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Re: nuclear power: abundant? and cheap?



----- Original Message -----
From: "John S. Denker" <jsd@MONMOUTH.COM>
To: <PHYS-L@lists.nau.edu>
Sent: Wednesday, August 07, 2002 10:33 AM
Subject: Re: nuclear power: abundant? and cheap?



Rick Tarara wrote:

In the end--once we either decide to stop using fossil
fuels or run out--we had better have something like
fusion working ...

What means "something like" fusion? There are precisely
zero fusion-based power plants right now. Thirty years
ago they said it would be about 20 years before the first
such plant would be built. Now they say it will be about
20 years before the first such plant will be built. That's
pretty slow progress. And the US applied an 80% budget cut
to fusion research a few years ago, so progress might get
even slower.

... or we may have to go to exotic things like space-based
solar collection satellites which will run to really big bucks.

How big?

If you could meet the US electricity demand with something
costing a trillion dollars, that would be reasonably attractive.
At current prices the cells alone would cost you a trillion
dollars, but prices have come down by a factor of three in
the last ten years, and presumably there would be economies
of scale to be had. Still, the budget is tight. On the
third hand, it wouldn't take much of a tightening in the
non-renewable carbon-fuels market to tip the scales.

I repeat one major point--if we aren't using the carbon-based fuels then all
of the energy that we were producing with oil, coal, and natural gas must
then be provided by new or 'green' resources. The current accounting is
that the demand for electrical energy is only about 20% of the total demand
(although over a third of the energy resources are used to make
electricity). So today the electrical demand is about 3e12 kWh per year but
the total demand for energy is about 16e12 kWh. The actual energy
consumption is about 21e12 kWh with the difference being the thermodynamic
efficiency of electrical production. The main point here is that if we
stopped using coal, oil, and natural gas tomorrow, we still have to produce
the 16e12 kWh of usable energy to meet the demand.

Now design a solar, wind, nuclear or whatever system to do that! Build in
population growth over whatever time period you choose to implement the
change over--this will increase demand (probably more than efficiency
efforts can reduce it). So consider a yearly need for 20-30e12 kWh and
figure out what you need. The work that my classes have done over the past
three years comes up with numbers like $40 trillion over 100 years with a
mix of coal, solar, wind, nuclear, hydro, biomass, and geothermal. If you
decide to go all wind or all solar the costs are more--and they did project
solar costs far below current levels. To put the whole thing in space--well
I'd estimate at least twice the cost but that's a wild guess. So a very
crude estimate of a US energy system based mostly on satellite solar
collectors might be on the order of $100 trillion?

Still in Boise without a lot of my data---

Rick