Transcript Energy Efficiency: The first and most profitable way to

Energy, Society, and the Environment
Unit 9
TRANSPORTATION and ENERGY
Outline
• Vehicle-Fuel link is strong
• The Demands for Transportation are strong and increasing
• Petroleum use has many problems: Dictatorships, sovereignty,
pollution, greenhouse gases
• But the fossil fuel supplies are large for the time being
• Policy and technology needed
million barrels per day
World Oil Use
180
160
140
120
100
80
60
40
20
0
1990
2000
2010
2020
Transportation
Source: World Oil Worksheet (WOW) Model, USDOE/OTT
2030
2040
All Other
2050
Liquid Fuels
Transportation Sector Key to Energy Use
b)
Industrial
Percentage
• Transportation accounts for ~1/3 of energy
use
• When electricity generation factored out,
transportation dominates
50
• Demand projected to increase
40
• 97% of transportation energy from
petroleum
30
• Relatively small number of technologies
20
employed
• Transportation sector energy use can
10
impact national security and
environmental impacts
0
1950
Transportation
Residential
Commercial
1960
1970
1980
Year
1990
2000
2010
Performance actually declining
2.0
U.S. Light Duty Vehicles
1.8
MPG
1.6
HP
1.4
1.2
Weight
1.0
0.8
0-60
0.6
0.4
0.2
0.0
1975
1980
1985
1990
1995
Model Year
2000
2005
2010
Source: EPA (2006)
CAFE: corporate average fuel economy
Source: Brandt and Farrell (2006)
Getting the oil out … to the last drop
Heavy
Oil
Heater
Well
Production
Well
Heater
Light Oil
Confining Strata
Sequestered
Carbon
Petrocoke
Refinery
Thermal Cracker
Heat
Wave
Heavy Oil
Tar Sands
Shale Oil
Coal
In-Situ Refining
Light Oil
Fischer-Tropsch Production
• Fischer-Tropsch. In addition to traditional refinery technologies,
there is one other technology that is used to produce liquid fuels:
Fischer-Tropsch synthesis.
• The Fischer-Tropsch process can convert any high-carbon stream
ultimately to liquid fuels at significant environmental costs.
• It is the process used today in several countries to convert coal and
natural gas to liquid fuels.
vehicles per 1000 capita
Vehicle Ownership and GDP/Capita
700
600
500
400
300
200
100
0
5000
10000
U.S.
15000
GDP per Capita
Japan
France
20000
U.K.
25000
World Vehicle Projections
• By 2050, 3.0 - 4.0 BILLION vehicles
in the world (depending on population
growth, economic growth, consumer
habits)
Where does a car’s gasoline go?
•
6% accelerates the car, <1% moves the driver
•
Three-fourths of the fuel use is weight-related
•
Because of efficiency, each unit of energy saved at the wheels saves
~7–8 units of gasoline in the tank (or ~3–4 with a hybrid)
•
So, first make the car dramatically lighter!
But Small cars are unsafe, right??
But Small cars are unsafe, right??
Addressing Transportation
• Efficiency is Job #1
•
Bring U.S. vehicle efficiency standards to world
standards
Addressing Transportation
• Efficiency is Job #1
•
Bring U.S. vehicle efficiency standards to world
standards
•
Promote the use of goal-appropriate vehicle use
Efficiency is not the entire answer
• Efficiency is not a source of energy, “fuels” will still be needed.
QuickTime™ and a
decompressor
are needed to see this picture.
Available Options and Criteria
• Fossil Fuel ICEs, Hybrid electric cars, Plug-in Hybrid Electric Cars,
Electric Cars, Biofuels, Hydrogen
• Criteria: Vehicle Technology, Supply Infrastructure, Resource Base,
Environment
Battery Electric Vehicle (BEV)
Use on on-board electricity
Recharged from electrical grid
No engine
Slide Credit: Dr. Mark Duvall
Electric Power Research Institute
Hybrid Electric Vehicle (HEV)
Combustion engine plus one or
more electric motors. Uses only
hydrocarbon fuel
Plug-in Hybrid Electric
Vehicle (PHEV)
Combustion engine and stored
electric energy both used
Adaptation of existing hybrids
Range-Extended Electric
Vehicle (REEV)
Drive power is primarily electric
Engine is used only when
stored electrical energy is
exhausted
EV and PHEV
• Environment
• Infrastructure
• Resource base
• Vehicle Technology
Gasoline Well-to-Tank
Gasoline Tank-to-Wheels
PHEV - Renewables
PHEV - Central Biomass
PHEV - Adv Nuclear
PHEV - Nuclear
PHEV - New 2010 GT
PHEV - Old 2010 GT
PHEV - Adv CC
PHEV - New 2010 CC
PHEV - Old 2010 CC
PHEV - IGCC with CCS
PHEV - IGCC
PHEV - Adv SPC
PHEV - 2010 New Coal
PHEV - 2010 Old Coal
Hybrid Vehicle
Conventional Vehicle
Well-to-Wheels Greenhouse Gas Emissions (g CO2e/mile)
Power Plant-Specific PHEV Emissions in 2010
PHEV 20 – 12,000 Annual Miles
500
450
400
350
300
250
200
150
100
50
-
Electricity Well-to-Wheels
Slide Credit: Dr. Mark Duvall
Electric Power Research Institute
EV and PHEV
• Environment: 
• Infrastructure: 
• Resource base:  (but keep in mind problems with overall energy
demand)
• Vehicle Technology: ?
Batteries
QuickTime™ and a
decompressor
are needed to see this picture.
An electrochemical energy storage device
chemical energy --> electrical energy (and back during recharging)
QuickTime™ and a
decompressor
are needed to see this picture.
EV and PHEV
• Environment: 
• Infrastructure: 
• Resource base:  (but keep in mind problems with overall energy
demand)
• Vehicle Technology: ? Getting there.
from the Arizona Daily Wildcat
Hydrogen Fuel Cells
DaimlerChrysler “F-Cell” Vehicle
Hydrogen
• The lightest element
• Abundant on Earth but not found in free form
• Most commonly found as H2O (water molecule) and CH4 (methane)
and a variety of other hydrocarbons.
• Hydrogen must, therefore, be produced from these molecules by
expending energy. It can then be stored as H gas.
Producing Hydrogen
• Steam reforming: from methane with very high temperature steam
CH4 + H2O → CO + 3 H2
• Electrolysis: passing electric current through water to separate it into
O2 and H2.
Hydrogen stores energy
• Steam reforming and electrolysis use energy: so why do it?
• Hydrogen can be stored and then recombined with oxygen and
release energy.
• Hydrogen is not a primary energy source; it stores energy similar to
the way a battery does.
Question: Why are hydrocarbons (e.g., methane,
petroleum…) primary energy sources but not
hydrogen?
Efficiency
• Is hydrogen an efficient energy storage mechanism?
Losses in production,
storage, recombination
Energy density
Energy Density
 need to compress hydrogen (by A LOT!) or liquefy it
to make it transportable
Storage
•
•
Optimal hydrogen storage system would have high energy density
(by weight and volume), low cost, quick refueling, and good safety
Major candidates are:
- compressed gas (~ 700 bar)
- cold liquid (cryogenic storage)
Compressed gas requires steel tanks that can withstand pressure (very
heavy) or expensive materials such as carbon nanotubes, polymers
Liquid hydrogen requires cryogenic tanks
In either case, hydrogen storage density is ~1% by weight
No realistic chemical storage is currently available
How do you use hydrogen?
• Fuel Cell:
reverse electrolysis
Recombine it with oxygen to produce energy and water
Efficiency
• Efficiencies multiply
• For example, if half the energy lost in step 1 and half of the
remaining is lost in step 2, overall efficiency is
 = 1/2 x 1/2 = 1/4 (25 %)
For hydrogen fuel cells:
Overall “well-to-wheel” efficiency = electrolysis efficiency x compression
efficiency x recombining efficiency in fuel cell
 = 70% x 80 % x 60% = 34 % (optimistic)
Comparison to EVs
Hydrogen Fueling Infrastructure
Hydrogen Energy Station in
Las Vegas, Nevada
Many challenges remain
for hydrogen fuel cell vehicles
Term Paper II
• You will need to use turnitin.com to submit it.
• Class ID: 2698159
• Class Password: energy
• You need to create a user profile asap. Go to turnitin.com and click
New User. Then, under New Students, click on Create a User
Profile.
• Bring printed copy to class on Friday.
• This information is also available on D2L.
Announcements 4/20
• Assignment #8 is posted on D2L.
It is due Monday April 27.
BIOFUELS
Plants high in sugar:
Sugarcane, sugar beet,
starch
Plants high in oil:
Oil palm, soybean, algae
Cellulosic ethanol from
Non-edible plants
Fermentation
Heat, purify
Bioalcohols
Burn in diesel engine
Convert to sugar with
Enzymes, ferment
Many pathways exist for liquid, gas, solid fuels
Bioalcohols
Limiting Factors
• Energetic favorability
• Land use
• Economical factors
• Technology
Algae Biofuels
“PetroSun has announced it will begin
operation of its commercial algae-to-biofuels
facility on April 1st, 2008. The facility, located
in Rio Hondo Texas, will produce an estimated
4.4 million gallons of algal oil and 110 million lbs.
of biomass per year off a series of saltwater ponds
spanning 1,100 acres. Twenty of those acres will
be reserved for the experimental production of a
renewable JP8 jet-fuel.” (gas2.org)
NPR’s Science Friday this past week had a discussion on algae biofuels:
http://www.sciencefriday.com/program/archives/200904171