Environmental performance of a battery electric vehicle: a descriptive Life Cycle Assessment approach

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1 Page EVS25 Shenzhen, China, Nov 5-9, 2010 Environmental performance of a battery electric vehicle: a descriptive Life Cycle Assessment approach Messagie M. 1, Boureima F. 1, Matheys J. 1, Sergeant N. 1, Timmermans J-M. 2, Macharis C. 3 and Van Mierlo J. 1 1 Mobility and Automotive Technology Research Group (MOBI), Faculty of Engineering, Vrije Universiteit Brussel, Abstract Pleinlaan 2, 1050 Brussels, Belgium, maarten.messagie@vub.ac.be. 2 ETEC Faculty of Engineering, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium. 3 MOSI-T Faculty of Engineering, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium. In this paper the environmental impacts of a battery electric vehicle (BEV) are assessed in a Belgian context. A full descriptive Life Cycle Assessment (LCA) is performed, including the well-to-wheel (WTW) emissions (for a BEV these are the emissions coming from the electricity production) and the cradle-tograve emissions (related directly and indirectly to the production and the end-of-life (EOL) processing of the vehicle). First an overview of the energy consumption of the different vehicle technologies is given. This clearly shows that battery electric vehicles are less energy intensive than other vehicle technologies. Secondly, the environmental impacts of a BEV during its entire life cycle are assessed in detail. This illustrates the relative importance of the manufacturing step for a BEV and the strongly reduced environmental impact when recycling the battery. Furthermore, the influence of the electricity supply mix on the overall environmental impact of a BEV is assessed. The investigated electricity production plants include renewable and non-renewable resources: wind, hydro, nuclear, biogas, natural gas, oil and coal. The assessed impact categories are: acidification, human health and the greenhouse effect (GHE). A BEV has a better scores than a petrol vehicle except for the full coal or oil electricity production scenario, for which the BEV can have a bad score for human health and acidification. Keywords: LCA, electric vehicle, Climate change, gasoline engine, electricity production 1 Environmental impact of different vehicle technologies Passenger transportation is responsible for large quantities of pollutants in the atmosphere [1]. In previous work, the environmental impacts of different fuels and vehicle technologies have been evaluated with the LCA methodology. A detailed description of the methodology, assumptions, inventory and model can be found in [2], [3]. The life cycle inventory, which was performed in the framework of the CLEVER project, covers all the life cycle phases of conventional and alternative vehicles. It includes the extraction of raw materials, the manufacturing of components, the assembly, the use phase (on a well-to-wheel (WTW) basis) and the end-of-life (EOL) treatment. [4] shows the results for an automotive Life Cycle Assessment (LCA) at country level (Belgium), covering different vehicle technologies: petrol, diesel, liquefied petroleum EVS25 World Battery,Hybrid and Fuel Cell ElectricVehicle Symposium 1

2 Page gas (LPG), compressed natural gas (CNG), bioethanol, bio-diesel, hybrid and battery electric vehicles. This shows clearly that a BEV, powered with electricity from the Belgian grid, has a better environmental score than all other vehicle technologies for air acidification, human health and greenhouse effect. To complete the comparison of the environmental impact of the different vehicle technologies, an overview of the energy consumption is shown in Figure 1. It can be distinguished that BEVs use less energy than all other considered technologies. BEV running on electricity produced with natural gas or wind energy are the most energy efficient vehicles. 600,00 500,00 400,00 300,00 200,00 100,00 0,00 Petrol Bio-ethanol (Rye) Hybrid petrol Diesel with DPF Bio-diesel (RME) CNG LPG Hydrogen ICE (Natural Gas) Energy consumption () [MJ/100km] Energy consumption (TTW) [MJ/100km] Figure 1: WTW energy consumption of equivalent 2010 passenger cars. The tank-to-wheel (TTW) fuel consumption (l/100km) of the different vehicle technologies is based on the assumptions from [5]. The values represent equivalent, small, Euro 4 passenger vehicles. For the electric vehicle, an electricity consumption of 16 kwh/100km is considered. The WTW energy consumption is calculated based on the cumulative energy demand [6] for the different fuels from [7]. The cumulative energy demand includes all direct and indirect energy uses throughout the life cycle of the fuel and the energy content. The WTW energy consumption is then divided between (wellto-tank) and TTW considering the lower heating value (LHV) from [5]. The included vehicle technologies or fuels are petrol, bio-ethanol from rye, hybrid drive train, diesel, bio-diesel from rape methyl ester (RME), CNG, LPG, hydrogen from natural gas in an internal combustion engine (ICE) and a BEV on electricity produced with the Belgian mix, natural gas and wind energy. BEV (BE mix) BEV (Natural Gas) BEV (wind) 2 Environmental performance of the different life cycle phases of a BEV The results presented in this paper, are produced with three calculation methods: the IPCC 2007 greenhouse effect over 100 years [8], the human health impact from [9] and the air acidification impact calculation method from [10]. All parameters in the LCA model, such as energy consumption, weight of the vehicle, weight of the battery and driven distance are described as statistical distributions covering all individual vehicles on the Belgian market. Hereby a dynamic model is created, allowing an automatic sensitivity analysis. The results of this automatic sensitivity analysis can be seen in figures 2 and 3. Detailed LCI data of a Lithium battery have been collected from the SUBAT project [11] and [12]. Thanks to the OVAM study [13] on the vehicles EOL in Belgium, all the recycling and energy recovery rates per material with respect to the real efficiency of Belgian recycling plants were collected. Figure 2 shows the impact of the different life cycle phases of a BEV using electricity from the Belgian electricity mix (approximately 46% nuclear, 21% natural gas and 9% coal) [7]. The box-plots are a five-number summary of the distribution of the results, showing the interquartile range, the mean, the 98th (maximum) and 2nd (minimum) percentile. The production phase of the vehicle covers the manufacturing of the vehicle components, the assembly and the transport between manufacturing plants and the end user. The needed lead battery is modeled within the production phase, the EOL of the lead battery is modeled together with the end-of-life the car. On average, the use phase is the main contributor to the assessed impact categories. When considering the greenhouse effect, the electricity consumption during the use phase is always the main contributor. In some scenarios however, the impact of the Lithium battery can be large for air acidification and human health, when considering the upper value of the box-plot (98th percentile). The high impact of the Lithium battery production on air acidification is mainly caused by sulphur oxides and nitrogen oxides emitted during the production of the electrode (30%), the copper (25%), the aluminum (10%) and the used EVS25 World Battery,Hybrid and Fuel Cell ElectricVehicle Symposium 2

3 Page electricity (10%). The processes contributing most to the human health impact category within the manufacturing step of the Lithium battery, are the needed electricity (25%), the production of the electrode (25%) and the production of copper (20%). The emissions with the highest impact are dioxins, sulphur oxides, nitrogen oxides, particulates and arsenic. Because the impacts are linked to the primary material production, the recycling of the main materials of the Lithium battery is of high importance. The recovered materials are modeled as an avoided production of primary materials, explaining the negative impact of the end-of-life treatment of the recycling step. As a result of the very good recycling rate rate of the Lithium battery, the overall life cycle of the battery has a very low impact on the considered impact categories. The included recycling process for Li-ion batteries is a hydrometallurgical process. This aqueous processing of metals involves a mechanical and a chemical step. The batteries are shredded in order to separate metals, paper, plastics and a residue. This residue is further processed to extract the dissolved metals. The input of 1 ton of batteries has an output of 340 kg Cobalt salt, 198 kg Lithium salt, 165 kg iron and steel and 150 kg aluminum [12]. oil based electricity production plants are emitting much more air pollutants compared to other types of electricity production plants. In general a BEV has a better score than a petrol vehicle except for the full coal or oil electricity production scenario, for which the BEV can have a bad score for human health and air acidification. For the GHE, the BEV is most of the times better than a petrol equivalent car, but in some extreme scenarios a small fuel-efficient petrol car can have a better score regarding GHE than a large BEV running only on coal-produced electricity. However, when considering only the interquartile ranges, a switch from petrol to BEV is always advisable. The Belgian electricity mix has a higher impact than the cleanest electricity production plants, but delivers a very good score compared to the petrol vehicle and BEV running on this electricity form is a first, feasible step towards cleaner passenger transportation. However, the production of electricity from renewable energy sources, such as hydro- and wind power, has a huge potential to lower transportation related emissions and impacts even further in the future. 16 CML-Air Acidification [kg eq. H+] IMPACT Human health [points] IPCC Greenhouse effect [1 E+7g eq. CO2] 14 2,5 2 1,5 1 0,5 0-0,5-1 -1,5-2 -2,5 CML-Air Acidification [kg eq. H+] IMPACT Human health [points] Figure 2: Results per life cycle phase for the BEV driving on the Belgian average electricity mix. 3 Influence of the electricity production on the environmental performance of a BEV Figure 3 shows the sensitivity of the environmental impact of a BEV to the type of electricity production. The included different feedstock for the electricity production plants are hydro, wind, nuclear, biogas, natural gas, oil and coal. The results are benchmarked against a BEV running on the Belgian electricity mix and a petrol car. The first issue to notice is that the impact is highly depending on the type of electricity production and that the options with the highest impacts (oil, coal) are the most sensitive ones to variations in the electricity consumption. Coal and IPCC Greenhouse effect [1 E+7g eq. CO2] Figure 3: The sensitivity of the environmental result of a BEV to the type of electricity production. 4 Conclusions The BEV (Belgian electricity mix) not only has the best score for air acidification, human health and the GHE compared to all other vehicle technologies, it is also the most energy efficient vehicle technology today. Like all other vehicle technologies, the use phase of a BEV is determining the overall result. When considering the greenhouse effect, the electricity consumption during the use phase is always the main contributor. The relative influence of the manufacturing step of a BEV (including production of the vehicle and the Lithium battery) is high for the considered impact categories. This means that the manufacturing step is an important life cycle phase to consider when searching for means to lower the environmental burden of a EVS25 World Battery,Hybrid and Fuel Cell ElectricVehicle Symposium 3

4 Page BEV even further. In this manufacturing step the production of a Lithium battery is the most significant component to consider. Recycling is essential to lower the environmental impact of batteries. Due to high recovery rates of the main materials, the EOL treatment has a positive effect on the environmental impact of the whole life cycle of a Lithium battery. The environmental performance of a BEV are influenced by the type of electricity production. On average, a BEV scores better than a petrol vehicle except for the full coal or oil electricity production scenario, for which the BEV can have a bad score for human health and air acidification. Acknowledgements This research has been made possible thanks to the support and funding of the Belgian Science Policy through the Science for a Sustainable Development (SSD) program. In this Framework the CLEVER Clean Vehicle Research: LCA and policy measure project was carried out by Vrije Universiteit Brussel, Université Libre de Bruxelles, Vlaamse Instelling voor Technologisch Onderzoek (VITO) and RDC-Environment. References [1] Van Mierlo J., Macharis C. Goederen- en Personenvervoer: Vooruitzichten en Breekpunten, Freight and passenger transport: prospects and breaking points. Brussels: Garant, ISBN , 579p, [2] Boureima F., Messagie M., Matheys J., Wynen V., Sergeant N., Van Mierlo J., De Vos M., De Caevel M. Comparative LCA of electric, hybrid, LPG and gasoline cars in a Belgian context. Stavanger, Norway: Edition:World Electric Vehicle Journal, Volume: 3, published by: WEVA, ISBN-ISSN: , [3] Van Mierlo J., Boureima F., Sergeant N., Wynen V., Messagie M.,Govaerts L., Denys T., Vanderschaeghe M.,Macharis C., Turcksin L., Hecq W., Englert M.,Lecrombs F.,Klopfert F.,De Caevel B., De Vos M. Clean Vehicle Research: LCA and policy measures (Clever), Final report Phase one. Brussels, Belgium: Belspo: ' ts/clever_finalreport_phasei_ml.pdf', [4] Messagie M., Boureima F., Matheys J., Sergeant N., Turcksin L., Macharis C., Van Mierlo J. "Life Cycle Assessment of conventional and alternative small passenger vehicles in Belgium. Submitted to " IEEE VPPC 2010, Vehicle Power and Propulsion Conference. Lille, France, [5] Concawe EUCAR. Well-to-Wheels analysis of future automotive fuels and power trains in the European context, Well-to-Wheels report version 2C. JRC, [6] VDI. "Cumulative Energy Demand - Terms, Definitions, Methods of Calculation." VDI- Richtlinien 46000, [7] Dones R., Bauer C., Bolliger R., Burger B., Faist Emmenegger M., Frischknecht R., Heck T., Jungbluth N., Röder A., Tuchschmid M. Life Cycle Inventories of Energy systems: Results for Current Systems in Switzerland and other UCTE Countries, Ecoinvent report No. 5. Dübendorf, CH: Paul Scherrer Institut Villingen, Swiss Centre for Life Cycle Inventories, [8] IPCC. Climate Change IPCC Fourth Assessment Report. The Physical Science Basis [9] Jolliet O, Margni M, Charles R, Humbert S, Payet J, Rebitzer G and Rosenbaum R. "IMPACT 2002+: A New Life Cycle Impact Assessment Methodology.." Int J LCA 8 (6), 2003: [10] CML. "CML 2 baseline method." University of Leiden, [11] Matheys J., Timmermans J., Van Mierlo J., Meyer S., Van Den Bossche P. "Comparison of the environmental impact of 5 electric vehicle battery technologies using LCA." International Journal of sustainable manufacturing, 2009: pp , ISBN-ISSN: [12] ERM. Battery Waste Management Life Cycle Assessment. Environmental Resources Management, [13] OVAM., IBGE/BIM, OWD, RDC Environment. Validation of the recycling rates of end-of life vehicles,. OVAM, EVS25 World Battery,Hybrid and Fuel Cell ElectricVehicle Symposium 4

5 Page Authors Maarten Messagie Maarten Messagie is an engineer specialized in industrial development. He also has a master degree in Sustainable Development and Human Ecology at the Vrije Universiteit Brussel and joined the MOBI team (Mobility and automotive technology research group) to work on several projects concerning the environmental burdens of vehicles. His research interests are alternative vehicles and LCA methodology. dr. Fayçal-Siddikou Boureima Fayçal-Siddikou Boureima received the degree of Environmental engineer in Water treatment in 2005, after which he specialized in Ecodesign and Environmental Management. He started working as a researcher at the ETEC department of the Vrije Universiteit Brussel on an LCA for conventional and alternative vehicles. dr. ir. Julien Matheys Julien Matheys graduated in 2003 as a Bio-engineer and obtained a Master degree in Sustainable Development and Human Ecology at the Vrije Universiteit Brussel. Currently he is a research assistant at ETEC, he was involved in an EU project (SUBAT) concerning LCA of batteries and worked on the Ecoscore for buses and passenger cars. ir. Nele Sergeant Nele Sergeant received the degree of Bio-engineer in biotechnology in 2003, after which she specialized in environmental science and technology. She started working as a PhD student at the Electrotechnical engineering department (ETEC) of the Vrije Universiteit Brussel on the Ecoscore methodology and the development of indicators to evaluate mobility measures for Brussels. dr. ir. Jean-Marc Timmermans Jean-Marc Timmermans graduated in 2003 as an Electromechanical Engineer. As an academic assistant, he was involved in several projects related to the evaluation of the environmental impact of both conventional and alternative vehicles and was involved in the development and evaluation of electric bicycles for postal delivery use. In 2010 he obtained a PhD at the Vrije Universiteit Brussel. Prof. Dr. Cathy Macharis Cathy Macharis is a Professor at the Vrije Universiteit Brussel. She teaches courses in operations and logistics management, as well as in transport and sustainable mobility. Her research group MOSI-Transport and logistics focuses on establishing linkages between advanced operations research methodologies and impact assessment. Prof. dr. ir. Joeri Van Mierlo Joeri Van Mierlo obtained his PhD in Engineering Sciences from the Vrije Universiteit Brussel. Joeri is now a full-time lecturer at this university, where he leads MOBI - Mobility and automotive technology research group. His research interests include vehicle and drive train simulation, as well as the environmental impact of transportation. EVS25 World Battery,Hybrid and Fuel Cell ElectricVehicle Symposium 5