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Re: [Phys-l] Efficiency problem

Just a few additional points to all of this.

Pumped storage is just that--storage--so from a physics point of view there
will always be additional losses from pumping and regenerating power versus
using the power initially and directly. One of the largest pumped storage
facilities is at Ludington Michigan
http://www.coal2nuclear.com/Ludington%20Pumped%20Storage.pdf and has a 2.5
mile long reservoir situated on a bluff above lake Michigan. However, the
use of this facility relies heavily on the Detroit area--clean across the
state--where power from their coal and nuclear plants are used at night to
pump the water and the 're-generated' power is used during peak times in the
city. Since the facility has a 1900 MW (full) output, it can substitute for
at least two conventional power plants during peak usage times. Hugh's idea
of using pumped storage to store wind and solar energy is just beginning to
be utilized but has been part of my energy class project for more than 12
years now.

This whole idea of becoming 'carbon-free' in anything like a decade or two
is pure fantasy--mostly because people don't realize of just how much energy
we actually use (with over 85% or it being carbon based. There is also this
constant misunderstanding (or ignorance) by the part of the media (and
others) that ENERGY is not just ELECTRICAL energy. Yes, we could probably
replace the carbon based electrical generation in 20 years (but fat chance
of closing down the coal industry in this country), but you also need to
replace all the oil based transportation energy sources and all the natural
gas and lp gas heating resources as well. The oil and gas end usages are
bigger than the electrical end usage--maybe by a factor of 2-3 (hard to
calculate actual energy requirements to run our transportation system), such
that to be carbon free we would need at least twice and probably 3 times the
electrical generation capacity as today. The only non-carbon resources that
could be scaled up to these levels (beyond some additional nuclear usage)
would be wind and solar and neither of those are ENERGY ON DEMAND resources.
For wind, the national average (and remember we have only been 'farming'
prime locations) is 30% operating efficiency. That means that you need 1000
1.5-MW generators to average out to a small 500 MW coal/nuclear power plant
and 2000 units for a more typical 1000 MW plant. Solar's problem is
obvious. The idea that spreading out the wind generators can somehow
guarantee a steady supply doesn't really work--especially in mid-summer when
the demand for electricity is highest (wind is lowest). THEREFORE, to
effectively use wind and solar on the massive scales necessary to really
supplant the fossil fuels requires some kind of storage system. We explore
two options--one being the pumped storage system and the other being
hydrolysis of water for the hydrogen and then a massive distribution system
for the hydrogen. Both are expensive--pipelines for the hydrogen can run to
3-5 trillion dollars, and any storage technique ADDS cost to that of the
primary power production. It also requires overbuilding the number of
wind/solar units so that you can both run directly off the energy generated
and store sufficient energy to insure a continuous flow of power even during
the calmest summers or darkest winters.

[The other idea that we would retain some fossil plants as back-ups to
wind/solar don't make economic sense for any power company--if you have
those plants it is more profitable to use them. This scheme would almost
demand government control of the energy production and distribution
system--and clearly we ALL want the government to control more of our life
(well I suspect some here actually do!)

Rick



--------------------------------------------------
From: "Michael Edmiston" <edmiston@bluffton.edu>
Sent: Saturday, May 29, 2010 12:38 PM
To: "phys-l" <phys-l@carnot.physics.buffalo.edu>
Subject: Re: [Phys-l] Efficiency problem

Most certainly the economic feasibility of these ideas depends more on
factors that don't involve physics rather than factors that do involve
physics. I'll state some questions, then explain why they're important.

(1) Where will you get the electricity to do the pumping?

(2) Where/How will you use the electricity you generate?

(3) How is the distribution, switchover, etc. handled?

If you are not the power company, but you buy/sell from/to the power
company
you cannot win with a scheme like this. When you buy the electricity to
pump the water, you pay the generation cost, the transmission cost, a
distribution management cost, and some administrative costs. In my area
these all add up to about 9-cents per kilowatt-hour. The generation
portion
costs users about 5 cents-per-kilowatt-hour, however, the actual cost for
the power company to generate the electricity (that is, to operate just
their generators) is about 3 cents-per-kwhr. When you buy from the power
company you have to pay all costs (9 cents). When you sell to the power
company they only pay you their actual generation cost (3 cents). Thus,
you
buy at 9 cents and sell at 3 cents. Please tell me how to make money from
this scheme. You lose big time even if you have 100% efficiency. Even if
the power company offers non-peak rates, that only lowers it from 9 cents
to
7 cents in my area. You still cannot win. Worse, the power company can
limit the electricity they buy from you if they don't need all that you
generate. You might not even have a market for the full generating
capacity
you have invested in.

In order to win at this game (assuming you are not the power company
yourself) you have to directly use the electricity you generate. If you
buy
at off-peak rates, then use the the energy yourself during peak times, you
are pumping water with energy that costs perhaps 7 cents/kwhr and then you
are using the stored energy to offset your peak usage that otherwise would
cost you 9 cents/kwhr. If you could reach 100% efficiency you could save
2
cents/kwhr during your peak usage times. However, there is a huge
"gotcha"
in this process...

If you are going to use your electricity directly (rather than selling it
to
the power company) you have to be able to distribute your electricity (get
it to your usage points, or to your local buyers) independently from the
distribution system owned by the power company. If you are able to save 2
cents per kilowatt hour, how long is your payback period if you not only
invest in the installation of the reservoir system with pumps/generators,
but also the cost installing a distribution system, and also the costs of
maintenance for both the generation and distribution. The payback is
either
non-existent or is getting well over 25 years, which puts it far enough
out
that you can't guarantee it will ever actually pay back. The only people
who can make this work are the power companies themselves.

Remarkably, the same is true for wind power and solar power (where you
don't
even have to buy electricity for your generation process.) I was on a
team
that explored installing a 3MW Vestas wind turbine on Bluffton University
land. The wind study was positive. The site was excellent. Including
the
purchase, installation, maintenance of the turbine, and selling the
electricity to the power company at 3 cents per kWhr, the payback appeared
to be 10 to 15 years if the turbine on average operated at 50% capacity,
and
if the power company would always purchase the entire output of the
turbine
(something they would not guarantee).

With a possible payback of 10-15 years, and without a guarantee that
American Electric Power would buy the full output of the turbine for the
next 15 years and beyond, there was no guarantee this project would ever
pay
back. Even if we could guarantee a 10-year payback, the administration
is
looking for guaranteed paybacks of 5 or 6 years or less.

However, if the energy from the turbine could be used directly on campus,
then the turbine's electricity is worth 9 cents rather than 3 cents/kwhr.
That cuts the payback down to 3 to 5 years... a definite green light...
except... we don't have the distribution system on campus that would allow
us to do this. Universities that already generate their own electricity
from coal or natural gas could do this because they are already set up to
use the electricity they generate. But a university or small town that is
not already set up this way would have a tremendous cost involved. The
local
distribution cost (including controls to utilize power from AEP when the
turbine is not generating the full needs of the users) was projected to
cost
up to twice the cost of the turbine itself. That puts us right back into
a
the long payback period.

The picture looked better if we would install 4 to 8 turbines and try to
power the whole university plus the whole Village of Bluffton and
surrounding area, but that moves the project from a 4 to 5 million-dollar
project to a 20 to 40 million dollar project and involves a partnership
between a private university, a village, a county, and American Electric
Power. Bottom line... not interested. The university is in the business
of
education. The village is in the business of providing schools, roads,
police, fire protection, etc. Neither wants to become the power company.

I found this whole study to be very sad and very discouraging. It made me
realize that doing the right thing is not something that individuals, or
small groups, or small communities can pull off. Getting us off of fossil
fuels and onto alternative sources (whether the sources are wind, solar,
nuclear, whatever) needs to be done on scales much larger than grass-roots
projects can pull off.


Michael D. Edmiston, Ph.D.
Professor of Chemistry and Physics
Bluffton University
1 University Drive
Bluffton, OH 45817
419.358.3270
edmiston@bluffton.edu


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