Re: [Phys-l] Nuclear Reactors

["LaMontagne, Bob" <RLAMONT@providence.edu>]

It's nice to see a reasonable approach championed.

Alternate energy sources are "alternate" because they are not quite
ready for prime time. We have an absurdly large supply of ridiculously
cheap coal (sorry - I'm not swayed by arguments of "true" cost). It is
national economic suicide not to use this supply. Clean it up - do
whatever will lessen its environmental impact - but use it. Many
"alternate" sources can be refined to the point where they will
eventually make economic sense. Wind power NEVER will. No one wants wind
farms near them. They may look wonderful to an environmental activist,
but to most sane people they are just plain ugly. When even the East
coast liberals won't live next to them you know you have a problem. When
I fly to California every couple of years and look at the windmills
outside of Vacaville blighting those beautiful California hills I get
angry enough to almost start shaking. What idiots would do that to such
magnificent countryside?

Centralized power from nuclear and coal feeding in to grids leaves the
rest of the land available for our use and enjoyment. Solar and wind
sources in diffuse arrays that are everywhere in sight are too big a
price to pay for a supposed couple of degree warming from models that
can't even hindcast.

Bob at PC



-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu
[mailto:phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of Rick
Tarara
Sent: Wednesday, April 08, 2009 8:12 AM
To: Forum for Physics Educators
Subject: Re: [Phys-l] Nuclear Reactors


----- Original Message ----- 
From: "Hugh Haskell" <hhaskell@mindspring.com>
> The point here, of course, is that if we keep thinking up reasons why
> something won't work, we will never solve the climate problem.
> Creative, but level-headed thinking and planning is needed, here and
> abroad. My sense right now is that much of the rest of the world is
> well ahead of us in both.
> -- 

It is not a case of thinking up reasons 'why it won't work', but rather 
trying to be realistic about what it is going to take TO make it work.

OK--'cleaner' coal, if you wish, but with one of the world's largest 
supplies, coal (as clean as we can make it) is very likely to be part of
our 
near future (next century) energy supplies.  With the inevitable phasing
out 
of oil and natural gas, the net environmental problems of coal can be 
minimized.  Together with some nuclear, coal can provide the
high-density 
power source that will be needed in _some_ locations.  It too can be
phased 
out, but to do so that big IF about shipping power across country (say
North 
Dakota to New York) has to be solved, a national (international if you
wish) 
grid has to be designed and implemented--(that cost is almost never
included 
in 'renewables' estimates)--or we really would need to develop something

like Fusion power.

There are several things to include in discussing using wind and solar
for 
the major fraction of energy needs:

1)  As you phase out fossil fuels, you then move many energy demands
from 
'chemical' to electrical.  Heating and transportation energy must now
come 
from the renewables.  Biomass could only handle a fraction of the 
transportation fuel needs--we just calculated (for our project) that 3%
of 
the energy needs in 2100 in the form of biodiessel (from soybeans) and 
ethanol (from switchgrass) would require 150,000 square miles of land
use. 
If we can back off of oil soon enough, then perhaps some specialized 
needs--big rig trucks and aviation might still draw from remaining
petroleum 
reserves.   The big point here is that the electrical demand could
triple 
without oil and natural gas, and then if you want to eliminate coal, the

numbers become daunting.

2)  The population (U.S.) is going to continue to increase.  Can we hold
the 
population down to say 450 million by 2100?  That will take some
aggressive 
work in immigration policy.  If the country keeps adding a million or
more 
immigrants a year, immigrants with traditionally higher fertility rates
than 
the 'native' population, and generally more religious attitudes against 
birth control, 450 million would be a very low estimate.  So lets assume
at 
least a 50% increase in population.

3)  Efficiency and conservation can certainly lower energy needs.  25% 
proves difficult (for my classes) to fully quantify, but that should be 
possible and maybe a bit better.  However, with the population growth it

means the overall energy demand will increase and with the reduction or 
elimination of most 'chemical' energy sources, the demand for
electricity 
rises sharply.

4)  So what's a 'reasonable' estimate of yearly energy demand in 2100?
We 
work with 20,000 TWh or a power demand of 2.3 TW.
What do such huge numbers really mean?  IF--you wanted to run the
country on 
wind (assuming you had a grid and had generators spread so that you
could 
guarantee the 25% availability at all times (according the Hugh), then
using 
1.5MW generators (pretty much the standard although bigger ones are 
available) you need over 6 MILLION wind generators.  In a more realistic

system, without any fossil fuel, you might split up the demand, but you 
can't get much more than 3% from Hydro (and the environmentalists want
to 
dynamite all the dams anyway), maybe 3% from geothermal, might push
10-12% 
from biomass, but then you have to split the rest--over 80% between wind
and 
solar.  Without coal and nuclear--this is huge.

5)  Effective use of solar (and to a lesser extent wind) will most
likely 
require storage techniques--maybe electrolysis to hydrogen--to assure an

'energy on demand' network.  Whatever the storage and distribution
system, 
it will cost some big bucks.  We've estimated about $5 trillion for a 
hydrogen capable pipeline distribution system.

6)  Cost estimates have to account for the likely shorter lifetimes of
wind 
generators and some forms of solar (PV panels) compared to
fossil/nuclear 
plants (about 75 years) and dams (100 years or more).  We don't have
enough 
experience to know the replacement rate for large wind generators, but
it is 
likely to be at least twice that of current plants--this increases the
cost 
above those normally estimated for the switch to renewables.  Again,
such 
estimates are just to be somewhat realistic about the task--not to
dismiss 
it.

**********************
To repeat what we do in my energy class--a MODEL of energy distribution
for 
100 years in the future (one that still uses coal and nuclear but is
heavy 
on wind and solar) costs out at $30-50 trillion--capital costs-- and
uses 
about half a million square miles (much for biomass) of land.  What
these 
numbers say, to me, is that this is not a 10 year, 20 year, or barely a
50 
year project.  To be affordable, the transition must be stretched over a

century time frame.  However, clearly we need to start now (we are
starting 
now) and will have to ramp up the transitions, but thinking we can
eliminate 
the fossil fuels in a couple decades is, IMO, delusional.

Rick

 

_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l