suddenly, someone got the idea to start a bus line that goes from the furthest town (the town of 800) and stops in each of the other towns thrice a day, before linking up with the large city's bus system by dropping you off at a major bus hub. People used it a lot, and they needed more buses. Then they decided to replace the buses with hybrid buses, and put solar panels on the roofs. Suddenly, it costs the public transport network a whole lot less to run the buses, it costs everyone making the trip (which some people do weekly) a lot less in gas, and there is less pollution from gas-burning cars, too. But no, it would never work to use public transit to replace cars.

@10ebbor10 - $191 billion at the least? Are you serious? Curiosity was gigantic and had to be sent to Mars with some of the most advanced technologies we have, and that cost $2.5 billion. I think your numbers are wildly off.

We're using nuclear fission at the moment. Exept with the Fukushima disaster everyone  is panicking about it and now they want to stop complely (This was part of the governement formation accord, so I don't really expect it to change, unless the governement falls again. Then again, the largest party, which somehow isn't part of the governement is pro nuclear power.). Also, Belgium is a quite important player in nuclear science, mostly specialized in loosing nuclear technology to nations who shouldn't have it. In fact, we partially developped said technology to reuse exess fuel. Fusion is still way of though, most optimistic prediction is 2050.

As for public transit. It's hard to run anywhere in Belgium without tripping over rails or being overrun by a bus. Every small town has got it's own station and bus stop. It's quite nice, especially if you're eligible for one of the many grant systems of the governement where you can travel free/ at a reduced price. They should invest a bit more in it, as things do tend to be quite crowded.

Note that we're talking about 191 billion for a 4 GW array. (Comparison: A 1 GW nuclear power plant cost between 5-20 billion). Curiosity was 1 ton. This thing would weight 4000, or 80000 if we fail to get lightweight pannels. I'm using data from the wiki, and the best spacecraft I could find.

As for the calculations:

Power beaming from geostationary orbit by microwaves carries the difficulty that the required 'optical aperture' sizes are very large. For example, the 1978 NASA SPS study required a 1-km diameter transmitting antenna, and a 10 km diameter receiving rectenna, for a microwave beam at 2.45 GHz. These sizes can be somewhat decreased by using shorter wavelengths, although they have increased atmospheric absorption and even potential beam blockage by rain or water droplets. Because of the thinned array curse, it is not possible to make a narrower beam by combining the beams of several smaller satellites. The large size of the transmitting and receiving antennas means that the minimum practical power level for an SPS will necessarily be high; small SPS systems will be possible, but uneconomic.

To give an idea of the scale of the problem, assuming a solar panel mass of 20 kg per kilowatt (without considering the mass of the supporting structure, antenna, or any significant mass reduction of any focusing mirrors) a 4 GW power station would weigh about 80,000 metric tons, all of which would, in current circumstances, be launched from the Earth

Now, the wiki article plans to go to LEO first, and then use ion engines to get into GEO. Sadly there doesn't seem to be much progress on those, so we're forced to go the GEO in one trip.
The most likely candidate for the trip seems to be the Delta IV-H, being the largest launch vessel in commision. This thing can carry 6,275 kg  in one trip, for a cost 300 million dollars.

80 000/ 6.275 tonnes= 12749 flights 

Now the amount of flights that this results in makes me pray I made a mistake, though I doubt it.

Now assuming we can use lightweight solar pannels

Very lightweight designs could likely achieve 1 kg/kW,[47] meaning 4,000 metric tons for the solar panels for the same 4 GW capacity station

This still means 638 flights at least, and that's just for the pannels, not counting the antennae or something.

Fake edit: Apparently the wiki comparison is incomplete, and the Ariana V can take a slightly larger payload into space. The Falcon Heavy (indevelopment) might also help, but both have a cargo capacity lower then 10.000 kg.

Note: One should take care not to confuse GTO (Geostationary transfer orbit), with GEO (Geostationary orbit.) There's a serious difference.

[MetalSlimeHunt]

I don't think we need to be worrying about this.

Alright, fine. I've been awake for way too long at this point, I will concede this whole thing about uranium because I am too damn tired to make rational arguments right now.