[ExI] How will air travel work in a green solar economy?

[John Clark]

On Thu, Jul 10, 2014 at 11:23 AM, Robert G Kennedy III, PE <
robot at ultimax.com> wrote:

> There are only 2 other sources that have the potential to power our
>> civilization for the next billion years:
>>
>> 1) Fusion reactors, but nobody is close to figuring out how to build even
>> a
>> working model much less a practical machine.
>> 2) Thorium fission reactors, and we?ve known how to build them for half a
>> century.
>>
>
> > No, there are 3:
> space-based photovoltaic satellites.
>

That's just another form of solar energy, and a form that is ln my opinion
least likely to do us any good in the immediate future.

> I would substitute fast breeders for the fusion reactors, since we do
> already know how to build and operate the former, but not the latter.


A LFTR is a breeder reactor, it's just not a fast breeder, that is to say
it uses slow neutrons not fast ones; and it breeds Uranium 233 not
Plutonium. And a Plutonium breeder could supply use with energy for
millions of years but probably not billions as Thorium can, Thorium is a
much more common element than Uranium;   but Plutonium breeders are
undesirable for a number of other reasons.

> We'd just have to be honest and call it as the "plutonium economy",


And that is one of those reasons.

> But of all of these, solar is the one with the most "headroom" for the
> human race,


As I've said, we will run out of Thorium in the Earth's crust about the
same time as the sun will run out of Hydrogen in it's core. And why do
people keep saying that solar energy is renewable?  Who renews the  600
million  tons of Hydrogen that the Sun transmutes into Helium each second?


> > One acre in the temperate zone can host 1/6th to 1/4th of a MW(e) of
> solar electric generating capacity, depending on technology and latitude
> and cloud cover.


The problem isn't just to find energy, the lukewarm oceans contain an
enormous amount of energy, the problem is in finding energy in a form that
can be easily converted into work, and that is where solar, terrestrial or
space based fails, it's just too dilute and unreliable to compete with
coal.  And if you're really serious about stopping global warming you're
going to have to convince the developing world to stop using coal, and
you're never going to be able to do that unless you show them a new
technology that can produce energy cheaper than coal. I think LFTR's  have
the potential to be that new technology, I don't think solar does.

> Btw, LNG would be an even better aviation fuel,


Nuclear reactors are BY FAR the safest way to produce electricity. Since
1969 Nuclear power plants have killed .0085 people per gigawatt year of
electricity produced,  for Liquefied Petroleum Gas plants it's 2.9 people
per gigawatt year of electricity produced.

  John K Clark
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