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Re: Fuel Cells and "green" energy

But today hydro produces only 8.5% of our electricity and electricity is
less than 20% of our total energy demand--so about 2% of the total.
Improving existing installations by 25% only brings us up to 2.5% total and
less than 11% of the electrical. While low-head systems can be of use in
certain areas, it is really hard to imagine that we could effectively double
the hydro production of electricity in the U.S., especially in light of the
fact that we are currently tearing down dams--not building them. Even so,
doubling the current capacity still brings us up to only 5% of the total
energy needs and since at saturation the capacity will be fixed, any
increases in population (and hence demand) will lower that percentage below
5%. We can (and do) import hydro from Canada, but the world view on hydro
is that can only provide 5-10% of the total energy needs. [Again as I
emphasize in all these energy posts, we must keep in mind that currently
electricity provides for about 20% of energy demand but as we move away from
the fossil fuels--currently providing 90% of our energy--we will be looking
at electricity providing an ever increasing percentage of the total energy
demand. This requires major infrastructure changes.]

Rick

**************************************************
Richard W. Tarara
Associate Professor of Physics
Department of Chemistry & Physics
Saint Mary's College
Notre Dame, IN 46556
219-284-4664
rtarara@saintmarys.edu

FREE Physics Instructional Software
www.saintmarys.edu/~rtarara

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----- Original Message -----
From: "Shapiro, Mark" <mshapiro@EXCHANGE.FULLERTON.EDU>
To: <PHYS-L@lists.nau.edu>
Sent: Wednesday, June 13, 2001 11:36 AM
Subject: Re: Fuel Cells and "green" energy


Rick,

The potential for hydro in the US may be a bit higher than you state.
Most
of the US hydro installations are quite old. Modernization of the
generating systems probably could squeeze an extra 25% out of existing
hydro
plants. (Operators tend to be reluctant to do this, because those old
turbines were built to last forever....)

Mark

-----Original Message-----
From: Rick Tarara [mailto:rbtarara@SPRYNET.COM]
Sent: Wednesday, June 13, 2001 8:56 AM
To: PHYS-L@lists.nau.edu
Subject: Re: Fuel Cells and "green" energy


I think you've got all the main problems with hydro listed. Extreme
environmental groups (such as Greenpeace) oppose just about anything with
an
environmental effect (excluding solar and wind for which they conveniently
ignore the effects).

Your last point is the most important. Today in the U.S. hydro provides
only about 3% of the total energy demand (about 10% of the electrical
demand). We have tapped about half of the economically feasible hydro
sources. Therefore, in a 100% renewable energy economy (one that is
almost
entirely electrical in nature), we could only provide about 5% of the
total
energy demands using hydro (and the percentage drops as the population
grows). This then puts the environmental damage in perspective--do we
really want to do this kind of damage for so little gain? Probably only
those projects which offer serious flood control and irrigation potential
will be considered in the future.

Rick Tarara

**************************************************
Richard W. Tarara
Associate Professor of Physics
Department of Chemistry & Physics
Saint Mary's College
Notre Dame, IN 46556
219-284-4664
rtarara@saintmarys.edu

FREE Physics Instructional Software
www.saintmarys.edu/~rtarara

Win9.x, WinNT/2000, Win3.x, Dos, Mac, and PowerMac
New: SIMLAB 2001 photo-realistic lab simulations.
Windows and Mac CD-ROMs now available.
****************************************************

----- Original Message -----
From: "RAUBER, JOEL" <JOEL_RAUBER@SDSTATE.EDU>
To: <PHYS-L@lists.nau.edu>
Sent: Wednesday, June 13, 2001 10:20 AM
Subject: Re: Fuel Cells and "green" energy


I"m curious, could you elaborate more on the environmental costs of
hydroelectric power. I've been mostly under the impression that its
mostly
aesthetic (you ruin the hatch-hatchie gorge), or not as renewable as one
thinks, the reservoir silts up and prevents fish spawning. And then the
usual cost of running the power lines everywhere (true of most power
plants); and the impact of the immediate construction of the dam.

In my mind, while these effects aren't negligible they tend to be
smaller
than many other alternatives; so I'm gathering there are some
significant
effects I haven't thought of.

The largest defect is that it can't satisfy the needs.

-----Original Message-----
From: Michael N. Monce [mailto:mnmon@CONNCOLL.EDU]
Sent: Wednesday, June 13, 2001 7:56 AM
To: PHYS-L@lists.nau.edu
Subject: Re: Fuel Cells and "green" energy


On Wed, 13 Jun 2001, Dr. Tom Wayburn wrote:


P.S. This type of thinking completely eludes the Green
Party, for example,
which hung up the phone in my ear whilst I was explaining
this spot of
bother. Hang-the-messenger still applies.

I just recently got hung out to dry by a student group and
some faculty
after they announced they had convinced our Board to pay 20%
more on our
electric costs for 30% of our electric needs by buying the
electrons from
a so-called "green" coop. This coop supposedly supplies the elctricity
from only hydro, solar, and wind. I asked the question as to
whether the
college had really researched the environmental costs of each of these
so-called green sources; citing the impossibility of skirting
around the
Second Law. The geophysicist in our department, whose specialty is
hydrology, also complained bitterly about the consequences of
hydroelectric. We were chastised quite a bit for pointing out such
issues. There's a lot of physics education to be done with
the public in
the energy arena.

Michael Monce
Connecticut College