ACKNOWLEDGEMENTS
This paper was prepared by the Office of Energy Efficiency,
Technology and R&D of the International Energy Agency (IEA).
It draws on substantial contributions by Lew Fulton, Madeline
Woodruff, Tom Howes and Sally Bogle of the IEA Energy Technology
Policy Division and by Martijn van Walwijk of Innas BV, Netherlands.
Assistance with preparation of the manuscript was provided by
Muriel Custodio, Corinne Hayworth and Bertrand Sadin.
The work benefited greatly from input by the IEA’s technology
committees and collaborative R&D programs and by other
government and private-sector experts. We are indebted to all
contributors and reviewers.
Nonetheless, the paper does not necessarily reflect the views of
all contributors or reviewers. All errors or omissions are solely the
responsibility of the IEA.
1
TABLE OF CONTENTS
Acknowledgments ..................................................................................................................................................... 1
ENERGY TECHNOLOGIES FOR A SUSTAINABLE FUTURE: THE CONTEXT ..............5
A Portfolio Approach ................................................................................................................................................6
Advanced Technologies for a Low-emissions Energy System ........................................................7
TRANSPORT TECHNOLOGIES FOR A SUSTAINABLE FUTURE .......................................... 9
Overview .......................................................................................................................................................................9
Greenhouse Gas Emissions from Transport ................................................................................................... 10
Near-term Technologies and Actions ............................................................................................................... 13
Technologies and Actions for the Long Term: Toward a Sustainable Transport System ................. 19
Transition Steps to a Sustainable Transport System .................................................................................... 27
Scenarios of Potential CO2 Emissions Reductions Using Near-term and Longer-term Actions .... 30
Challenges and Next Steps: Implications for Research and Development ........................................... 33
Putting it all Together: Near-term Steps Toward both Near-term and Long-term Goals ................. 37
Bibliography ............................................................................................................................................................... 40
2
Figures
1. Projected Growth in Transport CO2 Emissions to 2030, OECD and Non-OECD Regions ...............11
2. Average New Car Fuel Economy for Selected IEA Countries ......................................................... 13
3. Improving Fuel Economy: Technologies and their Use in Three Countries as of 2000 ................. 14
4. Estimated CO2 Emissions Reduction Costs from In-use Efficiency Measures
in Different Regions and Driving Conditions................................................................................. 16
5. Gasoline and Ethanol Prices in Brazil, 2000-2004 ........................................................................ 18
6. Biofuels: Cost per Tonne of CO2-equivalent Emissions Reduction, Current and Projected ........... 23
7. Steps and Sequence for a Transition to a Near-zero-emissions
Transport System Over the Long Term .........................................................................................29
8. Two Possible Scenarios for Greenhouse Gas Emissions Reduction in Light-duty Vehicles........... 32
Tables
1. Potential Well-to-wheels CO2 Emissions Reduction for Vehicle-related Technologies
(per kilometre of driving)............................................................................................................... 12
2. Potential Well-to-wheels CO2 Emissions Reduction for Alternative Fuels
(per kilometre of driving)............................................................................................................... 12
3. Example Scenarios: Assumptions Regarding Nearer-term and
Longer-term Actions and their Effects on Light-duty Vehicles...................................................... 32
Boxes
Essential Long-term Technologies ................................................................................................24
The IEA’s World Energy Outlook 2004 ........................................................................................... 31
Beyond R&D ..................................................................................................................................36
3
ENERGY TECHNOLOGIES FOR
A SUSTAINABLE FUTURE
THE CONTEXT
Climate change is one of the major challenges of the 21st century.
Its effects will increasingly influence the economic prosperity,
environmental sustainability and energy security of both OECD and
non-OECD countries. Stabilising concentrations of greenhouse gases
in the atmosphere, the ambitious goal of the parties to the United
Nations Framework Convention on Climate Change, will at the very
least require deep cuts in carbon dioxide (CO2) emissions.
Energy is a crucial area for action. Rising emissions of CO2 from energy
supply and use are a primary cause of human-induced climate change.
Most of today’s energy demand is met by fossil fuels – coal, natural gas
and oil – the combustion of which is responsible for over 80% of world
CO2 emissions.
Cutting emissions without stifling the economic growth and
development that energy makes possible poses a steep challenge for
policymakers. Energy is integral to economic prosperity, with demand
projected to grow rapidly in developing countries and steadily in the rest
of the world. Electricity demand alone is set to nearly double by 2030
and could reach many times that level by the end of the century. The
IEA's most recent World Energy Outlook (WEO) projects in its Reference
Scenario that, absent strong policy changes, global energy use could
grow by 60% over the next 30 years, with 85% of the increase likely
to come from fossil fuels (IEA, 2004a). Resulting CO2 emissions from
energy could be 60% higher than they are today. The WEO Alternative
Scenario shows that, if policies currently being considered by OECD and
other countries were implemented, energy use in 2030 could be cut by
11% compared with this reference case, and CO2 emissions could be
cut by 17%. But both would still be rising in 2030.
These scenarios already reflect some improvements in technologies for
energy supply and use. Much deeper reductions in energy use and CO2
emissions will require more extensive and fundamental technological
changes. Aggressive uptake of existing and new technology holds
the key to meeting the world’s energy needs over the next 100 years
while capping emissions, supporting economic growth and ensuring
security of energy supply.
5
A portfolio approach
Deep cuts in CO2 emissions will only come about by transforming
the ways in which energy is supplied and used. Producing fuels and
electricity, transferring them to users, and converting them into useful
services will need to rely principally, if not completely, on efficient and
cleaner technologies.
No single technology can accomplish this transformation alone. A
clean energy system will rely on a host of new technologies – some
will be the best examples available today, some will need to be betterperforming and much less costly versions of known technologies,
and some will be new technologies based on advances stemming
from scientific discovery. The infrastructure involved – power plants,
pipelines, transport systems, fuelling stations, vehicles, buildings and
so forth – will have to be equipped to support advanced technologies.
Countries and regions will emphasise varying technologies and fuels
in their own paths to a clean energy system. Only a broad technology
portfolio will be able to meet all these needs while providing flexibility,
reducing costs and hedging against uncertainty.
Accelerating the commercial availability of these technologies will
be central to greatly reducing CO2 emissions from energy. A full
transformation of the energy system could take place over a century or
more. But much of the infrastructure governing energy supply and use
that is put into place over the next few decades could last until late in
the century (PCAST, 1999). The sooner clean, efficient and cost-effective
technologies are available, the greater the prospects for stabilising
atmospheric greenhouse concentrations at acceptable cost.
Innovation in energy technology will be integral to meeting this
objective. Support will be needed for all components of the innovation
system – research and development (R&D), demonstration, market
introduction and its feedback to development, flows of information
and knowledge, and the scientific research that could lead to new
technological advances. Industry participation will be required to ensure
the best technologies are brought to market in a timely manner.
Up to 2050, known technologies can be readied to achieve deep
cuts in CO2 emissions. Beyond then, more fundamental changes in
energy technologies will be required. Even known technologies may
require extensive changes to bring their costs within reach. Basic
research in areas as diverse as biological processes, plasma physics and
nanoscience will be part of an integrated approach to meeting climate
change objectives over a 100-year time horizon.
6
Advanced technologies for a low-emissions energy system
Three major groups of technologies could provide ways of significantly lowering greenhouse
gas emissions while retaining energy security and supporting economic growth. These include
efficient technologies for providing energy services, technologies for producing “clean” fuels
and energy carriers, and technologies providing the electricity infrastructure that advanced
technologies will need to penetrate the energy system. A fourth component, advances in basic
science cutting across several technology areas, could make possible even further contributions.
transforming energy use
Technologies for using energy efficiently can lessen the CO2 emissions-reduction burden that
energy supply technologies and fuels will have to bear, without requiring that users do without
energy services. For example:
Vehicles. Dramatic reductions in CO2 emissions from transport can be achieved by using
available and emerging energy-saving vehicle technologies coupled with propulsion systems
that rely on cleanly produced biofuels, electricity produced centrally without accompanying
emissions, and electricity from fuel cells powered by cleanly produced hydrogen.
Buildings. Energy use in residential and commercial buildings can be substantially reduced
with integrated building design – combining measures such as insulation, advanced windows,
new lighting technology and efficient equipment so as to cut both energy losses and heating
and cooling needs. Solar technology, on-site generation of heat and power, and computerised
energy management systems within and among buildings could offer further reductions in
energy use and CO2 emissions.
Industry. Making greater use of waste heat, generating electricity on-site, and putting in
place ever more efficient processes and equipment could minimise external energy demands
from industry. New process designs and direct capture of CO2 could reduce emissions arising
directly from industrial operations. Advanced process control and greater reliance on biomass
and biotechnologies for producing fuels, chemicals and plastics could further reduce energy use
and CO2 emissions.
transforming energy supply
A wide range of technologies can reduce CO2 emissions from energy supply. For example:
Renewable Energy Sources. Renewable energy sources, such as wind, waves, solar flux
and biomass, offer emissions-free production of electricity and heat. When coupled with
advanced energy storage technologies, intermittent sources can increasingly be integrated
into electricity networks.
Advanced Fossil-fuel Combustion Technologies. Advanced fossil-fuel technologies could
significantly reduce the amount of CO2 emitted by increasing the efficiency with which fuels
are converted to electricity. Such advances would cut the burden on alternative technologies,
particularly when combined with CO2 capture and storage. Options for coal include integrated
gasification combined cycle (IGCC) technology, ultra-supercritical steam cycles and pressurised
fluidised bed combustion. Longer term, fuel cells could be incorporated into natural gas and
IGCC plants for further efficiency improvements.
CO2 Capture and Storage. Carbon dioxide can be captured from large point sources (electricity
generation, manufacturing processes and fuel processing) and stored in saline aquifers or
used, through injection, to enhance recovery of oil, gas and coal-bed methane. Fossil-fuel
7
dependent pathways to a low-emissions future are strongly dependent on CO2 capture and
storage technologies, which would enable fossil fuel use to be reduced gradually as new
options become available.
Hydrogen. Use of hydrogen, an energy carrier like electricity, would enable distributed and
centralised generation of electricity and heat using fuel cells and hydrogen gas turbines.
Hydrogen can also provide flexible electricity storage and, when used in fuel cells, emissionsfree vehicle propulsion. It can be produced using technologies that result in few or no emissions
of CO2, such as natural gas reforming or coal gasification with accompanying CO2 capture and
storage, and electrolysis of water using emissions-free sources of electricity.
Advanced Nuclear Fission Technologies. Nuclear fission can provide large-scale, centralised
production of electricity with low CO2 emissions. Its use depends on public acceptance,
enhanced safety, greater resistance to proliferation of nuclear materials, progress in dealing
with radioactive wastes, and reduction in investment costs.
Nuclear Fusion. Still at the threshold between science and basic research, nuclear fusion could
contribute to large-scale, low-emissions electricity generation over a 100-year horizon.
transforming electricity networks
Advanced Electricity Networks. Advanced electricity infrastructure and storage technologies
would enable an electricity system featuring integrated, low-emissions distributed and
intermittent electricity generation to emerge. “Smart” system controls and advanced hardware
will allow management of higher and more complex loads and increasing co-mingling of
energy and communication systems. Advances in electricity storage technologies will improve
the efficiency of network operations, help with maintaining high power quality and support
the use of intermittent energy sources.
basic research
Basic Research. Basic research could transform the world’s portfolio of energy technologies
into one that can make deep cuts in CO2 emissions over the next 100 years. Scientific progress
could lead to new materials, bio-processes, nanotechnologies and sensors that could radically
reduce costs for today’s technologies, create new technologies for supplying, storing and
using energy, and reveal completely new approaches to providing energy services.
This paper, which looks at Transport, is the first in a series of IEA Technology
Briefs examining the roles various energy technologies can play in reducing
CO2 emissions. Each paper assesses the status of individual technologies,
the R&D and demonstration needed for their further development, the
contributions they could make to a sustainable energy future, and the
challenges that lie ahead.
Not all technologies will be appropriate for every country – their ultimate
applicability will depend on national resource endowments and on the
strategies chosen by individual governments. By considering the span of
technologies, these briefs equip policymakers with a view of the range
of technology options that can help fulfil economic, environmental and
energy security needs.
8
TRANSPORT TECHNOLOGIES FOR
A SUSTAINABLE FUTURE
Overview
This IEA Technology Brief describes technologies and actions that could provide
the foundation for a sustainable1 transport system in OECD countries, in
particular a system with low or near-zero emissions of carbon dioxide (CO2) and
other greenhouse gases (GHGs). Such a system would probably no longer rely on
petroleum fuel. The paper looks at technologies that can contribute in the near
term, and at how further technology developments could build on these over
the next few decades to produce a very-low-emissions transport system in the
long term – a goal that might not be reached until 2050 or later. The primary
focus is on road transport, although some consideration is also given to other
transport modes.
The analysis in this paper leads to two important conclusions:
l Many of the actions available now to reduce greenhouse gas emissions
stemming from transport will also be important steps for a much longer
transition to a low-emissions, affordable and secure transport system.
l To achieve this long-term transition, it will indeed be necessary to take certain
actions very soon.
Many technologies and strategies are available today that can significantly
reduce transport CO2 emissions and oil use over the short to medium term (one
to ten years). Three technology groups are likely to be particularly important
during this time frame:
l “Incremental” technologies to both make vehicles more technically efficient
than they are now and lessen their fuel consumption per kilometre of driving.
l Technologies to make transport systems and infrastructure more efficient,
reducing the need for vehicle travel. These can enable more efficient routing,
better in-use fuel efficiency, and switching among travel modes. (This paper
does not consider outright reductions in travel demand.)
l New, lower-carbon fuels and fuels lower in greenhouse gas emissions on a “well-
to-wheels”2 basis. In some cases, new or modified vehicles will be required that
can run on these fuels.
1. In this paper, “sustainable” signifies very low emissions of greenhouse gases and low use of oil and other
fossil fuels.
2. “Well-to-wheels” refers to the full fuel chain, from feedstock production (the “well”) to fuel use in vehicles
(“the wheels”) .
9
The combination of lower-carbon, lower-emissions fuels and better vehicle
and system efficiency holds the potential for substantial reductions in both
greenhouse gas emissions and oil consumption over the next ten years
across OECD countries.
Looking farther ahead, a logical goal is to move toward a near-zero-emissions
transport system in the long term. Such a system would likely have very low
consumption of oil and perhaps of all fossil fuels.
There are only three known fuels or “energy carriers” around which such a
transport system could plausibly be built: electricity, hydrogen and verylow-emissions biofuels. The discussion of the longer term later in this paper
highlights technologies and transition strategies that will be important for
one or more of these fuels, without picking a winner from among them.
Among the most important are:
l Electric propulsion and powertrain systems.
l Hydrogen fuel-cell propulsion systems.
l Technologies that allow for production and use of biofuels having
near-zero emissions on a well-to-wheels basis.
Although at first glance it may appear that the main near- and longterm technologies do not align very closely, there is actually a great deal
of overlap, and near-term strategies can be designed that will provide
important benefits in spurring a transition to a transport system with very
low emissions of greenhouse gases.
After briefly reviewing today’s greenhouse gas emissions from transport and
the potential reductions in emissions associated with various strategies, the
paper describes near-term and then longer-term technologies and actions
that can reduce emissions. It then compares these and identifies steps that
can help achieve both near-term and long-term goals.
Greenhouse gas emissions from transport
The IEA's most recent World Energy Outlook (WEO) projects in its Reference
Scenario that, between 2002 and 2030, transport oil use and CO2 emissions
in OECD countries will increase by nearly 50% (Figure 1), despite recent and
continuing policy initiatives intended to dampen this growth (IEA, 2004a).
World wide, the increase is projected to be more than 80%. Transport currently
accounts for 21% of world energy-related CO2 emissions; this fraction is
expected to reach 23% by 2030. Stabilising atmospheric greenhouse gas
concentrations, the goal set by the parties to the United Nations Framework
Convention on Climate Change, may eventually require deep reductions in
energy-sector CO2 emissions, including emissions from transport.
10
figure 1.
Projected Growth in Transport CO2 Emissions to 2030,
OECD and Non-OECD Regions
Source: IEA, 2004a.
Carbon dioxide emissions from today's transport systems stem predominantly
from energy conversion in the propulsion system. For aeroplanes this is the
combustion of kerosene in the (jet) engine. For rail transport it is either
stationary generation of power for electric trains and trams, or combustion
of diesel fuel in diesel locomotives. Ships, road vehicles and off-road vehicles
are propelled primarily by gasoline and diesel fuel (and for large ships, heavy
fuel oil) used in internal combustion engines. Except for electric rail transport,
the fact that the energy is consumed in a mobile device puts high demands on
the energy carrier. The energy for propulsion has to be carried on-board the
vehicle, so on both a mass basis and a volume basis, the energy density of the
energy carrier must be high. Because of their high energy density, coupled with
abundant supply, easy refuelling and very reliable engines, liquid fossil fuels
have become the dominant fuels in transport.
For a fair comparison of the emissions associated with different energy carriers,
the total well-to-wheels fuel chains must be considered. The use of fuel in vehicles
is only the last stage in this chain. The total fuel chain consists of five stages:
feedstock production (the “well”), feedstock transport, fuel production, fuel
distribution, and fuel use in vehicles (the “wheels”). In current fossil-fuel chains, the
first four stages are greenhouse gas emitters, just like the vehicle. In the crude-oilto-gasoline and -diesel chains for road vehicles, the first four stages account for
approximately 10% of the total greenhouse gas emissions from the full fuel cycle.
Emissions from the vehicle dominate, accounting for the other 90%.
The potential contributions of various vehicle technologies and fuels to CO2
emissions reduction are shown in Tables 1 and 2. Only electricity, hydrogen
and biofuels can yield a near-zero-emissions transport system, although
11
efficiency technologies can play an important role in reducing energy demand.
The net CO2 emissions produced by electricity, hydrogen and biofuels can vary
widely, depending on how the fuels are produced. The more efficient vehicles
are, and the less fuel they need, the better the chances that all of this fuel can
be provided from sources having very low emissions of CO2 .
table 1.
Potential Well-to-wheels CO2 Emissions Reduction for Vehicle-related Technologies
(per kilometre of driving)
Well-to-wheels CO2 emissions
reduction potential
Technology
Condition
Higher gasoline engine efficiency
Higher diesel engine efficiency
Hybrid vehicle
Biggest efficiency gains in urban traffic
Lightweight vehicle
> 10%
> 50%
> 90%
R
R
R
R
Q
Q
£
£
Q
Q
Q
Q
Electric vehicle
When using electricity produced from renewable or
nuclear energy or from fossil energy with
CO2 capture and storage
R
R
R
Fuel-cell vehicle
When using hydrogen produced from renewable or
nuclear energy or from fossil energy with
CO2 carbon capture and storage
R
R
R
R
Q
Q
“Intelligent” transport system
Notes: R Criterion can be met.
£ Criterion may be met. Q Criterion cannot be met.
table 2.
Potential Well-to-wheels CO2 Emissions Reduction for Alternative Fuels
(per kilometre of driving)
Well-to-wheels CO2 emissions
reduction potential
Fuel
Condition
> 50%
> 90%
Q
Q
Q
Q
Q
Q
Dimethyl ether (DME)
Produced from natural gas
£
£
£
Ethanol, methanol (current
technologies)
Produced from starchy crops (e.g., wheat, sugar
beets); significant fossil energy in fuel chain
R
Q
Q
Biodiesel (current technologies) Produced from oil-seed crops; significant fossil
energy in fuel chain
R
£
Q
Advanced biofuels – ethanol,
diesel, DME
Produced from ligno-cellulosic biomass; primarily
renewable energy in fuel chain
R
R
£
Hydrogen
Produced from fossil energy (e.g., from fossilpowered electricity or directly from natural gas)
R
£
Q
Hydrogen
Produced from renewable or nuclear energy or
from fossil energy with CO2 capture and storage
R
R
R
Electricity
Produced from renewable or nuclear energy or
from fossil energy with CO2 capture and storage
R
R
R
Liquified petroleum gas (LPG)
Natural gas
Notes: R Criterion can be met.
12
> 10%
£ Criterion may be met. Q Criterion cannot be met.
Near-term technologies and actions
Numerous technologies are available today that can improve the efficiency of vehicles
and transport systems, and help develop and refine alternative fuels, so as to significantly
lower the expected growth in CO2 emissions over the next ten years. These fall into five
categories: improvements in the rated fuel economy of new cars, reductions in vehicle
“in-use” fuel consumption, reductions in vehicle travel, increased use of alternative
fuels, and improvements in freight transport efficiency.
Improvements in new car fuel economy
Substantial near-term improvements in the fuel economy3 of new light-duty vehicles (LDVs) can
be achieved using available, cost-effective technologies. The IEA (2001) and others (e.g., NRC, 2002)
have estimated that, by 2015, new car fuel consumption can be reduced by up to 25% at low cost
by fully exploiting available technologies. In some cases these have negative costs to consumers,
because the (time-discounted) value of fuel savings is greater than the cost of the technologies.
Technologies include direct injection systems, other engine and drive-train improvements,
lightweight materials, and better aerodynamics. Although stock-turnover considerations mean
that the full effect of these improvements would not be realised until 2020-2025, they could still
reduce the average fuel use per kilometre for the entire stock of cars by 10-15% over the next
10 years in IEA countries. This is a greater improvement than has occurred in some regions over
the past 10 years (Figure 2). As shown in Figure 3, a variety of efficiency-improving technologies
are available that have not yet penetrated the new car market to any great extent (as of 2000).
Greater use of these and other technologies on an incremental basis over the coming decade
can make a significant contribution to improving vehicle fuel economy.
figure 2.
Average New Car Fuel Economy for Selected IEA Countries
Source: IEA, 2004b.
3. In this paper, fuel economy means fuel consumption per kilometre of travel. In some countries, this is expressed as
kilometres per litre or miles per gallon. “Efficiency” refers to technologies and their effects on fuel economy.
13
figure 3.
Improving Fuel Economy: Technologies and their Use in Three Countries as of 2000
(percentage of new cars equipped with each technology)
Source: Saving Oil and Reducing CO2 Emissions in Transport (IEA, 2001).
Note: each technology provides a gain relative to a less advanced technology. For example, a 4-speed automatic transmission is
more fuel efficient than the 3-speed automatic transmission that was present on most cars with automatic transmissions in 2000.
Some efficiency-improving technologies, such as hybrid-electric propulsion
systems, are still fairly expensive. Hybrid cars on the market today cost several
thousand U.S. dollars more than their conventional-engine counterparts, although
costs are falling and there is some indication that companies such as Toyota (with
global sales of over 100,000 hybrid vehicles as of 2004 and a significantly improved
Prius model recently introduced) are now at least breaking even on cost. In North
America and Japan, consumers have shown enthusiasm for hybrids, although sales
are low due to small production volumes and the availability of only a few models.
In Europe, interest appears to be lower, perhaps because there are many diesel
vehicles on the market that already fulfill the demand for high-efficiency vehicles
to some extent. Although some governments (such as Japan and the United
States) provide consumers with financial incentives to purchase hybrid vehicles
(up to US$ 2,000 in tax rebates in both countries), most do not. For these vehicles
to emerge from niche markets, they may need to gain much greater attention
and consumer acceptance as a worthy investment. Governments can play an
important role here in highlighting “green” vehicle choices and encouraging
their purchase through information and incentive programmes.
The past 15 years have seen consumers increasingly choose larger, heavier and
more powerful vehicles. Vehicle efficiency improvements in many countries
(such as the United States) have only just kept up with this trend, resulting in flat
or even slightly deteriorating average fuel economy over this period. Therefore,
even a strong uptake of efficient technologies may not significantly reduce
14
average vehicle fuel consumption per kilometre unless these trends turn around.
The European voluntary agreements and the Japanese Top Runner programme
are good examples of policies that encourage technical improvements, but
neither has an explicit mechanism to discourage consumers from migrating
to ever-larger, more powerful vehicles. Nether do the current U.S. and Canadian
fuel economy regulatory systems discourage purchase of larger vehicles except
through a modest (sales-weighted) fuel economy floor that has remained
relatively unchanged since 1985. (Note that vehicle size is less important than
weight and power in determining fuel consumption – consumers need not be
forced to purchase smaller vehicles for substantial fuel economy gains to occur.)
There are several steps governments can take to maximise the efficiency gain
from technology. For example, they can adopt more effective information
campaigns to educate consumers about the fuel-economy implications of their
choices. Because similarly-sized vehicles can have widely varying fuel economies,
an important step is developing fuel-economy labelling systems that reflect this.
A recently adopted labelling system in the Netherlands highlights differences
among similarly-sized vehicles, which may be a more effective approach than
simply pointing out that large cars, vans and “sport-utility vehicules” use more
fuel than small cars.
Another promising approach to dampen shifts to heavier, more powerful vehicles
is a system of fuel-economy-based vehicle fees or revenue-neutral fees/rebates
(“feebates”) that encourage consumers to put greater emphasis on fuel economy
in the vehicles they purchase. Denmark and the Netherlands recently adopted
such systems and these appear already to be having significant effects on
consumers' vehicle choices4.
Reductions in vehicle in-use fuel consumption
Light-duty vehicles on the roads in IEA countries typically use 20-25% more fuel
per kilometre than indicated by their tested, rated fuel economy. While much
of this gap is inevitable owing to traffic congestion and other factors, there are
several measures that can reduce it considerably. The IEA, in co-operation with
the European Conference of Ministers of Transport (ECMT), recently completed
a study of technologies and measures to improve the “in-use” or “on-the-road”
fuel economy of LDVs (ECMT/IEA, 2004). The IEA estimates that a 10% reduction
in average fuel consumption per kilometre could be achieved for LDVs across IEA
countries through a combination of the following measures: stronger inspection
and maintenance programmes that target fuel economy; on-board technologies
that improve in-use fuel economy as well as driver awareness of efficiency, such
as adaptive cruise control systems and fuel economy computers; better and more
widespread driver training programmes; and better enforcement and control of
vehicle speeds. External control of vehicle speeds, though controversial, is being
looked at closely in some countries (for instance, the United Kingdom) for its
potential safety benefits. Safety is the main driver, but speed control can also
provide significant fuel savings.
4. The Netherlands' system of tax rebates for the most efficient vehicles in each size class had a strong effect
on sales of these vehicles during 2002, but this system was suspended in 2003.
15
Cost estimates for the CO2 emissions reductions offered by in-use technologies
and measures are shown in Figure 4. Costs are given for both warm and cold
environments, since technology performance can vary significantly with the
ambient temperature. Cost estimates vary, but many technologies show low or
negative cost per tonne of avoided emissions in some situations. The effects
of technologies and measures on fuel consumption (not shown) also vary, but
as noted earlier, a package of these can be developed that provides a 5-10%
improvement in vehicle fuel economy on-the-road, even if the tested fuel
economy doesn’t change as a result.
figure 4.
Estimated CO2 Emissions Reduction Costs from In-use Efficiency
Measures in Different Regions and Driving Conditions
Source: ECMT/IEA, 2004. Note that estimates are shown for the United States and the European Union (reflecting different
average fuel economy and travel levels) and are given separately for hot and cold ambient conditions (and thus can be
applied to northern and southern countries and regions). The estimates are based on a social cost analysis that assumes a
fuel cost of US$ 0.40/litre (untaxed, but with externalities reflected). Both technology costs and fuel savings are included in net
cost estimates. “Low RR Tyres” are low rolling-resistance tyres; “Shift Ind Light” is a shift indicator light that shows the driver
the optimal point to shift gears in a manual transmission.
Reductions in vehicle travel growth
Efforts to stem the growth in vehicle travel are often related to goals other
than saving energy or reducing CO2 emissions, but they can of course also have
important benefits in these areas. Technologies and measures are available that
can reduce the demand for vehicle travel while improving the general efficiency
of the transport system. These include improvements in transit systems (see the
IEA’s book, Bus Systems for the Future: Achieving Sustainable Transport Worldwide,
2002), “intelligent transport” technologies, better routing systems, measures to
reduce congestion, information systems that can help to reduce the need for
travel, and road-pricing programmes (such as the one introduced recently in
London). Aggressive application of such measures could cut car travel (or at least,
travel growth) on a national basis by at least 10% over a ten-year period (IEA,
2001).
16
Efforts to reduce vehicle travels are normally undertaken at the local or
regional government level, but national governments can put in place incentive
programmes to encourage adoption of strong approaches. Although it is
often the transport ministry that spearheads a country’s efficiency policies,
greater consideration of the effects of transport policies on energy use can be
championed by energy agencies.
Increased use of alternative fuels
A number of obstacles have prevented non-petroleum fuels from playing a larger
role in the transport sector in IEA countries. These include a lack of fuelling
infrastructure; high vehicle or fuel costs; poor consumer acceptance of other
vehicle attributes, such as range and refuelling time; and generally risk-averse
behaviour on the part of consumers. But change is possible – for example, the IEA
estimates that a 5% displacement of transport motor fuels across OECD countries
could be achieved by 2010 with stronger national programmes, particularly those
targeting liquid biofuels (IEA, 2004c). Biofuels have the advantage (compared
with gaseous fuels or electricity) that they can be blended with petroleum fuels,
avoiding the need for changes to the vehicle stock or major investments in
fuelling infrastructure.
The ethanol and biodiesel produced in IEA countries today are much more
expensive than conventional fuels. It may be less cost-effective to displace oil
with these fuels than to reduce oil use by other means (such as by improving fuel
economy). But biofuels offer an opportunity for rapid reductions in oil dependence
that could be of high value to IEA countries. As discussed in the IEA’s recent book,
Biofuels for Transport: An International Perspective (2004), with further research
and development (R&D) and expanded production, costs, especially for advanced,
very-low-emissions biofuels technologies, will very likely come down. Furthermore,
low-cost ethanol is already being produced in large quantities by Brazil using
sugar cane as a feedstock. As of mid-2004, Brazilian ethanol prices were below
those of Brazilian gasoline, even when adjusted for energy content and excluding
taxes (Figure 5). Other developing countries are ramping up production capacity
for the same (sugarcane-to-ethanol) fuel chain. If they can achieve similarly low
costs, which appears likely, the opportunities for global trade in inexpensive, lowCO2-emissions biofuels should expand rapidly. The cost of the rapid reductions in
oil use offered by these fuels would fall accordingly.
Gaseous fuels (such as compressed natural gas and liquefied petroleum gas) can
also play an important near-term role, although all of these fuels require new,
relatively expensive vehicles and new fuelling infrastructure. A major issue has
proven to be attracting consumers to new types of vehicles that have certain
drawbacks, such as limited retail fuel availability and few choices (in terms
of models). This type of problem may continue to be a major challenge, but
countries have had some success with highly targeted efforts to both develop
fuelling infrastructure and offer multiple vehicle choices in specific areas (e.g.,
the U.S. “Clean Cities” programme). But real success, in terms of developing and
sustaining large markets and displacing a significant amount of oil, will probably
require even larger efforts, with a long-term commitment on the part of national
and local governments – and it is still unclear whether the obstacles these fuels
face can ever be fully overcome.
17
figure 5.
Gasoline and Ethanol Prices in Brazil, 2000-2004
Source: Laydner, 2003, as cited in IEA, 2004c. Hydrous alcohol is not taxed in Brazil. Gasoline prices are shown with and without
Brazilian taxes. Prices shown for ethanol are per gasoline-equivalent litre, accounting for the differences in energy density between
ethanol and gasoline.
Improvements in freight transport efficiency
A variety of technologies and policies could improve freight transport efficiency.
These include improvements in vehicle efficiency, improvements in the systemwide efficiency of freight transport, and shifts of freight movement from trucks
to much more efficient modes such as rail and water-borne. The IEA estimates
that, for most countries, adoption of an aggressive freight transport efficiency
programme could yield a 10% reduction in the fuel used for freight movement
over the next ten years (IEA, 2001).
The efficiency of new trucks has improved steadily over time. Nevertheless, several
recent studies indicate that trucking companies have not implemented many of
the technical measures that could increase efficiency. Measures that encourage
maximum uptake and use of efficient technology could reduce average fuel
consumption per tonne-kilometre for new trucks by up to 5% by 2010 (beyond
what is expected to occur autonomously), which translate to a 3% reduction for
all trucks. Measures to promote more efficient driving habits, such as providing
technical assistance to trucking companies in monitoring the fuel use of their
trucks (as undertaken in the Netherlands and the United Kingdom) and in cutting
truck idling, could produce a similar, 2-3% reduction in fuel consumption per
tonne-kilometre by 2010 (IEA, 2001).
Technologies that improve transport system efficiency, such as better logistics
systems to combine shipments and make sure trucks use the most efficient
routes, could also have a large effect on fuel use. When used along with more
aggressive development of inter-modal facilities, these types of measures could
cut energy use for freight transport by 5-7% in urban settings and 2-3% for
18
a country as a whole. Finally, more aggressive measures to promote rail and
shipping, including pricing and infrastructure development, at a level that yields
a 5% shift away from truck-based freight movement, would yield (once again) at
least a 2-3% reduction in energy use for freight transport (IEA, 2001).
Overall, the freight efficiency measures outlined here could, together, save on
the order of 10% of the energy used for freight transport in most IEA countries.
Development of a new, aggressive package of measures would require a strong
push – such a package would require a combination of pricing, infrastructure
development, and technical assistance to companies that might not be simple
to construct. However, most countries have programmes in place that could be
expanded, with perhaps a stronger focus on energy savings to increase their
effectiveness. Many of these measures could be carried out at relatively low cost,
taking into account both the fuel savings and the improvements in operating
efficiency of freight systems that such measures would provide.
In sum, reductions in energy use and CO2 emissions on the order of 25-30%
across freight transport modes appear attainable over the next 15 to 20 years,
if aggressive actions are taken to promote maximum uptake of existing, often
fairly low-cost, technologies.
Technologies and actions for the long term:
toward a sustainable transport system
This section turns to a longer-term perspective, exploring what would be required
to achieve a sustainable, near-zero-GHG-emissions transport system that also
improves energy security and supports economic growth.
As was mentioned in the introduction, there are only three basic approaches to
achieving a transport system with very low emissions of greenhouse gases and
low reliance on fossil fuels: converting to a hydrogen fuel-cell system, moving to
a purely electric vehicle system, or relying on liquid fuels that are derived from
biomass, with advanced technologies to ensure that the biofuels are produced
with very low well-to-wheels GHG emissions.
A transition to a near-zero-emissions transportation system will likely take four
decades or more. Widespread use of purely electric vehicles or of fuel-cell vehicles
will require technological improvements and dramatic cost reductions, plus
market development and growth, all of which will take time. Over an assumed
fifty-year time horizon for a complete transition, the entire vehicle stock in IEA
countries will be replaced at least two to three times. Because cumulative CO2
emmissions play an important role in climate change, it will be important for the
new vehicles brought into use during the transition period to take advantage of
the many features available today that can help reduce emissions.
There are numerous technologies, and types of technologies, that are candidates
or logical components for inclusion in a low-emissions transport system. Some of
19
these, such as fuel cells, will take many years to develop and put into use. Others,
such as technologies to improve the efficiency of new cars, are available today.
The basic building blocks are laid out below, with some discussion of whether
they are likely to be near-term or longer-term components of a sustainable
transport system.
Electric vehicles and sources of electricity
Although some electric vehicles are being built today, the main focus in recent years
has shifted to hybrid-electric vehicles running on gasoline. But electric vehicles
are by no means “dead” and may play an important role in the future. Today’s
electric vehicles still suffer from important drawbacks, including limitations in
energy storage volume and density (and thus driving range and power), high cost,
and low component durability. Hybrid vehicles overcome most of these problems
and may eventually pave the way for purely electric vehicles, with “pluggable”
hybrids (which can be recharged using external sources of electricity) a possible
intermediate step. Many trains are already electric, but for trains electricity is
provided directly from a grid, so energy storage is not a concern.
A major area of concern for purely electric vehicles is energy storage. Battery
systems still fall far short of the power and energy density that would be
required for electric vehicles to have the same performance and range as today’s
conventional (and hybrid) vehicles. Batteries continue to improve, however. For
example, the recent generation of nickel-metal-hydride and lithium-ion batteries
is significantly improved over batteries available just a few years ago. Other energy
storage devices, such as ultra-capacitors and flywheels, are also undergoing
further R&D. If any of these technologies experiences large improvements over
the next 10 to 20 years, electric vehicles may re-emerge as the preferred longterm solution for achieving a sustainable transport system.
Fuel supply and upstream GHG emissions are also a concern for electric vehicles.
For any vehicle reliant on the electricity grid for its fuel, the extent to which
it provides well-to-wheels emissions reductions will depend primarily on the
upstream emissions from the electricity supply system. Electric vehicles running
on electricity produced from coal, for example, will not provide significant
emissions reductions compared with gasoline vehicles unless CO2 capture and
storage are also used. To meet both expected stationary electricity demand and
the demand arising from vehicles in a world where electric vehicles dominate,
it will be necessary to develop substantial amounts of new, low-emissions
generating capacity. It would likely require as much or more new capacity to
provide electricity for EVs as it would to provide hydrogen for fuel-cell vehicles, if
all of the hydrogen were produced using electrolysis.
Hydrogen and fuel cells
Many analysts now believe that hydrogen fuel-cell vehicles are the most
likely long-term, low-CO2-emissions transport outcome. If transport systems
eventually come to be dominated by fuel-cell vehicles, it increasingly appears that
these vehicles will rely on on-board hydrogen storage and off-board hydrogen
20
production, due to the relative simplicity, better end-use efficiency, lower
emissions, and lower cost of this approach compared with on-board reforming of
hydrogen from another fuel5. On-board storage of hydrogen means that vehicles
would have virtually zero tail-pipe emissions of any pollutants or greenhouse
gases (only water would be emitted). Producing hydrogen on board by reforming
other fuels – such as gasoline or methanol – results in some pollutant emissions
from the vehicle and adds considerable complexity. Whether on-board reforming
is used or not, some CO2 (or perhaps a lot) could still be emitted during fuel
production and distribution.
As with electricity, a principal question for hydrogen is how and where it will be
produced, what energy sources will be used to produce it, and what upstream
emissions will occur from its production. To have a truly near-zero-emissions
transport system based on fuel cells, it will be necessary to have a near-zeroemissions system of producing and transporting hydrogen. There are many ways
to do this, such as by electrolysing water at fuelling stations, using electricity
generated renewably or by nuclear power or by fossil fuels with accompanying
CO2 capture and storage. But whether enough near-zero emissions hydrogen can
be produced to meet transport demand, and whether this should take precedence
over other uses (for the hydrogen or the electricity used to produce it), is an open
question. If, in 2050 and beyond, all road vehicles in IEA countries ran on hydrogen
fuel, the amount of hydrogen required could be quite large. Even assuming that
fuel-cell vehicles in 2050 were 50% more efficient than conventional vehicles are
today, the IEA estimates that it could require 40 exajoules of hydrogen per year
to power these vehicles. If derived from electricity, this would require over two
terawatts of power, or more than 2,000 power plants, each with a capacity of one
gigawatt.
Biofuels
In the section on near-term technologies and actions, the potential for
securing near-term reductions in CO2 emissions using biofuels was discussed.
Ethanol and biodiesel, as typically produced today in IEA countries, can reduce
CO2 emissions per litre of fuel by 20% to 50% compared with gasoline and
diesel fuel, respectively, on a “well-to-wheels” basis6, but they are not nearzero-emissions fuels. Technologies now under development will help produce
advanced biofuels with near-zero net CO2 emissions. These include technologies
for producing ethanol using enzymatic hydrolysis of cellulosic feedstock (see
box, “Essential Long-Term Technologies”) and technologies for producing
various liquid fuels, such as synthetic diesel fuel, using biomass gasification or
pyrolysis. Hydrogen can also be produced through biomass gasification, with the
possibility of sequestering the resulting CO2 – in essence extracting CO2 from
the atmosphere and storing it in geological formations. But these methods of
5. See, for example, NRC, 2004, The Hydrogen Economy: Opportunities, Costs, Barriers and Needs, for a
discussion of on-board versus off-board production of hydrogen and of many other hydrogen and fuel cell
issues.
6. Well-to-wheels estimates take into account all vehicle and upstream emissions of CO2 and other greenhouse
gases. In the case of biofuels, this assessment includes CO2 absorbed by plants during their growth and
emissions arising from the energy used in crop and biofuels production.
21
production are not yet commercial and may require considerable additional R&D,
demonstration, and cost reduction through experience and learning, before they
reach a commercial state. Even before they reach the market, however, they
may provide GHG emissions reductions at a lower cost per tonne than today’s
approaches, since they provide much larger reductions per unit of fuel produced.
Thus the development of a biofuels infrastructure today will set the stage for
use of increasingly “green”, low-emissions biofuels tomorrow. Apart from fuel
production facilities, the infrastructure investment required to support use of
advanced liquid biofuels may be relatively small, since these fuels can be blended
with conventional fuels and transported using today’s fuel systems. In the future,
synthetic diesel fuel should be “blendable” anywhere from 0% to 100% with
petroleum diesel fuel and used in conventional diesel vehicles. Cellulosic ethanol,
like all fuel ethanol, will be compatible with today’s gasoline vehicles at blends
up to at least 10%, and up to much higher levels with relatively minor changes
to engines and fuel systems. But there are important hurdles that must be
overcome, such as convincing manufacturers to warrant their vehicles for higher
blend levels and to produce truly flexible-fuel vehicles that can run on blended
fuels, if use of biofuels is to increase substantially. Efforts to surmont these
hurdles have begun in some countries, such as Brazil and the United States.
Once advanced biofuels are being produced on a commercial scale, the benefits
of learning-by-doing and scale economies can begin to be realised. Although
certain countries have produced ethanol from grain crops (such as wheat and
corn, or maize) for dozens of years, and have achieved some reductions in
production costs, far more cost-reduction potential exists with new technologies.
Commercial use of such technologies as enzymatic hydrolysis to convert cellulose
to sugar, biomass gasification, and Fischer-Tropsch conversion of synthesis gas to
transport fuels will likely drive costs down substantially over the first few decades
of production. So although most of the benefits of R&D, scale economies and
learning-by-doing have already been realised for conventional biofuels, this process
is only just beginning for advanced biofuels. The process of commercialising
certain biofuels technologies will take time and may require a fairly long period
of pre-commercialisation experience. But moving from laboratories to largerscale testing must begin in earnest very soon. This appears to be happening
– construction of the first large-scale cellulosic ethanol conversion plant is
expected to occur (in North America) by 20067.
The IEA’s estimates of the current and projected cost per tonne of avoided CO2equivalent emissions reduction for different biofuels, technologies and regions
are shown in Figure 6. If costs for advanced technologies come down through
R&D, scale economies and learning-by-doing, as appears to be quite possible, the
cost per tonne of avoided emissions could drop below US$100 after 2010 (based
on an oil price of US$30 per barrel).
7. As indicated in announcements by Logen Corporation –e.g., in EV World, April 2004: http://www.evworld.com/
view.cfm?section=article&storyid=735.
22
figure 6.
Biofuels: Cost per Tonne of CO2-equivalent Emissions Reduction,
Current and Projected
Source: IEA, 2004c.
Even if very-low-CO2-emissions biofuels become commercially viable, however, a key
question will remain: how much of these fuels can be produced, given land availability
and other constraints? Today, producing biodiesel from oil-seed crops requires up
to five times as much land per unit of usable energy as producing ethanol. For a
high-volume approach, ethanol appears to be a better choice (at least to the extent
that the same land can be used to produce either fuel). In the future, producing both
cellulosic ethanol and other liquid fuels through biomass gasification will be able to
achieve much higher yields of useable energy per hectare of land.
The IEA’s book, Biofuels for Transport: An International Perspective (IEA, 2004c),
reviews several studies of the global potential for biofuels production. These
studies give a wide range of estimates, but all indicate that it may eventually be
possible for biofuels to provide a high share of transport fuel, with 50% to 100%
well within the range of several studies. Such estimates depend on assumptions
covering many factors, including population growth, food demand, demand for
alternative uses of biomass, and demand for transport fuel.
The higher the future fuel demand, the harder it will be for biofuels (or any energy
source) to fully meet this demand. Given the WEO 2004's projection of transport
fuel demand (IEA, 2004a), and the range of biofuels production potentials
estimated in the reviewed studies, it seems reasonable to conclude that at least
20% of future transport fuel demand, and possibly much more, could be met
by biofuels in the 2050 time frame. Whether this can be done cost effectively
is another matter. Other concerns include the effects of intensive biofuels
production on ecosystems and the possible effects of developing genetically
modified organisms. The latter might be important for improving productivity
and lowering costs, but is controversial.
23
Essential long-term technologies
Electric and Hybrid Vehicle Systems: Hybrid vehicles are nearly commercial, but substantial
cost reductions are still needed for these vehicles to eventually become “standard
equipment” on new light-duty and heavy-duty road vehicles. Improvements that allow
systems to provide greater power while preserving the fuel efficiency benefit are also
needed. Purely electric vehicles and “pluggable” hybrid electric vehicles (which can be
recharged using external sources of electricity) are unlikely to become commercial without
improvements in batteries (below).
Fuel Cell Systems: Although much R&D and testing of fuel-cell propulsion systems for
vehicles is underway world wide, these systems are still in the early stages of development.
Needed advances include greater power density, less costly and lighter materials, and
streamlined system designs, the ability to mass-produce propulsion systems, and
improvements in system reliability and in ability to handle real-world driving conditions.
Electricity Storage Technologies: The energy density of batteries remains relatively low.
Better batteries with higher energy storage density at lower cost will be important to
hybrid vehicles, electric vehicles, and probably fuel-cell vehicles as well. (The latter are likely
to include regenerative breaking and even full hybrid systems for maximum efficiency.)
Fundamental research is focusing increasingly on alternatives to batteries, such as ultracapacitors and flywheels. A major breakthrough in one of these areas will provide an
important boost to virtually all “next-generation” vehicle technologies.
Hydrogen Storage Technologies: As mentioned above for batteries, a major shortcoming of
advanced vehicle technologies, compared with today’s conventional vehicles, is the need
for energy storage on board the vehicle. For hydrogen and electric vehicles, the required
storage volume may be twice the size of that used in today's gasoline-powered vehicles, for
a similar driving range. New hydrogen storage systems, involving much higher pressures or
dissolution in a ceramic matrix, are being researched with the hope that, eventually, much
higher storage densities can be achieved.
Hydrogen Production and Distribution Technologies: A key consideration “upstream” of
hydrogen-powered vehicles will be where this hydrogen comes from and how it is delivered
to vehicles. There are many possibilities, ranging from reforming hydrogen on-board vehicles
to producing it at fuelling stations (from natural gas or electricity) to producing it at central
stations and shipping it to fuelling stations using trucks or pipelines. All options have
strengths and weaknesses and need to be tested and compared, although some approaches,
such as reforming hydrogen from natural gas without accompanying CO2 capture and
storage, clearly will not result in near-zero upstream emissions. Even for zero-emissions
options (such as electrolysis using renewably-generated electricity), it is unclear whether
a zero-emissions approach to producing hydrogen for transport makes sense when there
is still the opportunity to replace non-zero-emissions generation of electricity for other
purposes. Integrated system studies of transitions to zero-emission electricity systems are
needed to address this question.
Cellulosic Ethanol Production Technologies: Today, most ethanol in IEA countries is produced
from starch or sugar crops. Much greater overall efficiency, and lower greenhouse gas
emissions, could be achieved if the cellulosic parts of plants (or plants composed mainly of
cellulose) could be converted to alcohol. A variety of approaches are being researched to do this,
and to increase the net efficiency and lower the costs of known processes. Approaches include
acid hydrolysis and enzymatic hydrolysis. The concept of “bio-refineries” is being developed,
whereby industrial plants are designed to make use of all parts of a plant (sugar, starch, and
cellulose), and co-products are used to the maximum extent possible. Resulting products
can include fuels, chemicals, plastics and electricity. This approach could reduce net costs for
ethanol production substantially. It could even reduce net CO2 emissions to below zero, if, for
example, co-generated electricity displaced high-emissions electricity from other sources.
24
In the nearer term, through 2020, the most cost-effective liquid biofuel world wide
is likely to be ethanol produced from sugar cane, with production taking place in
warm climates, particularly in developing countries where costs of production are
low. For example, ethanol produced from sugar cane in Brazil is cost-competitive
with gasoline in that country (excluding taxes and taking into account differences
in energy content per unit volume). One of the studies reviewed in IEA, 2004c,
estimates that, by 2020, 10% of the world’s gasoline consumption could be
displaced cost-effectively by ethanol produced from sugar cane (and molasses).
The countries and regions with abundant sugar cane do not typically have very
high levels of gasoline demand, however, so reaching 10% globally would likely
require a large-scale international trade in ethanol, which does not yet exist.
Vehicle efficiency
Just as for short and medium-term reductions in CO2 emissions, a key element of
the ultimate goal – a sustainable, very-low-emissions transport system – will be
the efficiency of vehicles.
If hydrogen or electricity-powered vehicles become the norm, average vehicle
energy consumption per kilometre of travel will likely be half of what it is today,
or even lower. Even without fuel cells, it appears feasible to reach a 30-50%
reduction in average energy consumption per kilometre with hybrid-electric
engines and other advanced technologies. Not only will this be feasible, but it
will also be necessary in order to optimise vehicle design and lessen production
costs. For both electric and fuel-cell vehicles, the smaller the power system and
the energy storage requirements, the less expensive vehicles will be to produce
(since batteries and fuel-cell system components are expensive, and are sized
based on vehicle energy requirements). In addition, with lower energy demand,
vehicles will be able to travel farther per fuelling, and their fuel costs per kilometre
will be much lower. All of these improvements will be central to the success of
advanced vehicles.
Some efficiency measures can be taken in incremental steps over the next decade,
with existing vehicles (including hybrid-electric vehicles). These will also provide
benefits for “next generation” vehicles. They include:
l Improved drive-train efficiency and the introduction of more electric-drive-
train components, such as “drive-by-wire” (fully electric) steering.
l Hybrid-electric propulsion systems (with many components, such as motors
and controllers, also likely to be used in fuel-cell vehicles).
l Regenerative braking.
l Lightweight materials (including very advanced materials such as composites
and carbon-fibre-based materials).
l More efficient accessory equipment (such as air conditioners).
l Low-rolling-resistance tyres.
All of these technologies will likely be needed for future electric or fuel-cell
vehicles; all are available, to some extent, today. Therefore, there really is no need
to wait until advanced propulsion systems are commercial to begin building other
25
efficient components into new vehicles. In fact, waiting for fuel cells to solve the
transport emissions problem would be unwise because of the remaining time
required for technological improvements and dramatic cost reductions to occur
and the relatively rapid turnover of vehicle stocks. As was mentioned earlier,
over the next 50 years, the entire vehicle stock in IEA countries will be replaced
two to three times, offering numerous opportunities to reduce transport sector
emissions by bringing efficient, low-emissions technology into play. Above all,
whether vehicles are powered by hydrogen, electricity or liquid fuels (or some
combination) in 2050, if their demand for fuel can be cut by half or more, the job
of achieving a near-zero-emissions system will be that much easier.
Intelligent infrastructure
Views of future vehicles and transport systems often feature “intelligent”
infrastructure. There are many longer-term technologies under development
for use in such systems, but there is no need to wait for these – several types of
“intelligent” infrastructure are already in use or could be put into place over the
next decade. These include global positioning systems (GPSs) in vehicles, roadside
traffic information systems, and systems offering real-time schedule information
for public transit systems. Advances in technologies such as these will improve
vehicle driving efficiency in the same way as the automation and computerisation
of engines has improved engine efficiency. But much more is possible. Some areas
where both near-term and long-term objectives can be met include:
l Intelligent infrastructure for vehicles and systems. Intelligent infrastructure
technologies can play an important role, not just for vehicles, but also for the
manner in which transport systems are built and operated. Transport systems
could eventually rely on external controls strong enough to take over the driving
function (for example, on highways). In theory, this would improve both traffic
flow and safety. At a much more basic level, the introduction into vehicles of
real-time displays of traffic information and maps is already helping drivers avoid
congested areas within cities, thus helping to reduce congestion itself. This not
only improves travel times but also reduces fuel consumption. Such systems
can also be linked with congestion charging to provide real-time pricing that
discourages less valuable trips, making way for more valuable ones (as reflected in
willingness to pay the charge). Simple congestion charging is beginning to catch
on in Singapore, London and some other cities. Looking ahead, more advanced
systems will allow a more seamless approach to be taken over wider areas, with
better information provided to drivers.
l Technologies for public transit systems. Many new technologies are under
development that could lead to much improved public transit services and
therefore more demand for them. For example, the use of GPSs to track buses
allows bus operators to dispatch buses more efficiently and has led to the
introduction of real-time information displays at bus stops that indicate the
arrival time of the next bus. Similar displays can be used within buses to indicate
upcoming stops. Another intelligent system being introduced in many cities is
traffic signal priority for buses, which increases the probability that a bus will
have a green light when it arrives at an intersection, speeding trips.
26
These improvements are part of a broad array of transit system enhancements
that, collectively, have come to be called "bus rapid transit". These systems feature
dedicated bus lanes, pre-payment of fares, rapid passenger boarding and alighting,
and high-capacity, comfortable buses. Such systems are relatively inexpensive and
are being put into place even in some poorer developing countries. If such systems
were adopted widely, growth in demand for personal vehicle transport could be
slowed dramatically. In addition, the growth in revenues flowing from much
higher use of public transit systems would make it easier for transit companies to
pay for advanced bus technologies, such as hybrid buses and, eventually, fuel- cell
systems. But getting these advanced transit systems into place around the world
is proving to be very challenging. This topic is discussed in detail in IEA’s book, Bus
Systems for the Future: Achieving Sustainable transport Worlwide (2002).
l Telematics for movement of goods. Intelligent infrastructure technologies can be
used to make the movement of goods much more efficient than it is today. One
area of improvement is in the manner in which trucks are dispatched and routed
around cities when making deliveries. Many trucking systems have begun using
telematics (computerised tracking systems) to ensure that the shortest route is
taken and to select the best-located vehicles to handle a new delivery or pickup
en-route. Having individual trucking companies handle more types of goods could
also increase the efficiency of truck deliveries and pickups; this could be facilitated
with telematics. Finally, greater ability to track goods would help multimodal
distribution centres, where goods are stored and transferred from some modes
(such as trains) to others (such as trucks), provide "just-in-time" service. While some
of these improvements are being adopted by businesses around IEA countries,
more could be done to encourage widespread use of telematics for freight.
Transition steps to a sustainable transport sytem
Only one large transition has thus far taken place in energy supply for the
transport sector. It is the transition from muscle power to petroleum fuel
(except for trains, which used coal for about 100 years before switching to
petroleum and electricity). Some minor transitions – to natural gas or LPG, for
example – have taken place locally, but on a world-wide scale they have been
negligible. From this perspective, getting to a transport future characterised by
a completely different fuel or fuels will not be easy. There are quite a number of
challenges. Major ones include:
l Introduction of efficient vehicles capable of running on very-low-CO2-emissions
fuel, with high efficiency, at a cost acceptable to consumers and governments
and with acceptable performance.
l Introduction of very-low-emissions fuels and provision of such fuels in sufficient
quantity to meet the energy demands of the associated vehicles as the stock of
such vehicles grows over time.
l Provision of necessary infrastructure to produce and store the appropriate
fuels and to transport these fuels to the point of fuelling.
27
All three of these challenges must be met more-or-less simultaneously, in a market
situation where there are large market risks for all stakeholders (the “chicken-andegg” problem – see the section, “Putting It All Together”).
Potential steps and timing for the emergence of a sustainable, near-zero-GHGemissions transport system are outlined in Figure 7. As it indicates, developing the
necessary infrastructure for future vehicle and fuel systems, and completing a full
transition to these new systems, could require a half-century or more. But it cannot
begin in earnest until a pathway becomes clear and many questions are answered.
Thus it is essential that R&D, as well as demonstration programmes, be pursued
intensely in the near term so as to position countries to begin the long trek toward
a sustainable transport system.
The dates shown in the chart are indicative, but certain time requirements are
fairly fixed. There will most likely be at least 10 years, and perhaps 20, between
the first commercial appearance of a fuel-cell or electric vehicle and the date by
which nearly all new vehicles are of this type. Given the tremendous investment
required for new production capacity, the six-to-eight year product life cycle (the
time between the introduction of a new model and its eventual replacement), and
the inertia that must be overcome to change systems and infrastructure, even 20
years may be optimistic for such a transition. Moreover, once all new vehicles are of
the new technology type, it will take an additional 15 to 20 years before all vehicles
on the road are of this type, as the existing stock of vehicles turns over. Given the
amount of work that may be necessary before a serious transition can begin, this
process may require many decades.
For commercial sales of fuel-cell or electric vehicles to begin in earnest by (or possibly
before) 2030, a host of technologies will need intensive R&D and demonstration
over the next 20 to 30 years. The more of them that can be incorporated into
new vehicles over the next 10 to 15 years, the sooner that experience with these
technologies can be gained, and costs reduced, and the easier the overall transition
will be. Progress will be important in such areas as electrification of vehicle drive
trains, hybridisation, improved batteries (or other forms of energy storage on
hybrid vehicles), and increased blending of liquid biofuels with petroleum fuels in
today’s vehicles.
Certain advances will, however, most likely require at least another 10 to 20 years
before they can be incorporated into commercial vehicles. Apart from development
of fuel-cell systems, the most important areas for work include planning and
development of a distribution and fuelling system for hydrogen and/or electricity
(including development of adequate zero-emissions sources of each), development
of far better and cheaper on-board energy storage systems (for hydrogen as well
as electricity), advances in technologies (such as lightweight materials) that can
make conventional and future vehicles much more efficient, and improvements and
cost reductions in production processes for cellulosic ethanol and other advanced
biofuels. Research and development needs over the next 30 years are outlined later
in the paper, after a review of some potential transition scenarios.
28
figure 7.
Steps and Sequence for a Transition to a Near-zero-emissions
Transport System Over the Long Term
A lowemissions
transport
system…
Virtually all transport modes (except possibly air travel) are dominated by hydrogen-fuel-cell or
electric vehicles, or possibly conventional internal-combustion-engine (ICE) vehicles fuelled with
near-zero-GHG-emissions biofuels.
Abundant supply of near-zero-emissions electricity and hydrogen, from renewable or nuclear sources
or from fossil-fuel sources with accompanying CO2 capture and storage. Widespread commercial
availability of biomass to produce low-cost, very- low-GHG-emissions liquid biofuels or hydrogen.
Vehicles use one-half to two-thirds less energy per kilometre than current vehicles. Widespread
adoption of hybrid-electric drive systems, lightweight materials and better aerodynamics.
...and how to get there...
Commercialisation or near-commercialisation of at least one of the three key technology groups:
fuel-cell and/or electric vehicles, advanced efficiency technologies (such as hybrid vehicles), and
advanced biofuels.
Phase I
2000-2030 ?
Substantial improvements in the efficiency of conventional vehicles using available, in some
cases low-cost, incremental technologies. A reduction of one-third to one-half in energy use per
kilometre should be possible with hybridisation.
Initial development of a hydrogen or electric fuelling structure, at least in several "model cities"
across IEA countries.
Increased use of conventional and introduction of advanced biofuels. Initially low-level blends
with petroleum fuels; higher blends as production capacity grows. Sufficient experience and
scale economies are gained to significantly lower costs by 2030.
The “mass market” of consumers comes to accept the new propulsion technologies and demand for
vehicles with them grows rapidly. The combined market share of these vehicles also rises rapidly.
Phase II
2030-2050 ?
Major investments are made in production facilities for vehicles and fuels and in fuel distribution
infrastructure. Large-scale production leads to further learning, scale economies and cost
reductions. Upstream changes are made to gradually bring the fuel supply chain toward a zeroemissions state.
Vehicle efficiency continues to improve with use of the new propulsion systems, with a target
of reducing energy use per kilometre by 33% beyond that achieved in Phase I. Efficiency reaches
one-third that of today’s vehicles by mid-century.
The benefits of long-term transport planning and "intelligent" transport systems begin to
manifest themselves in substantial reductions in vehicle travel, at least compared with a
reference case level.
Nearly all new vehicles use the final type(s) of propulsion system – electric, fuel-cell, or advanced
hybrid ICE/electric.
The total, in-use stock of vehicles becomes dominated by near-zero-emissions vehicles, with a
20 to 30 year time lag after most new vehicles are of this type.
Final Phase
Post-2050 ?
The benefits of 50 years of efforts to introduce technologies and policies to reduce vehicle travel
demand are fully reflected in practices of the day: information technologies substitute for travel,
more efficient travel modes are increasingly used, land use practices are vastly more travelefficient, and so on.
A fairly complete system of fuel distribution for hydrogen and/or electricity to retail outlets is in
place in most IEA countries. Fuel supplied has near-zero GHG emissions on a well-to-wheels basis.
29
Scenarios of potential CO2 emissions reductions
using near-term and longer-term actions
The IEA’s energy scenarios are reported in its World Energy Outlook 2004
(WEO; see box). These project energy use and related factors out to 2030 for a
Reference Scenario and an Alternative Policy Scenario.
This paper presents two scenarios for transport (and in particular, for lightduty vehicles) that build on the WEO. Because they are intended to show how
very aggressive actions in both the near term and the long term are important
to achieving a sustainable transport future, these scenarios incorporate
measures beyond those included in the WEO. The projections look at the
potential for using new technologies and incorporate a "what-if" analysis of
the changes in CO2 emissions and oil use that could result if such technologies
as hybrid and fuel-cell vehicles were adopted fairly rapidly around the world.
The assessment below compares one scenario containing only longer-term
actions with another scenario that incorporates both near- and longer-term
actions. The assumptions used to generate these two scenarios are shown in
Table 3.
The table shows assumptions for trends, over the next 30 years (continuing
to some extent out to 2050), in four factors affecting vehicle energy use
and emissions. The first trend is improving fuel economy, which reflects
both technical improvements and changes in the vehicle sales mix (e.g., as a
result of policies discouraging purchase of larger, heavier and more-powerful
vehicles). The others are increasing sales of hybrid-electric vehicles; increasing
blending of biofuels in gasoline and diesel fuel; and slowing growth in lightduty vehicle travel.
In addition to these nearer-term, incremental actions, one longer-term action
is characterised: fuel-cell vehicles are introduced around 2020 and grow in
sales until they account for virtually all new light-duty vehicle sales in 2050
(and therefore displace all other types of light-duty vehicles, including hybrid
vehicles, which show zero sales in 2050). For the fuel-cell vehicles, it is assumed
that hydrogen (shown in the table) is produced initially using feedstocks and
processes that result in fairly high levels of GHG emissions, but that by 2050
it is produced with net, well-to-wheels emissions 75% below those associated
with gasoline vehicles. (This could occur, for example, if most hydrogen were
produced from renewable energy sources but some were still produced from
natural gas.)
A spreadsheet model developed by the IEA, "Energy Technology Perspectives",
was used to convert the assumptions in Table 3 into three projections: a
reference case (with no measures included, and calibrated to the WEO); a case
with only the longer-term actions (market penetration of fuel-cell vehicles and
30
The IEA’s World Energy Outlook 2004
The World Energy Outlook 2004 (WEO) contains IEA’s projections for future energy use and
related trends out to 2030. It reports both a Reference Scenario and an Alternative Policy
Scenario. The projections presented in this paper should be understood in the context of
these two IEA scenarios.
The WEO Reference Scenario makes projections based on current trends. It includes new
policies and their potential effects only if the policies were adopted by mid-2004. It does
not include any policy initiatives that might be adopted in the future. It assumes gradual
technology evolution, not rapid changes in direction that would most likely require strong
policy interventions to achieve.
The WEO Alternative Policy Scenario analyses how the global energy market could evolve
were countries around the world to adopt a set of policies and measures that they are
currently considering or might reasonably be expected to implement over the projection
period. The purpose of this scenario is to provide insights into how effective these policies
might be in addressing environmental and energy security concerns, and the implications
for energy supply, trade and investment.
The Alternative Policy Scenario includes measures such as continued application of
policies to improve fuel economy in OECD regions, increased adoption of biofuels in most
regions, and investments in transit systems in developing countries. The scenario results
in a significant reduction in oil use and CO2 emissions from transport, world wide, by 2030
– both are about 11% lower in 2030 than in the Reference Scenario.
accompanying hydrogen production); and a third case that adds to this all of
the nearer-term measures shown in Table 3. For the long-term and combined
long- and near-term cases, world emissions of greenhouse gases from lightduty vehicles were calculated, with the measures applied to both OECD and
non-OECD regions (the latter with a five-year lag behind OECD countries).
The resulting projections through 2050 are shown in Figure 8, in terms of wellto-wheels GHG emissions. These represent GHG emissions directly from vehicles
plus emissions from upstream activities related to production of all fuels.
The projections indicate that, in the reference case, GHG emissions from lightduty vehicles increase by more than 100% between 2000 and 2050. In contrast,
with strong uptake of fuel-cell vehicles, emissions from these vehicles level
off between 2030 and 2040, and begin dropping thereafter, returning to near
their 2000 level by 2050. When the nearer-term measures are added, a much
greater reduction in GHG emissions is achieved, beginning much sooner.
Emissions peak in 2020 and fall to about half of their 2000 level by 2050.
31
Not only do the nearer-term measures help pave the way for longer-term
measures (e.g., hybrid vehicles provide key components for electric and fuelcell vehicles), but they can also provide a much steeper reduction path for
greenhouse gas emissions from transport.
Although travel modes other than light-duty vehicles are not shown in this
example, similar results can be expected for other modes if similar efficiency
improvements, travel reductions and use of biofuels can be achieved.
table 3.
Example Scenarios: Assumptions Regarding Nearer-term
and Longer-term Actions and Their Effects on Light-duty Vehicles
2020
2030
2040
2050
Reduction in fuel use per kilometre, gasoline/
diesel vehicles (compared with a reference case)
15%
25%
30%
35%
Market (sales) share of hybrid vehicles
20%
35%
50%
0%
Blend share in gasoline and diesel fuel of
biofuels having 50% lower well-to-wheels
GHG emissions per kilometre than gasoline
10%
15%
20%
25%
Reduction in growth of light-duty-vehicle travel
(compared with a reference case)
5%
10%
15%
20%
Market (sales) share of fuel-cell vehicles
1%
10%
50%
100%
Hydrogen – reduction in well-to-wheels
GHG emissions associated with using hydrogen
in vehicles (compared with well-to-wheels
emissions associated with gasoline vehicles)
10%
25%
50%
75%
Near-term Actions
Long-term Actions
Note: hybrid sales share in 2050 (0%) reflects growth in fuel-cell vehicle sales to 100% of the market.
figure 8.
Two Possible Scenarios for Greenhouse Gas Emissions Reduction in Light-duty Vehicles
32
Challenges and next steps: implications
for research and development
Current R&D
As pointed out throughout this paper, nearly all technologies needed for a lowemissions transport system – fuel cells, hydrogen and electricity storage, fuel efficiency
technologies, cellulosic ethanol production, and more – exist today. Furthermore,
many of these technologies can be deployed over the next ten years to begin achieving
significant reductions in oil use and CO2 emissions.
The main longer-term objectives of publicly funded transport technology R&D are to
improve advanced technologies and make them less expensive. Many IEA countries are
working in this area. Automakers in the United States, the European Union and Japan
are receiving substantial government funding to assist them with research on fuel-cell
vehicles and on advanced efficiency technologies such as hybrid electric drive trains. The
United States and Canada have extensive programs to develop production processes
for cellulosic ethanol, and several European countries are putting considerable effort
into biodiesel.
An example of a comprehensive programme is the FreedomCAR program launched
recently in the United States. It has new initiatives in the areas of (1) batteries,
electronics and motors, (2) fuel-cell vehicles operating on hydrogen, and (3) improved
aerodynamics, reduced tire rolling resistance, lighter-weight materials and better
vehicle system optimisation8. Other U.S. R&D and demonstration activities include
research activities under the 21st Century Truck program (engines, diesel emission
controls, aerodynamics) and demonstrations of the viability of powering transit buses
with fuel cells. Substantial activities are also underway aimed at helping cities deploy
alternative fuel vehicles and associated fuelling infrastructure. The National Renewable
Energy Laboratory leads a major effort to develop cellulosic ethanol conversion
technologies and Oak Ridge National Laboratory leads the effort to develop feedstocks
(and improve their production efficiency) for this program.
The European Union carries out a series of Research Framework Programmes. Under the
Fifth Research, Technological Development and Demonstration Framework Programme,
a number of projects are supporting research or demonstrations of new technologies,
including fuel-cell buses. The CUTE programme, for example, involves demonstrations
in nine cities. The CIVITAS programme features a range of technological and trafficmanagement-efficiency projects in 16 cities. The Sixth Framework Programme
(2002-2006), which has just been launched, contains significant funding for technology
R&D into clean energy sources and their integration into the energy system; energy
savings and efficiency; alternative motor fuels; fuel cells; hydrogen technologies;
renewable energy technologies; and novel propulsion systems9.
8. For information on DOE Freedom Car and other programmes, see http://www.eere.energy.gov/vehiclesandfuels/.
9. For information on these and other EU Sixth Framework programmes, see http://europa.eu.int/comm/research/fp6/
index_en.html.
33
Most of the 15 EU Member States also have major transport research programmes
of their own. For example, in the United Kingdom these include the Foundation
Programme (for accelerating development of new and emerging technologies), the
Foresight Vehicle Programme, and the Powershift and Clean UP programmes.
Applied R&D needs
The IEA has compiled the following list of key applied R&D and demonstration needs
for transport (plus, in some cases, needs for assistance with implementation):
l Sustained, long-term improvement in vehicle fuel economy at acceptable cost will
require successful R&D on materials cost reduction, energy storage devices (such
as batteries, ultracapacitors, hydraulics and flywheels), fuel cells, power electronics,
lightweight materials, engine technology, aerodynamics, tyres and auxiliary power
units. Understanding consumers’ demands and their willingness to accept various
changes in vehicle attributes is also an important area for research.
l Improvement in system efficiencies will require development of automated
transport infrastructure (such as electronic/infra-red communication among
vehicles and between vehicles and infrastructure and satellite navigation systems).
l Broad reliance on low- and zero-emissions fuels will require successful R&D on
biomass production and processing, and development of low-cost technologies
for the production and storage of hydrogen.
l Research and development on improvements to multi-fuel distribution and
storage systems will lower both costs and the barriers to fuel choices.
l A detailed assessment of the potential role of cellulosic ethanol and other
advanced biofuels conversion technologies is needed. This assessment must
take into account various estimates for feedstock requirements and for land
availability to grow these, and should be done for all OECD countries as well as
other major crop-growing countries. The assessment should also investigate the
potential effects of expanded production of energy crops on food-crop prices
and on the environment (from changes in farming practice).
l Research and development is needed on improvements in the ability to blend
biofuels with gasoline and diesel fuels and to replace these fuels entirely. Widespread
introduction of vehicles capable of running on high-blend fuels (as is happening in
the United States and Brazil) will offer scale economies and learning, lowering the
cost of producing such vehicles.
l Continued development of options for the capture and storage of CO2 will enable
fossil fuels to be used as feedstocks in a very-low-GHG-emissions transport
system. The possibility of capturing CO2 from the exhaust stream of heavy
trucks, diesel locomotives and ships should also be given more attention.
l Research into the potential applications for aircraft of biofuels and hydrogen-
powered jet engines deserves more attention.
l Detailed modelling and analysis are needed to determine the optimal allocation
of the key fuels – biomass, electricity and hydrogen – between the transport
and stationary sectors. Whether the "marginal" hectare of land or kilowatt of
generating capacity for near-zero-emissions electricity saves more carbon when
it displaces other energy supply for mobile applications or for stationary purposes
is an important, and relatively unexplored, question.
34
Basic research needs
Basic research needs relevant to transport include:
l Nano-technologies. Nano-technologies can have broad utility for transport,
especially for the storage of hydrogen. Special attention should be paid
to the question of whether this technology can meet the energy density
requirements that hold for vehicle applications.
l Materials research. High strength and low weight is the combination that is
important for materials used in vehicles. The total materials life cycle must be
addressed to make sure that the reduction in vehicular energy consumption is
not offset by increases in other stages of the material life cycle.
l Basic electrochemistry. Creative, "trial and error" research is needed that could
lead to wholly new battery technologies. For this exploratory research, no
guarantees for the outcome can be given. Still, this type of research must go
on.
l Energy supply capacities. Research is needed into whether the domestic and
world-wide production capacity for clean and renewable energy carriers is
sufficient to fulfil all world energy needs (of which transport is just part). What
are the priorities for allocating available clean energy?
35
Beyond R&D
This paper covers a wide range of technologies that can contribute to the reduction of
greenhouse gas emissions from transport in the near term and the development of a nearzero-emissions transport sector in the long term. For the longer term, much of what is
needed appears to be more government and industry R&D. As described in this section,
much of what is needed is applied, not basic, research that is relevant to existing but noncommercial technologies. Resulting improvements in efficiencies and reductions in cost
can speed market uptake of such technologies. In addition, the market and government
policy context will be important in encouraging the use of such technology.
But beyond R&D, what is needed is more direct support for bringing technologies to a
commercial state and introducing them into the marketplace. For example, substantial
improvements in vehicle fuel economy can be achieved by applying incremental
technology improvements to today’s vehicles. This can be accomplished without much
additional R&D – but steps will be needed to encourage full use of existing technologies,
and to avoid having the benefits of these technologies offset by increases in vehicle size,
weight and power.
Historically, the trend has not been promising. The many technical improvements applied
to vehicles over the past ten years have mostly been lost through increases in average
vehicle size, weight, and power. What net efficiency gains have occurred have been
overwhelmed by growth in transport overall, ensuring that greenhouse gas emissions
continue to rise. Such a trend is even worse in developing countries, where technology
tends to be older and private transport growth faster.
For these reasons the technology issues discussion in this paper need to be addressed in
a systems context, where policies support the commercialisation and adoption of new
transport technologies. To use such a systematic approach, governments will need to take
steps falling into such broad categories such as:
l
l
l
l
Adjusting rules.
Setting standards and regulations.
Amending planning guidelines.
Providing financial incentives.
Such steps will help promote commercialisation of technologies and encourage
manufacturers to make the needed (but risky) investments. Support also must be geared to
making sure that new fuels are widely available, that fuel systems and vehicles themselves
are very safe, that they perform as well as or better than conventional vehicles, and that
they are cost competitive. If consumers are confident that they will benefit from switching,
and costs are not excessive, a “mass-migration” could occur as quickly as manufacturers
can develop and produce new models.
Getting supporting financial incentives in place is also clearly important. From 1975
through 1985, a period of supply shocks, high oil prices and strong policies to promote
efficiency, vehicle efficiency improved in most countries. Since 1985, as real fuel prices
have declined significantly and without the right fiscal incentives, consumers have become
disinterested in efficiency and have shifted to buying much larger, more powerful vehicles.
One benchmark of good practice is to adjust fiscal measures to reflect the GHG-emissionsreduction potential of each fuel type (as is occurring with vehicle taxation and fuel excise
duties in some countries, such as the United Kingdom).
36
At the same time, the adoption of technologies and policies to dampen vehicle travel
growth must be much more strongly encouraged. High-quality mass transit, inter-city
transport and “intelligent” infrastructure will be necessary if aggregate transport levels are
to be reduced through greater use of lower-emissions modes of transport. For developing
countries, similar support with a different focus will be necessary. Developing countries
have very different markets, cost structures, and needs. The adoption of local fuel sources
and lower-technology, clean mass transit systems may be most appropriate (IEA, 2002).
For more detailed policy analysis, see Saving Oil and Reducing CO2 Emissions in Transport: Options and Strategies
(IEA,2001); Policy Instruments for Achieving Environmentally Sustainable Transport (OECD, 2002a); Bus Systems
for the Future: Achieving Sustainable Transport Worldwide (IEA, 2002); Transport Logistics: Shared Solutions to
Common Challenges (OECD, 2002b); and Transports urbains durables: la mise en oeuvre des politiques: Rapport
final (ECMT, 2004).
Putting it all together: near-term steps
toward both near and long-term goals
Regardless of the final, low-emissions (and low-petroleum) transport system that
ultimately emerges – whether based on hydrogen fuel-cell propulsion systems,
electric propulsion and powertrain systems, or liquid biofuels, or possibly some
mix of the three, depending on the region and country – certain actions can be
undertaken over the next decade that will benefit them all:
l Securing substantial increases in vehicle efficiency from incremental
improvements and existing technologies, particularly in the areas of lightweighting, hybridisation and increasing use of electric drive systems.
l Increasing deployment of intelligent infrastructure and other technologies that
assist individuals and companies in finding alternatives to vehicle travel (and to
truck-based movement of goods). Increasing investment in transit systems and
efficient freight modes such as rail and shipping are also important. Assisting
developing countries in improving their transport systems, before cars become
the dominant mode of travel, can yield particularly large global benefits for
CO2 emissions reduction, while improving mobility for millions of people.
l Increasing use of bio-components in transport fuels, and introducing advanced
conversion technologies and feedstocks that allow a steady reduction in the
well-to-wheels GHG emissions from these fuels. Even if a clean transport
system features vehicles powered by hydrogen or directly by electricity, these
energy carriers can be produced from biomass, so experience gained today will
provide dividends in the future.
Not only can steps taken in these areas help to speed the eventual transition to a
sustainable transport system, but they can also provide substantial reductions in
oil use and CO2 emissions in their own right. In the scenarios shown earlier, more
than 50% of the reduction in CO2-equivalent GHG emissions from light-duty
vehicles seen through 2050 stems from near-term measures.
37
On the other hand, some steps are needed to prepare for the long-term transition
itself. Apart from the R&D and technology-related needs above, there are several
more general options that policymakers should consider:
l Beyond the need to develop technologies and bring down their costs, perhaps
the single greatest barrier to an energy future featuring significantly new
fuels and systems of vehicle propulsion will be the "chicken and egg" problem.
This refers to the inherent problem of convincing vehicle manufacturers to
produce and sell new vehicle types when there is no fuel available to run them
on, and simultaneously convincing fuel providers to provide the necessary fuel
when there are few vehicles yet on the road that use the fuel. A third part of
the problem comes in convincing consumers to buy both the vehicles and fuel
if made available. This set of inter-related requirements has proven a huge
barrier to many past efforts to promote alternative fuels. Governments must be
prepared to take strong measures, such as offering price incentives, providing
loan guarantees (to reduce risks to vehicle producers and fuel providers), and
investing directly in infrastructure, if they are to induce a rapid transition to new
vehicle and fuel systems.
l Although some things can be done ahead of time, there will come a point
(probably sometime between 2010 and 2030) when IEA governments will need to
work together to initiate and manage this transition. Much co-operative work will
also be needed before a "full-blown" transition begins. One of the most important
things early in this transition will be the testing of various vehicle, fuel, and
infrastructure configurations. Initial testing and demonstration work is already
underway in many countries. To maximise learning and avoid repetition of effort,
it will be necessary for countries to co-ordinate these efforts. For example, a tencity trial involving about three fuel-cell buses in each city is currently underway in
Europe. A study is co-ordinating this effort across the ten cities. If other countries
or cities are interested in running trials, it is imperative that they learn from the
current trials and undertake a project that is complementary or otherwise builds
on the learning that will come from the current effort.
l The amount of energy required to fuel even a much more efficient transport
system in 2050 and beyond will be formidable – perhaps 40 exajoules or more for
just road transport in IEA countries (assuming the full adoption of very efficient
fuel-cell vehicles). To improve the chances that very-low-GHG-emissions fuel
can be provided for all transport needs, governments will need to redouble their
efforts to identify and implement measures to dampen growth in travel demand,
particularly demand for personal vehicle travel, which is the most energyintensive travel mode.
l Along the same lines, countries will need to conduct detailed analysis, individually
and together, to better understand the energy, emissions and cost implications
of different energy future scenarios and transition pathways. For example, it may
be possible to achieve nearly as much GHG emissions reduction through 2030
(and perhaps even through 2050) using a combination of improved vehicle fuel
economy (including hybridisation), increased use of biofuels, and slower growth
in travel demand, as from a transition to fuel-cell or electric vehicles (though
38
ultimately it may not be possible to get to a zero-CO2-emissions system with
this pathway). In any case, it may be possible to delay the point before which
a major transition must begin through aggressive use of these other options.
Such tradeoffs and choices are still poorly understood and deserve more cooperative research. Otherwise there is a strong risk that there will be mis-timed
investments and over- or under-investment in some options and pathways.
l And of course, as with all "sustainable" technologies whose development and
adoption are not adequately supported or stimulated by the market, policies that
internalise the cost of using oil and emitting greenhouse gases into the cost of
all competing technologies would be a powerful, "no-regrets" policy option to
produce a transport system with low greenhouse gas emissions while improving
energy security and supporting economic growth.
39
BIBLIOGRAPHY
ECMT, 2004, Transports urbains durables: la mise en oeuvre des politiques:
Rapport final, European Conference of Ministers of Transport, ECMT/OECD,
Paris.
ECMT/IEA, 2004 (forthcoming), Technology and Policies to Improve Vehicle
In-use Fuel Economy, International Energy Agency and European Conference
of Ministers of Transport, ECMT/IEA/OECD, Paris.
IEA, 2001, Saving Oil and Reducing CO2 Emissions in Transport: Options and
Strategies, International Energy Agency, IEA/OECD, Paris.
IEA, 2002, Bus Systems for the Future: Achieving Sustainable Transport
Worldwide, International Energy Agency, IEA/OECD, Paris.
IEA, 2004a, World Energy Outlook 2004, International Energy Agency, IEA/
OECD, Paris.
IEA, 2004b, Oil Crises and Climate Challenges: 30 Years of Energy Use in IEA
Countries, International Energy Agency, IEA/OECD, Paris.
IEA, 2004c, Biofuels for Transport: An International Perspective, International
Energy Agency, IEA/OECD, Paris.
Laydner, L.O., 2003, 'The Search for New Markets' Brazil equity Update,
Brazilian Fuel Alcohol Sector, October 6.
NRC, 2002, Technology and Economic Analysis in the Prepublication Version
of the Report Effectiveness and Impact of Corporate Average Fuel Economy
(CAFE) Standards, U.S. National Research Council, Washington, DC.
NRC, 2004, The Hydrogen Economy: Opportunities, Costs, Barriers and Needs,
U.S. National Research Council, Washington, DC.
OECD, 2002a, Policy Instruments for Achieving Environmentally Sustainable
Transport, Organisation for Economic Co-operation and Development, Paris.
OECD, 2002b, Transport Logistics: Shared Solutions to Common Challenges,
Organisation for Economic Co-operation and Development, Paris.
PCAST, 1999, Powerful Partnerships: The Federal Role in International Cooperation on Technology Innovation, President’s Committee of Advisors on
Science and Technology, Executive Office of the President of the United
States, Washington, DC.
40