H2
‐
+
O2
Why
Are
We
Going
Here?
•  NYS
Science
Key
Idea
4:
Energy
exists
in
many
forms,
and
when
these
forms
change
energy
is
conserved.
•  The
first
fossil‐fuel
power
plants
were
around
4%
efficient.
Today’s
fossil
fuel
plants
are
~40%
efficient.
–  Is
this
good
enough?
U.S.
Energy
ConsumpSon
Liquids
Natural
Gas
Coal
45.000
Nuclear
Hydropower
40.000
Renewable
excluding
Hydro
Energy
consump.on
(quad
BTU)
35.000
30.000
25.000
20.000
15.000
10.000
5.000
0.000
1980
1990
2000
2005
2010
2020
2030
World
Energy
ConsumpSon
Sources
of
U.S.
Energy
U.S. Primary Energy Consumption by Source and Sector, 2007
(Quadrillion Btu)
1
Natural
2
Gas
23.6
70
24
96
2
2
3
34
34
30
44
37
9
3
Coal
22.8
9
8
<1
18
75
91
1
9
30
10
51
6
17
2
Renewable
4
Energy
6.8
Nuclear
Electric Power
8.4
Percent
of Sector
5 2
Petroleum
39.8
Percent
of Source
Transportation
29.0
Industrial
21.4
5
Residential
6
and Commercial
10.6
51
9
100
1
Does not include 0.6 quadrillion Btu of fuel ethanol, which is included in "Renewable Energy.”
2
Excludes supplemental gaseous fuels.
3
Includes less than 0.1 quadrillion Btu of coal coke net imports.
4
Conventional hydroelectric power, geothermal, solar/PV, wind, and biomass.
5
Includes industrial combined-heat-and-power (CHP) and industrial electricity-only plants.
21
Electric Power
7
40.6
6
Includes commercial combined-heat-and-power (CHP) and commercial electricity-only plants.
7
Electricity-only and combined-heat-and-power (CHP) plants whose primary business is to sell electricity,
or electricity and heat, to the public.
Note: Sum of components may not equal 100 percent due to independent rounding.
Sources: Energy Information Administration, Annual Energy Review 2007, Tables 1.3, 2.1b-2.1f and 10.3.
US
EIA:
www.eia.doe.gov
The
Energy
Gap
ConsumpSon
vs.
ProducSon
•  ProducSon
has
remained
virtually
flat
since
the
1970s
The
More
Recent
Past
Local
Emissions
Delivering
Energy
The
Cost
to
Drive
At
~$6/gallon,
the
fuel
cost
outweighs
the
vehicle
cost
ConflicSng
Messages
Point:
A
recent
Wall
Street
Journal
opinion
editorial
arScle
states,
“There’s
an
unavoidable
problem
with
renewable‐energy
technologies:
From
an
economic
standpoint,
they’re
big
losers”.
M.
Schulz,
“Don’t
count
on
‘countless’
green
jobs,”
Wall
Street
Journal,
20
February
2009,
p.
A15.
Counterpoint:
•  In
2000,
solar
cells
typically
used
15
g
of
expensive,
highly
refined
silicon
to
generate
1
W
of
power.
By
comparison,
new
SunPower
modules
currently
use
only
5.6
g/W.
The
manufacturing
cost
of
standard
crystalline
silicon
modules
produced
in
a
state‐of‐the‐art
facility
today
is
around
$1.40/W.
Swanson, Richard M. Photovoltaics Power Up, Science, 324, 891, 2009.
“With
Great
Power
Comes
Great
Responsibility…”
‐‐Uncle
Ben
•  We
efficiently
consume
ever‐increasing
amounts
of
energy
Energy
Sources
Sources
Solar
Energy
fossil
biogenic
Coal
Crude
oil
Natural
gas
Nuclear
fusion
biogenic
Biomass
photosynthesis
Heat/light
Wind
Waves
PrecipitaSon
Streams
Earth
Crust
fossil
mineral
Uranium
Geothermal
Nuclear
fusion
Planet
Movement
Tide
Energy
Carriers
Energy
Fluxes
Renewable
Energy
Matrix
The
Hydrogen
Cycle
Proposed
to
be
abandoned
by
the
DOE,
not
by
Congress
SyntheSc
Hydrocarbons
Fuel
Cells
Fuel
Cell
ApplicaSon
Space
Sta.onary
(buildings)
PAFC
SOFC
MCFC
In
space
AFC
PEM
Portable
electronics
DMFC
~
‐10ºC
>140ºC
Fuel
Used
can
vary
with
temperature
(general
rule
of
thumb)
PEM
SOFC
PAFC
Automo.ve
DMFC
Portable
electronics
SOFC
II
Automo.ve
600ºC
~1,000ºC
complexity
of
fuel
increasing
increasing
allowable
contaminants
in
H2
require
reformers,
or
very
clean
H2
can
run
on
direct
hydrocarbon
fuels,
or
“dirty”
H2
typical
operaSng
temperature
Fuels
and
Equivalent
Energy
Density
Wind
•  The
fastest
growing
technology
among
renewable
resources
•  Germany,
Spain,
the
U.S.,
India,
and
Denmark
are
the
top
five
wind
installers
(2005)
No
More
Nukes?
Green
Chemistry,
Manahan,
S.
E.,
2005
The
Nuclear
Lifecycle
Serle,
F.
A.
Journal
of
Chemical
EducaNon,
Vol.
86
No.
3
March
2009
DOE’s
stance
Geothermal
Geography
•  Sources
and
sites
are
limited
–  No
new
discoveries
Plants:
Our
best
solar
cells?
Let
nature
do
the
work
(we
can
take
the
credit)
Corn‐per‐car
area
Pietro,
W.
J.
Journal
of
Chemical
EducaSon,
Vol.
86
No.
5
May
2009 • •  A
trip
down
the
path
to
the
first
law
of
thermodyanamics
–  ReacSons
at
work
in
photosynthesis
and
fermentaSon
Corn‐per‐car
area
Pietro,
W.
J.
Journal
of
Chemical
EducaSon,
Vol.
86
No.
5
May
2009 • •  Sunlight
power
–  At
30‐45°
laStude,
photon
density
is
240
W/m2
–  Only
43%
is
photosyntheScally
acSve
=
103
W/m2
–  At
best,
farms
can
uSlize
80%
of
the
area
=
82
W/m2
•  Photosynthe.c
efficiency
–  Photosynthesis
requires
8
moles
of
photons
to
synthesize
one
molecule
of
carbohydrate
=
8
x
216
kJ
=
1.7
x
103
kJ
–  The
ΔG
(free
energy
of
formaSon)
of
carbohydrate
from
CO2
and
water
is
528
kJ
–  The
overall
photosyntheSc
efficiency
is
528
kJ/1.7
x
103
kJ
=
0.31
–  The
plant
grows
~200/365
days
per
year,
or
a
0.55
duty
cycle
•  Plant
requirements
–  Only
30%
of
the
corn
plant
can
be
used
to
produce
carbohydrate
for
ethanol
Corn‐per‐car
area
(cont’d)
•  FermentaSon
chemistry
–  The
fermentaSon
of
carbohydrate
to
ethanol
requires
has
a
ΔG
of
‐278
kJ/mole
–  18%
of
the
original
solar
energy
are
used
by
yeast
for
fermentaSon,
leaving
82%
in
the
ethanol
•  Automobile
use
–  We
consume
750
billion
kilograms
of
gasoline
for
cars
–  There
are
500
million
cars
in
the
world
–  This
amounts
to
7.0
x
107
kJ
of
energy
per
year
per
car
Corn‐per‐car
area
(cont’d)
•  Energy
conversion
–  82
W/m2
=
2.6
x
106
kJ/(year
m2)
–  MulSply
by
efficiency
factors:
–  Land
requirements:
–  This
is
equal
to
an
area
25m
on
edge
–  Other
consideraSons:
Carbohydrates
available
for
fermentaNon,
actual
duty
cycle,
fermentaNon
efficiency,
producNon
overhead
PV
and
Land
Use
Maximum
Solar
Cell
Efficiencies
A
Quote…
•  “Our
energy
future
is
becoming
clearer.
PV
will
not
be
a
panacea,
but
it
will
take
its
place
as
a
major
source
of
energy
alongside
energy
efficiency,
other
renewables,
nuclear,
and
improved
convenSonal
generaSon,
perhaps
with
carbon
sequestraSon,
as
we
transiSon
to
a
carbon‐free
electric
grid
over
the
next
half
century.”
Swanson, Richard M. Photovoltaics Power Up, Science, 324, 891, 2009.
NY
Physics
Standards
•
4.1
Energy
exists
in
many
forms,
and
when
these
form
change
energy
is
conserved.
•
•
4.1a
All
energy
transfers
are
governed
by
the
law
of
conservaSon
of
energy.
4.1b
Energy
may
be
converted
among
mechanical,
electromagneSc,
nuclear,
and
thermal
forms.
•
4.1d
KineSc
energy
is
the
energy
an
object
possesses
by
virtue
of
its
moSon.
•
4.1e
In
an
ideal
mechanical
system,
the
sum
of
the
macroscopic
kineSc
and
potenSal
energies
(mechanical
energy)
is
constant.
•
4.1f
In
a
non‐ideal
mechanical
system,
as
mechanical
energy
decreases
there
is
a
corresponding
increase
in
other
energies
such
as
internal
energy.
•
4.1g
When
work
is
done
on
or
by
a
system,
there
is
a
change
in
the
total
energy
of
the
system.
•
4.1h
Work
done
against
fricSon
results
in
an
increase
in
the
internal
energy
of
the
system.
•
4.1i
Power
is
the
Sme‐rate
at
which
work
is
done
or
energy
is
expended.
ConNnued…
•  4.1j
Energy
may
be
stored
in
electric
or
magneSc
fields.
This
energy
may
be
transferred
through
conductors
or
space
and
may
be
converted
to
other
forms
of
energy.
•  4.1k
Moving
electric
charges
produce
magneSc
fields.
The
relaSve
moSon
between
a
conductor
and
a
magneSc
field
may
produce
a
potenSal
difference
in
the
conductor.
•  4.1l
All
materials
display
a
range
of
conducSvity.
At
constant
temperature,
common
metallic
conductors
obey
Ohm’s
Law.
•  4.1m
The
factors
affecSng
resistance
in
a
conductor
are
length,
cross‐
secSonal
area,
temperature,
and
resisSvity.
•  4.1n
A
circuit
is
a
closed
path
in
which
a
current
can
exist.
•  4.1o
Circuit
components
may
be
connected
in
series
or
in
parallel.
SchemaSc
diagrams
are
used
to
represent
circuits
and
circuit
elements.
•  4.1p
Electrical
power
and
energy
can
be
determined
for
electric
circuits.
US
Renewable
Energy
Assessment
10
12
14
16
16
Solar
14
Wind
12
10
12
14
16
18
10
10
12
20
22 24
26
26
24
22 20 18
14
16
14
2
Megajoules/m
<10
10‐12
12‐14
14‐16
16‐18
18‐20
20‐22
22‐24
24‐26
26‐28
>28
Biomass
6.0‐6.5
m/s
13.4‐14.6
mph
6.5‐70
m/s
14.6‐15.7
mph
>7.0
m/s
15.7+
mph
Geothermal
Agricultural
resources
&
residues
Wood
resources
&
residues
Agricultural
&
wood
residues
Low
inventory
o
Temperature
<90C
Temperature
>90C
Geopressured
resources
o
Barriers to Change
•  US
energy
infrastructure
is
large
•
•
•
•
•
400,000+
miles
of
gas
and
oil
pipelines
160,000+
of
high
voltage
transmission
lines
176,000
gasoline
staSons
1000’s
of
oil
and
gas
wells
drilled
annually
in
the
Employment