Here is an excerpt from Nature.Com:
http://www.nature.com/news/2004/041004/full/041004-13.html>

Can anyone calculate or guesstimate, or opine on how large of an SSPS project would be required to achieve the same thing? Is this a more palatable solution than 1,000 nuclear plants?

> Here is an excerpt from Nature.Com:
> http://www.nature.com/news/2004/041004/full/041004-13.html>

> Can anyone calculate or guesstimate, or opine on how large of an
> SSPS project would be required to achieve the same thing? Is this
> a more palatable solution than 1,000 nuclear plants?

Well, a nuke plant produces 7.9 billion KWh in one year - enough to
supply electricity for 773,000 households.
http://www.nei.org/

Powersats produce more electricity the bigger they are, and the
standard seems to be 5 GW. But what is that in KWh?

>
>> Here is an excerpt from Nature.Com:
>> http://www.nature.com/news/2004/041004/full/041004-13.html>
>
>> Can anyone calculate or guesstimate, or opine on how large of an
>> SSPS project would be required to achieve the same thing? Is this
>> a more palatable solution than 1,000 nuclear plants?
>
>Well, a nuke plant produces 7.9 billion KWh in one year - enough to
>supply electricity for 773,000 households.
>http://www.nei.org/
>
>Powersats produce more electricity the bigger they are, and the
>standard seems to be 5 GW. But what is that in KWh?

Back of the envelope: a GW is a billion Watts, or a million KW. There are 8760 hours in a year so one GW full time would produce 8760 Billion Watt Hours or 8.760 billion kWh. So a 5GW SSPS would essentially produce a little more than about 5 nuke plants. If that's correct would need just under 200 SSPS to power a hydrogen based transportation economy instead of 1,000 nuke plants.

>>Well, a nuke plant produces 7.9 billion KWh in one year - enough to
>>supply electricity for 773,000 households.
>>http://www.nei.org/
>>
>>Powersats produce more electricity the bigger they are, and the
>>standard seems to be 5 GW. But what is that in KWh?

> Back of the envelope: a GW is a billion Watts, or a million KW.
> There are 8760 hours in a year so one GW full time would produce
> 8760 Billion Watt Hours or 8.760 billion kWh. So a 5GW SSPS would
> essentially produce a little more than about 5 nuke plants. If
> that's correct would need just under 200 SSPS to power a hydrogen
> based transportation economy instead of 1,000 nuke plants.

Cool. ISTR reading that "five nuclear power plants" figure
somewhere, but can't be sure. And if we build those 50GW powersats
that are sometimes mentioned, it would take only 20.

Of course it all comes down to price. Will the electricity be cheap
enough to produce hydrogen at a price that will be competitive with
gasoline? The rising price of gas makes that an easier target, I
suppose.

Xenophile (who will maybe write something about some of the
ramifications of this, if it were to happen)

Or fewer but bigger SPS's. Any idea what the size these satellites would be,
assuming average efficiency of photovotaics?

Val

The rising oil prices are probably unsustainable in the mid to long term
necessary to cause investment in ideas like SPS, or even extracting fossil
fuels from the tar sands in Canada. Right now the markets are clearly
responding in a negative way to near term uncertainty in oil supply, and mid
to long term uncertainty in demand. Both of these factors have built a
significant risk premium into the cost, but risk premiums are based on an
emotion - fear - and are as ephemeral as the fear. The real disruptions of
oil supply and the level of demand are far less than the price would lead us
to believe. Indeed, refining capacity in the US is more significant than
supply risk, but has had less than its historical effect relative to the
risk factors. As soon as the markets become more comfortable with the
geopolitical situation, you cxan expect significant price drops. In
addition, the Saudis and many other producers have been investing in their
infrastructure (specifically the ability to pump more and faster, and in the
case of the US, perhaps changes in refining capacity will occur, though
probably through more efficient use of existing facilities) after a long
hiatus, and so the supply will increase. They remember all to well the oil
fiascos in the 70's and how the West countered with enormous increases in
efficiency, therefore reducing demand and hitting the producers' income
streams negatively in regard to growth. In fact, the Saudis have stated that
they wish to keepo the price per barrel far lower than it currnetly is to
avoid that situation, and also to keep ideas like tar sands, oil shale,
nuclear, deep sea drilling, and SPS all in the prohibitively expensive
category. Truly, the best friend of SPS is sustained high oil prices, but
this is something that has huge players from both sides fighting against it.

One thing that may sustain higher prices - it looks like little guys have
figured out that by causing fear on the supply side by, say, threatening a
labor strike on the oil platforms in Nigeria, they can cause market
fluctuations in 1st world countries, and thereby bring the most serious heat
down upon their leaders. What a simple, low cost, and extraordinarlly
powerful tool to get more rights, benefits and pay... I expect to see more
of that in the coming year - we'll see.

At any rate, though it pains me to say it, we probably have a bit more to
wait - perhaps 1 to 2 decades - before sufficient economic pressure has
built up to drive these alternative efforts. Perhaps Tango would care to
weigh in on the subject?

Val

> Well, a nuke plant produces 7.9 billion KWh in one year - enough to
> supply electricity for 773,000 households.
> http://www.nei.org/

> Powersats produce more electricity the bigger they are, and the
> standard seems to be 5 GW. But what is that in KWh?

A 5 GW plant produces 5 GWh (=5000 MWh = 5000000 kWh) per hour, which is how you define a watt-hour. Multiply by number of hours per year, and you get 5*10^6*24*365=4.38*10^10 kWh per year, or 43.8 billion kWh. You could probably cover your current generator capacity by putting one such powersat + rectenna per state, on average, assuming that you dismantled all other power sources including hydroelectric, which I don't find likely. If 773000 households use 7.9 billion kWh per year, then that is a little more than 10000 kWh per year per household, or a little more than 1000 watts of electricity, averaged over night and day and year. I don't know if this includes heating of houses that use eg. oil, or it is just the average *electricity* use of houses with or without air conditioning, heat pumps and non-electric heating. But the little more than a thousand watts of electricity per household means that a 5 GW powersat can provide electricity for four and a quarter million households.
Multiply this by fifty, and you get considerably more electricity than is needed by American households, but of course electricity from the grid is not consumed only by them. What is the total output of central electric power plants in the USA today? Assume that your country needs to shift to only hydroelectric and SPS power and assume that ground solar power and wind power and the like may be left out of the calculations for being minor contributors. Quote this number in watts, subtract the contribution from hydroelectric plants, divide by 5 MW, and you know how many powersats your country needs with its current electricity consumption.
And then add another fifty powersats to make hydrogen for the new hydrogen cars, and then some to replace heating of buildings with oil. :-)
I live in Denmark, with a little more than 5 million inhabitants. One 5 MW powersat would suffice here.

Jon Lennart Beck.

As indicated, 1000 nuclear plants is about 1000 GW or 1 TW. Solar energy
at Earth's orbit is about 1.5 kW/sq meter; at 10% throughput efficiency
that would be about 6 sq meter/kW. a TW is a billion kW, so total area
would be 6 billion sq meters, or 6000 sq km or perhaps 2500 sq miles.

To do the same with solar on the ground, even at twice the efficiency
(since it doesn't have to be transmitted from orbit) would occupy 2-3
times as much area on the ground.

Arthur

--- In ssi_list@... "Valens Agnitio"

> Perhaps Tango would care to weigh in on the subject?

Val,

I think you did a good analysis, and besides, I'm still struggling to
get through Robinson's "Red Mars." Thankfully, I always have about 6
books on the go, and after forcing myself to read a few pages I put
the book down in disgust and read something else. This book really is
a chore to read. I don't usually read wizards and dragons books, but
this book reminds me of them, with it's constant invocations of
"magic" in the infrastructure of Mars simply being there. One
character hops into a glider to fly a few thousand km for a meeting,
then abandons the glider there and hops into a personal transport. The
discovery on Mars of life extension technologies (something that the
millions of researchers on Earth have missed but a dozen researchers
on Mars have cracked) (BTW, who shipped a whole biotech lab to Mars
and how did the reseachers steal lab time for this research instead of
doing Martian biotech research.) Arghh. I'm always willing to suspend
disbelief, for instance, Heinlein's "Farmer in the Sky," but
Heinlein's work was never held up as a bible for terraforming
Ganymede. It was just a tale and I enjoyed it as such.

As for the economics in the book, I might need to get glasses soon,
for all of my eye-rolling is sure to have a deleterious effect on my
eye muscles. I'm guessing that Robinson must have travelled in the
company of many socialists/leftists/activists. His references to the
term "transnational corporations" is almost wholly, in my experience,
restricted to people of that oeuvre. Others refer to them as
multinational. Then he completely neglects all of the costs associated
with developing Mars and why corporations and governments would sink
money into the planet whn things on Earth are so dire. Sure, he offers
a bone with reference to strategic metals, and even mentions asteroid
mining as an alternative source, but then with the magical creation of
a space elevator all will be equalized and thus favor Mars, never mind
the additional expense of creating a space elevator. Thus far, he
hasn't offered a persuasive rationale for why all of this capital is
being invested in Mars so I'm having trouble suspending my disbelief.

At this point in the book, the characters are arguing about
establishing a new economic system but are going about it in a top
down fashion rather than looking at what motivates individuals and
building from the ground up. There is nothing to incentivize behavior
in his system (as far as I've read.)

And why are nations all sending colonists? What really struck me was a
character having a traditional lamb dinner with a group of Muslims.
Who raised the lamb? Who slaughered it? Who grew the spices? Who
harvested them? Who made the oven? Who made the utensils? Who made the
pots? etc. All of the comforts of home which result from a complex
industrial infratructure, but in an exotic location? Add the spice of
different cultures wanting to preserve the Earth-bound individuality,
and what you get is a logical mishmash of fiction. How do Muslims pray
to Mecca and in what direction do they prey when they are on Mars?
Where exactly is Mecca in the sky?

I surely hope that "Green Mars" and "Blue Mars" are of higher quality
because thus far, "Red Mars" is a bunch of claptrap. However, I am now
starting to understand the illogic of many Mars advocates who take
their visions of Mars homesteading from this work. I've always been
struck by the illogic of their visions, and now I understand that
they're arguing from a "wizards and dragons" fantasy of what things
would be like.

Man, I thought I'd breeze through these books in a few weeks, but my
determination will be stretched for months I fear. What a perverse
punishment, LOL.

TangoMan

Hash: SHA1

Tangoman, your on a silly quest. When you complete reading these
books, if you ever do, you will have achieved nothing more than self
punishment.
Mitchell James

| I think you did a good analysis, and besides, I'm still struggling to
| get through Robinson's "Red Mars." Thankfully, I always have about 6
| books on the go, and after forcing myself to read a few pages I put
| the book down in disgust and read something else. This book really is
| a chore to read. I don't usually read wizards and dragons books, but

Version: GnuPG v1.2.4 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFBcaEN0doL2+r9FcgRAstGAKCGCoV0IWqcyZjxVl9S2M2YCQTEbQCglb9e
OImobECHnkfEWC/qecP++Bs=
=m+sp

Tango,

I thought you might say something like all that after reading 'Red Mars',
and I promise you, it gets much, much better. However, I feel privileged to
read you pragmatic analysis - certainly the only one to be done on the grand
ideas in this series that has affected the sensibilities of so many who
could otherwise contribute to the space thing in a more effective way. No
one else will do it, you know. So, I suppose that to you falls the duty and
whatever perverse punishment that might entail. And again, I am looking
forward to your take on the next two. A hint: There is quite a bit more
development in interplanetary politics...

Have Fun!

Val

>Date: Sat, 16 Oct 2004 21:00:23 -0000
>
>--- In ssi_list@... "Valens Agnitio"
>
> > Perhaps Tango would care to weigh in on the subject?
>
>Val,
>
>I think you did a good analysis, and besides, I'm still struggling to
>get through Robinson's "Red Mars." Thankfully, I always have about 6
>books on the go, and after forcing myself to read a few pages I put
>the book down in disgust and read something else. This book really is
>a chore to read. I don't usually read wizards and dragons books, but
>this book reminds me of them, with it's constant invocations of
>"magic" in the infrastructure of Mars simply being there. One
>character hops into a glider to fly a few thousand km for a meeting,
>then abandons the glider there and hops into a personal transport. The
>discovery on Mars of life extension technologies (something that the
>millions of researchers on Earth have missed but a dozen researchers
>on Mars have cracked) (BTW, who shipped a whole biotech lab to Mars
>and how did the reseachers steal lab time for this research instead of
>doing Martian biotech research.) Arghh. I'm always willing to suspend
>disbelief, for instance, Heinlein's "Farmer in the Sky," but
>Heinlein's work was never held up as a bible for terraforming
>Ganymede. It was just a tale and I enjoyed it as such.
>
>As for the economics in the book, I might need to get glasses soon,
>for all of my eye-rolling is sure to have a deleterious effect on my
>eye muscles. I'm guessing that Robinson must have travelled in the
>company of many socialists/leftists/activists. His references to the
>term "transnational corporations" is almost wholly, in my experience,
>restricted to people of that oeuvre. Others refer to them as
>multinational. Then he completely neglects all of the costs associated
>with developing Mars and why corporations and governments would sink
>money into the planet whn things on Earth are so dire. Sure, he offers
>a bone with reference to strategic metals, and even mentions asteroid
>mining as an alternative source, but then with the magical creation of
>a space elevator all will be equalized and thus favor Mars, never mind
>the additional expense of creating a space elevator. Thus far, he
>hasn't offered a persuasive rationale for why all of this capital is
>being invested in Mars so I'm having trouble suspending my disbelief.
>
>At this point in the book, the characters are arguing about
>establishing a new economic system but are going about it in a top
>down fashion rather than looking at what motivates individuals and
>building from the ground up. There is nothing to incentivize behavior
>in his system (as far as I've read.)
>
>And why are nations all sending colonists? What really struck me was a
>character having a traditional lamb dinner with a group of Muslims.
>Who raised the lamb? Who slaughered it? Who grew the spices? Who
>harvested them? Who made the oven? Who made the utensils? Who made the
>pots? etc. All of the comforts of home which result from a complex
>industrial infratructure, but in an exotic location? Add the spice of
>different cultures wanting to preserve the Earth-bound individuality,
>and what you get is a logical mishmash of fiction. How do Muslims pray
>to Mecca and in what direction do they prey when they are on Mars?
>Where exactly is Mecca in the sky?
>
>I surely hope that "Green Mars" and "Blue Mars" are of higher quality
>because thus far, "Red Mars" is a bunch of claptrap. However, I am now
>starting to understand the illogic of many Mars advocates who take
>their visions of Mars homesteading from this work. I've always been
>struck by the illogic of their visions, and now I understand that
>they're arguing from a "wizards and dragons" fantasy of what things
>would be like.
>
>Man, I thought I'd breeze through these books in a few weeks, but my
>determination will be stretched for months I fear. What a perverse
>punishment, LOL.
>
>TangoMan
>

FREE pop-up blocking with the new MSN Toolbar get it now!

--- In ssi_list@... "Xenophile"
>

> Cool. ISTR reading that "five nuclear power plants" figure
> somewhere, but can't be sure. And if we build those 50GW
powersats
> that are sometimes mentioned, it would take only 20.
>
> Of course it all comes down to price. Will the electricity be
cheap
> enough to produce hydrogen at a price that will be competitive
with
> gasoline? The rising price of gas makes that an easier target, I
> suppose.
>

That all depends on how you calculate the price, and how you account
for costs of collateral damage, which are usually ignored in pricing
fossil fuels.

If you include the cost of maintaining a military presence in the
middle east, and the cost of global warming, then the cost of oil
would probably quadruple.

Nuclear power might appear cheaper than SSPS at first sight, until
you factor in the cost of disposing of nuclear waste and
decommissioning the reactors, then it suddenly becomes horrendously
expensive and SSPS becomes attractive. But so far, nuclear
decommissioning costs have been ignored, so that is a problem that
future generations will have to figure out how to pay for.

Now I may be out in left field somewhere on this, but I seem to remember a
post sometime back regarding the total energy available from deposits of
uranium. If I am correct, it is not even close to enough for replacing
fossil fuels in a significant way. Is this true?

Val

--- In ssi_list@... "Valens Agnitio"
>
> Now I may be out in left field somewhere on this, but I seem to
remember a
> post sometime back regarding the total energy available from
deposits of
> uranium. If I am correct, it is not even close to enough for
replacing
> fossil fuels in a significant way. Is this true?
>
> Val
>

That sounds familiar. Instead, for long term nuclear power,
Plutonium fast breeders could be used, I believe they do not have a
fuel limitation, IIRC they synthesise their own fuel. So they could
supply the world's energy needs indefinitely.

Best regards,

Charles R.

>
>That sounds familiar. Instead, for long term nuclear power,
>Plutonium fast breeders could be used, I believe they do not have a
>fuel limitation, IIRC they synthesise their own fuel. So they could
>supply the world's energy needs indefinitely.
>
Not quite - they synthesize the fuel out of U-238 (or thorium), which is
much more plentiful than the U-235 that fissions in standard reactors -
about a factor of 1000 more energy there. Most studies of the dangers
and expense of breeder reactor processes (there's a bunch of hazardous
chemical processing) make it sound a little dubious, at least with
current technology. Not even the French have successfully commercialized
a breeder reactor - perhaps just a matter of time.

There is also a lot more uranium in seawater than in standard ore
deposits - also quite a bit in very low quality "ores" like granite. The
overall energy content for uranium in a once-through fission process (no
breeders) from standard ores is about the same as overall energy content
from fossil fuels in traditional (coal and oil) deposits. Adding in
seawater and granite as sources of uranium (again for once-through
fission of U-235) gives a total energy similar to that for
nontraditional sources of fossil fuels - methane hydrates, tar sands, etc.

Arthur

While the seawater method seems feasible (and how many other important
metals are also available from seawater?), the granite method most certainly
is not. Given the concentrations of uranium within the host rock, and the
therefore enormous quantities of granite required, would necessarily result
in destruction of large land areas. Not something we should be thinking
about, I suppose, given the bad experiences we have seen with other strip
mining operations.

So I guess I should reframe my question: How much total energy is available
for fission plants given the current level of extraction methods?

Val

In case you were curious, there is an awful lot of Uranium under Boulder Colorado. The batholith next to it is highly enriched and Uranium, etc tend to precipitate when it comes in contact with Carbon. The pierre shale next to it under Boulder is full ofcarbonand there is a known hazard in many neighborhoods of Radon gas seeping into the crawl spaces (rumored tobe enough to kill you by either asphixiation or lethal radiation exposure in some examples). If push ever came to shove, the front range of Colorado is a prime resource to be looked at. You would just have to dig up a few cities in the process :) - Thor
Valens Agnitio wrote: While the seawater method seems feasible (and how many other important metals are also available from seawater?), the granite method most certainly
is not. Given the concentrations of uranium within the host rock, and the therefore enormous quantities of granite required, would necessarily result
in destruction of large land areas. Not something we should be thinking about, I suppose, given the bad experiences we have seen with other strip mining operations.

So I guess I should reframe my question: How much total energy is available for fission plants given the current level of extraction methods?

Val

Hi, Thor!

I should have know to ask you that question! Thanks for the answer.
Precipitations out of a batholith... Hmmmm, would that make for radioactive
tourmaline? That mineral seems to have just about every other element in it
- why not a little U. However, I would still like to get an idea on how much
energy is practically available for nuke plants - how much of civilization's
energy needs could be met before depletion?

Val

Greetings Val, I'm not sure about Uranium in Tourmaline yet there is a lot of pitch blend and other minerals that are easy to spot under UV light. The best way to find smoky quartz and other minerals is to go out with a geiger counter and poke it under tree roots just to the West of Colorado Springs. I saw rates as high as 100 millirem/hr in some of cracks. There were lots of horror stories about people using old gold mines for water sources since they tested negative for lead etc only to take a black light in and discover how hot the place was. One prof looked a littlepale the next day after we told him about this. The best source of commercial Uranium that I know of is from sand dunes ironically enough. Uranium salts strick to sand grains preferentally and accumulate by leaching. Parts of Utah are amazingly hot and Australia has easily half the world recoverable Uranium without going to extreme lengths. This does not rule out the second best source whichis coal because of the reaction with carbon. The ash that is left over is rich in radioactive elements and has a reported 1.5 time as much recoverable heat as the origional carbon did. Between these two sources which are dominated by Australia and the US, you have enough Uranium to be comfortably producing power for the next 50-100 years unless you see a dramatic rise in demand. Add in secondary recovery techniques and less shielding of reactors (due to smaller scale) and you will get probably another century. A Japanese firm had a nice small sealed modular unit that would last something like 20 years and then you send it back to the factory. It was competitive with diesel generators in places like Alaska though it still has the approval and waste problems. The wild card in this assessment is that demand does not look like it will flatten out. It anything it looks to continue to be exponential so even Uranium will eventually become scarce. Both China and India are on their ascent into the industrial age and can pay for energy with goods and services. To reach anything like the standard of living in the West China will have to burn up even the very large supply of Uranium to get there. Cheers, Thor
Hi, Thor!
I should have know to ask you that question! Thanks for the answer. Precipitations out of a batholith... Hmmmm, would that make for radioactive tourmaline? That mineral seems to have just about every other element in it - why not a little U. However, I would still like to get an idea on how much energy is practically available for nuke plants - how much of civilization's energy needs could be met before depletion?
Val

>Date: Mon, 18 Oct 2004 12:20:19 -0700 (PDT)
>
>In case you were curious, there is an awful lot of Uranium under Boulder Colorado. The batholith next to it is highly enriched and Uranium, etc tend to precipitate when it comes in contact with Carbon. The pierre shale next to it under Boulder is full of carbon and there is a known hazard in many neighborhoods of Radon gas seeping into the crawl spaces (rumored to be enough to kill you by either asphixiation or lethal radiation exposure
>in some examples).
>
If push ever came to shove, the front range of Colorado is a prime resource to be looked at. You would just have to dig up a few cities in the process

> Hi, Thor!
>
> I should have know to ask you that question! Thanks for the answer.
> Precipitations out of a batholith... Hmmmm, would that make for
> radioactive tourmaline? That mineral seems to have just about every

A radioactive green crystal? Just don't ask Clark Kent to mine it.

> other element in it - why not a little U. However, I would still
> like to get an idea on how much energy is practically available for
> nuke plants - how much of civilization's energy needs could be met
> before depletion?
>
> Val

That I do not know, but I do know that powersats don't require
digging up cities!