[ExI] Power sats again, was Gigadeath was crosswords

Keith Henson hkeithhenson at gmail.com
Wed Apr 22 18:21:56 UTC 2015

On Tue, Apr 21, 2015 at 5:00 AM,   William Flynn Wallace
<foozler83 at gmail.com> wrote:


> ?Keith, I am old and tired and depressed a lot and have two cancers and
> unloving children and a lot more.  I am really sorry if my mood got into
> the post and of course it did.

Accepted.  We are, as I recall, about the same age, but I seem to be
resistant to depression.  I tend to be sensitive about this topic.
First time I published on The Oil Drum, the flame war over the
desirability of a massive human die off got so bad that other blogs
were commenting on it.

"If you take a few minutes to read this blog, and again the comments,
you find the dissonance on full display. On the one hand you have a
person saying that there may be an energy answer after fossil fuels.
On the other hand you have lots of people not only saying it is not
possible, but directly arguing that a human die-back is more desirable
than cheap energy."


Ran into this the first time back in 1975 at a Limits to Growth conference.

Mark S Bilk <mark at cosmicpenguin.com> wrote:


> What progress are you seeing in energy sources?
> Do you follow LENR/CANR and hydrino (Blacklight) research?
> Is any of that looking good to you these days*?


Though any cheap energy source would spell the end of the power
satellite project.  Collectively all such sources contribute to the
risk of the investment failing due to the market being taken by
something cheaper.

Over the past few months a proposal has come together to build power
satellites that deliver electricity from space cheaper than coal.

I have the physics and economics fairly well under control, but the
next step is selling the idea to the engineering community and then to
political leaders.  That is something I don't have good ideas on how
to do.

We have 7 minutes of gorgeous video of sending up the parts and
constructing a power satellite. Can't release it until May 24 because
of contest rules it was done for.

The proposal depends on Skylon hauling cargo to LEO for $120/kg and
ground powered electrical propulsion from LEO up to GEO that adds
another $65/kg for a total of less than $200/kg.  That's about a 100
to one reduction over current cost to lift communication satellites to
GEO and at least ten fold less than the most optimistic SpaceX

It also looks like thermal power satellites will mass about 6.5 kg/kW.
That makes the lift cost to GEO no more than $1300/kW.  The rectenna
and parts cost to build the power satellite comes in around $1100/kg
for a cost of $2400/kW.  The formula is 1/80,000 of the cost to get
cents per kWh so this would be 3 cents per kWh.  That undercuts coal
at 4 cents by 25%.

I have a couple of recent technical/economic articles that go into
detail.  The one on transport is here:

The other one is on analyzing the mass of a 5 GW power satellite.  Ask
if you want to see the current draft.


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