Re: Solar Wealth

From: Robert J. Bradbury (
Date: Thu Nov 01 2001 - 16:31:40 MST

James commented:

> It would be valuable to include geothermal wealth in that equation.

Yes but then I would have to change the title of the paper to
"Energy Resource Wealth" and I'd have to include Oil, Coal and
a whole bunch of other things.

Strictly speaking, neither solar nor geothermal are "renewable".
The Sun runs down in 4-6 billion years and though I haven't seen
calculations on the rate of production vs. the rate of extraction,
at some point using the geothermal *will* cool off the core of
the Earth. That will probably stop the dynamo and leave us
without a magnetic field to shield us from space hazards. It
will also stop the carbon recycler. The carbon will slowly
accumulate on the bottom of the ocean instead of getting
recycled through volcanoes and back into the atmosphere.
Now that "might" be useful if you could time it so as to
decrease the greenhouse effect at the same time the sun starts
to enter its red giant phase, but I doubt we are that smart yet.

There *is* a moderately short term useful effect of harvesting geothermal
in the Yellowstone area, because scientists say that that area
blows up every few million years with a fair degree of regularity
making Mt. St. Helens look like a warm up exercise. I would imagine
there are some very interesting dual-purpose strategies that could
make geothermal quite attractive in some locations. However, I'm
not so sure all the corrosion and bacterial fouling issues have
been solved for geothermal yet.

The main problem with geothermal and solar cells is that you have
to have people involved -- either drilling the wells or assembling
the panels. Having people involved drives up the costs. My entire
reason for exploring this is to see how low you you can drive the
human labor component of your infrastructure build. Or how low
tech you can make the infrastructure so it requires easily trained
low cost workers rather than expensive highly trained workers.
Pouring cement for the walls of solar bioreactor ponds is about
as low tech as I think you can get.


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