# 5976 bycrazy.ivan@... on Nov. 14, 2004, 11:10 p.m.
Member since 2021-10-03
Hi,
as the great justification for building these giant habitats (for the
SPS workers), but has anyone actually done an economical analysis if
SPS can compete with existing power sources? If it can't we should
drop that concept and rather spend our energy thinking up alternative
methods of getting from here to there.
Espen
# 5977 byian.woollard@... on Nov. 15, 2004, 1:12 a.m.
Member since 2021-10-03
On Sun, 14 Nov 2004 23:09:48 -0000, Espen Antonsen
wrote:
> has anyone actually done an economical analysis if
> SPS can compete with existing power sources?
> If it can't we should
> drop that concept and rather spend our energy thinking up alternative
> methods of getting from here to there.
The estimates that have been done seem to show that it costs 2 or more
times more than conventional hydrocarbon or nuclear power generation.
However, the overall environmental and political impacts of this form
of power generation are far lower; and factoring these factors means
that SPS is more cost effective than conventional approaches.
> Espen
--
-Ian Woollard
"In theory there is no difference between theory and practice, but in
practice there is."
"a society in which people can do and say what they want will also
tend to be one in which the most efficient solutions win" - Paul
Graham
# 5978 bylongsteven@... on Nov. 15, 2004, 1:40 a.m.
Member since 2021-10-03
Ian Woollard wrote:
>
> The estimates that have been done seem to show that it costs 2 or more
> times more than conventional hydrocarbon or nuclear power generation.
>
estimates, it would be nice to get some new ones. Then we could see
whether the trend is convergent or divergent.
> However, the overall environmental and political impacts of this form
> of power generation are far lower; and factoring these factors means
> that SPS is more cost effective than conventional approaches.
>
The environmental impacts will be lower, true; but I have the feeling
that the political impacts will be significant. And I don't think
accounting systems currently in use factor future effects against
present income to determine the true cost of making and distributing
something, so it will be a while before SPS will be seriously
considered except by us dreamers.
> "In theory there is no difference between theory and practice, but
> in practice there is."
Great quote! Is that Paul Graham's, too?
Steve
# 5979 bydante.feditech@... on Nov. 15, 2004, 1:54 a.m.
Member since 2021-10-03
> From: Ian Woollard [mailto:ian.woollard@...]
> The estimates that have been done seem to show
> that [SPS] costs 2 or more times more than
> conventional hydrocarbon or nuclear power
> generation.
billion dollars. A 1GW array would weigh roughly 10,000tons, and would have
a lifespan of between 20 and 30 years. Then it would be recycled into a new
SPS. (Assuming no advance in technology for simplicity's sake.) So if you
can launch ten thousand tons to GEO for less than $21B then you can make a
profit. This works out to a total construction cost limit of $2,100/kg. Then
you rysk the SPS onsite (no launch costs!) and the next lifecycle is almost
pure profit.
Such orbital costs are well within the capacity of an ion-drive system LEO
to GEO tug. Whether fabrication costs could be as easily absorbed remains
another question. Do remember though that launching from Earth is the worst
case scenario.
NASA's pencil-sketch for an asteroid tug capable of returning half a million
tons of material would weigh 10,000tons at departure, require 100 STS
launches and cost between $100B and $150B. If one fifth of that mass is used
to make more asteroid tugs, then that would leave enough material for 40 1GW
SPSs; which would then work out to $4B to $6B each; plus fabrication costs.
That's a cost drop of 50-75%.
Lunar mining involves (IIRC) roughly the same weight and cost for even
greater savings; though I cannot confirm that.
Alternatively a much simplier way to increase profit would be to sell the
power to europe, which would instantly double your income, and make SPSs
quite economical *today*! Unfortunately there is the slight problem of
public stupidity with reguards to microwaves, and political apathy towards
white-heat technology.
John
# 5980 byian.woollard@... on Nov. 15, 2004, 3:17 a.m.
Member since 2021-10-03
On Sun, 14 Nov 2004 20:39:19 -0500, Steve Long wrote:
> Conventionally-generated energy is becoming costly. If those are old
> estimates, it would be nice to get some new ones. Then we could see
> whether the trend is convergent or divergent.
allow for inflation.
Atleast, it does in America. In Russia, the price is going down.
> > However, the overall environmental and political impacts of this form
> > of power generation are far lower; and factoring these factors means
> > that SPS is more cost effective than conventional approaches.
> >
> The environmental impacts will be lower, true; but I have the feeling
> that the political impacts will be significant.
Um, you need to consider the effects of disconnecting from Middle
Eastern oil reserves. That seems to be desirable.
> And I don't think
> accounting systems currently in use factor future effects against
> present income to determine the true cost of making and distributing
> something,
They're starting too. For example you can get a pretty large (~70%)
grant in certain states to install solar panels to generate
electricity. The actual costs of solar energy are higher than
conventionally fuelled ones, but with the grant it gets cheaper.
> so it will be a while before SPS will be seriously
> considered except by us dreamers.
>
> > "In theory there is no difference between theory and practice, but
> > in practice there is."
>
> Great quote! Is that Paul Graham's, too?
Actually I think it's a slight misquote/improvement, I forget who is
supposed to have originally said it.
> Steve
--
-Ian Woollard
"In theory there is no difference between theory and practice, but in
practice there is."
"a society in which people can do and say what they want will also
tend to be one in which the most efficient solutions win" - Paul
Graham
# 5981 bycapcartoonist@... on Nov. 15, 2004, 3:07 p.m.
Member since 2021-10-03
"Espen Antonsen" wrote:
SPS workers), but has anyone actually done an economical analysis if
SPS can compete with existing power sources? >
Someone has, and they don't think SPS is going to warrent the cost of
colonizing space.
I don't remember where I read that, so I can't offer links. :(
If anyone is interested, I'm sure you can find something on the Net about
this.
That is why I mentioned the interest in NEA as an alternative, and more
profitable, incentive.
# 5982 byapsmith@... on Nov. 15, 2004, 5:14 p.m.
Member since 2021-10-03
Michael Capriola wrote:
>
>
> SPS workers), but has anyone actually done an economical analysis if
> SPS can compete with existing power sources? >
>
> Someone has, and they don't think SPS is going to warrent the cost of
> colonizing space.
Any cost estimate at this time is 99.9% speculation. Although we have
plenty of experience with the likely underlying technologies, we have
zero experience with building anything on the scale of a practical SPS
in space, and the low-cost launch technologies (space elevators?) or in
situ resource technolgies that could support it.
All we can say from a physics standpoint is SPS is one of only two
technologies that are scalable enough to supply power for humanity well
beyond this century. The other option is fusion - SPS of course relies
on the solar system's existing fusion reactor to function.
Basing a cost estimate for SPS purely on current technologies and ways
of doing business in space, for example the cost per kW for solar panels
on the International Space Station, leaves SPS at least 3-4 orders of
magnitude too expensive. But nobody is seriously considering building an
SPS the way the ISS solar panels are being built and installed.
Arthur
# 5983 bylucioc@... on Nov. 16, 2004, 1:47 p.m.
Member since 2021-10-03
On Mon, 15 Nov 2004 12:15:18 -0500, Arthur Smith wrote:
[snikt]
> All we can say from a physics standpoint is SPS is one of only two
> technologies that are scalable enough to supply power for humanity well
> beyond this century. The other option is fusion - SPS of course relies
> on the solar system's existing fusion reactor to function.
[snikt]
even well beyond this century.
# 5984 bya.goddard@... on Nov. 16, 2004, 2:39 p.m.
Member since 2021-10-03
Lucio wrote:
even well beyond this century.
I'd agree, and I have to say I'm sold on Thomas Gold's Deep Hot
Biosphere too (http://people.cornell.edu/pages/tg21/DHB.html for a brief
overview, and the book - an excellent read - is available via Amazon)
If that proposal is true only in part, then there's plenty of
opportunity for the world population to enjoy for centuries the rate of
energy use only available to under a billion of us (and only for the
next few decades given current supply chains) in the technological
nations.
That said, /all/ use of fossil fuels has a detrimental effect on the
planet's atmosphere, biosphere and climate. Common sense alone implies
we can't continually dump CO2 into the atmosphere without some resultant
effects on life on Earth. Given that, the solutions would seem to be:
1/ Recycle products better.
2/ Utilise sustainable energy sources only.
3/ Minimise energy use (more efficient vehicles, bulbs, etc.)
And therefore we may as well:
4/ Develop fusion power (the "easy" D and T reactions initially, with
proton-proton reactions "eventually")
5/ Build and utilise SPS's and microwave transmission for truly clean
energy production.
The astrophile in me sees the development of habitats to support
off-world energy production and industrialisation as a natural step in
ensuring a sustainable future on this increasingly over-crowded and
definitely over-polluted planet.
See? A green approach to the need for space-based habitats (and to
counter the anti-green message of the last few days). ;-)
Andy Goddard
# 5985 bylongsteven@... on Nov. 17, 2004, 12:18 a.m.
Member since 2021-10-03
Lucio de Souza Coelho wrote:
>
> On Mon, 15 Nov 2004 12:15:18 -0500, Arthur Smith wrote:
> [snikt]
> > All we can say from a physics standpoint is SPS is one of only two
> > technologies that are scalable enough to supply power for humanity well
> > beyond this century. The other option is fusion - SPS of course relies
> > on the solar system's existing fusion reactor to function.
> [snikt]
>
> I think that there are enough hydrocarbons to keep this planet running
> even well beyond this century.
>
Steve
# 5986 bylucioc@... on Nov. 17, 2004, 6:36 p.m.
Member since 2021-10-03
On Tue, 16 Nov 2004 14:33:03 -0000, Andrew Goddard
wrote:
(...)
> I'd agree, and I have to say I'm sold on Thomas Gold's Deep Hot
> Biosphere too (http://people.cornell.edu/pages/tg21/DHB.html for a brief
> overview, and the book - an excellent read - is available via Amazon)
>
> If that proposal is true only in part, then there's plenty of
> opportunity for the world population to enjoy for centuries the rate of
> energy use only available to under a billion of us (and only for the
> next few decades given current supply chains) in the technological
> nations.
(...)
my faith in the conventional explanation for oil and coal as fossil
fuels. However, I don't know if there will ever be a away to explore
directly the Methane Domain - if there is a viable way, then I think
that hydrocarbons would be virtually endless...
However, even if Gold is wrong and the Methane Domain does not exist,
the methane hydrates at the bottom of the ocean are yet another
humongous source of hydrocarbons. (And exploring it could perhaps have
interesting side effects like colonization of the ocean.)
If there is indeed a correlation between man-made CO2 and global
warming, though, current coastal cities will have to be abandoned, as
Steve pointed out. However, if that process is gradual, I think that
people in general will not perceive any prejudice in continuing to use
hydrocarbons.
And that (as well as the fact that breeder reactors could power Earth
for millennia) seriously undermine the need for SPS (or even fusion
reactors), unless green ideology is embraced.
# 5987 byapsmith@... on Nov. 17, 2004, 6:54 p.m.
Member since 2021-10-03
Lucio de Souza Coelho wrote:
> I also read "The Deep Hot Biosphere" and it also destroyed completely
> my faith in the conventional explanation for oil and coal as fossil
> fuels. However, I don't know if there will ever be a away to explore
> directly the Methane Domain - if there is a viable way, then I think
> that hydrocarbons would be virtually endless...
The question is replacement rate, no matter what the actual source of
the "fossil" fuels. The "deep hot biosphere", if it exists, is not very
productive. We are currently using fossil fuels at between hundreds of
thousands and tens of millions of times the replacement rate. That's
simply not sustainable.
World enegy use increased a factor of 16 during the 20th century. The
growth rate will slow somewhat this century, as population growth slows.
But an increase of a factor close to 10 isn't unlikely, and would be
good for the world if it could be sustainably supplied. That means that
for the next 100 years we actually need 1000 years worth of current
energy supply. Fossil fuels, even including methane hydrates, cannot
provide energy at such an increasing rate.
Arthur
# 5988 bytango_dancer@... on Nov. 17, 2004, 7:04 p.m.
Member since 2021-10-03
--- In spacesettlers@yahoogroups.com, Arthur Smith wrote:
> The growth rate will slow somewhat this century, as population
> growth slows.
Don't neglect the rise of China, India and other parts of the world
towards Western levels of energy consumption. The price of all
commodities has risen in the last years almost entirely due to China's
appetite.
Further, in the Middle East there is a tidal wave of youth (40% of
population under 14 yo) coming of age and entering the stage of their
lives where they will be consuming more energy.
TangoMan
# 5989 bylucioc@... on Nov. 17, 2004, 7:14 p.m.
Member since 2021-10-03
On Wed, 17 Nov 2004 13:55:44 -0500, Arthur Smith wrote:
(...)
> The question is replacement rate, no matter what the actual source of
> the "fossil" fuels. The "deep hot biosphere", if it exists, is not very
> productive. We are currently using fossil fuels at between hundreds of
> thousands and tens of millions of times the replacement rate. That's
> simply not sustainable.
(...)
not say that hydrocarbons are *produced* by the Deep Hot Biosphere.
Rather, they are abiogenic in origin and are just *contamined* by the
Deep Hot Biosphere.
According to Gold's predictions, there should be a layer 100 Km below
the surface where methane would be stable (despite the temperature,
due to the pressure). Depending on the thickness of that so-called
Methane Domain, there could be a kind of global "ocean" of methane
inside the Earth. If this "ocean" can be reached (technically and
economically speaking), then we would bypass any natural replacement
mechanism (namely, infiltration of hydrocarbons from below to the
surface) and have direct access to the source. And I don't think that
this huge reserve would be exhausted in any foreseeable future...
But of course the theory can be wrong (despite many favorable
evidences that I consider strong).
# 5990 byapsmith@... on Nov. 17, 2004, 7:44 p.m.
Member since 2021-10-03
Lucio de Souza Coelho wrote:
> this huge reserve would be exhausted in any foreseeable future...
How much energy would it take to drill down 100 km to retrieve this
stuff? Is it really closer to modern technical capabilities to drill 100
km down through solid rock than to launch things a few hundred km into
orbit? Energy payback for methane hydrates is questionable as well.
There is another limit, though one which would only kick in after a few
thousand years of "fossil" energy use: the oxygen in our atmosphere
needed to turn fossil fuel into energy (there are about 1200 trillion
tons of O2 in the atmosphere). Of course the climate on this planet
after any substantial portion of the O2 in our atmosphere had been
converted to CO2 would NOT be pleasant.
Given that the oxygen levels on our planet represent a billion years or
so of life's work, the fact that humanity could burn it down in a few
thousand years is further evidence of how unsustainably we are currently
using energy resources.
Arthur
# 5991 bylucioc@... on Nov. 17, 2004, 8:55 p.m.
Member since 2021-10-03
On Wed, 17 Nov 2004 14:45:44 -0500, Arthur Smith wrote:
(...)
> How much energy would it take to drill down 100 km to retrieve this
> stuff? Is it really closer to modern technical capabilities to drill 100
> km down through solid rock than to launch things a few hundred km into
> orbit? Energy payback for methane hydrates is questionable as well.
(...)
methane well too.
By the way, it has just occurred to me that, if a 100Km deep well ever
becomes economically and technically possible, then why use it to mine
the Methane Domain? Use it as a geothermic energy well instead,
extracting energy from the (huge) difference of temperature between
the mantle and the surface. (Duh!!!) In fact, even geothermal wells 10
Km deep would do the job (I think).
Geothermal energy would be sustainable and non-polluting (or so I
hope), so I guess that we have not to worry about Earth becoming
uninhabitable if we ever get access to such depths.
# 5992 byapsmith@... on Nov. 17, 2004, 9:49 p.m.
Member since 2021-10-03
Lucio de Souza Coelho wrote:
> Geothermal energy would be sustainable and non-polluting (or so I
> hope), so I guess that we have not to worry about Earth becoming
> uninhabitable if we ever get access to such depths.
Yes, geothermal could work - however drawing energy too fast can deplete
the resource (relative to the rate of heat transferred from Earth's
depths) - there's some experience with this at "The Geysers" in California:
http://www.unocal.com/geopower/evolution/
"Since 1987, The Geysers has experienced a decline in steam pressure and
electricity production that has coincided with older power plants in the
area reaching the end of their useful lives. Initial pressure in most
Geysers production wells was above 500 pounds per square inch (psi), but
by the mid-1990s many fell below 200 psi. And because pressure
determines production rate, it is no longer practical in most areas of
The Geysers to drill new wells to supplement steam supply."
Arthur
# 5993 bylongsteven@... on Nov. 17, 2004, 10:08 p.m.
Member since 2021-10-03
>
> Geothermal energy would be sustainable and non-polluting (or so I
> hope), so I guess that we have not to worry about Earth becoming
> uninhabitable if we ever get access to such depths.
>
# 5994 bylucioc@... on Nov. 18, 2004, 4:53 p.m.
Member since 2021-10-03
On Wed, 17 Nov 2004 17:07:25 -0500, Steve Long wrote:
(...)
> I occasionally hear that this approach is working in Iceland.
(...)
geothermally-powered ovens...
But that works there for two reasons:
- Iceland has volcanoes, geiseres, hot springs and all sorts of
geoenergetic "sources" everywhere. It is a shark contrast with the
geologically dead regions that make most of the Earth - like here in
Brazil, where we have neither volcanoes nor quakes and even hot
springs are almost non-existent.
- Iceland population is small (100K inhabitants?). I suspect that, had
the island millions of people, perhaps geothermal energy would not be
enough.
# 5995 bylongsteven@... on Nov. 18, 2004, 6:56 p.m.
Member since 2021-10-03
Lucio de Souza Coelho wrote:
>
> - Iceland population is small (100K inhabitants?). I suspect that, had
> the island millions of people, perhaps geothermal energy would not be
> enough.
>
a little more than you said, but less than I thought.
All of your points are good. I had forgotten that, though geothermal
energy is available everywhere, in some cases the cost to reach and use it
is prohibitive.
Steve