[ExI] Written for another list

Keith Henson hkeithhenson at gmail.com
Tue Jul 31 19:00:47 UTC 2012

On Tue, Jul 31, 2012 at 5:00 AM,   "Henrique Moraes Machado"
<cetico.iconoclasta at gmail.com> wrote:

> Have you tried kickstarter? Kidding (or am I?). I'd really love to see that
> happen in my life time.

I have not tried it yet, not having a part of the project that is
small enough to fund this way, at least not yet.  John Mankins tried
to raise money for something related and it failed.

> And what about that maglev launcher system that people have been talking
> recently. Better or worse (if it ever get built)?

A long time ago (before the net) I ran through the engineering
numbers.  At this remove all I remember of that effort was that it
really didn't look good at all.  It was barely possible on the moon.

I have been ask this so many times that I should either look up a
place where it is refuted or write one myself.  As I recall, at
constant acceleration it takes too much power near the end, at
constant power it gets too long.

Adrian Tymes <atymes at gmail.com> wrote:

> On Mon, Jul 30, 2012 at 7:36 AM, Keith Henson <hkeithhenson at gmail.com> wrote:
>> That's acceptable for powering
>> lasers, but I can't see much of a market for multiple GW at 20 times
>> the cost of electricity from nuclear plants.
> Nope.  If the cost of electricity is higher than what you get
> off the grid, then it's not acceptable for powering lasers,
> since you could just get it off the grid instead.

That would be lovely.  Do you have any suggestions of how to draw 7 GW
off the grid from GEO?

It is possible to send the laser beams up to GEO and bounce them from
there down to the launch vehicle path some 4000 km along the equator.
It may even be more economical because tracking mirrors should be
lighter, but the risk factor of it not working due to atmospheric
distortion is high.  After looking at alternatives, putting a first
power plant and laser in GEO with conventional rockets looked to be
the lower total cost and risk.  This is subject to further analysis.
Want to do it?

>> I can send you the spreadsheet for the financial model if you want to
>> try making money on conventional propulsion.
> I might be interested in taking a look *if* your spreadsheet
> includes the costs of the intermediate conventional
> propulsion stage.  If it does not, then you need to add that
> before it is a complete, realistic model.

It does, of course.  But only to build the first propulsion laser, not
to sell power for a dollar a kWh.  Now if you have a *market* for 5 GW
of power at a dollar a kWh, we are in business.

> (I could assume nanosanta for a nanotech project, and
> handwave the costs of developing nanosanta.  That wouldn't
> be a current real world business model either.)
>> Perhaps.  I freely admit the model may have errors in assumptions or
>> formula.  Though saying that without looking at the model seems a bit
>> over the top.
> No, it's basic business theory.  If you can make a profit with
> practice X after it's developed, and a lesser profit with
> practice Y that does not take significant development, then
> you can compare the efficiency of developing X and then
> making more money over time versus just using Y.

I f can figure out a way to get this started on a smaller scale,
please do.  If you can, I will support your efforts.  I am not welded
to this approach.

As an analogy, it is not possible to mine a low grade ore body and
make money if you try to do it on a small scale.  Sunlight is a low
grade (dilute) energy source.  Collecting it on a scale of tens of TW
is a big task no matter how you slice it.

>> I have no  present intention of showing this project to investors.
>> For one thing, I am assured that there is only one, the Chinese
>> government.  That is already underway.
> Nope.  If you really did have a case, there are private investors
> in the US.  There are, in fact, already startups actively
> pursuing this - maybe you should apply for a job so you can
> actually help make this future?
> http://www.spaceenergy.com/
> http://www.solarenspace.com/ (though information about their
> post-2009 status is hard to find)

I happen to be intimately knowledgeable about both of these.  I should
not say more on a public forum, but if you want to call sometime . .

>> I am mainly interested in making a case that there *is* a way out of
>> the energy/carbon problems without an 80% die off.
> The theoretical case has long been made.  The challenge now
> is the litmus test: actually doing it.

That's news to me.  Where?

>> The cost of power at current $10,000/kg is dominated by the lift cost
>> of ~50,000/kW.  Cost of power at that transport rate is ~$2/kWh.
>> For zero lift cost, the cost would be around 1.4 cents per kWh.  The
>> derivation of this is in the paper.
> It sounds like you have bigger concerns than the lift cost, if
> that is not a majority of the cost.

It's around a third of the total cost.  I really don't understand your
objection to the other costs.  Do you know of a less expensive way to
make and transmit power to the Earth?

> From: Dan <dan_ust at yahoo.com>
> On Sunday, July 29, 2012 4:37 PM Adrian Tymes <atymes at gmail.com
>> Demonstrate it at lower cost with existing technology
>> first, even if you have to accept a much, much slower
>> rate of payback at first.
> Or even no payback. It could just be a proof of concept that doesn't even break even, but merely shows it can be done at such and such a price and gives good clues to what it would be like to operate the thing and what might happen at larger scales. Also, in this case, you're not blowing all your resources on a gigantic project that might fail, but a very small one where a failure is far less costly and you can more easily recover from it to try again.

That's a great idea!  Wonder why it has not already been done?

If you can follow the physics, why not is in here:

There are scaling problems that are due to the transmission of
microwaves through the atmosphere and the distance to GEO.

It is about the same expense to built one demonstration power
satellite with conventional rockets as it is to set up the
transportation pipeline and build them by the hundreds.

As for a demonstration that satellites in GEO can deliver measurable
power to the earth, have you ever set up a satellite antenna?


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