Environmental impacts of hybrid, plug-in hybrid, and battery electric vehicles—what can we learn from life cycle assessment?

PurposeThe purpose of this review article is to investigate the usefulness of different types of life cycle assessment (LCA) studies of electrified vehicles to provide robust and relevant stakeholder information. It presents synthesized conclusions based on 79 papers. Another objective is to search for explanations to divergence and “complexity” of results found by other overviewing papers in the research field, and to compile methodological learnings. The hypothesis was that such divergence could be explained by differences in goal and scope definitions of the reviewed LCA studies.MethodsThe review has set special attention to the goal and scope formulation of all included studies. First, completeness and clarity have been assessed in view of the ISO standard’s (ISO 2006a, b) recommendation for goal definition. Secondly, studies have been categorized based on technical and methodological scope, and searched for coherent conclusions.Results and discussionComprehensive goal formulation according to the ISO standard (ISO 2006a, b) is absent in most reviewed studies. Few give any account of the time scope, indicating the temporal validity of results and conclusions. Furthermore, most studies focus on today’s electric vehicle technology, which is under strong development. Consequently, there is a lack of future time perspective, e.g., to advances in material processing, manufacturing of parts, and changes in electricity production. Nevertheless, robust assessment conclusions may still be identified. Most obvious is that electricity production is the main cause of environmental impact for externally chargeable vehicles. If, and only if, the charging electricity has very low emissions of fossil carbon, electric vehicles can reach their full potential in mitigating global warming. Consequently, it is surprising that almost no studies make this stipulation a main conclusion and try to convey it as a clear message to relevant stakeholders. Also, obtaining resources can be observed as a key area for future research. In mining, leakage of toxic substances from mine tailings has been highlighted. Efficient recycling, which is often assumed in LCA studies of electrified vehicles, may reduce demand for virgin resources and production energy. However, its realization remains a future challenge.ConclusionsLCA studies with clearly stated purposes and time scope are key to stakeholder lessons and guidance. It is also necessary for quality assurance. LCA practitioners studying hybrid and electric vehicles are strongly recommended to provide comprehensive and clear goal and scope formulation in line with the ISO standard (ISO 2006a, b).

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title: Plug-in Hybrid and Battery Electric Vehicles. Market penetration scenarios of electric drive vehicles
abstract: Electric-drive vehicles (EDVs) are currently emerging in the market and are seen as a promising option towards a less carbon intensive road transport. This report presents a prospective analysis in relation with two of the current bottlenecks for the diffusion of electric vehicles. These concern batteries performance and cost, and the access to charging infrastructures. Based on projections on these factors, the analysis develops scenarios for the future market for electric cars and provides indicative estimations of the impacts on energy consumption and CO2 emissions at EU level. To this end, a modelling approach was developed, enabling to assess the future market penetration of electric vehicles and evaluate the effects of some key factors determining electromobility, including battery costs and performance and access to grid to for recharging. It offers some possibilities to assess the effects of policies such as infrastructure investment and incentives to car consumers. The approach is mainly demand driven in the sense that the effects and, also, possible constraints from the electricity grid and from the power generation sector are not considered. The effects of a growing electricity demand and possible charging profiles are also not addressed at this stage. This is currently being carried out by using an EU-TIMES-based model of which conclusions will be presented reported in a subsequent report.

title: Urban electric vehicles: a contemporary business case
abstract: BackgroundHigh gasoline prices, global warming, pollution and dependence on foreign sources of oil are four major issues the world is facing today. In a world where energy supply security and environmental protection are major concerns, the development of green vehicles is becoming a necessity. The Electric vehicle (EV) is one of the most promising technologies that will make the “green dream” come true.MethodsA contemporary business case that encourages the immediate deployment of urban EVs is presented. It proposes a model in which we can profit from the benefits of urban EVs namely, high energy efficiency, emissions reduction, small size and noise reduction. The model mitigates the EV potential limitations such as energy source, charging infrastructure, impact on electrical power system and cost issues. It also provides ideas to overcome the barriers of the technology application in order to speed up their commercialization.Concluding remarksEnergy conservation and environmental protection are the main driving forces behind the development of electric vehicles. Urban EVs seem to be a good choice for cities and urban centers since their potential drawbacks are few and can be mitigated. This study reveals that having an environmentally friendly vehicle can soon become a reality if collaborative efforts are properly directed.

title: Realizing the electric-vehicle revolution
abstract: Substantial work has shown the potential energy and climate benefits of full battery electric vehicles (BEVs) — an important policy option to mitigate climate change — but there are still uncertainties about their market diffusion. Research shows the importance of assessing BEV diffusion from an integrated perspective, focusing on the interaction between technology and behaviour.

title: Alternative fuel buses currently in use in China: Life-cycle fossil energy use, GHG emissions and policy recommendations
abstract: The Chinese government has enacted policies to promote alternative vehicle fuels (AVFs) and alternative fuel vehicles (AFVs), including city bus fleets. The life cycle (LC), energy savings (ES) and GHG reduction (GR) profiles of AVFs/AFVs are critical to those policy decisions. The well-to-wheels module of the Tsinghua-CA3EM model is employed to investigate actual performance data. Compared with conventional buses, AFVs offer differences in performance in terms of both ES and GR. Only half of the AFVs analyzed demonstrate dual benefits. However, all non-oil/gas pathways can substitute oil/gas with coal. Current policies seek to promote technology improvements and market creation initiatives within the guiding framework of national-level diversification and district-level uniformity. Combined with their actual LC behavior and in keeping with near- and long-term strategies, integrated policies should seek to (1) apply hybrid electric technology to diesel buses; (2) encourage NG/LPG buses in gas-abundant cities; (3) promote commercialize electric buses or plug-in capable vehicles through battery technology innovation; (4) support fuel cell buses and hydrogen technology RD and (5) conduct further research on boosting vehicle fuel efficiency, applying low-carbon transportation technologies, and addressing all resultant implications of coal-based transportation solutions to human health and natural resources.

title: Comparative Environmental Life Cycle Assessment of Conventional and Electric Vehicles
abstract: Electric vehicles (EVs) coupled with low-carbon electricity sources offer the potential for reducing greenhouse gas emissions and exposure to tailpipe emissions from personal transportation. In considering these benefits, it is important to address concerns of problemshifting. In addition, while many studies have focused on the use phase in comparing transportation options, vehicle production is also significant when comparing conventional and EVs. We develop and provide a transparent life cycle inventory of conventional and electric vehicles and apply our inventory to assess conventional and EVs over a range of impact categories. We find that EVs powered by the present European electricity mix offer a 10% to 24% decrease in global warming potential (GWP) relative to conventional diesel or gasoline vehicles assuming lifetimes of 150,000 km. However, EVs exhibit the potential for significant increases in human toxicity, freshwater eco-toxicity, freshwater eutrophication, and metal depletion impacts, largely emanating from the vehicle supply chain. Results are sensitive to assumptions regarding electricity source, use phase energy consumption, vehicle lifetime, and battery replacement schedules. Because production impacts are more significant for EVs than conventional vehicles, assuming a vehicle lifetime of 200,000 km exaggerates the GWP benefits of EVs to 27% to 29% relative to gasoline vehicles or 17% to 20% relative to diesel. An assumption of 100,000 km decreases the benefit of EVs to 9% to 14% with respect to gasoline vehicles and results in impacts indistinguishable from those of a diesel vehicle. Improving the environmental profile of EVs requires engagement around reducing vehicle production supply chain impacts and promoting clean electricity sources in decision making regarding electricity infrastructure.

title: Electric cars: technical characteristics and environmental impacts
abstract: BackgroundElectric vehicles have been identified as being a key technology in reducing future emissions and energy consumption in the mobility sector. The focus of this article is to review and assess the energy efficiency and the environmental impact of battery electric cars (BEV), which is the only technical alternative on the market available today to vehicles with internal combustion engine (ICEV). Electricity onboard a car can be provided either by a battery or a fuel cell (FCV). The technical structure of BEV is described, clarifying that it is relatively simple compared to ICEV. Following that, ICEV can be ‘e-converted’ by experienced personnel. Such an e-conversion project generated reality-close data reported here.ResultsPracticability of today's BEV is discussed, revealing that particularly small-size BEVs are useful. This article reports on an e-conversion of a used Smart. Measurements on this car, prior and after conversion, confirmed a fourfold energy efficiency advantage of BEV over ICEV, as supposed in literature. Preliminary energy efficiency data of FCV are reviewed being only slightly lower compared to BEV. However, well-to-wheel efficiency suffers from 47% to 63% energy loss during hydrogen production. With respect to energy efficiency, BEVs are found to represent the only alternative to ICEV. This, however, is only true if the electricity is provided by very efficient power plants or better by renewable energy production. Literature data on energy consumption and greenhouse gas (GHG) emission by ICEV compared to BEV suffer from a 25% underestimation of ICEV-standardized driving cycle numbers in relation to street conditions so far. Literature data available for BEV, on the other hand, were mostly modeled and based on relatively heavy BEV as well as driving conditions, which do not represent the most useful field of BEV operation. Literature data have been compared with measurements based on the converted Smart, revealing a distinct GHG emissions advantage due to the German electricity net conditions, which can be considerably extended by charging electricity from renewable sources. Life cycle carbon footprint of BEV is reviewed based on literature data with emphasis on lithium-ion batteries. Battery life cycle assessment (LCA) data available in literature, so far, vary significantly by a factor of up to 5.6 depending on LCA methodology approach, but also with respect to the battery chemistry. Carbon footprint over 100,000 km calculated for the converted 10-year-old Smart exhibits a possible reduction of over 80% in comparison to the Smart with internal combustion engine.ConclusionFindings of the article confirm that the electric car can serve as a suitable instrument towards a much more sustainable future in mobility. This is particularly true for small-size BEV, which is underrepresented in LCA literature data so far. While CO2-LCA of BEV seems to be relatively well known apart from the battery, life cycle impact of BEV in categories other than the global warming potential reveals a complex and still incomplete picture. Since technology of the electric car is of limited complexity with the exception of the battery, used cars can also be converted from combustion to electric. This way, it seems possible to reduce CO2-equivalent emissions by 80% (factor 5 efficiency improvement).

title: A new comparison between the life cycle greenhouse gas emissions of battery electric vehicles and internal combustion vehicles
abstract: Electric vehicles have recently been gaining increasing worldwide interest as a promising potential long-term solution to sustainable personal mobility; in particular, battery electric vehicles (BEVs) offer zero tailpipe emissions. However, their true ability to contribute to greenhouse gas (GHG) emissions reductions can only be properly assessed by comparing a life cycle assessment of their GHG emissions with a similar assessment for conventional internal combustion vehicles (ICVs).

title: Modern individual mobility
abstract: The transport sector is responsible for almost 60% of the oil consumption or almost 30% of the total energy consumption in OECD countries (IEA 2011). The dominant share of this energy consumption is caused by individual passenger transport by roads and air transport. Even though technological progress has constantly improved the fuel efficiency of vehicles combustion engines, the energy consumption of individual road transports is constantly increasing, mainly due to increasing population and increasing distances travelled daily. This leads to an increase in CO2 emissions from road transport in the EU by 20% between 1990 and 2000 (de Haan et al. 2007). Thus, individual mobility is one of the most relevant and fastest growing contributors to climate change. Also, human-toxic emissions from this sector are not negligible despite increasingly rigorous emission standards. The daily limit values for PM10 and for NO2 in 2009 still exceeded at more than 30% of the traffic sites across Europe (EU-27) and (Kunzli et al. 2000) attributed about 3% of total mortality in Austria, France and Switzerland to air pollution of motorized road traffic. And also external costs from road passenger transport in the USA due to air pollution are estimated higher than those due to climate change (Delucchi and McCubbin 2011). From a global perspective, the transport sector is not only a very relevant but also a rapidly growing energy consumer: its share on worldwide primary energy consumption is expected to rise from 21.8% in 2000 to about 34% in 2050 (de Haan et al. 2007). Knowing that vehicle density per capita increases with increasing GDP (almost linear rise from 0 vehicles per capita at GDP 0 to 0.3 vehicles per capita at GDP $10,000) and considering that annual economic growth in emerging nations like India (population 1.2 billion, GDP per capita about $3,500, average annual growth ca. 7%) and China (population 1.3 billion, GDP per capita $7600, average annual growth rate ca. 10%) is considerable, a steep increase in vehicle numbers and kilometers driven is to be expected. By 2050 one expects 5 billion cars (2010: 1 billion) driving 50 trillion km per year, emitting 6 billion tons of CO2 (i.e. about 20% of overall annual emission in 2010). From this context, it is obvious that individual mobility is one of the most relevant issues in the discussions on climate change and urban pollution. Some years ago, biofuels were hoped to be the magic bullet to solve all problems. LCA, however, showed that even though many biofuels might have climate change mitigation potential, overall environmental effects of biofuel based mobility are often worse than for fossil fueled transports. And, just recently, the Scientific Committee of the European Environment Agency acknowledged a “serious error” in the greenhouse gas accounting methodology used for European Union regulations and policy targets.

title: Systematic Review Checklist
abstract: Systematic review, including meta‐analysis, is increasingly utilized in life cycle assessment (LCA). There are currently no widely recognized guidelines for designing, conducting, or reporting systematic reviews in LCA. Other disciplines such as medicine, ecology, and software engineering have both recognized the utility of systematic reviews and created standardized protocols for conducting and reporting systematic reviews. Based largely on the 2009 Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) statement, which updated the preferred format for reporting of such reviews in biomedical research, we provide an introduction to the topic and a checklist to guide the reporting of future LCA reviews in a standardized format. The standardized technique for assessing and reporting reviews of LCA (STARR‐LCA) is a starting point for improving the utility of systematic reviews in LCA.

title: What Can Meta-Analyses Tell Us About the Reliability of Life Cycle Assessment for Decision Support?
abstract: The body of life cycle assessment (LCA) literature is vast and has grown over the last decade at a dauntingly rapid rate. Many LCAs have been published on the same or very similar technologies or products, in some cases leading to hundreds of publications. One result is the impression among decision makers that LCAs are inconclusive, owing to perceived and real variability in published estimates of life cycle impacts. Despite the extensive available literature and policy need formore conclusive assessments, only modest attempts have been made to synthesize previous research. A significant challenge to doing so are differences in characteristics of the considered technologies and inconsistencies in methodological choices (e.g., system boundaries, coproduct allocation, and impact assessment methods) among the studies that hamper easy comparisons and related decision support. An emerging trend is meta-analysis of a set of results from LCAs, which has the potential to clarify the impacts of a particular technology, process, product, or material and produce more robust and policy-relevant results. Meta-analysis in this context is defined here as an analysis of a set of published LCA results to estimate a single or multiple impacts for a single technology or a technology category, either in a statisticalmore » sense (e.g., following the practice in the biomedical sciences) or by quantitative adjustment of the underlying studies to make them more methodologically consistent. One example of the latter approach was published in Science by Farrell and colleagues (2006) clarifying the net energy and greenhouse gas (GHG) emissions of ethanol, in which adjustments included the addition of coproduct credit, the addition and subtraction of processes within the system boundary, and a reconciliation of differences in the definition of net energy metrics. Such adjustments therefore provide an even playing field on which all studies can be considered and at the same time specify the conditions of the playing field itself. Understanding the conditions under which a meta-analysis was conducted is important for proper interpretation of both the magnitude and variability in results. This special supplemental issue of the Journal of Industrial Ecology includes 12 high-quality metaanalyses and critical reviews of LCAs that advance understanding of the life cycle environmental impacts of different technologies, processes, products, and materials. Also published are three contributions on methodology and related discussions of the role of meta-analysis in LCA. The goal of this special supplemental issue is to contribute to the state of the science in LCA beyond the core practice of producing independent studies on specific products or technologies by highlighting the ability of meta-analysis of LCAs to advance understanding in areas of extensive existing literature. The inspiration for the issue came from a series of meta-analyses of life cycle GHG emissions from electricity generation technologies based on research from the LCA Harmonization Project of the National Renewable Energy Laboratory (NREL), a laboratory of the U.S. Department of Energy, which also provided financial support for this special supplemental issue.  The first article on reporting considerations for meta-analyses/critical reviews for LCA is from Heath and Mann (2012), who describe the methods used and experience gained in NREL's LCA Harmonization Project, which produced six of the studies in this special supplemental issue. Their harmonization approach adapts key features of systematic review to identify and screen published LCAs followed by a meta-analytical procedure to adjust published estimates to ones based on a consistent set of methods and assumptions to allow interstudy comparisons and conclusions to be made. In a second study on methods, Zumsteg and colleagues (2012) propose a checklist for a standardized technique to assist in conducting and reporting systematic reviews of LCAs, including meta-analysis, that is based on a framework used in evidence-based medicine. Widespread use of such a checklist would facilitate planning successful reviews, improve the ability to identify systematic reviews in literature searches, ease the ability to update content in future reviews, and allow more transparency of methods to ease peer review and more appropriately generalize findings. Finally, Zamagni and colleagues (2012) propose an approach, inspired by a meta-analysis, for categorizing main methodological topics, reconciling diverging methodological developments, and identifying future research directions in LCA. Their procedure involves the carrying out of a literature review on articles selected according to predefined criteria.« less

title: Ageing mechanisms in lithium-ion batteries
abstract: The rechargeable lithium-ion battery has been extensively used in mobile communication and portable instruments due to its many advantages, such as high volumetric and gravimetric energy density and low self-discharge rate. In addition, it is the most promising candidate as the power source for (hybrid) electric vehicles and stationary energy storage. For these applications in durable equipment, the long-term cycling and storage behaviour becomes of increasing interest. In this paper, the mechanisms of lithium-ion battery ageing are reviewed and evaluated.

title: Potential Ecodesign Directive Contributions to Resource-Efficient Innovations. A Case Study on the Electric Motor Product Group Expansion and Rare Earth Element Use in Permanent Magnet Motors
abstract: This study looks at potential contributions of the Ecodesign Directive 2009/125/EC to eco-innovations addressing resource efficiency improvements of energy-related products. This aim is secondary to the prime objective of the Directive, the increase in energy efficiency of energy-related products. By conducting ten in-depth interviews, the study investigates whether and in what form the Directive, which is to address 31 product groups, can contribute to innovations, potentially with resource efficiency improvements, referred to as eco-innovations. The analysis reveals the success of the Directive in cutting off the worst performing products from the market, highlights the Energy label as a stronger driver for innovation and discusses the current limitations of the Directive regarding the implementation of resource efficiency objectives. Recognizing that many issues are product-specific, the study is narrowed down to focus on electric motors, which account for high energy consumption in industry and demonstrate significant ecodesign improvement potential. The extension of the Directive electric motor group to possibly comprise permanent magnet motors is related to whether it could foster innovations capable of achieving resource efficiency improvements of rare earth elements. These materials, classified as critical in the EU, are able to achieve high energy densities in permanent magnets and can contribute to developing motors with higher energy efficiency classes. The case study uses a selection of innovation drivers integrated in Geels’ (2002) multi-level perspective for technological transitions to evaluate their influence on permanent magnet motor developments. Perceptions of permanent magnet motor manufacturer participants of the first preparatory study meeting are gathered through questionnaires for this purpose and interviews with material experts complement the case study. With regulatory standards being one of the most relevant innovation drivers, and the option to request design for recycling, the potential of the Directive to contribute to rare earth element resource efficiency improvements is indicated.

title: Impact of recycling on cradle-to-gate energy consumption and greenhouse gas emissions of automotive lithium-ion batteries.
abstract: This paper addresses the environmental burdens (energy consumption and air emissions, including greenhouse gases, GHGs) of the material production, assembly, and recycling of automotive lithium-ion batteries in hybrid electric, plug-in hybrid electric, and battery electric vehicles (BEV) that use LiMn(2)O(4) cathode material. In this analysis, we calculated the energy consumed and air emissions generated when recovering LiMn(2)O(4), aluminum, and copper in three recycling processes (hydrometallurgical, intermediate physical, and direct physical recycling) and examined the effect(s) of closed-loop recycling on environmental impacts of battery production. We aimed to develop a U.S.-specific analysis of lithium-ion battery production and in particular sought to resolve literature discrepancies concerning energy consumed during battery assembly. Our analysis takes a process-level (versus a top-down) approach. For a battery used in a BEV, we estimated cradle-to-gate energy and GHG emissions of 75 MJ/kg battery and 5.1 kg CO(2)e/kg battery, respectively. Battery assembly consumes only 6% of this total energy. These results are significantly less than reported in studies that take a top-down approach. We further estimate that direct physical recycling of LiMn(2)O(4), aluminum, and copper in a closed-loop scenario can reduce energy consumption during material production by up to 48%.

title: Multi-level energy analysis of emerging technologies: a case study in new materials for lithium ion batteries
abstract: A range of new nanomaterials to replace the active materials in lithium ion batteries are currently being studied and employed in an attempt to overcome various performance limitations of previous technologies. Nanomaterial production and manufacturing techniques appear to fit into a general trend towards more energy intensive production methods for high-tech goods. This does not necessarily imply an increase in lifecycle energy use; artefacts that consume or transform energy during use could possibly regain this increased initial input via increased efficiency in use. In particular, this paper highlights that larger gains could be possible if the artefact in question allows a given service to be provided via an alternative and more efficient system entirely. The lifecycle energy efficiencies of lithium ion batteries constructed from several new advanced materials are analysed with several different system boundaries. Although nanomaterials require more energy input to produce, the implications of nanomaterials for energy flows in the use phase (i.e. driving), and higher levels such as the architecture of future transport fuel production systems are much larger in magnitude than the initial lifecycle inputs for producing the materials in question.

title: Recovery of metals from spent lithium-ion batteries with organic acids as leaching reagents and environmental assessment
abstract: A leaching process for the recovery of cobalt and lithium from spent lithium-ion batteries (LIB) is developed in this work. Three different organic acids, namely citric acid, malic acid and aspartic acid, are used as leaching reagents in the presence of hydrogen peroxide. The cathode active materials before and after acid leaching are characterized by X-ray diffraction and scanning electron microscopy. Recovery of cobalt and lithium is optimized by varying the leachant and H 2 O 2 concentrations, the solid-to-liquid ratio, and the reaction temperature and duration. Whereas leaching with citric and malic acids recovered in excess of 90% of cobalt and lithium, leaching with aspartic acid recovered significantly less of these metals. The leaching mechanism likely begins with the dissolution of the active material (LiCoO 2 ) in the presence of H 2 O 2 followed by chelation of Co(II) and Li with citrate, malate or aspartate. An environmental analysis of the process indicates that it may be less energy and greenhouse gas intensive to recover Co from spent LIBs than to produce virgin cobalt oxide.

title: Life-Cycle Analysis of Production and Recycling of Lithium Ion Batteries
abstract: This paper discusses what is known about the life-cycle burdens of lithium ion batteries. Constituent-material production and the subsequent manufacturing of batteries are emphasized. Of particular interest is estimation of the impact of battery material recycling on battery manufacturing. Because some materials come from comparatively less plentiful resources, the recycling of lithium ion batteries and the potential impact on battery-production life-cycle burdens are discussed. This effort represents the early stage of lithium ion battery life-cycle analysis, in which processes are characterized preparatory to detailed data acquisition. Notwithstanding the lack of data on production of battery materials, it is estimated that the energy use and greenhouse gas emissions associated with battery manufacturing make up only a small percentage of a plug-in hybrid vehicle's total life-cycle energy use. Further, the recycling of battery materials potentially can significantly reduce the material production energy.

title: Life cycle assessment of automobile/fuel options.
abstract: We examine the possibilities for a "greener" car that would use less material and fuel, be less polluting, and would have a well-managed end-of-life. Light-duty vehicles are fundamental to our economy and will continue to be for the indefinite future. Any redesign to make these vehicles greener requires consumer acceptance. Consumer desires for large, powerful vehicles have been the major stumbling block in achieving a "green car". The other major barrier is inherent contradictions among social goals such as fuel economy, safety, low emissions of pollutants, and low emissions of greenhouse gases, which has led to conflicting regulations such as emissions regulations blocking sales of direct injection diesels in California, which would save fuel. In evaluating fuel/vehicle options with the potential to improve the greenness of cars [diesel (direct injection) and ethanol in internal combustion engines, battery-powered, gasoline hybrid electric, and hydrogen fuel cells], we find no option dominates the others on all dimensions. The principles of green design developed by Anastas and Zimmerman ( 2003, 37, 94A-101A) and the use of a life cycle approach provide insights on the key sustainability issues associated with the various options.

title: Fuel cell hybrid taxi life cycle analysis
abstract: A small fleet of classic London Taxis (Black cabs) equipped with hydrogen fuel cell power systems is being prepared for demonstration during the 2012 London Olympics. This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO2 emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave. An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following energy pathways are compared: diesel, electricity and hydrogen (derived from natural gas steam reforming).  shows that the fuel cell powered vehicle configurations have lower energy consumption (4.34Â MJ/km) and CO2 emissions (235Â g/km) than both the ICE Diesel (9.54Â MJ/km and 738Â g/km) and the battery electric vehicle (5.81Â MJ/km and 269Â g/km).

title: Life Cycle Assessment of conventional and alternative small passenger vehicles in Belgium
abstract: In this paper it is examined how environmentally friendly conventional and new vehicle technologies are and how their environmental effects can be compared. An automotive Life Cycle Assessment (LCA) is being performed for small family passenger vehicles in Belgium. Next to the well-to-wheel (WTW) emissions (related to fuel production, distribution and fuel use in the vehicle), the LCA also includes cradle-to-grave emissions (related directly and indirectly to the vehicle production, transportation, maintenance and the end-of-life (EoL) processing of the vehicle). The considered impact categories are: air acidification, eutrophication, human health and greenhouse effect (GHE). Thanks to a range-based modeling system, the variations of the weight of the vehicles, the fuel consumption and the emissions are taken into account. The results show that the battery electric vehicle (BEV) has the best environmental score for all the considered impact categories. Petrol vehicles have the worst impact on the greenhouse effect, but hybridization of the drive train has a positive influence on this impact category. The impact of the hybrid vehicle is considerably lower than of the equivalent petrol vehicle. On the other hand, when assessing the acidification impact, one can notice that the hybrid car has a high impact. Without the recycling of the NiMH battery, the results for the hybrid vehicle would be even higher than for the equivalent petrol vehicle. This is due to the production of the nickel contained in the NiMH battery. Vehicles running on diesel have the highest impact on eutrophication. The tank-to-wheel (TTW) part contributes the most to the overall impact on eutrophication, as a result of the NOX emissions. The evaluation of the impact on human health shows that the petrol vehicle has the highest impact, due to the high NOX, particulate matter (PM) and SOX (WTT) emissions.

title: Comparison of the environmental damage caused by vehicles with different alternative fuels and drivetrains in a Brussels context
abstract: A comprehensive methodology has been developed to compare the environmental damage caused by vehicles with different alternative fuels, such as CNG, LPG, etc., and drivetrains, such as electric and hybrid drives. This paper describes how the environmental effect of vehicles should be defined and includes parameters concerning vehicle emissions and their influence on human wellbeing and the environment. It then describes how the environmental effect of vehicles could be defined, taking into account the availability of accurate and reliable data. Rating systems are analysed as a means of comparing the environmental effect of vehicles, allowing decision-makers to dedicate their financial and non-financial policies and measures as a function of the ecological damage. Different types of pollution (acid rain, photochemical air pollution, noise pollution, etc.) and their effect on numerous receptors such as ecosystems, buildings and human beings (e.g. cancer, respiratory diseases, etc.) and global warming are considered. The methodology described, known as Ecoscore, is based on a methodology similar to life cycle assessment (LCA) which considers the part played by emissions in certain types of damage (e.g. by using the exposure-response damage function). Total emissions involve oil extraction, transport and refinery, fuel distribution and electricity generation and distribution (well-to-wheel approach). Emissions due to the production, use and dismantling of the vehicle (cradle-to-grave approach) should also be considered. The different types of damage are normalized to make comparisons possible. Hence, a reference value (determined by a chosen reference vehicle) will be defined as a target value (the normalized value will thus measure a kind of distance to target). The contribution of the different normalized types of damage to a single value—Ecoscore—is based on a panel weighting method. This new approach differs from other methodologies in that it has been especially developed for the assessment of the environmental effect of vehicle emissions in an urban context, such as the Brussels Capital Region. Additionally, this methodology not only considers conventional vehicles but can also evaluate all alternative fuels and drivetrains with new vehicle technologies. Some examples of Ecoscore calculation are illustrated.

title: Life Cycle Assessment of Environmental and Economic Impacts of Advanced Vehicles
abstract: Many advanced vehicle technologies, including electric vehicles (EVs), hybrid electric vehicles (HEVs), and fuel cell vehicles (FCVs), are gaining attention throughout the World due to their capability to improve fuel efficiencies and emissions. When evaluating the operational successes of these new fuel-efficient vehicles, it is essential to consider energy usage and greenhouse gas (GHG) emissions throughout the entire lifetimes of the vehicles, which are comprised of two independent cycles: a fuel cycle and a vehicle cycle. This paper intends to contribute to the assessment of the environmental impacts from the alternative technologies throughout the lifetimes of various advanced vehicles through objective comparisons. The methodology was applied to six commercial vehicles that are available in the U.S. and that have similar dimensions and performances. We also investigated the shifts in energy consumption and emissions through the use of electricity and drivers’ behavior regarding the frequencies of battery recharging for EVs and plug-in hybrid electric vehicles (PHEVs). This study thus gives insight into the impacts of the electricity grid on the total energy cycle of a vehicle lifetime. In addition, the total ownership costs of the selected vehicles were examined, including considerations of the fluctuating gasoline prices. The cost analysis provides a resource for drivers to identify optimal choices for their driving circumstances.

title: Greenhouse gas implications of using coal for transportation: Life cycle assessment of coal-to-liquids, plug-in hybrids, and hydrogen pathways
abstract: Using coal to produce transportation fuels could improve the energy security of the United States by replacing some of the demand for imported petroleum. Because of concerns regarding climate change and the high greenhouse gas (GHG) emissions associated with conventional coal use, policies to encourage pathways that utilize coal for transportation should seek to reduce GHGs compared to petroleum fuels. This paper compares the GHG emissions of coal-to-liquid (CTL) fuels to the emissions of plug-in hybrid electric vehicles (PHEV) powered with coal-based electricity, and to the emissions of a fuel cell vehicle (FCV) that uses coal-based hydrogen. A life cycle approach is used to account for fuel cycle and use-phase emissions, as well as vehicle cycle and battery manufacturing emissions. This analysis allows policymakers to better identify benefits or disadvantages of an energy future that includes coal as a transportation fuel. We find that PHEVs could reduce vehicle life cycle GHG emissions by up to about one-half when coal with carbon capture and sequestration is used to generate the electricity used by the vehicles. On the other hand, CTL fuels and coal-based hydrogen would likely lead to significantly increased emissions compared to PHEVs and conventional vehicles using petroleum-based fuels.

title: A review of approaches to treat uncertainty in LCA
abstract: It is important to know to what extent the outcome of an LCA is affected by various types of uncertainty, such as parameter, scenario and model uncertainty. These types may occur in the goal and scope definition, the inventory analysis and the impact assessment of an LCA. Information on the uncertainty of the model outcomes provides useful information to assess the reliability of LCA-based decisions and to guide future research towards reducing uncertainty. This paper reviews several approaches to treat different types of uncertainty in LCA. It will discuss the typology of uncertainty that may be encountered in LCA, the qualitative and quantitative techniques that are available to address these uncertainties, the inclusion of these techniques in LCA software tools, the (graphical) possibilities to show uncertainty in LCA outcomes, ways to simplify the uncertainty analysis, the inclusion of uncertainty analyses in case studies and (the difficulties in) the interpretation of uncertainty information.

title: Characterizing, Propagating, and Analyzing Uncertainty in Life-Cycle Assessment: A Survey of Quantitative Approaches
abstract: Life-cycle assessment (LCA) practitioners build models to quantify resource consumption, environmental releases, and potential environmental and human health impacts of product systems. Most often, practitioners define a model structure, assign a single value to each parameter, and build deterministic models to approximate environmental outcomes. This approach fails to capture the variability and uncertainty inherent in LCA. To make good decisions, decision makers need to understand the uncertainty in and divergence between LCA outcomes for different product systems. Several approaches for conducting LCA under uncertainty have been proposed and implemented. For example, Monte Carlo simulation and fuzzy set theory have been applied in a limited number of LCA studies. These approaches are well understood and are generally accepted in quantitative decision analysis. But they do not guarantee reliable outcomes. A survey of approaches used to incorporate quantitative uncertainty analysis into LCA is presented. The suitability of each approach for providing reliable outcomes and enabling better decisions is discussed. Approaches that may lead to overconfident or unreliable results are discussed and guidance for improving uncertainty analysis in LCA is provided.

title: Recent developments in Life Cycle Assessment.
abstract: Life Cycle Assessment is a tool to assess the environmental impacts and resources used throughout a product's life cycle, i.e., from raw material acquisition, via production and use phases, to waste management. The methodological development in LCA has been strong, and LCA is broadly applied in practice. The aim of this paper is to provide a review of recent developments of LCA methods. The focus is on some areas where there has been an intense methodological development during the last years. We also highlight some of the emerging issues. In relation to the Goal and Scope definition we especially discuss the distinction between attributional and consequential LCA. For the Inventory Analysis, this distinction is relevant when discussing system boundaries, data collection, and allocation. Also highlighted are developments concerning databases and Input-Output and hybrid LCA. In the sections on Life Cycle Impact Assessment we discuss the characteristics of the modelling as well as some recent developments for specific impact categories and weighting. In relation to the Interpretation the focus is on uncertainty analysis. Finally, we discuss recent developments in relation to some of the strengths and weaknesses of LCA.

title: Comparative LCA of electric, hybrid, LPG and gasoline cars in Belgian context
abstract: In this paper, an environmental comparison of electric, hybrid, LPG and gasoline passenger vehicles is performed through a Life Cycle Assessment (LCA) approach. Thanks to a range-based modeling system, the variations of the weight, the fuel consumption and the emissions within the family car category are considered instead of the average values. Unlike in a classic LCA, the use phase of vehicles has been modeled to cover vehicles with both a short and long lifespan in such way that the number of times a vehicle needs to be produced to cover the comparison basis or functional unit is taken into account. According to the assumptions and the used impact calculation method, the greenhouse effect of the LPG hybrid and battery electric vehicles are respectively 20.27 %, 27.44 % and 78.27% lower than for the gasoline vehicles. The assessment of the impact on human health and the air acidification give the best environmental score to the battery electric vehicle. A sensitivity analysis has allowed the assessment of the correlation between the respiratory effects and the euro emission standards.

title: Identifying best existing practice for characterization modeling in life cycle impact assessment
abstract: PurposeLife cycle impact assessment (LCIA) is a field of active development. The last decade has seen prolific publication of new impact assessment methods covering many different impact categories and providing characterization factors that often deviate from each other for the same substance and impact. The LCA standard ISO 14044 is rather general and unspecific in its requirements and offers little help to the LCA practitioner who needs to make a choice. With the aim to identify the best among existing characterization models and provide recommendations to the LCA practitioner, a study was performed for the Joint Research Centre of the European Commission (JRC).MethodsExisting LCIA methods were collected and their individual characterization models identified at both midpoint and endpoint levels and supplemented with other environmental models of potential use for LCIA. No new developments of characterization models or factors were done in the project. From a total of 156 models, 91 were short listed as possible candidates for a recommendation within their impact category. Criteria were developed for analyzing the models within each impact category. The criteria addressed both scientific qualities and stakeholder acceptance. The criteria were reviewed by external experts and stakeholders and applied in a comprehensive analysis of the short-listed characterization models (the total number of criteria varied between 35 and 50 per impact category). For each impact category, the analysis concluded with identification of the best among the existing characterization models. If the identified model was of sufficient quality, it was recommended by the JRC. Analysis and recommendation process involved hearing of both scientific experts and stakeholders.Results and recommendationsRecommendations were developed for 14 impact categories at midpoint level, and among these recommendations, three were classified as “satisfactory” while ten were “in need of some improvements” and one was so weak that it has “to be applied with caution.” For some of the impact categories, the classification of the recommended model varied with the type of substance. At endpoint level, recommendations were only found relevant for three impact categories. For the rest, the quality of the existing methods was too weak, and the methods that came out best in the analysis were classified as “interim,” i.e., not recommended by the JRC but suitable to provide an initial basis for further development. With the realization of the potential importance of geographical differentiation comes the need for characterization models that are able to produce characterization factors that are representative for different continents and still support aggregation of impact scores over the whole life cycle. For the impact categories human toxicity and ecotoxicity, we are now able to recommend a model, but the number of chemical substances in common use is so high that there is a need to address the substance data shortage and calculate characterization factors for many new substances. Another unresolved issue is the need for quantitative information about the uncertainties that accompany the characterization factors. This is still only adequately addressed for one or two impact categories at midpoint, and this should be a focus point in future research. The dynamic character of LCIA research means that what is best practice will change quickly in time. The characterization methods presented in this paper represent what was best practice in 2008–2009.

title: Time and scale in Life Cycle Assessment: the case of fuel choice in the transport sector
abstract: Life Cycle Assessments (LCA, including Well-to-Wheel studies) that are to support decisions that strive to change large technical systems need to consider time and scale related factors, which are given little attention in standard LCA procedures. In this paper, the authors address 3 issues and provide examples from the case of alternate fuels. First, shifting time frame gives room for technical development that should affect not only the choice of performance data, but perhaps also the functional unit and selection of technologies under study. Secondly, background systems, such as heat and power production, change over time and increased production volumes of the alternative fuel change the transport system that is used to produce transport fuel. It is shown that such changes have consequences not only for greenhouse gas (GHG) emissions from each fuel-chain, but also for the ranking order of Rapeseed Methyl Esther (RME) and ethanol in terms of GHG emissions. Lastly, different types of feedstock are available in different quantities and different byproduct markets vary in size. Key markets for RME byproducts in the EU correspond to an RME production that covers about 3% of transport fuel demand. Consequently, GHG emissions allocated to the fuel should change with the scale of adoption.

title: Significance of decision-making for LCA methodology
abstract: Decision-making is central to life cycle assessment (LCA), both in the sense that LCA may be used as decision support and in the sense that different methodological choices in LCA are relevant to different applications. This latter issue is pursued in this paper: i.e., how the decision-making context, and thus goal definition, may be used to guide methodological choices in LCA. A distinction is made between a retrospective or accounting perspective and a prospective perspective, where the consequences of alternative actions are investigated. This has significant implications for LCA guidelines, including the standard on LCA compiled by the International Standardization Organization (ISO).

title: Life cycle model of alternative fuel vehicles: emissions, energy, and cost trade-offs
abstract: This paper describes a life cycle model for performing level-playing field comparisons of the emissions, costs, and energy efficiency trade-offs of alternative fuel vehicles (AFV) through the fuel production chain and over a vehicle lifetime. The model is an improvement over previous models because it includes the full life cycle of the fuels and vehicles, free of the distorting effects of taxes or differential incentives. This spreadsheet model permits rapid analyses of scenarios in plots of trade-off curves or efficiency frontiers, for a wide range of alternatives with current and future prices and levels of technology. The model is available on request. The analyses indicate that reformulated gasoline (RFG) currently has the best overall performance for its low cost, and should be the priority alternative fuel for polluted regions. Liquid fuels based on natural gas, M100 or M85, may be the next option by providing good overall performance at low cost and easy compatibility with mainstream fuel distribution systems. Longer term, electric drive vehicles using liquid hydrocarbons in fuel cells may offer large emissions and energy savings at a competitive cost. Natural gas and battery electric vehicles may prove economically feasible at reducing emissions and petroleum consumption in niches determined by the unique characteristics of those systems.

title: Life cycle water use of low-carbon transport fuels
abstract: In society's quest to mitigate climate change it is important to consider potential trade-offs in climate solutions impacting other environmental issues. This analysis explores the life cycle water consumption of alternative low-carbon energy sources for transportation. Energy sources analyzed include both biofuels used in internal combustion engines and low-carbon electricity generation methods used in conjunction with electric vehicles. Biofuels considered are corn-based ethanol, soybean biodiesel, cellulosic ethanol from switchgrass, and microbial biodiesel. Electricity sources analyzed are coal with carbon sequestration, photovoltaic cells, and solar concentrators. The assessment method used is hybrid life cycle assessment (LCA), which combines materials-based process method and the economic input-output (EIO) method. To compare these technologies on an even footing the life cycle water use to propel a passenger vehicle one mile is estimated. All technologies evaluated showed an increase in water consumption compared to unleaded gasoline when water use from vehicle manufacturing was included. Scale-up calculations showed that mass adoption of electric vehicles and some configurations of algae and switchgrass systems could potentially contribute to the decarbonization of transportation with tolerable increases in overall water consumption. Irrigated crop based biofuels however were found to have significant potential impact on water resources when scaled up to macroscopic production levels.

title: Life cycle assessment of greenhouse gas emissions from plug-in hybrid vehicles: implications for policy.
abstract: Plug-in hybrid electric vehicles (PHEVs), which use electricity from the grid to power a portion of travel, could play a role in reducing greenhouse gas (GHG) emissions from the transport sector. However, meaningful GHG emissions reductions with PHEVs are conditional on low-carbon electricity sources. We assess life cycle GHG emissions from PHEVs and find that they reduce GHG emissions by 32% compared to conventional vehicles, but have small reductions compared to traditional hybrids. Batteries are an important component of PHEVs, and GHGs associated with lithium-ion battery materials and production account for 2-5% of life cycle emissions from PHEVs. We consider cellulosic ethanol use and various carbon intensities of electricity. The reduced liquid fuel requirements of PHEVs could leverage limited cellulosic ethanol resources. Electricity generation infrastructure is long-lived, and technology decisions within the next decade about electricity supplies in the power sector will affectthe potential for large GHG emissions reductions with PHEVs for several decades.

title: Study of popularization policy of clean energy vehicles using life cycle assessment
abstract: Clean energy vehicles (CEVs) produce less CO2 emissions in the utilization phase and reduce total emissions overall. However, the ratio of emissions in the manufacturing phase becomes larger. This paper evaluates CEVs and compares the popularization policies used to promote CEVs using life cycle assessment (LCA). The authors use major criteria: life cycle CO2 emissions to be considered not only in the utilization phase but also in the manufacturing phase. In the simulation of the LCCO2 of CEVs, total driving distances affect total CO2 emissions. The LCCO2 of EVs decrease as total driving distance increases compared with other vehicles. The simulation results show that the LCCO2 of EVs are the lowest when the CEVs are driven for more than 35,700 km in Japan, more than 40,300 km in France, more than 78,400 km in the Netherlands, more than 72,200 km in Germany, more than 38,400 km in Iceland, more than 81,400 km in United States, more than 124,000 km in China and more than 193,000 km in India. This is caused by the differences between the CO2 emission consumption rates, since electrical power sources are different. The simulation results suggest that EVs are not always best suited for all drivers considered LCCO2 including the manufacturing phase, and the LCCO2 of vehicles are affected by total driving distances and the situation of countries' electric power sources.

title: The life cycle assessment of alternative fuel chains for urban buses and trolleybuses.
abstract: This paper describes a comparative analysis of public transport alternatives in the city of Kaunas, Lithuania. An LCA (Life Cycle Assessment) inventory analysis of fuel chains was undertaken using the midi urban bus and a similar type of trolleybus. The inventory analysis of fuel chains followed the guidelines provided by the ISO 14040 and ISO 14044 standards. The ReCiPe Life Cycle Impact Assessment (LCIA) methodology was used to quantify weighted damage originating from five alternative fuel chains. The compressed biogas fuel chain had the lowest weighted damage value, namely 45.7 mPt/km, whereas weighted damage values of the fuel chains based on electricity generation for trolleybuses were 60.6 mPt/km (for natural gas) and 78.9 mPt/km (for heavy fuel oil). The diesel and compressed natural gas fuel chains exhibited considerably higher damage values of 114.2 mPt/km and 132.6 mPt/km, respectively. The comparative life cycle assessment of fuel chains suggested that biogas-powered buses and electric trolleybuses can be considered as the best alternatives to use when modernizing the public transport fleet in Kaunas.

title: Can a prolonged use of a passenger car reduce environmental burdens? Life Cycle analysis of Swiss passenger cars
abstract: As a consequence of the introduction of limits on exhaust gas emissions and a target agreement between the Swiss association of car importers (auto-schweiz) and the Swiss government calling for a reduction in the specific fuel consumption, a considerable reduction of exhaust emissions of newly registered Swiss passenger cars occurred in the last 10 years. Also, for the near future an ongoing reduction of exhaust emissions of newly registered vehicles is expected. However, applying the concept of life cycle thinking, exhaust emission reductions may be outbalanced with an increase in specific car manufacturing expenditures and/or a longer use of the car. Thus, from the point of view of an individual car owner, a prolonged car use may be the environmentally preferable option. In order to investigate this question, a comprehensive analysis of the environmental performance of newly registered diesel and petrol passenger cars in the time period from 2000 to 2010 has been performed. Life Cycle Assessment (LCA) has been employed focusing on three transport components: ‘vehicle travel’ (exhaust and abrasion emissions), ‘fuel chain’ (supply of fuels) and ‘car infrastructure’ (manufacturing, maintenance and disposal of cars). The presented model aims to gain insight into the issue of longevity and prolonged car use for the Swiss case, rather than giving ultimate recommendations. The analysis focuses on classical road pollutants (NOx and PM2.5) as well as on fuel consumption reduction and CO2. Moreover, impact assessment has been applied, employing a common approach: Eco-Indicator (EI) 99. The ranking of different car replacement options revealed prolonged car use as the environmentally better option. As a consequence of the continuous use of the car representing 2000 average technology, the components ‘vehicle travel’ and ‘fuel chain’ show a 10% and 9% higher performance, respectively. This effect is compensated by savings in ‘car infrastructure’ (26%). Uncertainty analysis has been performed by additional model runs with different parameter settings. Despite the fact that a considerably prolonged car use scores best for all additional model runs, the resulting differences between options further decrease. This holds particularly true, if a higher yearly average fuel reduction rate of 3% is assumed. Furthermore, applying an avoided burden concept for infrastructure modeling (Value Corrected Substitution (VCS)) shows the same effect. In both cases the resulting scores differ merely marginally between the considered options and would not allow for discrimination. As a consequence of these outcomes, it is not possible to give any general recommendation to Swiss car owners to extend the use of their cars, in the short term.

title: Energy efficiency technologies for road vehicles
abstract: A key message of the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change is that improved energy efficiency is one of society’s most important instruments for combating climate change. This article reviews a range of energy efficiency measures in the transportation sector as discussed in AR4 and assess their potentials for improving fuel efficiency. The primary focus is on light-duty vehicles because they represent the largest portion of world transport energy use and carbon dioxide emissions; freight trucks, a rapidly expanding source of greenhouse emissions, are also discussed. Increasing energy efficiency can be achieved by improving the design and technology used in new vehicles, but vehicle technology is only one component of fleet fuel economy. Measures that create strong incentives for customers to take energy efficiency into consideration when buying and operating their vehicles will be crucial to policy success.

title: Life cycle environmental assessment of lithium-ion and nickel metal hydride batteries for plug-in hybrid and battery electric vehicles.
abstract: This study presents the life cycle assessment (LCA) of three batteries for plug-in hybrid and full performance battery electric vehicles. A transparent life cycle inventory (LCI) was compiled in a component-wise manner for nickel metal hydride (NiMH), nickel cobalt manganese lithium-ion (NCM), and iron phosphate lithium-ion (LFP) batteries. The battery systems were investigated with a functional unit based on energy storage, and environmental impacts were analyzed using midpoint indicators. On a per-storage basis, the NiMH technology was found to have the highest environmental impact, followed by NCM and then LFP, for all categories considered except ozone depletion potential. We found higher life cycle global warming emissions than have been previously reported. Detailed contribution and structural path analyses allowed for the identification of the different processes and value-chains most directly responsible for these emissions. This article contributes a public and detailed inventory, which can be easily be adapted to any powertrain, along with readily usable environmental performance assessments.

title: Environmental assessment of RAMseS multipurpose electric vehicle compared to a conventional combustion engine vehicle
abstract: The RAMseS project, financed by the European Commission under the 6th framework Program, has the purpose of developing a solar powered agricultural vehicle in order to replace the conventional vehicles based on internal combustion engines (ICE). In the present study, we report a comparison of life-cycle emission between two systems; a conventional ICE vehicle (ICEV) and the RAMseS electrical vehicle (EV). The study has been conducted by designing a specific model and using the SimaPro software. The results show that the RAMseS system is considerably more environmentally friendly than conventional ICE based system and that, specifically, it can avoid the emission of about 23 ton of CO 2equ per year. Regarding all other pollutants, we found that the RAMseS system is 2.6 times more efficient than the ICEV. The main contribution to emissions of the RAMseS system is due to the batteries which contribute for a 73% of the total. Therefore, further improvement can be obtained with the use of more advanced battery systems, not based on lead.

title: Comparative Environmental Life Cycle Assessment of Conventional and Electric Vehicles
abstract: Electric vehicles (EVs) coupled with low-carbon electricity sources offer the potential for reducing greenhouse gas emissions and exposure to tailpipe emissions from personal transportation. In considering these benefits, it is important to address concerns of problemshifting. In addition, while many studies have focused on the use phase in comparing transportation options, vehicle production is also significant when comparing conventional and EVs. We develop and provide a transparent life cycle inventory of conventional and electric vehicles and apply our inventory to assess conventional and EVs over a range of impact categories. We find that EVs powered by the present European electricity mix offer a 10% to 24% decrease in global warming potential (GWP) relative to conventional diesel or gasoline vehicles assuming lifetimes of 150,000 km. However, EVs exhibit the potential for significant increases in human toxicity, freshwater eco-toxicity, freshwater eutrophication, and metal depletion impacts, largely emanating from the vehicle supply chain. Results are sensitive to assumptions regarding electricity source, use phase energy consumption, vehicle lifetime, and battery replacement schedules. Because production impacts are more significant for EVs than conventional vehicles, assuming a vehicle lifetime of 200,000 km exaggerates the GWP benefits of EVs to 27% to 29% relative to gasoline vehicles or 17% to 20% relative to diesel. An assumption of 100,000 km decreases the benefit of EVs to 9% to 14% with respect to gasoline vehicles and results in impacts indistinguishable from those of a diesel vehicle. Improving the environmental profile of EVs requires engagement around reducing vehicle production supply chain impacts and promoting clean electricity sources in decision making regarding electricity infrastructure.

title: The anthropogenic stock extended abiotic depletion potential (AADP) as a new parameterisation to model the depletion of abiotic resources
abstract: PurposeRaw material availability is a cause of concern for many industrial sectors. When addressing resource consumption in life cycle assessment (LCA), current characterisation models for depletion of abiotic resources provide characterisation factors based on (surplus) energy, exergy, or extraction–reserve ratios. However, all indicators presently available share a shortcoming as they neglect the fact that large amounts of raw materials can be stored in material cycles within the technosphere. These “anthropogenic stocks” represent a significant source and can change the material availability significantly. With new characterisation factors, resource consumption in LCA will be assessed by taking into account anthropogenic material stocks in addition to the lithospheric stocks. With these characterisation factors, the scarcity of resources should be reflected more realistically. study introduces new characterisation factors—the anthropogenic stock extended abiotic depletion potentials—for the impact category depletion of abiotic resources. The underlying characterisation model is based on the conventional model but substitutes ultimate reserves by resources and adds anthropogenic material stocks to the lithospheric stocks.Results and discussionA fictional life cycle inventory, consisting of 1 kg of several metals, was evaluated using different characterisation factors for depletion of abiotic resources. Within this analysis it is revealed that materials with relatively large anthropogenic stocks, e.g. antimony and mercury, contribute comparatively less to abiotic depletion when using the new characterisation factors. Within a normalized comparison of characterisation factors, the impact of anthropogenic stock results in relative differences between −45% and +65%, indicating that anthropogenic stocks are significant.ConclusionsWith the new parameterisation of the model, depletion of abiotic resources can be assessed in a meaningful way, enabling a more realistic material availability analysis within life cycle impact assessment. However, a larger set of characterisation factors and further research are needed to verify the applicability of the concept within LCA practice.

title: Priority assessment of toxic substances in life cycle assessment. Part I: calculation of toxicity potentials for 181 substances with the nested multi-media fate, exposure and effects model USES-LCA.
abstract: Toxicity potentials are standard values used in life cycle assessment (LCA) to enable a comparison of toxic impacts between substances. In most cases, toxicity potentials are calculated with multi-media fate models. Until now, unrealistic system settings were used for these calculations. The present paper outlines an improved model to calculate toxicity potentials: the global nested multi-media fate, exposure and effects model USES-LCA. It is based on the Uniform System for the Evaluation of Substances 2.0 (USES 2.0). USES-LCA was used to calculate for 181 substances toxicity potentials for the six impact categories freshwater aquatic ecotoxicity, marine aquatic ecotoxicity, freshwater sediment ecotoxicity, marine sediment ecotoxicity, terrestrial ecotoxicity and human toxicity, after initial emission to the compartments air, freshwater, seawater, industrial soil and agricultural soil, respectively. Differences of several orders of magnitude were found between the new toxicity potentials and those calculated previously.

title: SUBAT: An assessment of sustainable battery technology
abstract: The SUBAT-project evaluates the opportunity to keep nickel–cadmium traction batteries for electric vehicles on the exemption list of European Directive 2000/53 on End-of-Life Vehicles. The aim of the SUBAT-project is to deliver a complete assessment of commercially available and forthcoming battery technologies for battery-electric, hybrid or fuel cell vehicles. This assessment includes a technical, an economical and an environmental study of the different battery technologies, including the nickel–cadmium technology. In a general perspective, the impacts of the different battery technologies should be analysed individually to allow the comparison of the different chemistries (lead–acid, nickel–cadmium, nickel-metal hydride, lithium-ion, sodium–nickel chloride, …) and to enable the definition of the most environmentally friendly battery technology for electrically propelled vehicles. The project officially ran from 2004-01-01 to 2005-03-31. This paper summarizes the outcome of the project at the time of the submission of the paper, i.e. January 2005.

title: Life cycle assessment of lithium-ion batteries for plug-in hybrid electric vehicles – Critical issues
abstract: The main aim of the study was to explore how LCA can be used to optimize the design of lithium-ion batteries for plug-in hybrid electric vehicles. Two lithium-ion batteries, both based on lithium iron phosphate, but using different solvents during cell manufacturing, were studied by means of life cycle assessment, LCA. The general conclusions are limited to results showing robustness against variation in critical data. The study showed that it is environmentally preferable to use water as a solvent instead of N-methyl-2-pyrrolidone, NMP, in the slurry for casting the cathode and anode of lithium-ion batteries. Recent years’ improvements in battery technology, especially related to cycle life, have decreased production phase environmental impacts almost to the level of use phase impacts. In the use phase, environmental impacts related to internal battery efficiency are two to six times larger than the impact from losses due to battery weight in plug-in hybrid electric vehicles, assuming 90% internal battery efficiency. Thus, internal battery efficiency is a very important parameter; at least as important as battery weight. Areas, in which data is missing or inadequate and the environmental impact is or may be significant, include: production of binders, production of lithium salts, cell manufacturing and assembly, the relationship between weight of vehicle and vehicle energy consumption, information about internal battery efficiency and recycling of lithium-ion batteries based on lithium iron phosphate.

title: Comparison between hydrogen and electric vehicles by life cycle assessment: A case study in Tuscany, Italy
abstract: The use of hydrogen produced from renewable energy sources is often reported as an attractive strategy to address the issue of urban environmental sustainability in automotive sector, and a potential alternative to fossil fuel-fed vehicles. The project ‘Filiera Idrogeno’ (Hydrogen Chain) has investigated the potential realisation of hydrogen production chains from renewables and its use as automotive fuel in Tuscany Region (Italy). In this context, life cycle assessment was used for evaluating the environmental sustainability of such chains, applied to a fleet of hydrogen vehicles for urban commercial delivery.

title: Regional assessment of local emissions of electric vehicles using traffic simulations for a use case in Germany
abstract: PurposeIn order to assess the global and local environmental impacts of different penetration rates of electric vehicles (EVs) within a region, we developed a life cycle approach based on a detailed traffic simulation assessing local emissions for individual roads with a high time resolution. The aim was to estimate the reduction potential of local emissions such as particulate matter within a region through a substitution of conventional with electric vehicles.Materials and methodsThe chosen approach assessing local emissions includes a detailed traffic simulation of a vehicle fleet composed of individual vehicles with a daily schedule. The driving pattern is modeled based on a survey of driving patterns in Germany. Incorporation of traffic density for each road and emissions of electric and conventional vehicles permits conclusions on the reduction potential for each street. Moreover, a feasible reduction potential for a particular region can be assessed. A case study for Aachen, Germany is presented within this paper. For the classification of the local emissions with the usual life cycle assessment approach, a comparison of EV, PHEV, and conventional vehicles has been conducted for Germany providing the results for impact categories according to CML 2001.Results and discussionBased on simulation results, an estimation of the reduction potential for Aachen for different penetration rates of electric vehicles including particulate matter (PM10), carbon monoxide (CO), and nitrogen oxygen (NOx) is carried out. Electric vehicles possess the highest reduction potential for CO and NOx. Assuming 50 % of the total vehicle fleet in 2010 substituted by electric vehicles, local emissions of CO reduce by 46.6 %, for NOx by 38.8 %, and for PM10 by 22.4 %. Due to fluctuations in driving patterns throughout a day, the results are highly time dependent. However, improvements in combustion engine technologies results in an increased reduction potential for conventional vehicles. The direct comparison between the vehicle types showed that the benefit of electric vehicles depends on the considered impact category.ConclusionsElectric vehicles are able to reduce local emissions within a region. Moreover, this approach focusing on the use phase of vehicles within a regional assessment and the resulting local emissions as well as the detailed analysis of the driving behavior allows a distinguished assessment of the reduction potential of electric vehicles. Additionally, an assessment of policy measures such as drive restrictions for conventional vehicles can be simulated on the base of this approach.

title: Life-Cycle Analysis of Alternative Automobile Fuel/Propulsion Technologies
abstract: We examine the economic and environmental implications of the fuels and propulsion technologies that will be available over the next two decades for powering a large proportion of the light duty fleet (cars and light trucks). Since R&D change is rapid, we treat the uncertainty about future technologies using bounding calculations. A life-cycle perspective is used to analyze fossil fuels [conventional unleaded and reformulated gasolines, low sulfur reformulated diesel, and compressed natural gas (CNG)], ethanol from biomass, and electricity together with current and advanced internal combustion engines (ICE, indirect (port) and direct injection, spark, and compression ignited) and electric vehicles (battery-powered, hybrid electric, and fuel cell). Technological advances continue to improve the efficiency and environmental performance of ICE automobiles powered by low sulfur fossil fuels. Absent a doubling of petroleum prices or stringent regulation [due, for example, to intense concerns about greenhouse g...