Environmental evaluation of future passenger vehicle technologies

E N V I R O N M E N TA L E VA L U AT I O N O F F U T U R E PA S S E N G E R V E H I C L E TECHNOLOGIES ashreeta prasanna

A Life Cycle Assessment with focus on electric drivetrains Ecole des Mines de Nantes Royal Insitutute of Technology Universidad Politechnica de Madrid Paul Scherrer Institute Photo Credit:Travis Sweet

INDEX NOTE

Report Title: Environmental evaluation of future passenger vehicle technologies Placement Title: Industrial project Year: 2012 Author: Ashreeta Prasanna Company: Paul Scherrer Institute Address: 5232 Villigen PSI Switzerland Company tutor: Christian Bauer Role: Life cycle analyst research engineer School tutor: Dr. Valerie Hequet Key words: Life cycle analysis, electric vehicles, lithium batteries, greenhouse gas, lightweighting, use phase modelling Summary: The present report summarizes the work undertaken as part of the ME3 Master’s final internship on the subject of Life Cycle Assessment (LCA) of future electric vehicles at Paul Scherrer Institute. This thesis is part of a larger project called Technology-centered Electric Mobility Assessment (THELMA), aimed at an integrated assessment of a significant penetration of electric vehicles into the Swiss transport sector, and the impacts on both the Swiss electric grid and Switzerland as a whole. The objectives of this thesis are to model the environmental inventories associated with production, use and end-of-life (EOL) of electric vehicles from a life cycle perspective. This will be done for different years (current, 2015, 2030). In addition, the environmental life cycle impacts (climate change, energy demand, air pollution, resource depletion) per km of transport are calculated. Finally, the LCA results of electric cars equipped with batteries are compared with conventional reference technologies (ICE cars fuelled with gasoline, diesel and natural gas).

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I never see what has been done; I only see what remains to be done. Buddha

ACKNOWLEDGMENTS

I would like to thank my supervisor Christian Bauer for his encouragement, guidance and support during this project. I would also like to thank Andrew Simons and Johannes Hofer for their guidance and help during this project. Lastly I would like to thank my academic supervisor Valerie Hequet and my classmates for their continued encouragement during this research work.

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CONTENTS 1

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introduction 5 1.1 Project Context 5 1.2 Objectives and Structure 5 lca scope and framework 7 2.1 Functional unit 7 2.2 System boundaries 8 vehicle life cycle analysis 11 3.1 Electric Vehicle Technologies: Manufacture, Use phase and End of Life 11 3.2 ICEV Vehicle Technologies: Manufacture and End of Life 17 3.3 Fuel Consumption Calculations 18 results 21 4.1 Life Cycle Impact Assessment Methods Used 21 4.2 Comparison of Battery Types 21 4.3 Life Cycle Emissions Results 23 4.4 Vehicle Light-weighting Results 24 4.5 Sensitivity Analysis 27 conclusions 33 limitations and future work 35

i appendix 37 a new data inventories created bibliography

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LIST OF FIGURES

Figure 2.1 Figure 3.1 Figure 3.2 Figure 4.1 Figure 4.2 Figure 4.3 Figure 4.4 Figure 4.5 Figure 4.6 Figure 4.7 Figure 4.8 Figure 4.9

LCA Boundary 9 Percentage composition of cell components 12 Manufacturing a cell 16 CO2 eq emissions of Batteries per kg and per kWh storage capacity 22 Environmental impacts of Cells, calculated using ReCiPe World (H,H) 23 Life Cycle CO2 eq emissions for all vehicles 23 ReCiPe Method results 25 Effect of light-weighting vehicle glider, EV and Gasoline vehicle 26 Comparison of Light-weighting the BIW in vehicle gliders with Aluminum, HHS and CFRP 27 Effect of light-weighting on EV and Natural gas vehicles 27 Sensitivity analysis using French and Swiss electricity mix for EV charging, IPCC GWP 100a Results 29 Sensitivity analysis using French and Swiss electricity mix for EV charging, ReCiPe (H,H) method 30

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L I S T O F TA B L E S

Table 3.1 Table 3.2 Table 3.3 Table 3.4 Table 3.5 Table 3.6 Table 3.7

Vehicle characteristics and source of datasets 12 Lithium Ion Batteries Characteristics 13 Li Air and Li S Battery Characteristics 14 Manufacturing energy demand calculated based on processing requirements 15 EV Vehicle characteristics and fuel consumption 16 ICEV Vehicle characteristics and fuel consumption 17 Constants used to calculate energy demand at the wheels

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EXPLANATION OF VARIOUS TERMS USED future batteries

Batteries expected to enter the market in 2030 to 2050

near future batteries

Batteries expected to enter the market in 2015 to 2020

Cradle to Grave

Full Life Cycle Assessment from resource extraction (’cradle’) to use phase and disposal phase (’grave’).

Well-to-Wheel

Well-to-wheel is the specific LCA used for transport fuels and vehicles. It incorporates the feedstock or fuel production and processing and fuel delivery or energy transmission as well as vehicle operation.

Cradle to Gate

Cradle-to-gate is an assessment of a partial product life cycle from resource extraction (cradle) to the factory gate (i.e., before it is transported to the consumer).

glider

All vehicle parts excluding the drivetrain. Includes Body in White

light-weighting

Reducing weight of vehicle BIW by substituting Steel with materials such as Aluminum, HSS and CFRP

embedded emissions

Emissions from production of a product. (Cradle to gate)

low carbon

Minimal output of greenhouse gas (GHG) emissions into the environment.

data sets/data inventories

The compilation and quantification of the relevant input and output flows for the the quantification of a product or process.

Body in White

BIW refers to the stage in automotive design or automobile manufacturing in which a car body’s sheet metal components have been welded together, but before moving parts (doors, hoods, and deck lids as well as fenders) the motor, chassis sub-assemblies, or trim (glass, seats, upholstery, electronics, etc.) have been added and before painting.

second life

When a battery reaches a point where it can no longer be used in an electric vehicle, it still retains 75-80% of its potential capacity for another use. The next use of the battery is referred to as its second life. 1

L I S T O F A B B R E V I AT I O N S

BEV

Battery Electric Vehicles

BIW

Body-in white

BMS

Battery Management System

CFRP

Carbon fiber reinforced composite

CH

Switzerland

CO2

Carbon dioxide

EU

European Union

EV

Electric Vehicles

FR

France

GHG

Green House Gases

GWP

Global Warming Potential

HHS

High Strength Steel

IPCC

Intergovernmental Panel on Climate Change

kg CO2 -eq LCA

Life Cycle Assessment

LCI

Life Cycle Inventory

LCIA

Life Cycle Impact Assessment

LFP

Lithium Iron Phosphate

LHV

Lower heating value

Li Air

Lithium Air

Li S

Lithium Sulfur

LW

Light weighted

MJ

Megajoules

NCA

Lithium Nickel Cobalt Aluminum Oxide

NG

Natural Gas Vehicle

NOx

Nitrogen oxides

PT ReCiPe (H/H)

Powertrain A life cycle impact assessment method which comprises harmonized category indicators at the midpoint and the endpoint level

TTW

Tank-to-wheel

UCTE

Union for the Co-ordination of Transmission of Electricity

vkm

vehicle kilometer

WTT

Well-to-tank

WTW

Well-to-wheels

wt

2

kilograms of carbon dioxide equivalent

weight

ABSTRACT

The transportation sector is projected to account for 82 percent of the total increase in world (energy related) liquid fuel consumption by 2035 and personal travel will support fast-paced growth in energy use for transportation both in the short term and over the long term [27]. With growing concern about the high level of contribution to greenhouse gases from the transportation sector, governments are responding with policy measures to increase the fuel efficiency of their vehicle fleets. Increasing the percentage of electric vehicles in the fleet is considered to be one of the solutions towards an environmentally sustainable transportation system. This research aims to assess the environmental performance of a range of vehicles expected to be introduced into the market between 2015 to 2030, using a life cycle approach. The vehicle technologies which have been assessed in this study are battery electric vehicles, natural gas, diesel and gasoline vehicles. By conducting a cradle-to-grave Life Cycle Assessment (LCA), a better idea of the impacts of future electric vehicles on the environment can be obtained, and suitable policy measures implemented [3]. The environmental performance of passenger transport vehicles in this thesis is evaluated by two LCIA methods, the IPCC GWP100a [26] and the ReCiPe World (H,H) [22] method; and impacts are calculated for one vehicle kilometer as a functional unit. The IPCC GWP method – providing cumulative Greenhouse Gas (GHG) emissions as result – is one of the most commonly used in LCA and the results can be easily interpreted. However, transport activities generate several other environmental impacts besides global warming emissions. Thus the ReCiPe method – addressing a comprehensive range of environmental burdens – is used to provide an understanding of the vehicle overall environmental profile in impact categories such as human toxicity, freshwater eutrophication, resource depletion, etc. As part of this thesis, several new data inventories have been created for future vehicles, using projections of technology improvements and assumptions on future battery technologies [10]. Some of the important aspects of this research are: • LCA of future electric vehicles with LFP, NCA, Lithium Air and Lithium Sulfur Batteries • Impacts of light-weighting of the vehicle BIW by using materials such as high strength steel (HHS), aluminum and carbon fiber reinforced composites (CFRP) • Calculations of use phase fuel demand based on decreased weight and improved drivetrain efficiencies with a driving cycle that reflects real world conditions • Recycling of the metallic content in vehicles and disposal of non-recyclable parts of the vehicle

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The results of this LCA show that the environmental performance of EV strongly depends on the electricity mix used for charging. Using the current average European electricity mix which is carbon intensive results in the life cycle GHG emissions of EV being similar to those of natural gas vehicles. Gasoline vehicles continue to have the highest greenhouse gas emissions while EV having batteries with high energy density have lower battery weight and thus lower manufacturing and use phase emissions per vehicle km. Results of light-weighting vehicles show that for the boundary conditions and assumptions used in this study, light-weighting of EV with CFRP does not decrease life cycle emissions. In the case where the charging electricity mix is renewable or with low carbon emissions, it is preferable not to lightweight EV or to lightweight them by using recyclable materials which are less energy intensive such as HHS or standard steel. This is because when the charging electricity mix has very low emissions, most of the emissions from EV life cycle come from the manufacturing stage and further reductions in life cycle emissions can only come from the manufacturing or end-of-life stages of the EV life cycle. Decreasing use phase emissions for the EV would have a minimal impact on life cycle emissions and thus for low carbon electricity mix, life cycle emissions of EV can be reduced more effectively by improving efficiency of manufacturing processes, using materials with high recyclability and by standardizing batteries and their production methods.

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INTRODUCTION

1.1

project context

As part of the Joint European Masters in Management and Engineering of Environment and Energy, this thesis has been undertaken at the Paul Scherrer Institute (PSI) in the Technology Assessment Group. PSI is the largest research centre for natural and engineering sciences within Switzerland and research work is undertaken in the subject areas of Matter and Material; Energy and the Environment; and Human Health. As part of the Laboratory for Energy and Environment Analysis (ENE), the technology assessment group at PSI assess present and future energy systems. These include electricity, heating and transportation systems. This LCA has been undertaken under a broader project called Technology Centered Electric Mobility Assessment (THELMA), which is aimed at understanding the multi-criteria sustainability implications of widespread electric vehicle use in Switzerland. The project is being undertaken by a partnership of 6 different research groups within the domain of the Swiss Federal Institutes of Technology, and funded by a range of stakeholders led by the Competence Center for Energy & Mobility and SwissElectric Research [40]. This thesis is written under the scope of Work Package 1 (WP1) which is part of the THELMA project. The main goal of WP1 is the LCA-based environmental performance evaluation of vehicles and energy supply chains (electricity and fuels). The focus is set on technologies and materials related to EV, with competing vehicle technologies included for comparison. The analysis also addresses future advances in vehicle technology up to 2030. 1.2

objectives and structure

The objectives of this project are to assess the environmental aspects and potential impacts associated with future electric vehicles by conducting research divided into the following stages: • Familiarization with LCA methodology and the current work completed under the THELMA project at PSI. • Familiarization with the LCA software, databases and current datasets (LCA software SimaPro and the Ecoinvent v2.2 database). • Literature review focusing on future development of electric drivetrains. • Interaction with the fuel cell and battery development groups at PSI in order to get information on material composition of future batteries.

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• Compilation of Life Cycle Inventories (LCI) of production, use phase and end-of-life of future passenger cars. • Interpretation and discussion of LCA results for these cars. • Writing the thesis report (in parallel to the tasks above) Some of the main aspects of this thesis are to identify and quantify use of energy, water and materials usage and environmental releases (e.g., air emissions, solid waste disposal, waste water discharges) for the various data sets collected. The focus while conducting this thesis research was on the following: • Material composition of future batteries, future battery chemistries and their characteristics • Performance of these batteries (life time, efficiency, energy density, weight, etc) • Production of future batteries (process emissions, energy requirements) • Potential recycling of vehicle components • Impacts of vehicle light-weighting • Technology-specific performance of vehicles in the future: exhaust and non-exhaust emissions, energy demand for driving, etc • Impacts of the charging electricity mix LCA is an iterative process, and the details of this indicated work program have been adapted during the project. The results of this work provide a good estimation of the environmental performance of various car technologies in the future (until 2030, with an outlook until 2050). The environmental performance significantly depends, especially for battery vehicles, on the origin of fuel, i.e. the source of electricity mix which is used to power the EV.

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LCA SCOPE AND FRAMEWORK

This LCA has been carried out according to the procedure described by ISO 14040:2006 and 14044:2006 and the various components in this LCA are described as follows: • Goal: To carry out an environmental evaluation of future battery electric vehicles and in addition, compare their environmental performance to gasoline, diesel and natural gas vehicles of the future. Future vehicles are modeled with improved drivetrain efficiencies and light-weighting, but fuel chains, electricity, emission levels and vehicle weight are modeled according to current current conditions. • Inventory analysis: In this study new data inventories for battery materials and various other components in the vehicle life cycle have been created. The Ecoinvent database v2.2 [50] is used as background from which new datasets have been constructed to conduct the LCA study. The newly created datasets are listed in Appendix A. In some cases, where information on air and water emissions is not available, importance has been placed on accurate material and energy requirements of the the product or process and emphasis has been placed on CO2 equivalent emission results which would give a more accurate picture of the environmental impacts. • The LCIA has been carried out using the methods GWP100a [26] and ReCiPe World (H,H) [22]. Evaluation of the results of the inventory analysis and impact assessment has been carried out by selecting the preferred method to decrease GHG emissions from passenger transport, with a clear understanding of the uncertainty and the assumptions used to generate the results. A sensitivity analysis has been carried out to evaluate the effect of using different charging electricity mix. 2.1

functional unit

The functional unit in this LCA varies according to the product or life cycle stage being evaluated. However, for final results, environmental impact indicators are expressed on a per vehicle km basis. For the battery LCA, the functional unit considered is per kilograms. This is because the material composition of the battery has been defined in kilograms and battery weight is an important factor in electric vehicle use phase. In the results section, the environmental impacts of the various batteries are also shown on a per kWh basis. This would be more relevant in the case that batteries are to be compared independent of their use phase and end of life.

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The various vehicles modeled have been defined as a combination of vehicle glider, drivetrain and battery. All of these components can be evaluated individually on a per part basis. In this study an additional analysis has been conducted with respect to vehicle light-weighting. The effect of light-weighting in the emissions produced by manufacturing a vehicle are measured on a per part basis. To evaluate the effects of light-weighting on the use phase, the vehicles are assumed to have a lifetime of 150,000 km and the results are calculated on a per km basis. In general, for all evaluations which involve a product, the results are obtained on a per kg basis, while use phase evaluations are done on per vehicle km basis. 2.2

system boundaries

LCA is conducted for future vehicles, which are categorized as battery electric, gasoline, diesel and natural gas vehicles. The vehicles are modeled on the Volkswagen Golf A4 and the data inventories for the vehicle shell and drivetrain have been derived from Schweimer and Levin [46], Habermacher [24]. The life cycle of a vehicle consists of its manufacture, its use phase, the fuel chain used in its use phase and finally its end of life or recycling. Descriptions of these and the corresponding boundaries are shown in Figure 2.1.

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Primary Energy

Distribution and Infrastructure

Processing

Primary energy of fuel Primary energy location Energy Extraction process Embedded emissions

Process Efficiency By Products Fuel quality Processing

People Number of Workers Environmental legislation

Method of distribution Infrastructure

Boundary for Fuel Chain LCA

(a) Elements in Fuel Chain

Design and Development R&D Prototypes Supplier selection Testing

Vehicle Specification

Materials and Energy

Vehicle size Vehicle mass Powertrain Battery choice

Material Selection Source of Material Extraction process Recycled content Material Availability Energy Mix

Production Processes

Logistics

Manufacturing process Manufacturing efficiency Location Waste Produced Re-use of waste

Supply chain Types of transport Transport distance

People Number of Workers Environmental legislation

Boundary for vehicle production LCA

(b) Elements in vehicle manufacture

Vehicle Specification Vehicle size Vehicle mass Powertrain technology Battery choice Tailpipe emissions Fuel Consumption Price

Fuel Fuel type Fuel quality Fuel supplier Real world consumption

Driver Driving habits Annual mileage Care of vehicle Air conditioning

Geography Location Terrain Climate and weather Road congestion Urban/Motorway

Maintenance & Servicing Service interval Oil and coolant changes Replacement parts Vehicle lifetime

Boundary for Use Phase LCA

(c) Elements in vehicle Use Phase

Figure 2.1: LCA Boundary

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V E H I C L E L I F E C Y C L E A N A LY S I S

A detailed description of the various vehicles modeled in this LCA is shown in Table 3.1.

3.1

electric vehicle technologies: manufacture, use phase and end of life

Inventory data has been collected for four different battery chemistries used in EV; two types of Lithium Ion chemistries and Lithium Air and Lithium Sulfur battery chemistries. Table 3.2 and Table 3.3 give an overview of the detailed characteristics of these battery chemistries and Figure 3.1 shows the percentage composition of various components of the cell for the various batteries evaluated in this thesis. These particular chemistries have been chosen for evaluation since after conducting a literature review they have been identified as those with the most potential for development and the possibility to offer the highest specific densities and thus lowest battery weight [5, 10, 16, 35, 54]. All modeled batteries are assumed to be made up of cells, a Battery Management System (BMS), busbars, cabling, shunts, wiring harnesses, and housing. The cells are usually packaged in pouch configuration, since pouch cells can achieve a packaging efficiency of 90 – 95% and absence of a metal can allows for lower weight and higher energy density. This cell construction uses a polymer for the electrolyte, and is thus less volatile and less prone to leakage. All cells consist of the basic components, the anode, cathode and electrolyte. The anode and cathode are usually positive and negative charged plates in contact with an electrolyte that produces an electrical charge by means of an electrochemical reaction. On discharge, electrolytic cells convert chemical energy to electrical energy. Besides the material composition and percentage in mass of the components in cells, data with respect to manufacturing cells and batteries is another important aspect for environmental evaluation. Due to reasons of confidentiality it was not possible to collect detailed information from battery manufacturers with respect to material composition, emissions, water usage or energy requirements. Thus the main sources of information used to model the various cells and corresponding batteries were from publications and cost estimates. (Table 3.4) [37, 18, 19, 16, 53, 27, 41, 54, 5]. Some battery manufacturers have offered feedback on the data collected, and this ensures that the modeled batteries and cells are based on justified assumptions. The standard energy and heat required in the manufacture of battery and cells is calculated based on the energy demand for various processes involved in cell and battery manufacture and assembly. Figure 3.2 describes the various required processes based

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