Transportation

Life Cycle Assessment has been used to analyze the emissions and potential environmental impacts of transportation. In this session, the focus is on LCA of motorcycles, and passenger vehicles including autonomous vehicles. The impact of particulate matters emission on carbon footprint of gasoline and electricity for vehicles will also be discussed.

Key Discussion Points:

  1. LCA of disruptive road transportation technology (Autonomous Vehicles)
  2. Framework for LCA of various transportation modes in the Swiss transport fleet
  3. Role of LCA in choosing more climate-friendly vehicle fleet
  4. Impacts of PM 2.5 contribution to global warming
LOCATION: 2309
10:30 Brian Cox and Chris Mutel

Environmental Assessment of Motorcycles and Two-Wheeled Fleet Development from 1990-2050
SPEAKER: Brian Cox / Presentation

ABSTRACT. This work describes a life cycle assessment of motorcycles and scooters and examines two-wheeled fleet development from 1990-2015 with projections until 2050.

We performed life cycle assessment for four motorcycle size classes for conventional, battery, and fuel cell powertrains and corresponding technology developments over time. Parameters such as motorcycle power, mass, fuel consumption, and annual survival probability are determined using large datasets of existing motorcycles. These are used to calibrate performance models for current and future motorcycles, ensuring transparent and consistent comparison across motorcycle classes and powertrain types. Swiss national data is used as a case study to examine two-wheeled fleet dynamics, the penetration rates of new technologies, and the development of overall fleet environmental impacts over time.

Our preliminary results show that the environmental impacts and energy demand of motorcycles are strongly dependent on motorcycle size, powertrain type, driving characteristics, and year of manufacture. Battery electric powertrains are found to be well suited to smaller motorcycles and show strong climate benefits, but are less suited to larger motorcycles due to weight and range limitations. For these motorcycles, fuel cells are seen to be a potential alternative, though the resulting environmental benefits remain uncertain. The environmental benefits of tailpipe emissions regulations, efficiency improvements, and adoption of electric powertrains are found to be significant for individual motorcycles. However, in Switzerland, these improvements are largely overshadowed by fleet growth and increasing average motorcycle power until at least 2030 for many environmental impact categories. After 2030 a significant portion of the motorcycle fleet is calculated to be powered by alternative powertrains, resulting in potentially large decreases in environmental impacts. However, these environmental impacts are strongly dependent on the primary energy sources used to produce electricity and hydrogen.

This work provides a framework that will be used to develop a life cycle assessment of all transportation modes in the Swiss transport fleet. Results of the fleet analysis provide insights regarding the ability of the Swiss transport sector to meet the challenges of the Energy Turnaround in Switzerland. This work is supported by the SCCER Mobility project (www.sccer-mobility.ch).

10:45 William Morrow

Autonomous Vehicles – a game changer in transportation’s environmental impacts?

ABSTRACT. Autonomous vehicles (AVs) are a potentially disruptive technology with significant potential to alter the transportation sector’s environmental impacts. But the magnitude and direction of their impact on energy and environmental impacts are uncertain. AVs could enable unprecedented levels of efficiency and radically reduce transportation sector’s energy use and environmental impacts. However, consumer choices could result in a net increase in energy consumption and environmental impacts. Because AVs are such a new technology, performing a full LCA of AVs is difficult. In their current form, these vehicle are not significantly different that current Light-Duty Vehicles (LDVs), and an LCA of current AV would not be significantly different than that of current vehicle. Thus life-cycle energy impacts are prospective. Anticipating the “order of magnitude” life-cycle changes that AV could enable is a first step in the LCA of this emerging technology.

This presentation will outline several key drivers that will most likely influence AV’s impact on transportation sector energy consumption and environmental impacts. Exploring the ranges of plausible futures across each of these key drivers highlights the uncertainty of AV’s future life-cycle impacts. This provides bounding “book ends” of how AVs could alter the energy consumption patterns of the U.S. transportation sector in the future.

At this early stage of an exciting potential AV future, the research community should be aware of the magnitude of influence that AVs can have on transportation’s energy future and its life-cycle impacts.

11:00 Marco MiottiGeoffrey SupranElla Kim and Jessika Trancik

Using parametrized LCA to evaluate over 120 passenger vehicle models against climate change mitigation targets
SPEAKER: Marco Miotti

ABSTRACT. Climate policy targets in many developed nations require that greenhouse gas (GHG) emissions peak within the next decade and then fall more than twice as fast as they have been rising for the last century. A considerable fraction of emissions comes from light-duty vehicles (20% in the U.S. in 2012 [1]), and Life Cycle Assessment (LCA) studies have analyzed the potential of alternative powertrain technologies to lower these emissions.

Here, we aim to improve our understanding of the pathways towards a cleaner vehicle fleet by capturing the wide variety in size, shape and performance of vehicles on the market, and by comparing this performance to emission targets. We simultaneously assess costs of ownership to draw conclusions about the affordability of a decarbonization transition. We achieve this by building a GREET-based parameterized LCA model to calculate the lifecycle GHG emissions and costs of over 120 light-duty vehicle models sold in the U.S. in 2014, considering all powertrain technology options. We then evaluate these options against vehicle emission targets for 2030, 2040 and 2050, which we derive from overall climate change policy goals [2].

The carbon intensity of the average car sold in 2014 exceeds the GHG emissions target for 2030 by more than 50%, but most hybrid and battery electric vehicles meet this target. However, no vehicle model meets the 2040 and 2050 targets, when using the current U.S. electricity mix. Furthermore, we find that there is no trade-off between cost and carbon intensity across the group of vehicle models examined. A clean vehicle is also a low-cost vehicle, independent of the powertrain technology. Simultaneously, emissions and costs strongly depend on vehicle size and performance. By 2050, only battery electric vehicles supplied with almost completely carbon-free electric power can meet climate policy targets.

These results can help consumers and technology developers from the public and private sectors to evaluate light-duty vehicle technology options against climate change mitigation goals, thereby finding feasible pathways towards climate-friendly personal transport.

[1] EPA, 2007: Inventory of U.S. Greenhouse gas emissions and sinks: 1990-2012. [2] Den Elzen, M., Höhne, N., 2011: Sharing the reduction effort to limit global warming to 2 C. Climate Policy, 37–41.

11:15 John Beath

Should PM 2.5 Be Added to The Carbon Footprint?

ABSTRACT. Recent scientific studies have indicated that PM 2.5 is not only a direct contributor to the environment as a criteria pollutant, but it also can contribute to global warming by absorbing incoming solar radiation and warming the atmosphere. Based on proposed relative global warming potential, this paper presents carbon footprint data related to cradle-to-gate gasoline and electricity based on the potential added impacts contributed if PM 2.5 contribution to global warming is considered. This impact has been discussed in several publications, but to date no calculations have been identified based on Internet searches.

The process used to estimate the impacts for this paper was to leverage PM 2.5 data published in the Argonne National Laboratory’s GREET transportation fuels model (GREET1_2014) for emissions of PM from power plants and oil extraction and processing facilities.

Results show whether the comparison between gas and electric fuel for vehicles may be significantly altered based on this modification to the carbon footprint, or if previous analyses still apply. The science behind Global Warming Potential (GWP) values for black carbon (PM 2.5) is evolving, but current estimates begin at a lower end of 48, which was the primary value used for this analysis. The upper end of the range can be as high as 4600, and this was evaluated as a sensitivity.

Since carbon black is contributed by sources other than industrial and transportation combustion, the impacts from major global sources were also considered. Poorly designed cook stoves and open fires are major contributors to PM 2.5, particularly in Africa and Asia. The benefits predicted based on reduced carbon footprint are greatly enhanced when a PM 2.5 impact is added. Comparisons to other potential fuels could be altered where carbon dioxide and PM 2.5 do not vary at the same proportion.