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Topic 2 – Urban Transportation and Energy

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. Transportation and Energy Consumption. A. 1. Energy in a Mobile World 2. Utility Factors

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Topic 2 – Urban Transportation and Energy

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  1. 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

  2. Transportation and Energy Consumption A • 1. Energy in a Mobile World • 2. Utility Factors • 3. Petroleum Dependency • 4. Combustion of Hydrocarbons • 5. Energy Consumption

  3. Energy in a Mobile World A-1 • 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.

  4. Sources of Energy A-1 Non-Renewable • Chemical • Fossil fuels (Combustion) • Nuclear • Uranium (Fission of atoms) Renewable • Chemical • Muscular (Oxidization) • Nuclear • Geothermal (Conversion) • Fusion (Fusion of hydrogen) • Gravity • Tidal, hydraulic (Kinetic) • Indirect Solar • Biomass (Photosynthesis) • Wind (Pressure differences) • Direct Solar • Photovoltaic cell (Conversion) Energy

  5. Energy Content of some Fossil Fuels (in MJ/kg) A-1

  6. World Fossil Fuel Consumption, 1950-1998 (in million of tons of equivalent oil) A-1

  7. Energy in a Mobile World A-1 • 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.

  8. Energy in a Mobile World A-1 • Choice of an energy source • Depend on a number of utility factors. • Factors that favors a specific source. • Currently favoring the usage of fossil fuels, notably petroleum. • Energy and work • 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.

  9. Energy in a Mobile World A-1 • 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).

  10. Energy in a Mobile World A-1 • 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.

  11. Energy in a Mobile World A-1 • 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.

  12. Demand for Refined Petroleum Products by Sector in the United States, 1970-1998 (in Quadrillion BTUs) A-1

  13. Evolution of Energy Sources A-1

  14. Energy in a Mobile World A-1 • 15th Century • 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. • Mid 19th Century • 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.

  15. Energy in a Mobile World A-1 • 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.

  16. Global Energy Systems Transition, (% of market) A-1 100 Wood Solids Coal 80 Gases 60 Hydrogen 40 Liquids Oil 20 Natural Gas 0 2000 2050 2100 2150 1850 1900 1950

  17. Utility Factors A-2 • 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.

  18. Utility Factors A-2 • 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.

  19. Economies of Scale in Oil Transportation Modern VLCC (305 m) 1975 T2 Tanker (153 m) 1942 A-2

  20. Utility Factors A-2 • 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.

  21. Utility Factors A-2 • Some contemporary military interventions were performed to insure the reliability of oil sources and their transport. • Storability • 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.

  22. Utility Factors A-2 • 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.

  23. Utility Factors A-2 • 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.

  24. Petroleum Dependency A-3 • 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.

  25. Oil Energy Consumption by Sector for OECD countries, 1973-1995 A-3

  26. Petroleum Dependency A-3 • Impacts of increasing prices • Increasing the fuel efficiency of vehicles. • Use of alternative sources of energy.

  27. World Oil Production and Demand, 1996 (in m tons) A-3

  28. World Oil Production and Estimated Resources, 1900-2100 (in billions of barrels) A-3

  29. Cost of Gasoline, United States, 1999 A-3

  30. Gasoline Prices, 1978-1999 Selected Countries (current 1998 dollars per gallon) A-3

  31. Combustion of Hydrocarbons A-4 • 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.

  32. Combustion of Hydrocarbons A-4 • Chemical reaction • 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. Gasoline Oxygen Combustion Carbon Dioxide Water Energy

  33. Combustion of Hydrocarbons A-4 • 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.

  34. Combustion of Hydrocarbons A-4 Imperfect combustion • 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. Gasoline Sulfur Benzene Nitrogen Oxygen Air Combustion Carbon Dioxide Carbon monoxide Nitrogen Oxides Water Energy VOC + HC

  35. Combustion of Hydrocarbons A-4 • 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.

  36. Transportation and Energy Consumption A-5 • 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.

  37. Transportation and Energy Consumption A-5 10 Helicopter Worst performance Car Supersonic plane Jet plane Propeller plane Bus 1 Train Cargo plane Gas pipeline Truck Energy costs Bicycle .1 Container ship Freight Oil Pipeline Passengers Train .01 Tanker Best performance Speed (m/sec) .002 300 10 30 100 1000

  38. Energy used by transportation A-5

  39. Transportation and Energy Consumption A-5 • 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%).

  40. Factors of Fuel Use by Transportation A-5 Technology Vehicle efficiency Type of fuel Economics Prices and incomes Fuel Use Infrastructure Provision and Levels of service Urban Form Density and distribution

  41. Typical Energy Use for a Car A-5

  42. Average Gasoline Consumption for New Vehicles, United States, 1972-2001 (in miles per gallon) A-5

  43. Light-Duty Vehicles Sales in the United States, 1975-2001 (in 1,000s) A-5

  44. Change in Average Vehicle Characteristics, 1981-2001 (in %) A-5

  45. Average Miles per Gallon Traveled by Road Vehicle in the United States, 1996 A-5

  46. Energy Consumption by Mode of Transportation in the United States (in Trillion BTU) A-5

  47. Energy Consumption by Road Transportation in the United States (in Trillion BTU) A-5

  48. Energy, Transportation and Urban Form B • 1. The Notion of Distance • 2. Factors Affecting Distance Traveled

  49. Factors Affecting Distance Traveled A-1 • 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.

  50. Factors Affecting VMT Growth A-1 Vehicle Ownership Vehicle Occupancy Population Age VMT Economic Activity Trip Length Spatial Structure Cost of Driving Alternatives available

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