From: Doug Jones (random@qnet.com)
Date: Sat Aug 28 1999 - 07:18:48 MDT
Robert J. Bradbury wrote:
>
> Well, my questions to Robert Freitas regarding the "hypsithermal
> limit" (heat tolerance of the planet), have drawn a response.
>
> [Yes, I am an angel from god... :-)]
>
> And the conclusions are not much different. He basically says
> that from the conservative to the optimistic sides we are limited
> to 100-1000 KW/person. That is pretty much what I had said
> with my 400 KW. If you want more, you have to borrow or buy
> from someone else (if you are going to be ethical at any rate).
To maintain the "natural" heat balance of the earth, could you not maintain
the _average_ albedo of the area used for sunlight collection? Make
photovoltaic panels that reflect any wavelengths not used, and intersperse
them with white reflective panels to cool the total insolation. This could
make large amounts of power available without adding to the planet's heat
load.
Delivering mansions from orbit would carry a 3MJ/kg heat penalty for the
atmosphere entry and deceleration from 7750 m/s, unless spinning skyhooks
were used very effectively. Probably more like 6MJ/kg for material
delivered from escape via aerobraking. Hmmm, skyhooks would actually make
that energy available *in space* in low entropy form, but total momentum
control would be tricky- both orbital and spin.
By moving out to sea,
* more area would be available for power production
* reduced carbon in the form of seabottom ooze would be available
* a wider variety of elements would be available
* a very large heatsink can smooth the load- even an albedo of
zero, applied for several years, would produce very little
temperature rise of a full ocean column depth
Finished products could then be delivered to the homesite.
Of course, the total area used by any entity must be limited, or else a
tragedy of the commons hits when a major fraction of the oceans is
obscured.
-- Doug Jones, Freelance Rocket Plumber
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