[ExI] How Electricity Became a Luxury Good

Keith Henson hkeithhenson at gmail.com
Tue Sep 10 01:41:57 UTC 2013

From: "spike" <spike66 at att.net>

> But one thing I would like everyone to realize is that there is likely to be
no magic new technology, nothing likely to replace oil.

Of all the people on this list, I expected you to know better.

>From a paper I am about to put up on The Energy Collective:

Economic Analysis of GEO Laser Propulsion

It is not hard to get the cost for 5kg/kW power satellites down in
this range if the cost of lifting parts to GEO can be brought down to
$100/kg or less.  Solar power on earth ties up material in the range
of 500 kg/kW(average). Power plants built in space, where they get
full time sunlight and are not subject to wind and gravity, allows a
hundred to one materials reduction to 5 kg/kW and an energy payback
time of less than two months.  Given a 20-year lifetime for the power
satellites, the EROEI would be around 120, good as the best days of
oil. However, the cost of transporting even a greatly reduced mass to
space is a big problem. One hundred dollars per kg is a hundred to one
cost reduction compared to the current cost of around $10,000 per kg
paid to put communication satellites in GEO.

A two-orders-of-magnitude reduction in transport cost seems to be
possible, but not using chemical energy (other than the first step
where a Skylon type vehicle burns hydrogen with air for about 1/4 of
the velocity to orbit).

Beyond Skylon's air-breathing phase (above 25 km and Mach 5.5), it
takes a 3 GW laser located in GEO to accelerate the vehicle for the
last 6 km/s to orbit.

I think you reviewed the long version for the JBIS.


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