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PURPOSE: A literature review is undertaken to understand how well existing studies of the environmental impacts of hybrid and electric vehicles (EV) address the full life cycle of these technologies. Results of studies are synthesized to compare the global warming potential (GWP) of different EV and internal combustion engine vehicle (ICEV) options. Other impacts are compared; however, data availability limits the extent to which this could be accomplished. METHOD: We define what should be included in a complete, state-of-the-art environmental assessment of hybrid and electric vehicles considering components and life cycle stages, emission categories, impact categories, and resource use and compare the content of 51 environmental assessments of hybrid and electric vehicles to our definition. Impact assessment results associated with full life cycle inventories (LCI) are compared for GWP as well as emissions of other pollutants. GWP results by life cycle stage and key parameters are extracted and used to perform a meta-analysis quantifying the impacts of vehicle options. RESULTS: Few studies provide a full LCI for EVs together with assessment of multiple impacts. Research has focused on well to wheel studies comparing fossil fuel and electricity use as the use phase has been seen to dominate the life cycle of vehicles. Only very recently have studies begun to better address production impacts. Apart from batteries, very few studies provide transparent LCIs of other key EV drivetrain components. Estimates of EV energy use in the literature span a wide range, 0.10–0.24 kWh/km. Similarly, battery and vehicle lifetime plays an important role in results, yet lifetime assumptions range between 150,000–300,000 km. CO2 and GWP are the most frequently reported results. Compiled results suggest the GWP of EVs powered by coal electricity falls between small and large conventional vehicles while EVs powered by natural gas or low-carbon energy sources perform better than the most efficient ICEVs. EV results in regions dependant on coal electricity demonstrated a trend toward increased SO x emissions compared to fuel use by ICEVs. CONCLUSIONS: Moving forward research should focus on providing consensus around a transparent inventory for production of electric vehicles, appropriate electricity grid mix assumptions, the implications of EV adoption on the existing grid, and means of comparing vehicle on the basis of common driving and charging patterns. Although EVs appear to demonstrate decreases in GWP compared to conventional ICEVs, high efficiency ICEVs and grid-independent hybrid electric vehicles perform better than EVs using coal-fired electricity.

PURPOSE: Although a significant number of environmental protection measures concerning industrial products and processes have emerged over the past few years, similar measures have only started to appear in road construction and related practices. There is a need for understanding what a “sustainable pavement” would entail in terms of greenhouse gas emissions and energy consumption. Since environmental impact assessment of major projects is becoming mandatory in many countries, various research projects attempt to evaluate the environmental impact of different pavement materials, technologies, or processes over the road life cycle. To support these efforts, there is a need to measure and describe different aspects of sustainability related to road pavements. In particular, keeping road pavements at high service levels through a preventive maintenance approach during the pavement service life has been proven to provide significant improvement of their performance and reduce their deterioration rate. METHODOLOGY: This paper describes an innovative methodology to evaluate the environmental impact of preventive maintenance activities. It relates these activities to performance and cost during the service life of the pavement through a multi-attribute “life cycle cost, performance, and environmental analysis”. Emissions and energy saved adopting several preventive maintenance strategies were computed, relating them to cost and performance. Equipment and materials usually involved in road maintenance practices were also analyzed in order to assess specific fuel consumption and energy spent. An ad hoc index was ultimately created, adopting a script file to evaluate the best strategy through the multi-attribute approach. RESULTS AND CONCLUSIONS: Results show how eco-effective it can be to improve pavement management practices on roads by implementing energy efficient treatments and strategies. Furthermore, eco-saving factors could represent a new and innovative feature to be added in the sustainability assessment process for pavements to evaluate different alternatives and assist authorities choosing between different investment solutions as a part of a decision support system.

PURPOSE: The purpose of this paper is to take steps towards a life cycle assessment that is able to account for changes over time in resource flows and environmental impacts. The majority of life cycle inventory (LCI) studies assume that computation parameters are constants or fixed functions of time. This assumption limits the opportunities to account for temporal effects because it precludes consideration of the dynamics of the product system. METHODS: System dynamics methods are used in a consequential, fleet-based LCI that accounts for some aspects of the dynamics of the wider system. The LCI model compares the life-cycle energy consumption of car body-in-whites (BIWs) in Australia made from steel and aluminium. It incorporates two dynamic processes: the flow of BIWs into and out of the fleet, and the recycling of aluminium from end-of-life BIWs back into new BIW production. The dynamical model computes both product-based and fleet-based estimates. RESULTS AND DISCUSSION: The product-based computations suggest that an aluminium BIW consumes less energy than a steel BIW over a single life cycle. The fleet-based computations suggest that the energy benefits of aluminium BIWs do not begin to emerge for some time. The substitution of aluminium for steel is a low-leverage intervention that changes the values of a few parameters of the system. The system has a delayed, damped response to this intervention because the large stock of BIWs is a source of high inertia, and the long useful life leads to a slow decay of steel BIWs out of the fleet. The recycling of aluminium back into BIW production is a moderate-leverage intervention that initially strengthens a reinforcing feedback loop, driving a rapid accumulation of energy benefits. Dominance then shifts to a balancing loop, slowing the accumulation of energy benefits. Both interventions result in a measureable reduction in life-cycle energy consumption, but only temporarily divert the underlying growth trend. CONCLUSIONS: The results suggest that product-based LCIs overestimate the short-term energy benefits of aluminium by not accounting for the time required for the stock of preexisting steel components to decay out of the fleet, and underestimate the long-term energy benefits of aluminium components by not accounting for changes in the availability of recycled aluminium. The results also suggest that interventions such as lightweighting and other efficiency measures alone can slow the growth of energy consumption, but are probably inadequate to achieve sustainable energy consumption levels if the fleet is large.

PURPOSE: There are methodological questions concerning life cycle assessment (LCA) and carbon footprint evaluation of road pavements, including allocation among co-products or at end-of-life (EOL) recycling. While the development and adoption of a standard methodology for road pavement LCA would assist in transparency and decision making, the impact of the chosen method on the results has not yet been fully explored. METHODS: This paper examines the methodological choices made in UK PAS 2050 and asphalt Pavement Embodied Carbon Tool (asPECT), and reviews the allocation methods available to conduct road pavement LCA. A case study of a UK inter-urban road construction (cradle-to-laid) is presented to indicate the impact of allocation amongst co-products (bitumen and blast furnace slag); a typical UK asphalt production (cradle-to-gate) is modelled to show the influence of allocation at EOL recycling. RESULTS AND DISCUSSION: Allocation based on mass is found to consistently lead to the highest figures in all impact categories, believed to be typical for construction materials. Changing from industry chosen allocation methods (Eurobitume, asPECT) to 100 % mass or economic allocation leads to changes in results, which vary across impact categories. This study illustrates how the allocation methods for EOL recycling affect the inventory of a unit process (asphalt production). CONCLUSIONS AND RECOMMENDATIONS: Sensitivity analysis helps to understand the impact of chosen allocation method and boundary setting on LCA results. This initial work suggests that economic allocation to co-products used as secondary pavement materials may be more appropriate than mass allocation. Allocation at EOL recycling by a substitution method may remain most appropriate, even where the balance of credits between producers and users may be hampered by an inability to confidently predict future recycling rates and methods. In developing sector-specific guidelines, further sensitivity checks are recommended, such as for alternative materials and traffic management during maintenance.

Purpose In the transportation sector, reducing vehicle weight is a cornerstone strategy to improve the fuel economy and energy efficiency of road vehicles. This study investigated the environmental implications of lightweighting two automotive parts (Ford Taurus front end bolster, Chevrolet Trailblazer/GMC Envoy assist step) using glass-fiber reinforced polymers (GFRP) instead of steel alloys. Methods The cradle-to-grave life cycle assessments (LCAs) for these studies consider a total service life of 150,000 miles for two applications: a 46 % lighter GFRP bolster on the 2010 Ford Taurus that replaced the 2008 steel and GFRP bolster, and a 51 % lighter GFRP running board for the 2007 Chevrolet Trailblazer/GMC Envoy that replaced the previous steel running board including its polymer fasteners. The life cycle stages in these critically reviewed and ISO-compliant LCA studies include the production of upstream materials and energy, product manufacturing, use, and the end-of-life treatment for all materials throughout the life cycle. Results and discussion The results show that the lighter GFRP products performed better than the steel products for global warming potential and primary energy demand for both case studies. In addition, the GFRP bolster performed better for acidification potential. The savings of fuel combustion and production during the use stage of a vehicle far outweigh the environmental impacts of manufacturing or end-of-life. An even greater benefit would be possible if the total weight reduction in the vehicle would be high enough to allow for the reduction of engine displacement or an elongation of gear ratio while maintaining constant vehicle dynamics. These so-called secondary measures allow the fuel savings per unit of mass to be more than doubled and are able to offset the slightly higher acidification potential of the GFRP running board which occurs when only the mass-induced fuel savings are considered. Conclusions The lightweight GFRP components are shown to outperform their steel counterparts over the full life cycle mainly due to the reduced fuel consumption of the vehicle in the use phase. To harvest the benefits of light weighting to their full extent, it is recommended that the sum of all mass reductions in the design process be monitored and, whenever feasible, invested into fuel economy by adapting the drive train while maintaining constant vehicle performance rather than leveraging the weight reduction to improve vehicle dynamics.

PURPOSE: A major task concerning the greening of freight transportation is to influence the process of choosing an appropriate transport solution for a shipment. This paper presents the results of a detailed environmental benchmark study of freight transport chains recorded during a shipper survey administered in Switzerland in 2008. MATERIALS AND METHODS: For the environmental evaluation, life cycle assessment was applied and enhanced with a new method for integrating damage to human health caused by traffic accidents based on the disability adjusted life year concept. RESULTS AND DISCUSSION: The results show that in land-based transport, road generally has a lower environmental performance compared to intermodal and rail-only transport. Exceptions exist, e.g. for long pre- and post-haulage distances in intermodal transport or for very low train-load factors. The most relevant environmental interventions to pay attention to are, according to the methods applied, emissions of CO₂, NOₓ and particulates as well as accident damages. CONCLUSIONS: Rail transport is often, but not always, environmentally preferable than truck transport. Accident damages to human health should be included in each benchmark study. For practical application, a simplified benchmark methodology is proposed requiring a reduced level of detail for the input data.

PURPOSE: While the application of Life Cycle Assessment (LCA) to lubricants can be considered fully operational for general purposes outside the lubricants industry, where Life Cycle Inventories (LCIs) of mineral and synthetic base oils can be used interchangeably and where additives can be excluded, this is not the case for research and development purposes within the industry. Previous LCAs of base oils are not sufficiently detailed and comprehensive for R&D purposes, and there are no LCAs of lube additives and fully formulated lubricants. The aim of this paper is to integrate and expand previous LCAs of base oils and to investigate on the contribution of lube additives to the environmental impacts of a fully formulated lubricant. MATERIALS AND METHODS: This study considers three base oils (mineral, poly-alpha-olefins (PAO) and hydrocracked) and a set of lubricating additives typically used in fully formulated engine oil. The LCA model is based on both industry and literature data. RESULTS AND DISCUSSION: Trends in the lubricants industry towards more sophisticated base oils correspond to remarkably higher environmental impacts per kilogram of product but lead to reduced impacts per kilometre. The contribution of additives to the life cycle impacts of commercial lube oil was found to be remarkably high for some impact categories (nearly 35 % for global warming). CONCLUSIONS: As base oil is concerned, this study made the point on data availability and provided a contribution in order to integrate and expand previous LCAs of mineral base oil and PAO. On the side of additives, the main conclusion is that in modern lubricants, the contribution of additives in terms of environmental impact can be remarkably high and, therefore, they should not be excluded.

PURPOSE: In the Indonesian transportation sector, gasoline is the most consumed fuel; in 2008 it accounted for 60% of the total fuel consumption in transportation. Increasing concern regarding environmental issues, particularly urban air quality, makes the utilization of gasoline in transport a crucial aspect to be analyzed. However, besides tailpipe emissions, there are many upstream processes when producing gasoline which need to be evaluated in terms of impacts to the environment. MATERIALS AND METHODS: Life cycle assessment (LCA) is used as a tool for the assessment of resource consumption and associated impacts generated from utilization of gasoline in the transportation sector including crude oil extraction, oil refining and the use of gasoline in car. The impact categories considered are global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), abiotic resource depletion potential (ADP), human toxicity potential (HTP), and ecotoxicity potential (ETP). RESULTS AND DISCUSSION: The results show that for global warming, gasoline combustion during end use contributes 93% of the total. The second largest contributor to GWP is oil refining (5%) followed by crude oil extraction (2%). In AP, combustion plays a significant role too with a contribution of 84%, followed by refining with 13% and crude oil extraction with 2%. The most significant process contributing to EP is once again gasoline combustion (95%) and the second contributor is the refining stage (4%), while transport contributes only 1%. For abiotic resource depletion on the other hand, almost 100% of the impact is from crude oil extraction. For HTP, the refining stage plays a very significant role to the life cycle of gasoline contributing 99.6%, whereas for ETP it is refining (62%) and extraction (38%). CONCLUSION: Using gasoline as transport fuel indicates that gasoline combustion is predominantly responsible for GWP, AP and EP whilst ADP is dominated by crude oil extraction stage and refinery is mainly responsible for human toxicity and ecotoxicity potential, PERSPECTIVES: The result of this study can be used as an overview for gasoline production and to compare with other transportation fuel options in Indonesia.

PURPOSE: Increasing mobility demands and growing industrial tissue come with a burden for the environment. Inventive solutions are necessary to address this challenge. This paper compares the environmental impact of two alternative container transportation methods over a 25-year time period for a specific trajectory and transport volume in the Antwerp harbor. One is a pipeline concept; the other a road concept to link the Deurganck dock with the right bank in order to transport 2 million containers per year. MATERIALS AND METHODS: With a detailed bill of material and the use of the Ecolizer method, a Monte Carlo simulation was performed to calculate the environmental impact in terms of ECOPOINTS on a life cycle perspective. RESULTS AND DISCUSSION: The results remark that in 94% of the cases the pipeline concept has less than half of the environmental impact of the road concept. Furthermore, in both concepts the operational phase is the largest contributor to the total environmental impact. CONCLUSIONS: The pipeline concept results suggest a much lower total environmental impact over a road concept if a large enough volume of containers can effectively be transported. Some considerations have to be given to the used electricity mix, the applied impact assessment method and the case specificities.

PurposeInvestigating potential social and socio-economic impacts should play a key role for the development of sustainable mobility alternatives. Social life cycle assessment (S-LCA) is becoming increasingly important to ensure holistic sustainability assessments. The present work aims at identifying and evaluating social and socio-economic impact subcategories in S-LCA. A novel participatory approach implying all concerned stakeholders is proposed to select relevant impact subcategories and thus contribute to a thorough interpretation of S-LCA results. It is applied to assess electric and conventional vehicles.MethodologyThis paper describes a comprehensive step-by-step S-LCA framework. The innovation of this work consists in defining a structured S-LCA framework integrating a systematic approach based on two stages: (1) a sectorial risk analysis for the identification of impact subcategories and (2) a participatory approach for their prioritization. The proposed participatory approach considers all concerned stakeholders to enable the selection of the most relevant impact subcategories. A set of social inventory indicators is attributed to subcategories that were perceived as the most relevant. These are used to perform the social evaluation and carry out a full analysis in the result interpretation allowing thus to integrate a multi-actor perspective to the materiality assessment.ResultsThe defined S-LCA framework is implemented to compare two mobility scenarios, corresponding to electric and conventional vehicle technologies. A new set of mobility-related impact subcategories is proposed for users’ stakeholder. Following the new designed participatory approach, subcategories for all stakeholders are prioritized according to different actors’ perceptions. For example, “safe and healthy living conditions,” “local employment,” and “delocalization and migration” were perceived for local communities as the most relevant subcategories by the different consulted stakeholders (industrial, academic, and public actors and users). These results also showed that social significance varies depending on the consulted actors and on the geographical area of the study. Using PSILCA database, we have investigated the subcategories that were perceived as the most relevant. Results for the evaluation and interpretation phases are presented for both transportation technologies.ConclusionsThis approach aims at increasing local relevance of S-LCA results and their representativeness. Results for the considered mobility scenarios have demonstrated the need to extend the scope of the materiality assessment, generally used for determining subcategories’ social significance from a single stakeholder perspective, by involving other stakeholders into the prioritization stage. Moreover, the proposed comprehensive S-LCA framework integrating the participatory approach is general enough to be applied to other product systems and sectors.