[ExI] EP and Peak oil.

[Keith Henson]

On Thu, Apr 3, 2008 at 8:32 AM, John K Clark <jonkc at att.net> wrote:
> "Keith Henson" <hkeithhenson at gmail.com> Wrote:
>
>  > According to New Scientist, 25 years till peak coal.
>
>  Maybe, maybe not; although I admit New Scientist is not the only one
>  to make this claim. Similar arguments are made in the book "The Coal
>  Question: An Inquiry Concerning the Progress of the Nation, and the
>  Probable Exhaustion of our Coal-mines" written by the English economist
>  and logician William Stanley Jevons. The interesting thing is that this
>  book was written in 1865.

Well, there is no question they are exhausted now.

>  Me:
>  >> 2) Tar Sands
>
>  You:
>
> >Being exploited now.  They would benefit hugely from power sats
>  > to supply upgrade hydrogen.
>
>  I don't know what that means,

That stuff is too thick to pump because the high hydrogen hydrocarbons
are gone.  If you are going to use it as liquid fuels, you have to add
hydrogen, much as is done converting coal to liquid fuels.  The
problem is making the hydrogen, it uses up a substantial fraction of
the energy in the input material to make it and about doubles the CO2
released for a given amount of transport.

I really wish that knowledge of basic chemistry and industrial
processes was more common on this list.  It freely available.
http://en.wikipedia.org/wiki/Tar_sands

>  but I do know that Canada's reserves
>  of Tar Sands approximately equal to the world's total reserves of
>  conventional crude oil, and Venezuela may have more reserves than
>  Canada.

You have to deflated these sources by half because it takes a lot of
the energy in the deposits to get them out.  There are good reasons
they have not been exploited before. Open the article above and go
down to:

Global direct effects

Input energy

Producing synthetic crude takes so much energy that they are about to
put in a 2.2 GW nuclear plant to supply some of it.

>  Me:
>   >>Oil Shale
>
>  You:
>
> > Environmental problems you would not believe.
>
>  Bigger environmental problems than Power Satellites?

Yes.

>  I'll tell you
>  one thing, even if they turns out to be totally benign environmentalists
>  will fight you every inch of the way.

You expect that.  It's less expected to find opposition here.

snip
>
>  Me:
>  >>  5) Nuclear Fission
>
>  You:
>
> > Every version I know about can be tapped for neutrons.
>
>  Yes, that is indeed a serious problem, possibly a lethal problem. If
>  environmentalists don't get out of the way on what to do with this stuff
>  they could kill us all.

I don't think you understand the problem.  Neutrons plus depleted
uranium equals weapons grade plutonium better than any made in the
cold war.  And there is at least one way to make it into weapons
that's so easy a well funded street gang could do it.  You don't need
complicated electronics, you can fire one with a fuse.  We may have to
build reactors in every country of the world.  There may be some
really drastic side effects.

>  >  There is no reason to think it won't work, the physics is more than
>  > 200  years old.
>
>  Well 103 years old, you need the Photoelectric effect; but nobody is
>  saying power satellites are physically imposable, the question is
>  are they economically rational? I have my doubts.

That's a number question.  I have put some numbers on it.  If you can
build a moving cable mechanical elevator then a power sat that masses
less than 3 kg/kW repays the lift energy to GEO in a single day of
operation.  If it can be built at all, the elevator lifts it own mass
every 50-100 days.

These numbers by themselves don't make the project economically
rational, but they indicate more analysis is worth doing.

On the other hand, "economically rational" is context dependent.  If
we knew a K/T class asteroid was going to hit in a few years . . . .
The energy problem is in the same gigadeath class.

>  Ok maybe 200 after all, I wonder if it would be better to use a
>  parabolic reflector and a heat engine?

It might be, it's not obvious.  If you have access to moon rock or
asteroid material for heat sink fluid it would help.

Keith