1. Define fuel efficiency, and list the five factors that affect it. (2 points)
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2. Petroleum (crude oil) is the dominant energy source for the transportation sector, responsible for 90% of its energy use. If fuel consumption continues at its current rate, in what year will known reserves of petroleum run out? Hint: See Chapter 7 – Page 5 of the Bloom textbook. (2 points)
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3. In what year(s) did the USA peak (reach a maximum) in oil production? What happened to the amount of oil imported by our country from 1980 to 2010? (2 points)
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4. Name five alternative energy sources for transportation. List one benefit and one challenge of each. (2 points)
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5. Which alternative energy source for transportation appeals most to you, and why? Use 3-5 sentences for your response. (2 points)
Metr 112: Activity 8
1. Define fuel efficiency, and list the five factors that affect it. (2 points)
2. Petroleum (crude oil) is the dominant energy source for the transportation sector,
responsible for 90% of its energy use. If fuel consumption continues at its current rate, in
what year will known reserves of petroleum run out? Hint: See Chapter 7 – Page 5 of the
Bloom textbook. (2 points)
3. In what year(s) did the USA peak (reach a maximum) in oil production? What
happened to the amount of oil imported by our country from 1980 to 2010? (2 points)
4. Name five alternative energy sources for transportation. List one benefit and one
challenge of each. (2 points)
5. Which alternative energy source for transportation appeals most to you, and why? Use
3-5 sentences for your response. (2 points)
Mitigation Strategies:
Transportation
Outline
▪ Energy Consumption
▪ Transportation and Emissions
▪ Fuel Efficiency
▪ Peak Oil
▪ Alternative Fuels for Transportation
Reading: Chapter 7, pages 1-65
2
Class Meeting
▪ Watch the videos for this lecture at:
https://www.youtube.com/watch?v=7Sjvo7hmHds
Fossil Fuels
▪ Extraction and combustion of fossil fuels
account for 65% of anthropogenic greenhouse
gas emissions
▪ The remaining 35% come from changes in land
use and agricultural sources
▪ Provide 84% of world’s total energy production
– Most energy for transportation
Energy Consumption Increase
▪ Over the past 30 years, global energy usage
has increased by approximately 2% per year
– Mainly due to population growth and
economic development
▪ Not much change in energy usage per capita
(person)
Greenhouse Gas Emissions (Left) and Energy
Consumption (Right)
Energy Consumption per Capita
Energy Consumption per GDP
Greenhouse Gas Emissions (Left) and Energy
Consumption (Right)
Transportation
▪ Globalization of world’s economy requires that
humans and products move long distances
▪ Passenger and freight travel will increase
greatly during the next 30 years
– Due to both population increase and longer
travel distances
Travel Increase
Petroleum
▪ Currently the overwhelming energy source for
travel (90%)
▪ Top 3 producing countries are Saudi Arabia,
USA, and Russia
Petroleum Production by Region
Transportation
▪ 14% of global emissions come from
transportation sector (28% in USA, 7% in
China)
▪ Light-duty vehicles, freight trucks, and airplanes
contribute the largest shares
▪ Lower total emissions from boats, trains, buses,
and motorcycles
Transportation Emissions: 2000-2050
Energy Usage: Transportation Sector (USA)
Fuel Efficiency
▪ Fuel efficiency = distance traveled divided by
volume of gasoline required for that distance
▪ Commonly measured in units of kilometers per
liter (most of world) or miles per gallon (USA)
Fuel Efficiency of Light-Duty Vehicles
▪ Varies by region of globe
▪ Factors affecting fuel efficiency
– Driving conditions (speed, highway vs. city)
– Taxes on petroleum and vehicles
– Consumer preferences
– Use of diesel powered vehicles
– Automobile manufacturer agreements
Fuel Efficiency of Light-Duty Vehicles
In the early 2000’s,
fuel efficiency in
France, Germany,
and the UK was
29-32 mpg
It was 20-22 mpg
in the USA,
Australia, and
Japan
Fuel Efficiency of Light-Duty Vehicles
By 2018, fuel
efficiency of new
vehicles in the USA
had increased to
25.1 mpg.
Fuel Efficiency: Relation to Speed
▪ Due to increased wind resistance at higher
speeds, fuel efficiency decreases at speeds
above 50 mph
– Vehicles traveling at 75 mph are 20% less
efficient than those at 55 mph
Fuel Efficiency: Relation to Speed
▪ In 1974, National
Maximum Speed Limit Law
was enacted by Congress
– In response to 1973 Oil
Crisis that resulted in
increased prices and
supply disruptions
– Set maximum speed
limits at 55 mph
nationwide
– Designed to reduce oil
consumption
Stretch of State Highway 130 in Texas
Fuel Efficiency: Highway/City
▪ Quick acceleration and heavy braking decrease
fuel efficiency by over 30%
– Automobile companies advertise two
efficiencies for each car
▪ City
▪ Highway
▪ Due to number of cars increasing faster than
road capacity, congestion is rising
Fuel Efficiency: Taxes
▪ 2006 average cost of extracting,
transporting, and refining a gallon of
gasoline was $2.01
▪ 2013 average price of gasoline at the
pump was between $0.09 and $9.50
per gallon, varying by country
– Depends on subsidies and taxes
– Major oil exporting countries tend to
subsidize fuel
– Most others tax fuel
▪ November 14, 2020 USA Gas Price:
$2.12 per gallon
– California: $3.22 per gallon
Transportation Efficiency – Taxes on Fuel
▪ In many countries, taxes on fuel represent a
major source of government revenue
Percentage of revenues deriving from taxes
on fuels
Transportation Efficiency – Taxes on Fuel
▪ In the USA, gasoline prices vary greatly by
state due to tax differences
Current USA gas prices as of April 25th, 2021
Transportation Efficiency – Consumer
Preferences
▪ Some consumers prefer
smaller and cleaner
vehicles
▪ Others prefer larger
vehicles with faster
acceleration
▪ Through technological
innovation, efficiency
has still increased
slightly
USA
Transportation Efficiency – Diesel
Powered Vehicles
▪ Diesel is denser than gasoline, and contains
11% more energy per volume
▪ Diesel engines are more efficient than gasoline
engines in converting fuel energy into
mechanical work
▪ Diesel engines obtain about 40% higher fuel
efficiency per volume than gasoline engines of
same power
Transportation Efficiency – Regulating
Automobile Manufacturers
▪ 1975 – US enacted Corporate Average
Fuel Economy (CAFE) regulations
– Fuel efficiency of cars and small
trucks in a manufacturer’s US fleet
must meet minimum average value
▪ 1978: 18/17.2 mpg
▪ 1985: 27.5/21.6 mpg
– Controversial
Public Transportation and Efficiency
▪ Cycling, walking, and running have the lowest
carbon footprint
▪ In general, public transportation has lower
carbon emission intensity than private
Public Transportation and Efficiency
▪ Despite incentives for carpool lanes and toll breaks over recent
years, single occupancy vehicles remain the most popular mode of
transportation
USA
Relationship between prices of oil and
gasoline (USA)
http://www.roperld.com/science/minerals/Oil_USGasolinePricesPrediction.htm#gasoline
USA Peak Oil
https://www.eia.gov/todayinenergy/detail.php?id=34772
USA Crude Oil Production and Importation,
1910-2012
World Oil Production + Population
http://www.financialsense.com/contributors/michael-shedlock/2012/01/10/what-level-of-human-population-is-sustainable
Bumpy Plateau of Peak Oil?
Peak Oil
▪ Once global peak oil has passed, half of oil
ever available will have been extracted and
consumed
▪ Production will then enter decline, and cost will
increase
▪ Another reason to transition to alternative fuels
for transportation
Alternative Fuels for Transportation
▪ The USA Department of Energy has set a “30 by 30”
goal
– 30% of gasoline use from alternative fuels by 2030
▪ Alternative Energy Sources for Transportation
– Natural Gas
– Hydrogen
– Electric
– Hybrid
– Biofuels (Biodiesel, Ethanol)
Alternative Fuels – Natural Gas
▪ Extracted from oil wells, coal beds,
natural gas fields, and landfills
– Made of hydrocarbons and
releases CO2 (like other fossil
fuels)
▪ Compared to gasoline, considered
‘clean burning’ for transportation
– Produces 80-90% fewer aerosols
– Emits 12% less greenhouse
gases
▪ Low density presents transport
challenges
– Many USA pipelines near
capacity
Natural Gas Buses in LA
2012 Honda Civic (Natural Gas)
Alternative Fuels – Natural Gas
▪ The three countries with
the highest number of
vehicles powered by
natural gas in 2010 were
Pakistan, Iran, and
Argentina
▪ In the USA, 110,000
vehicles were powered
by natural gas (1 in every
2500)
Alternative Fuels – Natural Gas
▪ Number of natural gas vehicles has increased
greatly for certain regions in the past 15 years
Alternative Fuels – Natural Gas
▪ Represents cleaner alternative to petroleum,
but still a non-renewable resource
Alternative Fuels – Hydrogen
▪ 2003 State of the Union
– “A simple chemical reaction
between hydrogen and oxygen
generates energy, which can be
used to power a car producing only
water, not exhaust fumes. With new
national commitment, our scientists
and engineers will overcome
obstacles by taking these cars from
the laboratory to the showroom so
that the first car driven by a child
born today could be powered by
hydrogen, and be pollution free.”
▪ Technology has not progressed on this
optimistic timeline
Alternative Fuels – Hydrogen
▪ Storage
– Hydrogen has the lowest
energy content per unit
volume of any fuel
▪ Need to store a lot in the
vehicle which presents
technical challenges
▪ Cost
– Fuel cells require extremely
expensive compounds
▪ Many components cost
more than their weight in
gold
– $30,000 for platinum
Alternative Fuels – Hydrogen
▪ Reliability
– Fuel cells are extremely sensitive to
external temperature and moisture
▪ Production
– Hydrogen is not an energy source,
but an energy carrier
– Earth has no recoverable deposits of
hydrogen
– Over 95% of hydrogen generated
today derives from fossil fuels
▪ Other means of production
comprise an area of active
research
Toyota Mirai
Alternative Fuels – Electric Vehicles
▪ Electric motors that require only
recharging (not refueling)
▪ Challenges
– Limited distance, speed
– High recharge times, cost
– Carbon footprint of batteries
▪ Benefits
– Don’t emit greenhouse gases
directly
– Don’t release aerosols
– Save consumer money on
gasoline
Prices and Ranges (2018)
Tesla Model S
Tesla Model 3 (from $35,000)
Elon Musk and Tesla Roadster 2
Chevrolet Bolt: Plug-In Electric
Ford Focus (Electric)
65
Hybrid Electric Vehicles
▪ Connect both gasoline
powered engine and electric
motor to the wheels
– Gasoline engine charges
battery
– Gasoline engine shuts
down when the vehicle
stops
– Use regenerative braking
▪ Hybrids improve fuel
efficiencies by about 30% in
city driving
Toyota Prius at Mount Hamilton
(November 2019)
Chevrolet Volt: Plug-In Hybrid
Biofuels
▪ Biofuels are produced
from living materials
▪ Most modern engines
have flexibility to combust
mixtures of biofuels
▪ In theory, biofuels should
produce no net
greenhouse gases for
same reason that human
breathing produces no net
greenhouse gases
Ethanol
▪ Can be produced from sugarcane or maíz
▪ Ethanol has about a third less energy content
per volume compared to gasoline
▪ E85 (85% ethanol, 15% gasoline) is less
expensive than gasoline
▪ E85 has lower fuel efficiency than gasoline,
helping to negate lower CO2 emissions upon
combustion of same volume
Biofuels
▪ In practice, biofuels have a large carbon
footprint
– Production
▪ Machinery, fertilizers, pesticides, and
water
– Transport
▪ Plant biomass has a low energy density
– Processing
▪ Conversion from biomass to ethanol
takes energy
▪ Diversion of food to fuels
– Raises food prices
Ethanol Stations in the USA
http://www.eia.gov/todayinenergy/detail.cfm?id=6050#tabs_AltTransportFuelStations-4
Nuclear Powered Car?
▪ Benefits
– High energy per volume
▪ Can travel far without
needing to refuel
▪ Major challenges
– Radiation exposure
– Weight
http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/nuclear-powered-car.htm