[ExI] cost of SBSP and thorium

[Keith Henson]

On Fri, Aug 17, 2012 at 5:00 AM,  John Clark <johnkclark at gmail.com> wrote:

> On Thu, Aug 16, 2012 at 12:43 PM, Keith Henson <hkeithhenson at gmail.com>wrote
>
>> You have to understand how cheap these things are.  They produce power at
> less cost than any other way.  If they can't be made that cheap, then there
> is no point in building them at all.
>
> Cheap? Find a way to cheaply put something as small as a life jacket into
> low earth orbit, actually do it in reality and not just on paper, and then
> it might be meaningful to talk about how much it would cost to put a
> supertanker into geosynchronous orbit; until then all the cost numbers are
> imaginary numbers not real numbers.  And I hope I'm wrong, I hope you can
> find a way to make power satellites work.

There are sound engineering reasons that a few pounds by itself will
always be expensive.  It's like the difference in transport cost
between a FedEx letter and a trainload of coal.

And real projects, power lines, dams, power plants (thorium included)
always started with imaginary ideas.  Physics, math, economics lets
you filter out the ones that obviously will not work, the rest might
work if something unexpected doesn't come along.

I might add that there are no thorium power reactors in spite of
places like India having a lot of it and needed energy badly.  Why?

For power sats, I can tell you one reason.  Before early this year
there were no proposals to get the transport cost down to where power
sats made sense.

>> That wasn't the question.  If the human race were pulling the majority of
>> power from thorium reactors, how long would it [Thorium] last?
>>
>
> The amount of coal mined per year worldwide is about 6 billion tons, the
> USA accounts for only about 1 billion tons of that. One ton of Thorium
> contains as much energy as 3 million tons of coal so you'd need 2 thousand
> tons of Thorium to equal coal. The U.S.Geological Survey's latest estimate
> says that one company, Thorium Energy Inc, has  915,000 tons of thorium
> reserves in Idaho and Montana. That alone could replace coal for about 450
> years, and that's just from the claims that one company has in 2 states.
> And Norway has as much Thorium as the entire USA,  and Australia about
> twice as much, and India has about 3 times as much. And we've already
> discovered Thorium deposits on the Moon and Mars.

I think the chances of mining thorium on the Moon or Mars is close to
zero.  If we had that kind of space presence, power sats would be the
obvious choice.

By taking the known and projected reserves and figuring in using
thorium to make synthetic fuels (unless you want to give up jet
travel) and world wide energy growth rates, the thorium doesn't last
as long as a century.  Now admittedly that's probably long enough to
reach the singularity and who knows what the energy situation will be
then.  More?  Less?  Hard to say.  Going from none to 30,000 one GW
thorium burners is as much of a boggle factor going from none to 30 TW
of power sats.  Or so it seems to me.

Keith