Impacts
of
Climate
Change,
Carbon
Capture,
and
Population
Growth
on
Water
Use
at
Selected
EPA
Region
V
Power
Stations
Carol
Rosenfeld,
Student
Research
Participation
Program
Princeton
University
Argonne
National
Laboratory
Argonne,
Illinois
August
6,
2004
Prepared
in
partial
fulfillment
of
the
requirements
of
the
Argonne
National
Laboratory
Student
Research
Participation
Program
under
the
direction
of
Richard
Doctor
in
the
Energy
Systems
Division
at
Argonne
National
Laboratory.

Participant:
__________________________________________
Signature
Research
Advisor:
__________________________________________
Signature
ii
Table
of
Contents
Table
of
Contents
......................................................................................................................
ii
ABSTRACT
.............................................................................................................................
iii
INTRODUCTION
....................................................................................................................
1
METHODS................................................................................................................................
3
1.
Current
cooling
water
usage............................................................................................
3
a)
EIA
data
calculation
......................................................................................................
3
b)
F767
cooling
water
data
calculation
..............................................................................
4
c)
Thermodynamics
equation
calculation
..........................................................................
4
2.
Cooling
water
usage
today
if
carbon
dioxide
is
captured
...............................................
4
3.
Cooling
water
usage
in
2050
............................................................................................
5
a)
If
global
warming
occurs
..............................................................................................
5
b)
If
global
warming
occurs
and
CO2
must
be
captured.....................................................
5
c)
If
global
warming
occurs,
CO2
must
be
captured,
and
the
population
increases
..........
6
RESULTS..................................................................................................................................
6
DISCUSSION............................................................................................................................
7
CONCLUSIONS.....................................................................................................................
10
ACKNOWLEDGMENTS
......................................................................................................
11
REFERENCES
.......................................................................................................................
11
TABLES
AND
FIGURES.......................................................................................................
13
iii
ABSTRACT
Impacts
of
Climate
Change,
Carbon
Capture,
and
Population
Growth
on
Water
Use
at
Selected
EPA
Region
V
Power
Stations.
CAROL
ROSENFELD
(
Princeton
University,
Princeton,
New
Jersey,
08544)
RICHARD
DOCTOR
(
Argonne
National
Laboratory,
Argonne,
Illinois,
60439).

In
the
future,
coal­
fired
power
plants
may
decrease
carbon
dioxide
emissions
by
capturing
carbon
dioxide
(
CO2),
a
process
which
requires
power.
Additionally,
if
the
climate
warms
due
to
global
warming,
there
will
be
plant
efficiency
losses
due
to
rejecting
heat
against
a
higher
ambient
temperature.
Finally,
as
the
population
grows,
electricity
demands
will
increase.

All
three
of
these
cases
would
require
plants
to
produce
more
power
(
and
therefore
use
more
water)
in
order
to
continue
delivering
the
same
net
amount
of
power
per
capita
to
the
grid.
This
is
a
concern
because
cooling
water
withdrawal
and
consumption
have
become
sources
of
environmental
degradation.
Datasets
from
the
Energy
Information
Administration
(
EIA)
were
used
to
analyze
current
cooling
water
usage
at
coal­
fired
power
plants
in
Environmental
Protection
Agency
(
EPA)
region
V
states
with
coal
resources
(
that
is,
Illinois,
Indiana,
and
Ohio).

Current
cooling
water
usage
was
calculated
in
three
different
ways
for
the
purpose
of
comparison:
one
calculation
was
done
using
EIA's
"
Monthly
Utility
Power
Plant
Database",
one
calculation
was
done
calculation
using
EIA's
"
Annual
Steam­
Electric
Plant
Operation
and
Design
Data"
(
form
767),
and
one
calculation
was
done
using
thermodynamics
equations
modeling
the
operation
of
a
power
plant.
The
last
method
allows
ambient
temperature
changes
to
be
incorporated
into
cooling
water
calculations.
Water
usage
at
the
target
plants
if
carbon
dioxide
is
captured
was
also
determined.
Capturing
CO2
was
found
to
increase
water
consumption
by
75
to
120
percent.
Additionally,
projections
of
future
(
2050)
water
usage
as
the
population
increases,
CO2
is
captured
and
global
warming
occurs
were
done.
Climate
model
iv
results
were
used
to
find
the
change
in
temperature
between
current
conditions
and
2050.
The
thermodynamics
equations
were
then
used
to
find
the
decreased
plant
efficiencies
as
a
result
of
climate
change.
This
set
of
future
scenarios
was
found
to
increase
water
consumption
by
170
to
260
percent.
These
results
suggest
that
in
the
future
water
could
become
a
major
limiter
of
power
production,
even
in
water­
rich
areas
such
as
EPA
region
V.
Meeting
future
electricity
demands
will
therefore
require
investigating
new
cooling
technology
as
well
as
more
efficient
methods
of
power
production.
INTRODUCTION
American
power
plants
generated
over
3
trillion
(
3719.5
x
109)
kilowatt­
hours
(
kWh)
in
2001
[
1].
Meeting
this
enormous
energy
demand
has
serious
consequences
for
the
environment.

Power
generation
requires
large
amounts
of
natural
resources,
one
of
which
is
water
for
cooling.

The
majority
of
plants
use
either
once
through
or
recirculating
cooling
systems.
Plants
that
use
once
through
cooling
discharge
the
cooling
water
back
into
a
water
body
where
the
heat
diffuses
and
therefore
(
theoretically)
does
not
impact
the
overall
temperature
of
the
body
so
that
more
low­
temperature
cooling
water
can
be
drawn
from
the
same
body.
Other
plants
use
recirculating
cooling
systems,
where
water
is
cooled
in
a
cooling
tower
and
then
reused.

Cooling
water
withdrawals
are
the
water
withdrawn
from
a
water
body,
whereas
cooling
water
consumption
is
the
difference
between
the
water
withdrawn
and
the
water
returned
to
the
cooling
water
system
or
the
water
body.
Once
through
systems,
therefore,
require
large
cooling
water
withdrawals
because
water
exiting
the
condenser
is
simply
discharged
into
the
environment.
Once
through
systems
are
usually
assumed
to
have
zero
consumption,
because
all
of
the
water
withdrawn
is
discharged.
Recirculating
systems
require
much
smaller
water
withdrawals
than
once
through
systems
because
only
the
water
they
consume
needs
to
be
replaced
(
or
made
up).
Consumption
due
to
evaporation
is
not
assumed
to
be
zero
in
recirculating
systems
because
the
water
remains
within
the
system.
Recirculating
systems
therefore
consume
larger
amounts
of
water
than
once
through
systems.

There
are
three
sources
of
water
consumption
in
recirculating
systems.
First,
water
droplets
are
carried
away
with
the
upward
current
of
air
as
they
enter
the
cooling
tower
(
drift).

Second,
water
that
escapes
to
the
atmosphere
as
water
vapor
due
to
the
evaporative
cooling
in
the
cooling
tower
must
also
be
made
up.
Third,
when
water
evaporates,
impurities
concentrate
in
2
the
remaining
water,
and
so
some
water
must
be
"
blown
down,"
meaning
that
some
water
is
bled
from
the
system
and
replaced
with
freshwater
to
decrease
the
concentration
of
impurities.
By
far
the
majority
of
the
water
demand
at
power
plants
is
due
to
evaporative
cooling.
The
net
result
of
these
water
demands
is
that
about
1.8
percent
of
cooling
water
in
recirculating
systems
is
consumed,
and
this
is
the
same
amount
that
must
be
made
up
through
withdrawals
[
2].

Currently,
thermoelectric
power
plants
use
so
much
cooling
water
that
they
have
surpassed
agricultural
irrigation
systems
as
the
largest
total
water
withdrawers
in
the
United
States
(
thermoelectric
power
plants
are
responsible
for
48
percent
of
total
water
withdrawals,

whereas
irrigation
is
responsible
for
just
34
percent)
[
3].
Cooling
water
withdrawal
and
consumption
have
become
sources
of
environmental
degradation.
Large
withdrawals
can
affect
water
levels
and
therefore
have
a
deleterious
effect
on
aquatic
ecosystems
[
4].
For
recirculating
systems,
any
water
blown
down
is
concentrated
and
pumped
into
injection
wells,
which
are
finite
in
size
and
not
guaranteed
to
remain
sealed.
Once
through
systems
discharge
used
cooling
water
at
a
higher
temperature
than
when
it
was
withdrawn,
so
that
over
time
water
sources
increase
in
temperature,
making
them
inhospitable
to
certain
species
or
unlivable
for
organisms
that
cannot
sustain
the
temperature
fluctuations
(
this
is
known
as
thermal
pollution).
In
the
end,
in
terms
of
environmental
impact,
choosing
between
once
through
and
recirculating
cooling
systems
mainly
comes
down
to
trading
off
between
thermal
pollution
and
blow
down
disposal.

As
the
population
grows,
power
demands
will
increase.
Power
plants
may
also
be
required
to
decrease
carbon
dioxide
(
CO2)
emissions
through
carbon
dioxide
capture,
a
process
which
requires
power.
Additionally,
if
the
climate
warms
due
to
global
warming,
there
are
small
efficiency
losses
due
to
rejecting
heat
against
a
higher
ambient
temperature.
All
three
of
these
3
scenarios
would
require
plants
to
produce
more
power
(
and
therefore
use
even
more
water)
in
order
to
continue
delivering
the
same
net
amount
of
power
per
capita
to
the
grid.

This
paper
will
evaluate
cooling
water
use
at
power
stations
in
EPA
region
V,
which
is
comprised
of
Illinois,
Indiana,
Michigan,
Minnesota,
Ohio,
Wisconsin,
and
35
Indian
tribes.

Coal
(
bituminous
or
subbituminous)
is
the
main
energy
source
for
these
power
stations.
To
investigate
the
majority
of
the
water
demand,
this
project
focused
on
larger
(
500
MW
or
more)

coal­
fired
power
plants
in
region
V
states
with
coal
resources
(
Illinois,
Indiana,
and
Ohio).

METHODS
Data
obtained
from
the
Energy
Information
Administration's
(
EIA)
website
was
used
to
compile
a
database
of
power
plant
information.
Initially,
EIA's
"
Existing
Electric
Generating
Units
in
the
United
States,
2003"
dataset
was
used
to
find
the
target
power
plants.
Three
calculations
involving
these
plants
were
done.

1.
Current
cooling
water
usage
Current
cooling
water
usage
was
calculated
in
three
different
ways
for
the
purpose
of
comparison:
the
EIA
data
calculation
(
a),
the
F767
cooling
water
data
calculation
(
b),
and
the
thermodynamics
equation
calculation
(
c).

a)
EIA
data
calculation
In
the
EIA
data
calculation,
EIA's
"
Monthly
Utility
Power
Plant
Database"
was
used
to
find
the
efficiency
of
each
plant
based
on
the
plant's
reported
electricity
and
heat
generation.

The
efficiency
was
then
used
to
find
the
total
amount
of
water
withdrawn
and
consumed
annually.
Withdrawal
and
consumption
rates
were
calculated
differently
depending
on
whether
plants
use
once
through
or
recirculating
cooling
systems.
Data
on
the
type
of
cooling
system
(
once
through
or
recirculating)
in
operation
at
each
plant
was
obtained
from
EIA's
"
Annual
4
Steam­
Electric
Plant
Operation
and
Design
Data,
2002."
Several
plants
used
two
types
of
cooling
systems,
so
two
cases
were
created
 
one
where
it
was
assumed
that
all
plants
with
both
types
of
cooling
systems
just
had
once
through
cooling
systems,
and
one
where
it
was
assumed
that
all
plants
with
both
types
of
cooling
systems
just
had
recirculating
cooling
systems.

b)
F767
cooling
water
data
calculation
In
the
F767
cooling
water
data
calculation,
reported
cooling
water
withdrawal
and
consumption
information
from
EIA's
"
Annual
Steam­
Electric
Plant
Operation
and
Design
Data,

2002"
dataset
(
from
Form
767,
or
F767)
was
used.

c)
Thermodynamics
equation
calculation
In
the
thermodynamics
equation
calculation,
monthly
plant
efficiencies
were
found
using
a
set
of
thermodynamics
equations.
Each
plant's
boiler
was
assumed
to
run
on
the
Rankine
cycle
with
superheat.
The
expansion
turbine
was
assumed
to
be
designed
to
operate
at
150
°
F
at
the
average
annual
temperature
at
each
plant's
location.
The
average
annual
temperature
was
found
using
Legates
and
Wilmott's
dataset
of
observed
temperatures
[
7].
The
difference
between
the
actual
observed
temperatures
in
this
dataset
and
the
average
annual
temperature
was
added
to
the
design
temperature
for
the
steam
leaving
the
turbine
(
150
°
F).
This
allowed
the
impact
of
climatic
variations
on
plant
efficiency
to
be
represented
in
the
calculation.
From
there,
the
total
amount
of
water
withdrawn
and
consumed
annually
was
found.

The
results
of
these
three
calculation
methods
were
then
plotted
against
one
another
to
check
each
method's
accuracy
and
precision.

2.
Cooling
water
usage
today
if
carbon
dioxide
is
captured
The
thermodynamics
equation
method
of
calculating
cooling
water
usage
was
used
as
a
basis
for
finding
the
cooling
water
usage
if
carbon
dioxide
is
captured.
CO2
capture
was
5
assumed
to
require
plants
to
derate
to
103/
150
of
their
previous
electricity
output
[
8].
The
remainder
of
the
electricity
demand
was
assumed
to
be
met
through
the
construction
of
new
plants
which
would
also
be
required
to
capture
CO2.
Each
new
plant's
parameters
(
electricity
and
heat
generation,
efficiency,
etc.)
were
assumed
to
be
the
average
of
these
parameters
from
the
set
of
target
plants.
All
new
plants
were
assumed
to
use
recirculating
cooling
systems.
To
find
the
cooling
water
necessary
if
carbon
dioxide
were
captured,
the
total
amount
of
water
withdrawn
and
consumed
annually
for
the
new
plants
was
added
to
the
previously
calculated
total
amount
of
water
withdrawn
and
consumed
annually
by
the
older
(
original)
plants.

3.
Cooling
water
usage
in
2050
The
effects
of
global
warming,
CO2
capture,
and
population
increases
were
layered
on
top
of
one
another
to
find
cooling
water
use
for
various
scenarios
in
2050.

a)
If
global
warming
occurs
Climate
model
temperature
projections
for
2050
were
obtained
from
five
climate
models.

The
difference
between
the
2050
temperatures
and
the
current
climate
was
added
to
the
design
temperature
for
the
steam
leaving
the
turbine.
From
there,
the
method
used
in
the
thermodynamics
equation
calculation
to
find
plant
efficiencies
was
used.
Cooling
water
withdrawals
and
consumption
based
on
these
efficiencies
were
calculated.
The
amount
of
cooling
water
used
by
the
new
plants
needed
to
make
up
generation
in
order
to
meet
demand
was
found.
This
was
added
to
the
2050
cooling
water
use
found
for
the
original
plants
to
obtain
the
total
amount
of
water
withdrawn
and
consumed
annually
if
the
climate
warms.

b)
If
global
warming
occurs
and
CO2
must
be
captured
As
in
the
calculation
2,
it
was
assumed
that
current
plants
would
reduce
their
electricity
outputs
to
the
busbar
in
order
to
produce
the
energy
necessary
to
capture
CO2.
The
amount
of
6
cooling
water
used
by
the
new
plants
needed
to
make
up
electricity
generation
was
found.
This
was
added
to
the
2050
cooling
water
use
found
for
the
original
plants
to
obtain
the
total
amount
of
water
withdrawn
and
consumed
annually
if
the
climate
warms
and
CO2
must
be
captured.

c)
If
global
warming
occurs,
CO2
must
be
captured,
and
the
population
increases
Again,
the
same
plant
efficiencies
were
used
as
in
the
calculation
of
cooling
water
usage
in
2050
with
just
global
warming.
The
increase
in
electricity
consumption
due
to
population
growth
was
found
using
the
current
per
capita
consumption
of
electricity
in
Illinois,
Indiana,
and
Ohio,
and
linearly
projecting
the
state
populations
to
2050.
The
number
of
new
plants
required
to
make
up
this
generation
was
added
to
the
number
of
new
plants
necessary
to
make
up
lost
generation
due
to
global
warming
and
CO2
capture.
The
total
cooling
water
use
if
global
warming
occurs,
CO2
is
captured,
and
the
population
increases
was
found
by
adding
the
cooling
water
use
of
the
old
and
new
plants,
as
above
in
calculations
2,
3a,
and
3b.

RESULTS
Table
1
lists
the
41
target
plants.
Figure
1
shows
the
locations
of
all
41
target
plants.

Figure
2
shows
the
relationship
between
the
cooling
water
withdrawal
rates
found
in
the
thermodynamics
equation
calculation
(
1c)
and
the
F767
cooling
water
data
calculation
(
1b).

Figure
3
shows
the
same
relationship
for
the
cooling
water
consumption
rate.
Figure
4
shows
the
relationship
between
the
cooling
water
withdrawal
rates
found
in
the
EIA
data
calculation
(
1a)

for
just
coal­
fired
units
and
the
F767
data
calculation
(
1b).
Figure
5
shows
the
same
relationships
for
the
cooling
water
consumption
rate.
Figure
6
shows
the
relationship
between
the
cooling
water
withdrawal
rates
found
in
the
EIA
data
calculation
(
1a)
for
all
units
(
not
just
coal­
fired)
and
the
F767
data
calculation
(
1b).
Figure
7
shows
the
same
relationship
for
the
cooling
water
consumption
rate.
Figure
8
shows
the
relationship
between
the
cooling
water
7
withdrawal
rates
found
in
the
EIA
data
calculation
(
1a)
and
the
thermodynamics
equation
calculation
(
1c).
Figure
9
shows
the
same
relationships
for
the
cooling
water
consumption
rate.

Figure
10
compares
the
total
withdrawal
amounts
found
using
the
EIA
data
calculation
(
1a),
the
F767
data
calculation
(
1b),
and
the
thermodynamics
equation
calculation
(
1c).
Figure
11
does
the
same
for
total
consumption
amounts.

Figure
12
shows
the
current
total
cooling
water
withdrawals
(
from
the
thermodynamics
equation
calculation)
and
the
current
cooling
water
usage
if
CO2
is
captured.
Figure
13
shows
the
current
total
cooling
water
consumption
with
and
without
CO2
capture.

Table
2
lists
the
climate
models
used
to
find
the
2050
temperatures
and
the
Intergovernmental
Panel
on
Climate
Change
(
IPCC)
scenarios
run
by
each
model.
Figure
14
is
a
plot
of
the
efficiencies
found
for
the
target
plants
today
versus
the
efficiencies
calculated
for
the
target
plants
in
2050
if
the
climate
warms.
Figure
15
shows
the
increases
in
Illinois,
Indiana,
and
Ohio's
populations
between
1980
and
2025
and
the
linear
relationships
found
for
this
growth.

Figure
16
shows
the
cooling
water
withdrawals
if
global
warming
occurs,
if
global
warming
occurs
and
CO2
is
captured,
and
if
global
warming
occurs,
CO2
is
captured
and
the
population
increases.
Current
water
withdrawals
with
and
without
CO2
capture
are
plotted
for
comparison.
Figure
17
shows
the
same
quantities
for
cooling
water
consumption.

DISCUSSION
Figures
2
though
9
show
the
relationships
between
different
ways
of
calculating
the
current
cooling
water
use.
Figures
8
and
9
show
that
the
thermodynamics
equation
and
EIA
data
calculations
results
are
almost
the
same.
Figures
2
and
3
show
that
there
is
no
discernible
relationship
between
the
thermodynamics
equation
and
F767
data
calculation
results.
The
same
is
true
in
figures
4
and
5
for
the
results
of
the
EIA
data
calculation
and
F767
data
calculation.
8
There
are
several
explanations
for
the
discrepancy
between
the
EIA
and
thermodynamics
calculations
and
the
actual
cooling
water
usage
reported
in
the
F767
dataset.
The
target
plants
are
probably
not
discharging
cooling
water
at
a
constant
25
°
F
temperature
increase,
which
the
thermodynamics
and
EIA
data
calculations
assume.
Plants
that
are
discharging
water
at
a
higher
temperature
would
need
less
cooling
water
than
calculated,
while
plants
that
discharge
at
a
lower
temperature
would
need
more
cooling
water
than
calculated.
Additionally,
water
right
regulations
include
"
use
it
or
lose
it"
clauses
so
that,
in
an
attempt
to
retain
water
rights,
plants
may
be
withdrawing
larger
amounts
of
cooling
water
than
necessary.

While
recirculating
systems
may
consume
more
water
than
once
through
systems,

recirculating
systems
are
preferable
to
once
through
systems.
Figures
10
and
11show
that
withdrawals
are
two
orders
of
magnitude
larger
than
consumption
in
either
system
(
for
example,

in
the
thermodynamics
equation
calculation
for
cooling
water
usage
today,
withdrawals
were
between
2.78
x
1013
lb
and
4.34
x
1013
lb,
whereas
consumption
was
between
4.92
x
1011
lb
and
7.77
x
1011
lb).
The
amount
of
water
impacted
by
higher
withdrawals
is
therefore
significantly
larger
than
the
amount
of
water
impacted
by
higher
consumption,
so
the
impact
of
once
through
cooling
systems
is
greater
than
that
of
recirculating
systems.
Also,
disposing
of
the
blow
down
generated
by
new
recirculating
systems
will
cause
less
environmental
damage
if
done
properly
than
the
increases
in
thermal
pollution
resulting
from
new
once
through
cooling
systems.

Figures
12
and
13
compare
current
cooling
water
withdrawals
and
consumption
with
current
withdrawals
and
consumption
if
power
plants
were
required
to
capture
CO2.
As
figure
12
shows,
capturing
CO2
does
not
affect
cooling
water
withdrawals
significantly.
Withdrawals
only
increase
by
between
1.35
percent
(
if
once
through
systems
are
preferred)
and
2.11
percent
(
if
recirculating
systems
are
preferred).
Capturing
CO2
does,
however,
have
a
large
impact
on
9
water
consumption
 
figure
13
shows
that
capture
increases
consumption
by
between
75.4
percent
(
recirculating
preferred)
and
119
percent
(
once
through
preferred).
This
disparity
in
the
increases
of
withdrawals
and
consumption
is
because
the
additional
recirculating
systems
needed
to
cover
the
energy
needed
to
achieve
capture
withdraw
very
little
water
compared
to
current
withdrawals.
All
of
the
increase
in
withdrawal
due
to
CO2
capture
is
also
consumed,
though,
and
this
results
in
a
large
increase
in
consumption
when
added
to
current
consumption
(
which
is
relatively
low
because
once
through
systems
are
assumed
to
have
zero
consumption).

The
decrease
in
efficiency
of
the
power
plants
due
to
climate
change
is
shown
in
figure14.
Plotting
current
versus
future
plant
efficiencies
if
the
climate
warms
results
in
a
line
well
below
a
one
to
one
relationship
(
due
to
rejecting
heat
against
a
higher
ambient
temperature).

Global
warming,
CO2
capture,
and
population
increases
have
feedbacks
among
one
another,
so
that
calculating
their
effects
separately
would
not
estimate
the
full
impact
if
more
than
one
occurs.
Examining
the
changes
in
cooling
water
use
as
they
are
layered,
however,

provides
information
about
the
relative
impact
of
each
circumstance.
Figure
16
shows
the
increases
in
cooling
water
withdrawals
as
the
temperature
increases,
CO2
is
captured,
and
the
population
grows.
There
are
only
small
increases
in
withdrawals
if
these
scenarios
occur
by
2050.
Withdrawals
if
all
three
events
occur
only
increase
by
between
3.44
percent
(
preferring
once
through)
and
5.12
percent
(
preferring
recirculating).
Again,
this
is
because
any
extra
electricity
demand
is
made
up
with
recirculating
systems,
and
the
additional
recirculating
systems
withdraw
very
little
water
compared
to
current
withdrawals.
Figure
17
shows
the
increases
in
cooling
water
consumption
under
the
various
scenarios
in
2050.
It
is
noteworthy
that
temperature
increases
alone
result
in
higher
consumption
than
current
levels,
but
lower
consumption
than
if
plants
currently
captured
CO2.
The
decrease
in
efficiency
due
to
climate
10
change
therefore
has
less
of
an
impact
on
consumption
than
the
derating
of
the
plants
caused
by
CO2
capture.
All
of
the
increase
in
withdrawal
due
to
the
three
events
is
also
consumed,
and,
as
figure
17
shows,
this
results
in
a
large
increase
in
consumption
when
added
to
current
consumption.
Consumption
if
all
three
events
occur
therefore
increases
by
between
168
percent
(
preferring
recirculating)
and
265
percent
(
preferring
once
through).

CONCLUSIONS
Extensions
of
this
work
should
involve
in­
depth
uncertainty
calculations.
Calculations
of
future
cooling
water
usage
should
also
be
done
using
maximum
and
minimum
(
not
just
mean)

temperatures
found
by
climate
models.
After
that,
future
work
may
take
several
different
directions.
These
include
determining
the
increase
in
water
usage
if
hydrogen
is
produced,
and
calculating
the
difference
between
water
availability
and
requirements
in
each
scenario.

As
the
climate
warms,
regulations
require
the
capture
of
carbon
dioxide,
and
the
population
grows,
these
issues
promise
to
only
become
more
pronounced.
Moving
to
a
hydrogen
economy
would
add
even
more
cooling
water
demands
on
top
of
current
demands.
The
results
of
this
project
demonstrate
that
no
matter
which
future
scenario
is
examined,
cooling
water
demand
threatens
to
limit
electricity
production.
Even
assuming
that
all
new
plants
install
less
water
intensive
recirculating
cooling
systems,
cooling
water
consumption
threatens
to
more
than
double
in
the
best
case
and
almost
quadruple
in
the
worst
case.
Even
the
water­
rich
EPA
region
V
will
not
be
immune.
Serious
consideration
should
be
given
to
the
theory
that
water
can
and
soon
will
be
a
limiting
factor
in
power
production
across
the
entire
United
States.
At
the
very
least
this
encourages
the
installation
of
recirculating
cooling
systems
on
all
new
power
plants
and
the
replacement
of
old
once
through
systems
with
recirculating
ones.
Beyond
that,
current
cooling
systems
might
also
be
made
more
water
efficient.
Desalination
and
water
purification
11
schemes
that
use
saline
or
brackish
water
for
cooling
(
and
therefore
reduce
the
use
of
freshwater)

could
also
be
refined
to
make
them
more
commercially
viable.
Additionally,
other
cooling
technologies
could
be
considered,
such
as
dry
cooling
or
the
ammonia
bottoming
cycle
[
10].

Whatever
the
answer
to
the
dilemma
presented
by
this
energy­
water
nexus,
the
solution
promises
to
increase
the
costs
of
our
currently
under­
valued
electricity.
There
are
ways
to
satisfy
our
electricity
demands
without
overdrawing
our
surface
waters,
thermally
polluting
them,

leaking
concentrated
chemicals
into
aquifers
through
blow
down
disposal,
or
destroying
aquatic
life,
but
they
require
that
we
accurately
value
electricity
and
the
natural
resources
that
go
into
generating
it.

ACKNOWLEDGMENTS
I
am
immensely
grateful
to
Argonne
National
Laboratory
for
giving
me
the
opportunity
to
participate
in
this
summer
internship.
Without
the
help
and
encouragement
of
Matt
Schiff,
I
would
not
have
been
at
Argonne
at
all.
Thanks
to
Tom
Moore
for
all
of
his
help,
wisdom,
and
offers
to
reformat
my
hard
drive.
Last,
but
certainly
not
least,
an
enormous
thank
you
to
my
supervisor,
Richard
Doctor,
for
his
patience,
for
his
indomitable
yet
informed
optimism,
for
teaching
me
everything
I
know
about
the
energy­
water
nexus,
and
for
lending
me
half
of
his
library
as
I
explored
power
plants
and
beyond
this
summer.

REFERENCES
[
1]
U.
S.
Census
Bureau.
No.
914.
Electric
power
industry
 
Sales,
prices,
net
generation,
net
summer
capability,
and
consumption
of
fuels:
1990
to
2001.
Statistical
Abstract
of
the
United
States:
2003.
[
Online].
Available:
http://
www.
census.
gov/
prod/
2004pubs/
03statab/
pop.
pdf
[
2]
C.
B.
Panchal,
"
Ammonia
bottoming
cycle
for
dry
cooling,"
Argonne
National
Laboratory,
2003.
12
[
3]
U.
S.
Geological
Survey.
Estimated
Use
of
Water
in
the
United
States
in
2000
 
Total
Water
Use.
Estimated
Use
of
Water
in
the
United
States
in
2000.
[
Online].
Available:
http://
water.
usgs.
gov/
pubs/
circ/
2004/
circ1268/
htdocs/
text­
total.
htmlGS
water
use
survey
[
4]
E.
Baum,
"
Wounded
waters:
The
hidden
side
of
power
plant
pollution,"
Clean
Air
Task
Force,
Boston,
MA,
2004.

[
5]
R.
C.
Lewis,
"
Northeast
attorneys
general
sue
over
EPA's
clean
water
rules,"
Newsday.
July
26,
2004.
[
Online].
Available:
http://
www.
newsday.
com/
news/
local/
wire/
ny­
bc­
ny­­
cleanwater0726jul26,0,4073771.
story?
coll=
ny­
ap­
regional­
wire
[
6]
R.
D.
Doctor,
C.
D.
Livengood,
J.
L.
Anderson,
D.
B.
Garvey,
and
P.
S.
Farber,
"
Coal
cleaning
as
a
sulfur
reduction
strategy
in
the
Midwest,"
Journal
of
the
Air
Pollution
Control
Association,
vol.
35,
pp.
331
 
336,
April
1985.

[
7]
D.
R.
Legates,
and
C.
J.
Willmott,
"
Mean
seasonal
and
spatial
variability
in
global
surface
air
temperature,"
Theoretical
and
Applied
Climatology,
vol.
41,
pp.
11­
21.
1990.

[
8]
R.
D.
Doctor,
J.
C.
Molburg,
M.
H.
Mendelsohn,
and
N.
F.
Brockmeier,
"
CO2
capture
for
PC
boilers
using
flue
gas
recirculation:
Evaluation
of
CO2
recovery,
transport,
and
utilization,"
presented
at
the
7th
International
Conference
on
Greenhouse
Gas
Technologies,
Vancouver,
BC,
Canada,
2004.

[
9]
R.
D.
Doctor,
J.
C.
Molburg,
M.
H.
Mendelsohn,
and
N.
F.
Brockmeier,
"
CO2
capture
for
PC
boilers
using
flue
gas
recirculation:
Evaluation
of
CO2
recovery,
transport,
and
utilization,"
presented
at
the
7th
International
Conference
on
Greenhouse
Gas
Technologies,
Vancouver,
BC,
Canada,
2004.

[
10]
C.
B.
Panchal,
"
Ammonia
bottoming
cycle
for
dry
cooling,"
Argonne
National
Laboratory,
2003.
13
TABLES
AND
FIGURES
Plant
ID
number
Plant
name
State
Nameplate
Capacity
(
MW)
384
Joliet
29
IL
1320
856
E
D
Edwards
IL
780.3
861
Coffeen
IL
1005.4
867
Crawford
IL
597.4
876
Kincaid
Generation
LLC
IL
1319
879
Powerton
IL
1785.6
883
Waukegan
IL
802.7
884
Will
County
IL
1268.8
887
Joppa
Steam
IL
1099.8
889
Baldwin
Energy
Complex
IL
1892.1
898
Wood
River
IL
500.1
981
State
Line
Energy
IN
613
983
Clifty
Creek
IN
1303.2
988
Tanners
Creek
IN
1100.1
990
Harding
Street
IN
698
994
AES
Petersburg
IN
1872.9
995
Bailly
IN
615.6
997
Michigan
City
IN
540
1001
Cayuga
IN
1062
1008
R
Gallagher
IN
600
1010
Wabash
River
IN
1164.7
2828
Cardinal
OH
1880.4
2830
Walter
C
Beckjord
OH
1221.3
2832
Miami
Fort
OH
1378
2836
Avon
Lake
OH
766
2837
Eastlake
OH
1257
2840
Conesville
OH
2174.8
2850
J
M
Stuart
OH
2440.8
2866
W
H
Sammis
OH
2455.6
2872
Muskingum
River
OH
1529.4
2876
Kyger
Creek
OH
1086
6017
Newton
IL
1234.8
6019
W
H
Zimmer
OH
1425.6
6031
Killen
Station
OH
666.4
6085
R
M
Schahfer
IN
1943.3
6113
Gibson
IN
3339.5
6137
A
B
Brown
IN
530.4
6166
Rockport
IN
2600
6213
Merom
IN
1080
6705
Warrick
IN
755
8102
General
James
M
Gavin
OH
2600
Table
1:
Target
set
of
power
plants
and
their
nameplate
capacities.
These
are
plants
located
in
Illinois,
Indiana,
or
Ohio,
that
burn
bituminous
or
subbituminous
coal,
and
whose
coal­
burning
units
have
a
generating
capacity
of
500
MW
of
electricity
or
more.
14
Figure
1:
Locations
of
the
41
target
plants.
15
Figure
2:
Relationship
between
withdrawal
rates
found
using
the
thermodynamics
equation
calculation
and
the
F767
cooling
water
data
calculation.

Figure
3:
Relationship
between
consumption
rates
found
using
the
thermodynamics
equation
calculation
and
the
F767
cooling
water
data
calculation.
Withdrawal
rates
­
Thermodynamics
equation
calculation
vs.
F767
data
calculation
y
=
0.7995x
+
1E+
08
y
=
0.5682x
+
1E+
08
y
=
x
0.00E+
00
5.00E+
07
1.00E+
08
1.50E+
08
2.00E+
08
2.50E+
08
3.00E+
08
3.50E+
08
4.00E+
08
4.50E+
08
5.00E+
08
0.00E+
00
5.00E+
07
1.00E+
08
1.50E+
08
2.00E+
08
2.50E+
08
3.00E+
08
3.50E+
08
4.00E+
08
4.50E+
08
Yearly
averages
of
thermodynamics
equation
calculations
(
lb/
hr)
F767
data
calculation
(
lb/
hr)

Preferring
recirculating
Preferring
once
through
1:
1
line
Linear
(
Preferring
recirculating)

Linear
(
Preferring
once
through)

Linear
(
1:
1
line)

Consumption
rates
­
Thermodynamics
equation
calculation
vs.
F767
data
calculation
y
=
0.8199x
+
804876
y
=
0.709x
+
2E+
06
y
=
x
0.00E+
00
2.00E+
06
4.00E+
06
6.00E+
06
8.00E+
06
1.00E+
07
1.20E+
07
1.40E+
07
1.60E+
07
0.00E+
00
2.00E+
06
4.00E+
06
6.00E+
06
8.00E+
06
1.00E+
07
1.20E+
07
Yearly
averages
of
thermodynamics
equation
calculations
(
lb/
hr)
F767
data
calculation
(
lb/
hr)
Preferring
recirculating
Preferring
once
through
1:
1
line
Linear
(
Preferring
recirculating)

Linear
(
Preferring
once
through)

Linear
(
1:
1
line)
16
Figure
4:
Relationship
between
withdrawal
rates
found
using
the
EIA
data
calculation
(
just
for
coal­
fired
units)
and
the
F767
cooling
water
data
calculation.

Figure
5:
Relationship
between
consumption
rates
found
using
the
thermodynamics
equation
calculation
(
just
for
coal­
fired
units)
and
the
F767
cooling
water
data
calculation.
Withdrawal
rates
­
EIA
data
calculations
(
just
coal
units)
vs.
F767
data
calculation
y
=
0.8596x
+
1E+
08
y
=
0.6205x
+
1E+
08
y
=
x
0.00E+
00
5.00E+
07
1.00E+
08
1.50E+
08
2.00E+
08
2.50E+
08
3.00E+
08
3.50E+
08
4.00E+
08
4.50E+
08
5.00E+
08
0.00E+
00
5.00E+
07
1.00E+
08
1.50E+
08
2.00E+
08
2.50E+
08
3.00E+
08
3.50E+
08
4.00E+
08
Yearly
averages
of
EIA
data
calculations
(
lb/
hr)
F767
data
calculation
(
lb/
hr)

Preferring
recirculating
Preferring
once
through
1:
1
line
Linear
(
Preferring
recirculating)
Linear
(
Preferring
once
through)
Linear
(
1:
1
line)

Consumption
rates
­
EIA
data
calculations
(
just
coal
units)
vs.
F767
data
calculation
y
=
0.8799x
+
813776
y
=
0.7551x
+
2E+
06
y
=
x
0.00E+
00
2.00E+
06
4.00E+
06
6.00E+
06
8.00E+
06
1.00E+
07
1.20E+
07
1.40E+
07
1.60E+
07
0.00E+
00
1.00E+
06
2.00E+
06
3.00E+
06
4.00E+
06
5.00E+
06
6.00E+
06
7.00E+
06
8.00E+
06
9.00E+
06
1.00E+
07
Yearly
averages
of
EIA
data
calculations
(
lb/
hr)
F767
data
calculation
(
lb/
hr)
Preferring
recirculating
Preferring
once
through
1:
1
line
Linear
(
Preferring
recirculating)
Linear
(
Preferring
once
through)
Linear
(
1:
1
line)
17
Figure
6:
Relationship
between
withdrawal
rates
found
using
the
EIA
data
calculation
for
all
units
and
the
F767
cooling
water
data
calculation.

Figure
7:
Relationship
between
consumption
rates
found
using
the
EIA
data
calculation
for
all
units
and
the
F767
cooling
water
data
calculation
Withdrawal
rates
­
EIA
data
calculations
(
all
units)
vs.
F767
data
calculation
y
=
0.848x
+
1E+
08
y
=
0.6178x
+
1E+
08
y
=
x
0.00E+
00
5.00E+
07
1.00E+
08
1.50E+
08
2.00E+
08
2.50E+
08
3.00E+
08
3.50E+
08
4.00E+
08
4.50E+
08
5.00E+
08
0.00E+
00
5.00E+
07
1.00E+
08
1.50E+
08
2.00E+
08
2.50E+
08
3.00E+
08
3.50E+
08
4.00E+
08
Yearly
averages
of
EIA
data
calculations
(
lb/
hr)
F767
data
calculation
(
lb/
hr)

Preferring
recirculating
Preferring
once
through
1:
1
line
Linear
(
Preferring
recirculating)
Linear
(
Preferring
once
through)
Linear
(
1:
1
line)

Consumption
rates
­
EIA
data
calculation
(
all
units)
vs.
F767
data
calculation
y
=
0.8789x
+
812866
y
=
0.7547x
+
2E+
06
y
=
x
0.00E+
00
2.00E+
06
4.00E+
06
6.00E+
06
8.00E+
06
1.00E+
07
1.20E+
07
1.40E+
07
1.60E+
07
0.00E+
00
1.00E+
06
2.00E+
06
3.00E+
06
4.00E+
06
5.00E+
06
6.00E+
06
7.00E+
06
8.00E+
06
9.00E+
06
1.00E+
07
Yearly
averages
of
EIA
data
calculations
(
lb/
hr)
F767
data
calculation
(
lb/
hr)
Preferring
recirculating
Preferring
once
through
1:
1
line
Linear
(
Preferring
recirculating)
Linear
(
Preferring
once
through)
Linear
(
1:
1
line)
18
Figure
8:
Relationship
between
withdrawal
rates
found
using
the
EIA
data
calculation
and
the
thermodynamics
equation
calculation
Figure
9:
Relationship
between
withdrawal
rates
found
using
the
EIA
data
calculation
and
the
thermodynamics
equation
calculation
Withdrawal
rates
­
EIA
data
calculations
vs.
thermodynamics
equation
calculations
0.00E+
00
5.00E+
07
1.00E+
08
1.50E+
08
2.00E+
08
2.50E+
08
3.00E+
08
3.50E+
08
4.00E+
08
4.50E+
08
0.00E+
00
5.00E+
07
1.00E+
08
1.50E+
08
2.00E+
08
2.50E+
08
3.00E+
08
3.50E+
08
4.00E+
08
4.50E+
08
EIA
data
calculations
(
lb/
hr)
Thermodynamics
equation
calculations
(
lb/
hr)

Preferring
recirculating
Preferring
once
through
1:
1
line
Linear
(
1:
1
line)

Consumption
rates
­
EIA
data
calculations
vs.
thermodynamics
equation
calculations
0.00E+
00
2.00E+
06
4.00E+
06
6.00E+
06
8.00E+
06
1.00E+
07
1.20E+
07
0.00E+
00
2.00E+
06
4.00E+
06
6.00E+
06
8.00E+
06
1.00E+
07
1.20E+
07
EIA
data
calculations
(
lb/
hr)
Thermodynamics
equation
calculations
(
lb/
hr)

Preferring
recirculating
Preferring
once
through
1:
1
line
Linear
(
1:
1
line)
19
Figure
10:
Comparison
of
the
total
withdrawal
amounts
found
using
the
EIA
data
calculation,
the
F767
cooling
water
data
calculation,
and
the
thermodynamics
equation
calculation
Figure
11:
Comparison
of
the
total
consumption
amounts
found
using
the
EIA
data
calculation,
the
F767
cooling
water
data
calculation,
and
the
thermodynamics
equation
calculation
Comparison
of
current
withdrawal
calculations
EIA
withdrawals
(
OT),
3.90E+
13
Thermo
withdrawals
(
OT),
4.34E+
13
EIA
withdrawals
(
recirc),
2.52E+
13
Thermo
withdrawals
(
recirc),
2.78E+
13
F767
withdrawals,
5.93E+
13
0
1E+
13
2E+
13
3E+
13
4E+
13
5E+
13
6E+
13
7E+
13
1
Total
withdrawals
(
lb)

EIA
withdrawals
(
OT)

Thermo
withdrawals
(
OT)

EIA
withdrawals
(
recirc)

Thermo
withdrawals
(
recirc)

F767
withdrawals
"
recirc"
=
preferring
recirculating
cooling
systems
"
OT"
=
preferring
once
through
cooling
systems
Comparison
of
current
consumption
calculations
EIA
consumption
(
OT),
4.59E+
11
Thermo
consumption
(
OT),
4.92E+
11
EIA
consumption
(
recirc),
7.12E+
11
Thermo
consumption
(
recirc),
7.77E+
11
F767
consumption,
8.58E+
11
0
1E+
11
2E+
11
3E+
11
4E+
11
5E+
11
6E+
11
7E+
11
8E+
11
9E+
11
1E+
12
1
Total
consumption
(
lb)

EIA
consumption
(
OT)

Thermo
consumption
(
OT)

EIA
consumption
(
recirc)

Thermo
consumption
(
recirc)

F767
consumption
"
recirc"
=
preferring
recirculating
cooling
systems
"
OT"
=
preferring
once
through
cooling
systems
20
Figure
12:
Comparison
of
the
current
withdrawals
found
with
and
without
CO2
capture
Figure
13:
Comparison
of
the
current
consumption
found
with
and
without
CO2
capture
Comparison
of
withdrawal
calculations
with
and
without
CO2
capture
Withdrawals
(
OT),
4.34E+
13
Withdrawals
with
CO2
capture
(
OT),
4.40E+
13
Withdrawals
(
recirc),
2.78E+
13
Withdrawals
with
CO2
capture
(
recirc),
2.84E+
13
0
5E+
12
1E+
13
2E+
13
2E+
13
3E+
13
3E+
13
4E+
13
4E+
13
5E+
13
5E+
13
1
Total
withdrawals
(
lb)
Withdrawals
(
OT)

Withdrawals
with
CO2
capture
(
OT)

Withdrawals
(
recirc)

Withdrawals
with
CO2
capture
(
recirc)

"
recirc"
=
preferring
recirculating
cooling
systems
"
OT"
=
preferring
once
through
cooling
systems
Comparison
of
consumption
calculations
with
and
without
CO2
capture
Consumption
(
OT),
4.92E+
11
Consumption
(
recirc),
7.77E+
11
Consumption
with
CO2
capture
(
OT),
1.08E+
12
Consumption
with
CO2
capture
(
recirc),
1.36E+
12
0
2E+
11
4E+
11
6E+
11
8E+
11
1E+
12
1.2E+
12
1.4E+
12
1.6E+
12
1
Total
consumption
(
lb)
Consumption
(
OT)

Consumption
(
recirc)

Consumption
with
CO2
capture
(
OT)

Consumption
with
CO2
capture
(
recirc)

"
recirc"
=
preferring
recirculating
cooling
systems
"
OT"
=
preferring
once
through
cooling
systems
21
Model
source
Model
Scenarios
run
Center
for
Climate
System
Research
and
the
National
Institute
for
Environmental
Studies
CCSRNIES
A1a
A1T
A1F
B1a
A2a
B2a
Canadian
Centre
for
Climate
Modelling
and
Analysis
CGCM1
A2a
B2a
Australia's
Commonwealth
Scientific
and
Industrial
Research
Organisation
CSIRO­
Mk2
A1a
B1a
A2a
B2a
Geophysical
Fluid
Dynamics
Laboratory
GFDL­
R30
A2a
B2a
Hadley
Centre
for
Climate
Prediction
and
Research
HADCM3
A1F
A2a
A2b
A2c
B1
B2a
B2b
Table
2:
Climate
models
used
to
find
mean
2050
temperatures
and
the
IPCC
scenarios
run
by
each
of
the
models
22
Figure
14:
Efficiencies
found
for
target
plants
today
versus
the
efficiencies
found
for
the
target
plants
in
2050
Figure
15:
Population
growth
in
Illinois,
Indiana,
and
Ohio
from
1980
to
2025
(
projected)
and
the
linear
relationships
for
this
growth
Comparison
of
efficiencies
currently
and
if
climate
warms
y
=
x
29.3
29.4
29.5
29.6
29.7
29.8
29.9
30
30.1
29.6
29.65
29.7
29.75
29.8
29.85
29.9
29.95
30
30.05
30.1
Current
efficiencies
(%)
Efficiencies
if
climate
warms
(%)
JAN
Efficiency
FEB
Efficiency
MAR
Efficiency
APR
Efficiency
MAY
Efficiency
JUN
Efficiency
JUL
Efficiency
AUG
Efficiency
SEP
Efficiency
OCT
Efficiency
NOV
Efficiency
DEC
Efficiency
1:
1
line
Linear
(
1:
1
line)

Population
growth
in
IL,
IN,
and
OH,
1980
­
2025
y
=
25.857x
+
5502.4
R
2
=
0.9137
y
=
22.193x
+
10851
R2
=
0.8824
y
=
45.685x
+
11371
R
2
=
0.8868
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
0
5
10
15
20
25
30
35
40
45
50
Years
from
1980
Population
(
thousands)

Illinois
Indiana
Ohio
Linear
(
Indiana)

Linear
(
Ohio)

Linear
(
Illinois)
23
Figure
16:
Cooling
water
withdrawals
if
global
warming
occurs,
if
global
warming
occurs
and
CO2
must
be
captured,
and
if
global
warming
occurs,
CO2
must
be
captured,
and
the
population
grows.
Current
withdrawals
with
and
without
CO2
capture
are
plotted
for
comparison.

Figure
17:
Cooling
water
consumption
if
global
warming
occurs,
if
global
warming
occurs
and
CO2
must
be
captured,
and
if
global
warming
occurs,
CO2
must
be
captured,
and
the
population
grows.
Current
consumption
with
and
without
CO2
capture
are
plotted
for
comparison.
Comparison
of
future
withdrawal
calculations
Current
withdrawals
(
OT),
4.34E+
13
Current
withdrawals
with
CO2
(
OT),
4.40E+
13
Temp
withdrawals
(
OT),
4.38E+
13
Temp,
CO2
withdrawals
(
OT),
4.45E+
13
Temp,
CO2,
pop
withdrawals
(
OT),
4.49E+
13
Current
withdrawals
(
recirc),
2.78E+
13
Current
withdrawals
with
CO2
(
recirc),
2.84E+
13
Temp
withdrawals
(
recirc),
2.82E+
13
Temp,
CO2
withdrawals
(
recirc),
2.88E+
13
Temp,
CO2,
pop
withdrawals
(
recirc),
2.92E+
13
0
5E+
12
1E+
13
2E+
13
2E+
13
3E+
13
3E+
13
4E+
13
4E+
13
5E+
13
5E+
13
1
Total
withdrawals
(
lb)
Current
withdrawals
(
OT)

Current
withdrawals
with
CO2
(
OT)

Temp
withdrawals
(
OT)

Temp,
CO2
withdrawals
(
OT)

Temp,
CO2,
pop
withdrawals
(
OT)

Current
withdrawals
(
recirc)

Current
withdrawals
with
CO2
"
recirc"
=
preferring
recirculating
cooling
systems
"
OT"
=
preferring
once
through
cooling
systems
Comparison
of
future
consumption
calculations
Current
consumption
(
OT),
4.92E+
11
Current
consumption
with
CO2
(
OT),
1.08E+
12
Temp
consumption
(
OT),
7.11E+
11
Temp,
CO2
consumption
(
OT),
1.39E+
12
Temp,
CO2,
pop
consumption
(
OT),
1.79E+
12
Current
consumption
(
recirc),
7.77E+
11
Current
consumption
with
CO2
(
recirc),
1.36E+
12
Temp
consumption
(
recirc),
9.97E+
11
Temp,
CO2
consumption
(
recirc),
1.68E+
12
Temp,
CO2,
pop
consumption
(
recirc),
2.08E+
12
0
5E+
11
1E+
12
1.5E+
12
2E+
12
2.5E+
12
1
Total
consumption
(
lb)
Current
consumption
(
OT)

Current
consumption
with
CO2
(
OT)

Temp
consumption
(
OT)

Temp,
CO2
consumption
(
OT)

Temp,
CO2,
pop
consumption
(
OT)

Current
consumption
(
recirc)

Current
consumption
with
CO2
(
recirc)

Temp
consumption
(
recirc)

Temp,
CO2
consumption
(
recirc)

Temp,
CO2,
pop
consumption
(
recirc)

"
recirc"
=
preferring
recirculating
cooling
systems
"
OT"
=
preferring
once
through
cooling
systems
