Energy Conservation in Transport
1.3 Transportation system
Transportation is another sector that has increased its comparative portion of primary energy. This sector has
serious concerns as it is a important beginning of CO2 emanations and other airborne pollutants, and it is
about wholly based on oil as its energy beginning ( Figure 1.5 ; Kreith, West, and Isler 2002 ) . In 2002, the
transit sector accounted for 21 % of all CO2 emanations worldwide. An of import facet of future
alterations in transit depends on what happens to the available oil resources, production and monetary values.
At present, 95 % of all energy for transit comes from oil.
As explained subsequently in this chapter, irrespective of the existent sum of oil staying in the land,
oil production will top out shortly. Therefore, the demand for careful planning for an orderly passage off
from oil as the primary transit fuel is pressing. An obvious replacing for oil would be biofuels
such as ethyl alcohol, methyl alcohol, biodiesel, and biogases. Some believe that H is another option,
because if it could be produced economically from RE beginnings or atomic energy, it could supply a
clean transit option for the hereafter. Some have claimed H to be a “wonder fuel” and
hold proposed a “hydrogen-based economy” to replace the present carbon-based economic system ( Veziroglu
and Barbir 1992 ) . However, others ( Shinnar 2003 ; Kreith and West 2004 ; Mazza and Hammerschlag
2005 ) difference this claim based on the deficiency of substructure, jobs with storage and safety, and the
lower efficiency of H vehicles as compared to plug-in intercrossed or to the full electric vehicles ( West
and Kreith 2006 ) . Already hybrid-electric cars are going popular around the universe as
crude oil becomes more expensive.
The environmental benefits of renewable biofuels could be increased by utilizing plug-in intercrossed electric
vehicles ( PHEVs ) . These autos and trucks combine internal burning engines with electric motors to
1971 1980 1990 2002
Share of conveyance in planetary oil demand
Share of oil in conveyance energy demand
FIGURE 1.5 Share of conveyance in planetary oil demand and portion of oil in conveyance energy demand. ( Data and
prognosis from IEA, World Energy Outlook, IEA, Paris, 2004. With permission. )
Global Energy System 1-5
maximise fuel efficiency. PHEVs have more battery capacity that can be recharged by stop uping it into a
regular electric mercantile establishment. Then these vehicles can run on electricity entirely for comparatively short trips. The
electric-only trip length is denoted by a figure, for example, PHEV 20 can run on battery charge for 20 stat mis.
When the battery charge is used up, the engine begins to power the vehicle. The intercrossed combination
reduces gasolene ingestion appreciably. Whereas the conventional vehicle fleet has a fuel economic system of
about 22 mpg, loanblends such as the Toyota Prius can achieve about 50 mpg. PHEV 20s have been shown to
attain every bit much as 100 mpg. Gasoline usage can be decreased even further if the burning engine runs on
biofuel blends, such as E85, a mixture of 15 % gasolene and 85 % ethyl alcohol ( Kreith 2006 ; West and Kreith
2006 ) .
Plug-in intercrossed electric engineering is already available and could be realized instantly without
farther R & A ; D. Furthermore, a big part of the electric coevals substructure, peculiarly in
developed states, is needed merely at the clip of peak demand ( 60 % in the United States ) , and the remainder is
available at other times. Hence, if batteries of PHEVs were charged during off-peak hours, no new
coevals capacity would be required. Furthermore, this attack would levelize the electric burden and
cut down the mean cost of electricity, harmonizing to a survey by the Electric Power Research Institute ( EPRI )
( Sanna 2005 ) .
Given the potency of PHEVs, EPRI ( EPRI 2004 ) conducted a large-scale analysis of the cost, battery
demands, economic fight of plug-in vehicles today and in the hereafter. As shown by West
and Kreith, the net present value of lifecycle costs over 10 old ages for PHEVs with a 20-mile electric-only
scope ( PHEV20 ) is less than that of a similar conventional vehicle ( West and Kreith 2006 ) . Furthermore,
presently available Ni metal hydride ( NiMH ) batteries are already able to run into needed cost and
public presentation specifications. More advanced batteries, such as lithium-ion ( Li-ion ) batteries, may
better the economic sciences of PHEVs even further in the hereafter.
7.5.4 Transportation Energy Consumption
Energy ingestion in the transit sector is projected to turn at an mean one-year rate of
1.7 % between 2003 and 2025 in the projection, making 39.4 quadrillion Btu in 2025. The growing in
transit energy demand is mostly driven by the increasing personal disposable income,
projected to turn yearly at approximately 3 % , consumer penchants for driving larger autos with more
HP, and an addition in the portion of visible radiation trucks and athleticss public-service corporation vehicles that make up lightduty
vehicles. Entire vehicle stat mis traveled by light-duty vehicles is projected to increase at an one-year
rate of 2 % between 2003 and 2025 because of the addition in personal disposable income and other
This chapter presents tendencies in land usage, cargo, ground-transportation manners for people and cargo,
transit fuel supply, and the chances for preservation that exist within each country. The
chapter starts with a treatment of the transportation–land usage relationship for a better apprehension of
the model within which the transit system maps and the design theories that purpose to
influence manner pick and trip coevals. Next is a description of mass theodolite, with peculiar accent
on how its energy usage compares to the energy usage of the car. The motion of cargo, its manners,
and energy ingestion relation to the remainder of the transit system follows. Then, emerging hereafter
engineerings are described ; the focal point of this subdivision is on vehicle efficiencies to conserve energy resources.
Finally, the well-to-wheel energy analysis uniting fuel production and vehicle public presentation is
presented, concentrating on what feedstocks are available and how they can be refined expeditiously into a fuel.
8.2 Land Use
8.2.1 Land Use and Its Relationship to Transportation
There is a cardinal relationship between transit and land usage, because the distance between
one’s beginning and finish will find the feasibleness, path, manner, cost, and clip necessary to go
from one topographic point to another. Likewise, transit influences land usage as it impacts people’s determinations
approximately where to populate and work, sing factors such as commute clip and cost, the distance to a quality school for a family’s kids, the safety and convenience of the paths to school, work, activities,
and entree to goods and services.
The best chance for preservation in transit Begins with the transportation–land usage
relationship. An energy-efficient transit system feats and integrates all manners instead than merely
the main road. However, current land usage ordinances, codifications, and development tendencies are designed
entirely for the single-occupant vehicle ( SOV ) and do non expeditiously back up other travel options. A
more balanced system that incorporates mass theodolite, walking, bicycling, and other options would be
more energy-efficient. These manners are less energy intensive and would cut down traffic congestion, vehicle
idleness, and inefficient stop-and-go traffic. However, land usage must be designed for multimodal
motion for such a balanced system to be realized.
Land usage and the population in the U.S. have become more decentralised over clip ( see Figure 8.1 ) .
The distribution of land utilizations into residential, commercial, and concern countries increases the distances
between the many day-to-day necessities of life so that walking and bicycling are either impracticable or insecure ; it
besides makes mass theodolite inefficient because Michigans would be required to function each individual’s needs.
Therefore, personal vehicles are the most convenient and most widely chosen manner of transit for
day-to-day travel demands given the type of development most normally used in the U.S. A more systemsoriented
attack, incorporating prosaic, bike, car, and mass-transit webs within a
higher-density developmental construction would be more energy-efficient, but this state of affairs is non the
norm in the U.S. today.
8.3 Alternate Transportation system: Mass Transit
The efficiency of mass-transit service typically decreases with the denseness of land utilizations. However, denseness is
non the individual factor finding the success or failure of a theodolite system. Vuchic ( 1999 ) notes the success
of the theodolite webs in fanned countries of San Francisco, Washington, Montreal, Calgary, and
peculiarly the suburbs of Philadelphia ( with a lower population denseness than that of Los Angeles: 3500
people per square stat mi ) . Many contrivers and designers suggest a “hierarchy” of manners instead than the
individual manner system that dominates most countries: at the base is a web of bicycle- and pedestrianfriendly
streets that support the local coach system, which in bend feeds a regional theodolite web. As each
constituent relies on the others, their integrating is indispensable for transit’s success ( Calthorpe and Fulton
2001 ) . Furthermore, “the balance between auto and theodolite usage in cardinal metropoliss is strongly influenced by the
character of the country ( its physical design, organisation of infinite, and types of development ) and by the
comparative convenience and attraction of the two systems” ( Vuchic 1999 ) .
10. Narrow streets
9. Traffic volumes
7. Street trees
6. Interconnected streets
5. On-street parking
4. Lower traffic velocities
3. Mixed land usage
2. Buildings looking the street
1. Small block size
FIGURE 8.3 Top 10 walkability factors. ( From Hall, R. , Walkable thoroughfares through balanced design.
Presentation at The Nuts & A ; Bolts of Traditional Neighborhood Development Conference, Richmond, VA, 2005. )
Several different types of theodolite exist to function the demands of the populace. “Demand response” describes the
paratransit manner, by which a rider calls a starter who sends the theodolite vehicle ( a bird coach
or cab ) to the passenger’s door and delivers her to her finish. Commuter rail denotes regional rail
operating between a metropolis and its suburban countries ; light rail implies one or two autos utilizing overhead
electricity as a power beginning and operating within a metropolis, frequently sharing the streets with cars ; heavy
rail operates at high velocities within a separate right-of-way. Bus rapid theodolite ( BRT ) is deriving popularity
as a system that grants buses their ain right-of-way so that they do non acquire caught in traffic congestion.
BRT operates parallel to the street, such as in the median between travel lanes or in an sole bus-only
lane ( see Figure 8.4 ) , and depending on the system, may besides acquire prioritization at traffic signals so that
upon attack, the light bends green and the coach will non hold to wait at a ruddy visible radiation. Table 8.3 summarizes
the features of each manner. Table 8.4 illustrates what percentages of the theodolite fleets use alternate
fuels ( i.e. , fuels other than the conventionally used gasolene ) .
The factors that determine what manner and what engineering are best for a given theodolite system include:
† The handiness of a separate right-of-way
† The distance between/frequency of Michigans ( i.e. , will it be regional, express or local service? )
† The denseness of the environing country ( to find at what speeds the vehicle can safely go )
† Expected rider volumes
† Size of the metropolis being served
A separate right-of-way is non dependent on the bing conditions of the street web and provides
great dependability ( since there are no traffice congestion holds ) , high velocity, short trip times, and overall
convenience for riders.
The potency of mass theodolite to conserve energy is a big, untapped resource. Table 8.5 illustrates how
much fuel could be saved by one individual exchanging to mass theodolite for their day-to-day commute to work.
The ground for mass transit’s high efficiency is its energy strength, which is a consequence of the burden factor of
each vehicle. Table 8.6 provides passenger travel and energy usage informations for 2002, while Figure 8.5 provides
the theodolite manner split on a passenger-mile footing ( i.e. , the distribution of travel on each manner per
rider per stat mi ) . Mass transit’s efficiency could surely be much higher compared to cars if
more riders used it and increased its burden factor ( Greene and Schafer 2003 ) .
FIGURE 8.4 BRT exposure. ( From U.S. General Accounting Office ( GAO ) , Mass Transit: Bus Rapid Transit Shows
Promise, GAO-01-984, Washington, DC, 2001. )