Transcript Topic 2 - Urban Transportation and Energy

Transport and the Urban Environment
Topic 2 – Urban Transportation and Energy
A – Transportation and Energy
Consumption
B – Energy, Transportation and Urban
Form
C – Alternative Sources of Energy for
Urban Transportation
A
Transportation and Energy Consumption





1. Energy in a Mobile World
2. Utility Factors
3. Petroleum Dependency
4. Combustion of Hydrocarbons
5. Energy Consumption
A-1
Energy in a Mobile World

Nature






Energy is movement or the possibility of creating movement.
Exists as potential (stored) and kinetic (used) forms.
Conversion of potential to kinetic.
Movement can be ordered (mechanical energy) or disordered
(thermal energy).
Major tendency is to move from order to disorder.
Importance






Human activities are closely dependant to the usage of several forms
and sources of energy.
Development processes have increased demand and reliance on
energy.
Human activities are strongly supported by the usage of energy.
Overcoming territories in a global economy requires a substantial
amount of work.
Work related to transfers of goods, people and information has
increased significantly.
Growing share of transportation in the total energy spent.
A-1
Sources of Energy
Non-Renewable
Chemical
• Fossil fuels (Combustion)
Nuclear
• Uranium (Fission of atoms)
Renewable
Chemical
• Muscular (Oxidization)
Nuclear
• Geothermal (Conversion)
• Fusion (Fusion of hydrogen)
Gravity
Energy
• Tidal, hydraulic (Kinetic)
Indirect Solar
• Biomass (Photosynthesis)
• Wind (Pressure differences)
Direct Solar
• Photovoltaic cell (Conversion)
A-1
Energy Content of some Fossil Fuels (in MJ/kg)
Wood
Coal
Crude Oil
Kerosene
Ethanol
Methanol
Methane
Natural Gas
Gasoline
Hydrogen
0
20
40
60
80
100
120
140
9,000
8,000
7,000
6,000
5,000
4,000
3,000
2,000
1,000
19
62
19
65
19
68
19
71
19
74
19
77
19
80
19
83
19
86
19
89
19
92
19
95
19
98
9
19
5
6
19
5
3
19
5
0
0
19
5
A-1
World Fossil Fuel Consumption, 1950-1998 (in million
of tons of equivalent oil)
A-1
Energy in a Mobile World

Energy exists in various forms



Mechanical, thermal, chemical, electrical, radiant, and atomic
and are all interconvertible.
Forms of energy come from sources qualified as renewable
and non-renewable.
Renewability



Based upon the scale of human events and if the source can
be replaced during that period.
Wood is a renewable biomass energy source as long as
adequate conditions are kept for reserves to be replenished.
Rates of exploitation / deforestation in a number of areas are
so high that biomass may be considered as a non-renewable
source in those circumstances.
A-1
Energy in a Mobile World

Choice of an energy source




Energy and work



Depend on a number of utility factors.
Factors that favors a specific source.
Currently favoring the usage of fossil fuels, notably petroleum.
Many efforts have been done to alleviate work.
Creating more work performed by extra-human agents like
motors and the usage of even more energy.
Modification of the environment

Rendering space suitable for human activities.
 Clearing land for agriculture.
 Modifying the hydrography (irrigation).
 Establishing distribution infrastructure.
 Constructing and conditioning (temperature and light)
enclosed structures.
A-1
Energy in a Mobile World

Appropriation and processing resources




Extraction of agricultural products from the biomass and raw
materials (minerals, oil, lumber, etc.) for human needs.
Disposal of wastes, which are in an advanced industrial
society very work intensive to safely dispose.
Modifies products from the biomass, raw materials and goods
to manufacture according to economic needs.
Over the last 200 years, work related to processing was
considerably mechanized (e.g. robotized assembly lines).
A-1
Energy in a Mobile World

Transfer







Movements of freight, people and information from one place
to another.
Attenuate the spatial inequities in the location of resources by
overcoming distance.
The less energy costs per ton or passenger - kilometer, the
less importance has transfers.
Overcoming territories in a global economy requires a
substantial amount of work.
Work related to transfers of goods, people and information has
increased significantly.
Growing share of transportation in the total energy spent.
The United States is an economy using massive amounts of
energy in the transport sector.
A-1
Energy in a Mobile World

United States




Huge consumer of energy.
Pattern of consumption is strongly linked to the attributes of
the American economy and territory.
Accounts for 5% of the global population, but for 25% of the
produced energy.
Transportation accounts for about 24% of all the energy used
in the United States.
A-1
Demand for Refined Petroleum Products by Sector in
the United States, 1970-1998 (in Quadrillion BTUs)
25
20
Transportation
Residential & Commercial
Industrial
Electric Utilities
15
10
5
0
1970
1975
1980
1985
1990
1991
1992
1993
1994
1995
1996
1997
1998
A-1
Evolution of Energy Sources
Mid 21st Century
Animal
Biomass
Coal
Oil
Natural Gas
Nuclear
Hydrogen
Late 20th Century
Early 20th
Century
Mid 19th Century
15th Century
0%
20%
40%
60%
80%
100%
A-1
Energy in a Mobile World

15th Century




Mid 19th Century

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
Traditional societies.
Rely only on muscular and biomass sources to answer their
energy needs.
Mainly the characteristics of the Middle Ages and other
previous historical periods.
Beginning of the Industrial revolution.
Considerably modified energy sources.
Greater reliance on coal.
Early 20th Century



Middle of the industrial revolution.
Coal is dominant source of energy.
Gradual shift towards higher energy content sources like oil.
A-1
Energy in a Mobile World

End of 20th Century




Modern energy intensive society.
Contemporary technological developments allowed:
 Higher occurrence, a better transferability, reliability,
storability, flexibility, safety and cleanliness of high energy
content sources for a low price.
Emphasis on petroleum products as the main provider of
energy.
Reached the point where the world economy highly depends
on the internal combustion engine and supporting industries.
A-1
Global Energy Systems Transition, (% of market)
100
Wood
Solids
Coal
80
Gases
60
Hydrogen
40
Liquids
Oil
20
Natural Gas
0
1850
1900
1950
2000
2050
2100
2150
A-2
Utility Factors

Nature



Favor the usage of petroleum as the main source of energy for
transport activities.
The utility factors were so convenient that a dependency on
petroleum was created.
Occurrence





Location of energy sources considering the demand.
Several energy sources are only available when a
transportation system exists
Can support transfers between the supply and the demand.
Exploitation of oil fields in several regions of the World (Middle
East, Siberia, etc.).
Only possible when an efficient transportation system based
upon pipelines and tankers was established.
A-2
Utility Factors

Transferability





Distance over which an energy source can be transported.
Depends on its physical form (solid, liquid or gas), its energy
content, and on the available transport technology.
Most petroleum products are in a liquid, more or less viscous,
form.
Offer an efficient form to be transferred.
Economies of scale in transportation enhance transferability.
A-2
Economies of Scale in Oil Transportation
Modern VLCC (305 m)
T2 Tanker (153 m)
1942
1975
A-2
Utility Factors

Energy content





Available energy per weight or volume unit of a source.
A low energy content is inadequate when demand is high and
concentrated in space.
Gasoline and other petroleum products have a high energy
content compared to other fossil fuels like coal.
Even more when compared to gravity and solar energy.
Reliability


Continuous availability is an advantage over intermittent
sources.
Many sources and continuous supply through maritime and
land routes have given a relative reliability for petroleum
products.
A-2
Utility Factors


Storability



Some contemporary military interventions were performed to
insure the reliability of oil sources and their transport.
An energy source has an advantage when it can be stored to
answer variations in demands and interruptions of supplies.
In liquid form, petroleum products are easily stored.
Flexibility



Capacity of an energy source to answer multiple usage.
Petroleum by-products are the basis of whole industrial sectors
(petrochemical).
Synthesize goods like plastics, pharmaceutical products, and
synthetic rubber.
A-2
Utility Factors

Safety




Sources that can be provided and used at low risks (human
and environmental) are an advantage.
The petrochemical industry presents some risks (accidents
during extraction, refining, transport and usage).
Oil is considered a safe source of energy for its production and
usage.
Cleanliness


Sources that produce few waste and are cleanly used have an
advantage.
In regards of other conventional energy sources like coal and
wood and of the available technology, oil is cleaner to use and
produces a limited amount of waste.
A-2
Utility Factors

Price






Sources at low cost are generally more used.
A function of the occurrence, the transferability and the energy
content of the source.
Massive investments on large scale extraction, refining and
transport of petroleum products.
Constant supply.
Intensive competition from several oil producing countries
(although with some monopolistic control - OPEC).
Oil price is cheaper than many other sources.
A-3
Petroleum Dependency

The reliance on petroleum







Petroleum products account for more than 97% of the energy
consumption by transportation modes.
Transportation accounts for a growing share of the oil used.
The share of transportation has increased in the and now
accounts for more the 55% of the oil used.
Since 1973 the price of petroleum has increased significantly.
The transport sector consumed 42% of the oil in OECD
countries in 1973.
This share climbed to 55.1% in 1995.
The sprawl of economic activities, notably in urban areas, is
strongly linked to this trend.
A-3
Oil Energy Consumption by Sector for OECD countries,
1973-1995
55.1
1995
20
6.3
18.6
Transportation
Industry
Non-Energy Use
Other Sectors
1973
42
0%
20%
26.3
40%
60%
6.3
25.3
80%
100%
A-3
Petroleum Dependency

Impacts of increasing prices


Increasing the fuel efficiency of vehicles.
Use of alternative sources of energy.
A-3
World Oil Production and Demand, 1996 (in m tons)
1000
800
600
400
200
0
North America
Latin America
Middle East
Asia/Oceania
Africa
-200
-400
-600
Production
Demand
Balance
Western
Europe
Eastern Europe
30
25
Actual
Predicted
20
15
10
5
0
19
00
19
10
19
20
19
30
19
40
19
50
19
60
19
70
19
80
19
90
20
00
20
10
20
20
20
30
20
40
20
50
20
60
20
70
20
80
20
90
21
00
A-3
World Oil Production and Estimated Resources, 19002100 (in billions of barrels)
A-3
Cost of Gasoline, United States, 1999
14%
Crude Oil
37%
13%
Federal and State Taxes
Refining costs and
profits
36%
Distribution, retail &
marketing costs and
profits
A-3
Gasoline Prices, 1978-1999 Selected Countries
(current 1998 dollars per gallon)
5
4.5
4
3.5
Japan
France
United Kingdom
Germany
Canada
United Statesd
3
2.5
2
1.5
1
0.5
0
1978
1982
1986
1990
1994
1996
1997
1998
1999
A-4
Combustion of Hydrocarbons

Internal combustion engine




Almost all transportation modes depend on the internal
combustion engine.
For the majority of internal combustion engines, gasoline
(C8H18; four strokes Otto-cycle engines) serves as fuel.
Other sources like methane (CH4; gas turbines), diesel (mostly
trucks) and kerosene (turbofans) are used.
Perfect combustion


If all internal combustion engines had perfect combustion,
emissions and thus environmental impacts of transportation
would be negligible (except for carbon dioxide emissions).
Combustion in internal combustion engines is imperfect and
incomplete.
A-4
Combustion of Hydrocarbons

Chemical reaction

Gasoline


Oxygen
Carbon Dioxide
Water
Energy
Combustion

Complete and perfect
combustion of gasoline:
(2) C8H18 + (25) O2 = (16) CO2
+ (18) H2O + energy
Gasoline produces around
46,000 Btu per kilogram
combusted.
Requires from 16 to 24 kg of air.
A-4
Combustion of Hydrocarbons

Control or the process







Energy released by combustion causes a rise in temperature
of the products of combustion.
Temperature attained depends on the rate of release and
dissipation of the energy and the quantity of combustion
products.
Air is the most available source of oxygen.
Air also contains vast quantities of nitrogen.
Nitrogen becomes the major constituent of the products of
combustion.
Rate of combustion may be increased by finely dividing the
fuel to increase its surface area and hence its rate of reaction.
Mixing it with the air to provide the necessary amount of
oxygen to the fuel.
A-4
Combustion of Hydrocarbons
Imperfect combustion

Gasoline
Sulfur
Benzene
Air

Nitrogen Oxygen
Combustion
Carbon Dioxide
Carbon monoxide
Nitrogen
Water
Oxides
Energy
VOC + HC

The fuel and the oxider are not
pure.
Gasoline is known to have
impurities
 Sulfur (0.1 to 5%).
 Sometimes lead (anti-knock
agent).
 Other hydrocarbons (like
benzene and butadiene).
Air is composed of 78%
nitrogen and 21% oxygen.
A-4
Combustion of Hydrocarbons

Consequences of incomplete combustion




Incomplete combustion emits other residuals.
Because of the technology of the engine.
Besides carbon dioxide and water, a typical internal
combustion engine will produce:
 Carbon monoxide (CO).
 Hydrocarbons (HC; benzene, formaldehyde, butadiene and
acetaldehyde).
 Volatile organic compounds (VOC).
 Sulfur dioxide (SO2), particulates, and nitrogen oxides
(NOx).
These combustion products are the main pollutants emitted in
the environment by transportation.
A-5
Transportation and Energy Consumption

Issue




Differences between speed, energy costs, mode and type of
loads (freight and passengers).
Economies of scale play a crucial role in freight transportation
 Transposed in its general levels of energy consumption.
 Transportation operators always ponder a compromise
between speed (returns in overcoming distance) and
energy (costs in overcoming distance).
Lowest consumption levels are associated with bulk freight
travelling at slow speed (like oil).
 Compromise of energy over speed.
High levels correspond to passengers or merchandises being
carried at high velocities.
 Compromise of speed over energy.
Transportation and Energy Consumption
10
Helicopter
Car
Propeller Jet
plane plane
Bus
Supersonic
plane
1
Train
.1
Cargo plane
Truck
Bicycle
Gas
pipeline
Container ship
Oil Pipeline
Energy costs
A-5
Freight
Passengers
Train
.01
Tanker
Speed (m/sec)
.002
10
30
100
300
1000
A-5
Energy used by transportation
17%
Vehicle operation
Vehicle maintenance
5%
Vehicle manufacture
7%
1%
4%
66%
Infrastructure
provision
Raw material
manufacture
Energy generation
A-5
Transportation and Energy Consumption

Car








Poor energetic performance.
Road transportation consumes 85% of the total energy used
by the transport sector in developed countries.
Only 12% of the fuel used by a car actually performs work.
Exhaust (33%).
Cylinder cooling (29%).
Engine friction (13%).
Transmission and axles (5.5%).
Braking (7.5%).
A-5
Factors of Fuel Use by Transportation
Technology
Vehicle efficiency
Type of fuel
Economics
Prices and incomes
Fuel Use
Infrastructure
Provision and
Levels of service
Urban Form
Density and
distribution
A-5
Typical Energy Use for a Car
8%
12%
6%
13%
32%
29%
Momentum
Exhaust
Cylinder cooling
Engine friction
Transmission and axles
Braking
A-5
Average Gasoline Consumption for New Vehicles,
United States, 1972-2001 (in miles per gallon)
30
28
26
24
22
20
18
16
Cars
Light Trucks
Average
14
12
00
20
98
19
96
19
94
19
92
19
90
19
88
19
86
19
84
19
82
19
80
19
78
19
76
19
74
19
19
72
10
A-5
Light-Duty Vehicles Sales in the United States, 19752001 (in 1,000s)
18000
Trucks
Cars
16000
14000
12000
10000
8000
6000
4000
2000
0
75
9
1
77
9
1
79
9
1
81
9
1
83
9
1
85
9
1
87
9
1
89
9
1
91
9
1
93
9
1
95
9
1
97
9
1
99
9
1
01
0
2
A-5
Change in Average Vehicle Characteristics, 1981-2001
(in %)
90
80
70
60
50
40
30
20
10
0
-10
Fuel Economy
Weight
Horsepower
Acceleration
A-5
Average Miles per Gallon Traveled by Road Vehicle in
the United States, 1996
Average
Heavy trucks
Light trucks
Buses
Motorcycles
Passenger cars
0
10
20
30
40
50
A-5
Energy Consumption by Mode of Transportation in the
United States (in Trillion BTU)
25,000
20,000
Pipeline
Water
Rail
Transit
Road
Air
15,000
10,000
5,000
0
1970 1975 1980 1985 1990 1991 1992 1993 1994 1995 1996
20,000
18,000
16,000
Bus
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
19
70
19
75
19
80
19
85
19
90
19
91
19
92
19
93
19
94
19
95
19
96
A-5
Energy Consumption by Road Transportation in the
United States (in Trillion BTU)
Combination Truck
Single-Unit 2-Axle 6-Tire or
More Truck
Other 2-Axle 4-Tire Vehicle
Passenger Car &
Motorcycle
B
Energy, Transportation and Urban Form


1. The Notion of Distance
2. Factors Affecting Distance Traveled
A-1
Factors Affecting Distance Traveled

Trends



The distance traveled has increased over the last 20 years in
developed countries.
Predominantly in urban areas.
VMT (VKT)





Vehicle-Miles Traveled (or Vehicle-KM).
Important measure of the usage of energy by transportation.
Has increased 3% per year on average since 1970.
Growth systematically higher than population growth and GDP
growth.
VMT growth has been linked to a set of factors.
A-1
Factors Affecting VMT Growth
Vehicle Ownership
Population
Vehicle Occupancy
Age
VMT
Economic Activity
Trip Length
Spatial Structure
Cost of Driving
Alternatives available
A-2
Factors Affecting Distance Traveled

Population and economic activity




Both a dominant factor.
Population growth is accompanied by an increase in urban
travel.
Economic activity, often expressed by GDP, is linked with
increasing urban travel.
 Wealthier population can afford to travel more often and
over longer distances.
 Increased consumption requires added deliveries of goods
and resources.
Vehicle ownership



Access to a personal vehicle promotes its use.
Correlated with the wealth of the population.
From 1969 to 1995, the number of vehicles per household has
increased from 1.2 to 1.8 in the United States.
A-2
Annual Growth Rates of VMT, Population and GDP,
1970-1995, United States
GDP
Population
VMT
1990-95
1985-90
1980-85
1975-80
1970-75
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
A-2
Changes in Population, GDP and VMT, 1969-1995,
United States (1969=100)
240
220
VMT
Population
GDP
200
180
160
140
120
100
1969
1977
1983
1990
1995
A-2
Factors Affecting Distance Traveled

Location of population




Age of the population




Significant changes in the location of the population, notably in
developed countries.
New spatial structures, such as sub-urbanization.
Lower average population densities.
Strong correlation between age and mobility.
People over 65 are on average 40% less mobile than people
between 35 and 54.
Aging of population will slow VMT growth.
Trip length


Correlated with locational changes in population.
Longer distances between home and place of work.
A-2
Annual VMT by Age Group and Gender, United States,
1995
20,000
18,000
16,000
14,000
12,000
Males
Females
10,000
8,000
6,000
4,000
2,000
0
16-19
20-34
35-54
55-65
65+
A-2
Home-to-Work Commute Profile, United States, 19831995
40
35
33.6
32.3
30
28
25
20
18.2
15
10.6
10
20.7
19.7
11.6
8.5
5
0
1983
1990
1995
Average Length of Work
Trips (miles)
Average Work Trips Travel
Time (minutes)
Average Speed (Miles per
Hour)
A-2
Factors Affecting Distance Traveled

Vehicle Occupancy




Cost of driving




Reflects the intensity of use of private and public urban
transportation.
Dropped significantly in most developed countries.
The most significant drop was for work-related trips.
Act as a deterrent.
Involve several costs such as car ownership, insurance,
maintenance, taxes and fuel.
Have remained similar over the last 25 years.
Alternatives available

Involve public transit, walking, cycling, carpooling or working at
home.
A-2
Vehicle Occupancy by Purpose, 1977-1995, United
States
Average
Work
1995
1977
Family / Personal
Social / Recreation
0.0
0.5
1.0
1.5
2.0
2.5
3.0
C
Alternative Sources of Energy for Urban
Transportation


1. Context
2. Alternative Fuels
A-1
Context

Emergence





Received increasing amounts of attention since the first oil
crisis in 1973.
Attention ebbs and flows with fluctuations in the price of oil.
Several of alternate sources need further research before they
can become truly viable alternatives.
Moving from carbon-based sources to non-carbon based.
Unsustainability of fossil fuels



The resource itself is finite; its use contributes to the global
warming problem.
Some 35% of the carbon emissions in the USA is attributable
to electric power generation.
Employing substitutes for fossil fuels in that area alone would
help alleviate our greenhouse gas problem.
A-1
Context

Fuel use efficiency






Not an alternate energy source but can have a great impact on
the conservation side of the ledger.
After 1973, many industries were motivated to achieve greater
efficiency of energy use.
Many appliances (including home air conditioners) were made
more energy efficient.
The motivation to do this declined during the 1980s with
declining energy costs.
The USA continually ranks behind Europe and Japan in
energy efficiency.
Contributes to our lack of competitiveness with those
economies.
A-1
Context




Besides electricity generation, another 32% of the carbon
emissions in the USA is due to vehicular use.
More fuel-efficient cars would help reduce this amount.
Alternate energy sources, such as electricity, might make a
greater difference.
Require a great behavioral adjustment on the part of the carusing public, especially in the USA.
A-2
Alternative Fuels

Hydrogen


Hydrogen
Oxygen


Fuel

Fuel Cell
Fuel cells


Catalytic conversion
Water
Electricity
Considered in itself the cleanest fuel.
Compose 90% of the matter of the
universe.
Non polluting (emits only water and
heat).
Highest level of energy content.

Convert fuel energy (such as
hydrogen) to electric energy.
No combustion is involved.
Composed of an anode and a
cathode.
 Fuel is supplied to the anode.
 Oxygen is supplied to the
cathode.
 Electrons are stripped from a
reaction at the anode and
attracted to form another
reaction at the cathode.
A-2
Alternative Fuels

Fuel cell cars



Most likely replacement for the internal combustion engine.
Efficiency levels are between 55% and 65%.
Where to get the hydrogen from?



Not naturally occurring.
Electrolization of water.
 Electricity from fossil fuels not a environmentally sound
alternative.
 Electricity from solar or wind energy is a better alternative.
Extraction from fossil fuels.
 From natural gas.