Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Environmental Effects of Battery Electric and
June 16, 2020
Internal Combustion Engine Vehicles
Richard K. Lattanzio
Increased deployment of battery electric vehicles (BEVs) and other alternative-fueled vehicles in
Specialist in Environmental
the United States could have a variety of effects on energy security, the economy, and the
Policy
environment. In an effort to address certain environmental concerns, including climate change,

some Members of Congress and some stakeholder interest groups have expressed interest in the
Corrie E. Clark
promotion of these technologies—specifically BEV technologies. This interest may include an
Analyst in Energy Policy
analysis of the environmental effects of BEVs from a systems perspective, commonly referred to

as “life cycle assessment” (LCA).

Practitioners of LCAs strive to be comprehensive in their analyses, and the environmental effects
modeled by many rely on a set of boundaries referred to as “cradle-to-grave.” Cradle-to-grave assessments in the
transportation sector model the environmental effects associated with the “complete” life cycle of a vehicle and its fuel. This
consists of the vehicle’s raw material acquisition and processing, production, use, and end-of-life options, and the fuel’s
acquisition, processing, transmission, and use. LCA practitioners focus on a variety of potential environmental effects,
including global warming potential, air pollution potential, human health and ecosystem effects, and resource consumption.
Literature analyzing the life cycle environmental effects of BEV technology—both in isolation and in comparison to internal
combustion engine vehicle (ICEV) technology—is extensive and growing. However, as the literature grows, so does the
range of results. The divergence is due to the differing system parameters of each study, including the selected goals, scopes,
models, scales, time horizons, and datasets. While each study may be internally consistent based upon the assumptions within
it, analysis across studies is difficult. Because of these complexities and divergences, CRS sees significant challenges to
quantifying a life cycle assessment of BEV and ICEV technologies that incorporates all of the findings in the published
literature. A review of the literature, however, can speak broadly to some of the trends in the life cycle environmental effects
as well as the relative importance of certain modeling selections.
Broadly speaking, a review of the literature shows that in most cases BEVs have lower life cycle greenhouse gas (GHG)
emissions than ICEVs. In general, GHG emissions associated with the raw materials acquisition and processing and the
vehicle production stages of BEVs are higher than for ICEVs, but this is typically more than offset by lower vehicle in-use
stage emissions, depending on the electricity generation source used to charge the vehicle batteries. The importance of the
electricity generation source used to charge the vehicle batteries is not to be understated: one study found that the carbon
intensity of the electricity generation mix could explain 70% of the variability in life cycle results.
In addition to lower GHG emissions, many studies found BEVs offer greater local air quality benefits than ICEVs, due to the
absence of vehicle exhaust emissions. However, both BEVs and ICEVs are responsible for air pollutant emissions during the
upstream production stages, including emissions during both vehicle and fuel production. Further, BEVs may be responsible
for greater human toxicity and ecosystems effects than their ICEV equivalents, due to (1) the mining and processing of
metals to produce batteries, and (2) the potential mining and combustion of coal to produce electricity. These results are
global effects, based on the system boundaries and input assumptions of the respective studies.
In addition to a review of the literature, CRS focused on the results of one study in order to present an internally consistent
example of an LCA. This specific study finds that the life cycle of selected lithium-ion BEVs emits, on average, an estimated
33% less GHGs, 61% less volatile organic compounds, 93% less carbon monoxide, 28% less nitrogen oxides, and 32% less
black carbon than the life cycle of ICEVs in the United States. However, the life cycle of the selected lithium-ion BEVs
emits, on average, an estimated 15% more fine particulate matter and 273% more sulfur oxides, largely due to battery
production and the electricity generation source used to charge the vehicle batteries. Further, the life cycle of the selected
lithium-ion BEVs consumes, on average, an estimated 29% less total energy resources and 37% less fossil fuel resources, but
56% more water resources. These results are global effects, based on the system boundaries and input assumptions of the
study.
Congressional Research Service

link to page 5 link to page 6 link to page 9 link to page 9 link to page 10 link to page 10 link to page 10 link to page 11 link to page 14 link to page 15 link to page 15 link to page 17 link to page 18 link to page 19 link to page 20 link to page 23 link to page 24 link to page 24 link to page 24 link to page 25 link to page 27 link to page 27 link to page 28 link to page 28 link to page 29 link to page 35 link to page 35 link to page 36 link to page 37 link to page 7 link to page 16 link to page 16 link to page 30 link to page 31 link to page 31 link to page 32 link to page 32 link to page 33 link to page 33 link to page 34 Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Contents
Introduction ..................................................................................................................................... 1
Life Cycle Assessment .................................................................................................................... 2
Life Cycle Stages ............................................................................................................................. 5
A. Raw Material Extraction and Processing ............................................................................. 5
Factors Affecting the Raw Material Stage .......................................................................... 6
Environmental Assessment of Selected Materials for the Car Body for ICEVs and
BEVs ................................................................................................................................ 6
Environmental Assessment of Selected Materials Specific to BEVs .................................. 7
B. Vehicle and Battery Production .......................................................................................... 10
Factors Affecting the BEV Production Stage ..................................................................... 11
Environmental Assessment of Battery Manufacturing ...................................................... 11
C. Vehicle In-Use (Including the Fuel Life Cycle) ................................................................. 13
Factors Affecting the ICEV In-Use Stage ......................................................................... 14
Environmental Assessment of ICEV In-Use ..................................................................... 15
Factors Affecting the BEV In-Use Stage .......................................................................... 16
Environmental Assessment of BEVs In-Use .................................................................... 19
D. Vehicle End-of-Life ............................................................................................................ 20
Factors Affecting the End-of-Life Stage ........................................................................... 20
Environmental Assessment of End-of-Life Management ................................................. 20
Environmental Assessment of Battery Recycling ............................................................. 21
A Discussion of the Published LCA Literature ............................................................................. 23
Review of the Findings from Selected LCAs .......................................................................... 23
Review of the Findings from Dunn et al., 2015 (Updated in 2019) ........................................ 24
Dunn et al., 2015 (Updated) Modeling Assumptions ........................................................ 24
Selected Environmental Effects Categories ...................................................................... 25
Issues for Consideration ................................................................................................................ 31
Summary of Findings .............................................................................................................. 31
Considerations Affecting Life Cycle Performance ................................................................. 32
Issues Regarding LCA and Policy Development .................................................................... 33

Figures
Figure 1. Simplified Illustration of the Complete Life Cycle of Vehicles and Fuels ...................... 3
Figure 2. Components of a Battery Electric Vehicle ..................................................................... 12
Figure 3. Components of an Internal Combustion Engine Vehicle ............................................... 12
Figure 4. Life Cycle Assessment: Global Warming Potential ....................................................... 26
Figure 5. Life Cycle Assessment: Volatile Organic Compounds ................................................... 27
Figure 6. Life Cycle Assessment: Carbon Monoxide .................................................................... 27
Figure 7. Life Cycle Assessment: Nitrogen Oxides ...................................................................... 28
Figure 8. Life Cycle Assessment: Sulfur Oxides ........................................................................... 28
Figure 9. Life Cycle Assessment: Fine Particulates ...................................................................... 29
Figure 10. Life Cycle Assessment: Black Carbon ......................................................................... 29
Figure 11. Life Cycle Assessment: Total Energy Consumption .................................................... 30
Congressional Research Service

link to page 34 link to page 35 link to page 38 link to page 41
Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Figure 12. Life Cycle Assessment: Total Fossil Fuel Consumption .............................................. 30
Figure 13. Life Cycle Assessment: Water Consumption ............................................................... 31

Appendixes
LCA Bibliography ....................................................................................................... 34

Contacts
Author Information ........................................................................................................................ 37

Congressional Research Service

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Introduction
Increased deployment of battery electric vehicles (BEVs)1 and other alternative-fueled vehicles in
the United States could have a variety of effects on energy security, the economy, and the
environment.2 In an effort to address certain environmental concerns, including climate change,
some Members of Congress and some stakeholder interest groups have expressed interest in the
promotion of these technologies—specifically BEV technologies. Much of this interest has
focused on the electrification of passenger vehicles. This focus reflects the fact that, historically,
passenger vehicles have dominated emissions (of both greenhouse gases and other air pollutants)
in the transportation sector and that passenger vehicles have shorter development and in-use times
than other modes of transportation (e.g., aircraft, trains, and ships), and thus can be more readily
and systematically addressed.
Motor vehicle electrification has emerged in the past decade as a potentially viable alternative to
the internal combustion engine.3 In 2018, more than 361,000 plug-in electric passenger vehicles
(including plug-in hybrid electric vehicles [PHEVs] and BEVs) were sold in the United States, as
well as more than 341,000 hybrid electric vehicles (HEV).4 Nearly all automakers offer plug-in
electric vehicles for sale: 42 different models were sold in 2018, with Tesla and Toyota recording
the largest numbers. Sales of PHEVs and BEVs in 2018 rose by over 80% from the previous year,
bringing total U.S. sales of plug-in vehicles since 2010 to just over 1 million.5 The plug-in hybrid
and battery electric share of the U.S. passenger vehicle market in 2018 was 2.1%.6
This report discusses and synthesizes analyses of the environmental effects of BEVs as compared
to the internal combustion engine vehicle (ICEV)7 and is part of a suite of CRS products on
electric vehicles and related technology (see text box below). This report employs research done
by federal agencies,8 other (non-U.S.) government agencies, and academics concerning the short-

1 Some sources use the term all electric vehicles (AEVs). For consistency, this report uses BEV throughout.
2 U.S. Department of Energy, “Chapter 1: Energy Challenges,” Quadrennial Technology Review: An Assessment of
Energy Technologies and Research Opportunities, September 2015, pp. 16-17, https://www.energy.gov/quadrennial-
technology-review-2015.
3 For more information on the electric vehicle market, see CRS Report R45747, Vehicle Electrification: Federal and
State Issues Affecting Deployment, by Bill Canis, Corrie E. Clark, and Molly F. Sherlock, and CRS Report R46231,
Electric Vehicles: A Primer on Technology and Selected Policy Issues, by Melissa N. Diaz.
4 Hybrid electric vehicles (HEVs) have both internal combustion engines and electric motors that store energy in
batteries. Plug-in electric vehicles include two types: (1) plug-in hybrid electric vehicles (PHEVs) use an electric motor
and an internal combustion engine for power, and they use electricity from an external source to recharge the batteries;
and (2) battery electric vehicles (BEVs) use only batteries to power the motor and use electricity from an external
source for recharging.
5 U.S. Department of Energy, “One Million Plug-In Vehicles Have Been Sold in the United States,” November 26,
2018, at https://www.energy.gov/eere/vehicles/articles/fotw-1057-november-26-2018-one-million-plug-vehicles-have-
been-sold-united.
6 CRS calculations based on Oak Ridge National Laboratory data; Oak Ridge National Laboratory, Transportation
Energy Data Book, Tables 3.11 and 6.2, at https://tedb.ornl.gov/wp-content/uploads/2019/03/TEDB_37-2.pdf#page=
178.
7 While the report discusses certain data and findings pertaining to HEV technology (a hybrid of internal combustion
engines and electric engines), it focuses primarily on a comparison of the environmental effects of BEVs and ICEVs
due to the technological distinction.
8 Government agencies in the United States and elsewhere have monitored progress in integrating environmental
objectives in passenger vehicle technology since the 1950s. U.S. agencies involved in this research include the U.S.
Department of Energy (DOE, including the national laboratories), the U.S. Department of Transportation (DOT), and
the U.S. Environmental Protection Agency (EPA).
Congressional Research Service
1

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

and long-term environmental performance of the passenger vehicle sector as assessed from a
systems perspective across the life cycle of the vehicles.9
CRS Products on Electric Vehicles and Related Technology

CRS Report R46231, Electric Vehicles: A Primer on Technology and Selected Policy Issues, by Melissa N. Diaz.

CRS Report R41709, Battery Manufacturing for Hybrid and Electric Vehicles: Policy Issues, by Bil Canis.

CRS Report R45747, Vehicle Electrification: Federal and State Issues Affecting Deployment, by Bil Canis, Corrie E.
Clark, and Mol y F. Sherlock.

CRS Video WVB00276, Electric Vehicles: Federal and State Policy Issues, by Bil Canis, Corrie E. Clark, and Mol y
F. Sherlock.

CRS In Focus IF11017, The Plug-In Electric Vehicle Tax Credit, by Mol y F. Sherlock.

CRS In Focus IF11101, Electrification May Disrupt the Automotive Supply Chain, by Bil Canis.

CRS In Focus IF10941, Buy America and the Electric Bus Market, by Bil Canis and Wil iam J. Mallett.
Life Cycle Assessment
This report examines the environmental effects of two types of passenger vehicles—BEVs and
ICEVs—from a systems perspective, commonly referred to as “life cycle assessment” (LCA).10
LCA is an analytic method used for evaluating and comparing the environmental effects of
various products and processes (e.g., the environmental effects from the production and use of
passenger vehicles). Practitioners use LCA as a method to inform policy development at local,
state, federal, and international levels. Through LCA, policymakers can look to increase their
understanding of the environmental effects and trade-offs of products. For example, BEV and
ICEV technologies have many similarities (e.g., basic vehicle components) as well as many
differences (e.g., source of fuel and the production and operation of the battery). Through the
LCA approach, practitioners can assess the similarities and differences of these technologies and
determine which characteristics are most relevant to an understanding of the types and intensities
of environmental effects.
LCA practitioners strive to be comprehensive in their analyses, and the environmental effects
modeled by many LCAs are based on a set of boundaries referred to as “cradle-to-grave.”11
Cradle-to-grave assessments in the transportation sector encompass the environmental effects

9 The primary source materials for this report include research conducted by, and CRS correspondence with, the U.S.
Department of Energy; Argonne National Laboratory (see U.S. Department of Energy, Argonne National Laboratory,
“The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET®) Model, 2018,”
https://greet.es.anl.gov/; and J.B. Dunn, L. Gaines, J.C. Kelly, C. James, and K.G. Gallagher, “The Significance of Li-
Ion Batteries in Electric Vehicle Life-Cycle Energy and Emissions and Recycling’s Role in Its Reduction,” Energy and
Environmental Science, vol. 8 (2015), pp. 158-168, https://pubs.rsc.org/en/content/articlehtml/2015/ee/c4ee03029j
(hereinafter Dunn et al., 2015)); the European Environment Agency (see European Environment Agency, “Electric
Vehicles from Life Cycle and Circular Economy Perspectives, TERM 2018: Transport and Environment Reporting
Mechanism (TERM) Report,” EEA Report No. 13/2018 (hereinafter EEA Report No. 13/2018),
https://www.eea.europa.eu/publications/electric-vehicles-from-life-cycle)); and the peer-reviewed academic research
articles listed in the Appendix of this report.
10 A “system” refers to a set of unit processes that are included in the LCA. In the case of vehicles, this could include
the various steps necessary to manufacture a specific vehicle model (e.g., Nissan Leaf).
11 “Cradle-to-grave” LCAs use a system boundary that considers impacts through the product life cycle (from raw
material extraction to end-of-life disposal). Elsewhere in the report, practitioners refer to “Cradle-to-gate.” “Cradle-to-
gate” LCAs focus on production activities, and use a system boundary that considers impacts from raw material
extraction through the manufacturing stage and exclude the use stage and end-of-life stage.
Congressional Research Service
2

link to page 7
Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

associated with the “complete” life cycle of the equipment (i.e., the vehicle) and its fuel (see
Figure 1). LCA practitioners define the equipment life cycle to incorporate the environmental
effects associated with the vehicle’s raw material acquisition and processing, production, use, and
end-of-life, including recycling options. The fuel life cycle includes the environmental effects
associated with extracting, gathering, processing, transporting to market, and combusting the fuel
in the vehicle and/or using the fuel for electricity generation to power the vehicle. All LCA
practitioners necessarily exclude some considerations in their analysis because they define the
system with specific boundaries. Whether certain factors external to the system boundaries are
material to the results of a given analysis is an ongoing question for LCA practitioners and their
target audiences.12
Figure 1. Simplified Illustration of the Complete Life Cycle of Vehicles and Fuels

Source: CRS, adapted from A. Nordelöf, M. Messagie, A. Til man, M.L. Söderman, J. Van Mierlo, “Environmental
Impacts of Hybrid, Plug-In Hybrid, and Battery Electric Vehicles—What Can We Learn from Life Cycle
Assessment?” International Journal of Life Cycle Assessment, vol. 19 (2014), pp. 1866–1890.
LCA practitioners may focus on a variety of metrics to assess environmental effects, including air
quality, water quality, or resource availability. They can use the results of an LCA to evaluate the
intensity of certain environmental effects at various stages of the supply chain or to assess the
intensity of environmental effects of one type of technology, fuel, or method of production
relative to another, given consistent system boundaries and consistent functional units to enable
comparison. For example, LCA practitioners can estimate emissions of carbon dioxide (CO2) and
other greenhouse gases (GHGs) arising from the development of a given product and express
them in a single, universal metric (e.g., CO2 equivalent [CO2e]) of GHG emissions per functional

12 For a more detailed discussion on the methodologies, challenges, and opportunities for using LCAs for public policy
application, see S. Hellweg and L. Milà i Canals, “Emerging Approaches, Challenges and Opportunities in Life Cycle
Assessment,” Science, vol. 344 (June 6, 2014), pp. 1109-1113.
Congressional Research Service
3

link to page 38 Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

unit (e.g., per unit of energy produced, unit of fuel consumed, or unit of distance traveled).13 They
may then use this result in comparing different life cycle stages, technologies, or fuels.
This report groups the environmental effects under the following categories (see text box “Life
Cycle Assessment Environmental Effects” for more specificity):
 global warming potential—CO2 emissions, other GHG emissions, and black
carbon formation;
 air pollution potential—ozone (O3) formation, volatile organic compound (VOC)
emissions, carbon monoxide (CO) emissions, nitrogen oxides (NOx) emissions,
particulate matter (PM) emissions, and sulfur oxide emissions (SOx), including
sulfur dioxide (SO2);
 human health and ecosystem effects—human toxicity; terrestrial acidification;
eutrophication;14 and terrestrial, freshwater, and marine ecotoxicity; and
 resource consumption—water consumption and mineral and fossil resource
consumption.
As exemplified in the review of the published literature in the Appendix of this report, many
LCA practitioners quantify and analyze the categories of global warming potential, air pollution
potential, and resource consumption. Data for emissions of pollutants such as CO2, other GHGs,
and other air pollutants, as well as data for energy and mineral use, can be estimated with some
robustness using the databases and modeling tools employed by most LCA practitioners.
Conversely, human health and ecosystem effects (e.g., human toxicity, freshwater eutrophication)
are less commonly quantified and analyzed by LCA practitioners. These effects are based on
second-order modeling assumptions (i.e., they are effects that potentially result from a given level
of emissions). Many LCA practitioners assign greater difficulty to analyzing and quantifying
these effects. Practitioners mention data variance and analytic uncertainties as reasons to find
estimates in these categories less reliable. Further, the scale of these effects may vary, and their
impacts may differ locally and globally depending upon regional variabilities, population size and
characteristics, exposure rates, and the environmental regulations and management practices of
the exposed areas. Thus, this report focuses on the primary emissions categories as opposed to the
second-order health and ecosystem effects, specifically when expressing findings quantitatively.
The report discusses the second-order categories qualitatively.
The subsequent sections examine the selected environmental effects categories identified above
(i.e., global warming potential, air pollution potential, human health and ecosystem effects, and
resource consumption) that occur at the various stages of the life cycle for BEVs and ICEVs,
from raw material extraction through end-of-life management.

13 GHGs are quantified using a unit measurement called carbon dioxide equivalent (CO2e), wherein the radiative
forcing potential of gases are indexed and aggregated against one mass unit of CO2 for a specified time frame. This
indexing is commonly referred to as the Global Warming Potential (GWP) of the gas. For example, the
Intergovernmental Panel on Climate Change (IPCC) 2013 Fifth Assessment Report reported the GWP for methane as
ranging from 28 to 36 when averaged over a 100-year time frame. Consistent with international GHG reporting
requirements, EPA’s most recent GHG inventory (2018) uses the GWP values presented in the IPCC’s 2007 Fourth
Assessment Report, in which the GWP of methane was 25 when averaged over a 100-year time frame. The uncertainty
in the GWP for a particular GHG could be of interest for policymakers.
14 Eutrophication is the excessive loading of nutrients into a body of water, which induces algal growth. Excessive algal
growth can lead to low-oxygen waters, which can result in fish kills and other effects.
Congressional Research Service
4

link to page 38 Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Life Cycle Assessment Environmental Effects
Many environmental effects relate to one another. Below is a list of selected factors that LCA practitioners may
evaluate. These may or may not have interdependencies. The definitions listed in the text box are sourced (and
summarized) from the peer-reviewed academic research articles listed in the Appendix of this report.

global warming potential: reporting all CO2 emissions and other GHG emissions as CO2-equivalents,
indicating global and regional climate change, oceanic warming, and ocean acidification.

black carbon formation: black carbon potential, indicating harm to human respiratory and cardiac function
and contribution to climate change.

ozone (O3) formation: photo-oxidant creation potential, indicating how local air pol utants (NOx and
unburned hydrocarbons) build up ground-level ozone (i.e., smog) under the influence of sunlight, harming
both human respiratory and cardiac function and agricultural crops.

volatile organic compound (VOC) emissions: reporting all VOC emissions, indicating harm to human
respiratory and cardiac function, as well as ozone formation.

carbon monoxide (CO) emissions: reporting all CO emissions, indicating harm to human respiratory and
cardiac function.

nitrogen oxides (NOx) emissions: reporting all NOx emissions, indicating harm to human respiratory and
cardiac function.

particulate matter (PM) emissions: reporting all PM emissions, indicating harm to human respiratory and
cardiac function.

sulfur dioxide (SO2) emissions: reporting all SO2 emissions, indicating harm to human respiratory and cardiac
function.

human toxicity: indicating the potential harm of chemicals released into the environment on human health,
based on both the inherent toxicity of the compounds and their potential doses.

terrestrial ecotoxicity: indicating the potential harm of chemicals released into the environment on terrestrial
organisms, based on both the inherent toxicity of the compounds and their potential doses.

acidification: indicates the potential environmental impact of acidifying substances such as NOx and SOx.

freshwater ecotoxicity: indicating the potential harm of chemicals released into the environment on aquatic
organisms, based on both the inherent toxicity of the compounds and their potential doses.

freshwater eutrophication: indicating the effect of macronutrients pol ution in soil and water resources.

water consumption: indicating the effects associated with the consumption and discharge of water resources
for the production of products, materials, and energy.

mineral resource consumption: indicating the effects associated with the extraction of raw material resources
for the production of products, materials, and energy.

fossil resource consumption: indicating the effects associated with the extraction of fossil fuel resources for
the production of products, materials, and energy.
Life Cycle Stages
The type and the extent of environmental effects associated with BEV and ICEV life cycles can
vary widely based on vehicle type, fuel type, and life cycle stage. This section provides a
summary of the potential life cycle environmental effects of BEVs and ICEVs categorized
sequentially by life cycle stage.
A. Raw Material Extraction and Processing
Generally, studies of the life cycle of BEVs and ICEVs combine the effects associated with raw
material extraction and processing with the later stage of vehicle manufacturing and assembly; as
a result, quantitative information specific to this first stage is limited. However, raw material
extraction and processing is typically resource intensive, often requiring large volumes of water
Congressional Research Service
5

link to page 17 link to page 17 Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

and energy and releasing emissions into air and water. For ICEVs, specific potential
environmental effects associated with raw material extraction and processing are primarily related
to petroleum production and refining under the fuel life cycle (see section “C. Vehicle In-Use”).
For BEVs, specific potential environmental effects associated with raw material extraction and
processing are related to fuel extraction and processing for electricity generation under the fuel
life cycle (see section “C. Vehicle In-Use”) and mineral extraction and processing for battery
production under the vehicle life cycle (see below). Most BEVs rely on lithium-ion batteries.15
While there are likely impacts associated with extraction of materials for other vehicle
components (e.g., metals for vehicle frame and body), this section focuses on those components
of ICEVs or BEVs that are unique for each vehicle type and that are potentially materially or
energy intensive.
Factors Affecting the Raw Material Stage
A number of characteristics can affect LCA results for the raw material stage. In addition to
vehicle type and size, other factors include the material composition—both of the vehicle body
and of any batteries—and the location where these materials are sourced. As the industry is
currently structured, the life cycle environmental effects of raw material extraction for battery
production are largely beyond the borders of the United States and outside of the jurisdiction of
the U.S. legislative and regulatory framework.16
Environmental Assessment of Selected Materials for the Car Body for ICEVs
and BEVs
Production of ICEVs and BEVs requires a range of raw materials for the car body and for vehicle
components. Materials in the car body include steel, aluminum, carbon fiber, and plastic.
Differences in the materials required for BEVs and ICEVs are primarily due to the battery, power
electronics, and electric motor in a BEV compared to the engine, transmission, and other
drivetrain components of the ICEV.17 BEV components contain copper, iron, nickel, and critical
minerals.18 Critical minerals used in BEVs include aluminum, cobalt, graphite, lithium, and

15 Lithium-ion batteries made up 70% of the rechargeable battery market in 2016; since then, BEV-driven demand for
lithium-ion batteries has risen. Bloomberg New Energy Finance, “Electric Vehicle Outlook 2018,” as reported in U.S.
International Trade Commission Journal of International Commerce and Economics, “The Supply Chain for Electric
Vehicle Batteries,” December 2018, https://www.usitc.gov/publications/332/journals/
the_supply_chain_for_electric_vehicle_batteries.pdf. While not included in the analysis for this report, other types of
batteries are used for different vehicles and include nickel-metal hydride (widely used in hybrid electric vehicles), lead-
acid batteries (internal combustion vehicles and electric-drive ancillary load vehicles), and ultracapacitors (for
secondary energy-storage or power assist purposes). U.S. Department of Energy, “Batteries for Hybrid and Plug-In
Electric Vehicles,” https://afdc.energy.gov/vehicles/electric_batteries.html.
16 Initiatives exist that try to address some of these issues; for example, the Extractive Industries Transparency Initiative
(EITI) established a standard for governance to promote the open and accountable management of extractive resources
(i.e., oil, gas, and mineral resources).
17 EEA Report No. 13/2018, p. 14.
18 EEA Report No. 13/2018, pp. 14-15. According to the National Research Council, a critical mineral “performs an
essential function for which there are few or no satisfactory substitutes ..., and if there is a high probability that its
supply may become restricted.” National Research Council, Minerals, Critical Minerals, and the U.S. Economy,
National Academies Press, 2008. For a list of critical minerals, see U.S. Department of the Interior, “Final List of
Critical Minerals 2018,” 83 Federal Register 23295, May 18, 2018.
Congressional Research Service
6

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

manganese.19 ICEV components contain copper, iron, and the critical mineral aluminum, among
other materials.20
Aluminum is typically used in lightweighting vehicles—an approach that reduces the overall
mass of a vehicle to improve fuel efficiency and performance. As the batteries for BEVs could
otherwise add additional mass to a vehicle, BEVs often use more lightweighting materials than
ICEVs. Aluminum processing is energy intensive and can result in the direct emissions of GHGs
including perfluorocarbons, which can lead to more GHG emissions during the aluminum
processing stage than the steel processing stage.21 However, one study estimates that the use of
aluminum, glass-fiber reinforced plastic, and high-strength steel (typical lightweighting materials
that can replace conventional steel) can decrease vehicle life cycle energy use and GHG
emissions for ICEVs.22 Another study finds that lightweighting BEVs may be less effective in
reducing GHG emissions than lightweighting ICEVs; however, the benefits differ substantially
for different vehicle models.23
Environmental Assessment of Selected Materials Specific to BEVs
Lithium-ion batteries are made from critical minerals, including cobalt, graphite, and lithium. One
study estimates that the steps for extracting and processing critical minerals are responsible for
approximately 20% of the total GHG emissions from battery production.24 The GHG emissions
from extraction and processing depend upon the fuel source (e.g., electricity, heat, or fossil fuel)
for the energy consumed during these activities. One study estimates that the potential human
toxicity effects of the production phase to be between 2.2 and 3.3 times greater for BEVs than
ICEVs.25 The “production phase” of the study includes raw material extraction, processing, and

19 L.A-W. Ellingsen and C.R. Hung, Research for TRAN Committee—Resources, Energy, and Lifecycle Greenhouse
Gas Emission Aspects of Electric Vehicles, European Parliament, Policy Department for Structural and Cohesion
Policies, IP/B/TRAN/IC/2017-068 (Brussels, 2018) (hereinafter Ellingsen et al., 2018), pp. 33-34. For more
information on critical minerals, see CRS Report R45810, Critical Minerals and U.S. Public Policy.
20 J. Sullivan, J. Kelly, and A. Elgowainy, Vehicle Materials: Material Composition of Powertrain Systems, Argonne
National Laboratory (August 2018), p. 12. (Hereinafter Sullivan et al., 2018).
21 Perfluorocarbons (PFCs) typically have high global warming potentials compared to carbon dioxide. The electrolysis
process in aluminum production can produce PFCs; primary aluminum production is a major source of PFCs. See EEA
Report No. 13/2018, p. 16; Eric Jay Dolin, “PFC Emissions Reductions: The Domestic and International Perspective,”
Light Metal Age, February 1999, https://www.epa.gov/f-gas-partnership-programs/pfc-emissions-and-reductions-
domestic-and-international-perspective.
22 H.C. Kim and T.J. Wallington, “Life-Cycle Energy and Greenhouse Gas Emission Benefits of Lightweighting in
Automobiles: Review and Harmonization,” Environmental Science and Technology, vol. 47 (2013), pp. 6089-6097; X.
He, et al., “Cradle-to-Gate Greenhouse Gas (GHG) Burdens for Aluminum and Steel Production and Cradle-to-Grave
GHG Benefits of Vehicle Lightweighting in China,” Resources, Conservation and Recycling, vol. 152 (2020), p.
104497.
23 H.C. Kim and T.J. Wallington, “Life Cycle Assessment of Vehicle Lightweighting: A Physics-Based Model To
Estimate Use-Phase Fuel Consumption of Electrified Vehicles,” Environmental Science and Technology, vol. 50
(2016), pp. 11226-11233.
24 H.C. Kim, et al., “Cradle-to-Gate Emissions from a Commercial Electric Vehicle Li-Ion Battery: A Comparative
Analysis,” Environmental Science and Technology, vol. 50 (2016), pp. 7715-7722 (hereinafter Kim et al., 2016).
25 T. Hawkins, B. Singh, G. Majeau Bettez, A. Stromman, “Comparative Environmental Life Cycle Assessment of
Conventional and Electric Vehicles,” Journal of Industrial Ecology, vol. 17 (2012), pp. 53-64; and T. Hawkins et al.,
“Corrigendum to: Hawkins, T. R., B. Singh, G. Majeau-Bettez, and A. H. Strømman. 2012. Comparative
Environmental Life Cycle Assessment of Conventional and Electric Vehicles. Journal of Industrial Ecology DOI:
10.1111/j.1530-9290.2012.00532.x,” Journal of Industrial Ecololy, vol. 17 (2013), pp. 158-160 (hereinafter Hawkins et
al., 2013). The human toxicity potential (HTP) is a calculated index that reflects the potential harm of a unit of
chemical if released into the environment. The range in magnitude accounts for the variety of electric vehicle options
and the variety of electricity sources that recharge the battery. The higher human toxicity from BEVs can be
Congressional Research Service
7

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

vehicle manufacturing; however, the toxicity effects are largely associated with disposal of mine
tailings.26 As discussed below, toxicity effects of other phases vary based on the fuel source of
electricity during the BEV in-use stage.
Mining of selected materials for BEVs typically takes place in countries where health and safety
precautions are generally considered to be less stringent than those in the United States. Activities
associated with mining can produce GHG emissions, PM emissions, NOx emissions, and other air
pollutant emissions from fossil fuel combustion to operate mining equipment, or to generate heat
or electricity for processing. In addition, some studies have raised concerns associated with
mining and the bioaccumulation and toxicity of minerals among aquatic species.27
Cobalt
More than half of the global supply of cobalt comes from the Democratic Republic of Congo
(DRC).28 In the DRC, cobalt is mined using both conventional and artisanal methods. In
conventional mining, cobalt is typically a by-product of copper or nickel mining activities. In
artisanal mining, miners work independently of a company, generally relying upon manually
intensive methods such as hand tools. Reports link such artisanal mining with environmental
effects such as polluting soil and surface dust.29 Conventional mining and smelting activities in
the DRC leave tailings and slags that are leachable and potentially hazardous to the
environment.30 Mining activities in the DRC have been linked with elevated human exposure to
cobalt and other metals.31 Some estimate that uncontrolled growth in mining activities in Central
Africa—including cobalt mining—could directly impact regions that provide key habitat for bird

attributable, in part, to the additional copper and nickel requirements, which result in production chain disposal of
sulfidic mine tailings. Other toxicity impacts are largely due to disposal of spoils from lignite and coal mining.
Freshwater ecotoxicity and eutrophication effects from BEVs can be higher due to the associated effects of mining,
processing metals, and burning coal to produce electricity.
26 Mine tailings are waste generated from mining activities and typically are a slurry mixture of solids such as silt, sand,
and other minerals, and water.
27 EEA Report No. 13/2018, p. 17; K. T. Rim, K. H. Koo, and J. S. Park, “Toxicological Evaluations of Rare Earths and
Their Health Impacts to Workers: A Literature Review,” Safety and Health at Work, vol. 4 (2013), pp. 12-26
(hereinafter Rim et al., 2013); and G.A. MacMillan, J. Chetelat, and J. P. Heath, et al., “Rare Earth Elements in
Freshwater, Marine, and Terrestrial Ecosystems in the eastern Canadian Arctic,” Environmental Science Processes and
Impacts, vol. 19 (2017), pp. 1336-1345.
28 According to the U.S. Geological Survey, “identified world terrestrial cobalt resources are about 25 million tons. The
vast majority of these resources are in sediment-hosted stratiform copper deposits in Congo (Kinshasa) and Zambia;
nickel-bearing laterite deposits in Australia and nearby island countries and Cuba; and magmatic nickel-copper sulfide
deposits hosted in mafic and ultramafic rocks in Australia, Canada, Russia, and the United States,” U.S. Geological
Survey, “Cobalt,” Mineral Commodity Summaries, January 2018, https://minerals.usgs.gov/minerals/pubs/commodity/
cobalt/.
29 Evidence of increased oxidative DNA damage found among the exposed children (those who lived in the study area
but were not engaged in mining) in the study points to an increased risk of cancer in later life; see C. B. L. Nkulu, et al.,
“Sustainability of Artisanal Mining of Cobalt in DR Congo,” Nature Sustainability, vol. 1 (2018), pp. 495–504.
30 Arthur Tshamala Kaniki and Kiniki Tumba, “Management of Mineral Processing Tailings and Metallurgical Slags of
the Congolese Copperbelt: Environmental Stakes and Perspectives,” Journal of Cleaner Production, vol. 210 (February
2019), pp. 1406-1413.
31 Celestin Lubaba Nkulu Banza, Tim S. Nawrot, and Vincent Haufroid, et al., “High Human Exposure to Cobalt and
Other Metals in Katanga, a Mining Area of the Democratic Republic of Congo,” Environmental Research, vol. 109
(2009), pp. 745-752; S. Squadrone et al., “Human Exposure to Metals Due to Consumption of Fish from an Artificial
Lake Basin Close to an Active Mining Area in Katanga (D.R. Congo),” Science of the Total Environment, vol. 568
(2016), pp. 679-684.
Congressional Research Service
8

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

species.32 In addition to environmental effects at the mining site, the recovery of cobalt (and
nickel) from ores requires smelting, which without pollution controls can raise air quality
concerns with the emission of sulfur oxides in addition to other air pollutants.33
Graphite
The United States is an importer of graphite. These imports come mainly from China.34 Graphite
mining tailings can have high heavy metal content, which can lead to soil contamination and
other ecological impacts. A study of graphite mining in Luobei County in Heilongjiang, China,
found farmland and residential areas within the watershed of the mining area to be affected by
impacts from mining activities.35 Further, reports link graphite mining and processing with air
pollution, water pollution, and crop damage.36
Lithium
The United States also is an importer of lithium.37 Production of lithium primarily relies on brine
mining, but hard rock mining of spodumene, a mineral, can also produce lithium. Some have
argued for further research to evaluate the environmental effects of lithium mining, including
establishing a baseline for water consumption and understanding potential effects on wildlife and
ecosystems.38

32 This region is known for high biological endemism, particularly for birds. Endemism refers to species that are
restricted to a defined geographic location or habitat type. See D.P. Edwards, et al., “Mining and the African
Environment,” Conservation Letters, vol. 7 (2014), pp. 302-311.
33 Smelting is a process that applies heat and a chemical reducing agent to an ore to extract out a metal. Dunn et al.,
2015.
34 China produced 67% of the world’s graphite in 2017 and is the largest supplier of natural graphite by tonnage to the
United States; see U.S. Geological Survey, “Graphite,” Mineral Commodity Summaries, January 2018,
https://minerals.usgs.gov/minerals/pubs/commodity/graphite/. For more information on China’s mineral industry and
critical minerals, see CRS Report R43864, China’s Mineral Industry and U.S. Access to Strategic and Critical
Minerals: Issues for Congress, by Marc Humphries.
35 Zhang, L., Liu, X., Wan, H., and Liu, X., “Luobei Graphite Mines Surrounding Ecological Environment Monitoring
Based on High-Resolution Satellite Data,” Proc. SPIE 9263, Multispectral, Hyperspectral, and Ultraspectral Remote
Sensing Technology, Techniques and Applications V, November 26, 2014, 92632N, https://doi.org/10.1117/
12.2069232.
36 See Peter Whoriskey, Michael Robinson Chavez, and Jorge Ribas, “In Your Phone, in Their Air,” Washington Post,
October 2, 2016, https://www.washingtonpost.com/graphics/business/batteries/graphite-mining-pollution-in-china/;
Shu, J., Lui, L., Zhang, D., Zhang, W., Li, G., “Study on Ecological Restoration of Lands Disturbed by Mining
Graphite,” China Environmental Science, vol. 16, no. 3 (June 1996); and Sun, J.-B., Wang, X.-F., Liu, C.-H., Zhao, Y.-
S., “Correlation and Change Between Soil Nutrient and Heavy Metal in Graphite Tailings Wasteland during Vegetation
Restoration,” Journal of Soil and Water Conservation, vol. 23, no. 3 (2009).
37 The U.S. largely imports lithium from South America, with 53% of imports from Argentina and 40% of imports from
Chile for the years between 2015 and 2018. Domestic production of lithium is limited to one brine operation in Nevada
and two companies that produce downstream lithium compounds from domestic and imported lithium resources. Due
to limited domestic activities, USGS withholds production data for the United States to avoid disclosing proprietary
data. U.S. Geological Survey, “Lithium,” Mineral Commodity Summaries, January 2020, https://pubs.usgs.gov/
periodicals/mcs2020/mcs2020-lithium.pdf.
38 D. B. Agusdinata, et al., “Socio-environmental Impacts of Lithium Mineral Extraction: Towards a Research
Agenda,” Environmental Research Letters, vol. 13 (2018), p. 123001.
Congressional Research Service
9

link to page 16 link to page 16 Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Rare Earth Elements
BEVs use rare earth elements (REEs) in their magnets and batteries. REEs are moderately
abundant in the earth’s crust, with some in greater abundance than copper, lead, gold, and
platinum.39 However, most REEs are not concentrated enough to make them easily exploitable
economically.40 Rare earth elements often occur with other elements, such as copper, gold,
uranium, phosphates, and iron, and are often a byproduct of their production.
Some studies have identified negative effects on human health associated with the mining of
REEs, some of which are used in BEV magnets.41 One REE used in BEV magnets is neodymium.
Neodymium dust can irritate the skin, eyes, and mucous membranes, and neodymium dust can
cause pulmonary embolisms and liver damage over long accumulated exposures.42 Another REE
that is used in BEV magnets is dysprosium. Soluble dysprosium salts are mildly toxic when
ingested. Dysprosium can also pose occupational and safety hazards due to explosion risk.43
Additionally, REE deposits often contain radioactive substances and present a risk of emitting
radioactive water and dust.44 For example, concerns over radioactive hazards associated with
monazites (one type of deposit for REEs) have nearly eliminated it as an REE source in the
United States.45
B. Vehicle and Battery Production
The second stage of the equipment life cycle is vehicle and battery manufacturing and assembly.
While many parts of a vehicle do not necessarily differ between BEVs and ICEVs, several
important components distinguish the technologies, including components for energy storage,
propulsion, and braking (see Figure 2 and Figure 3).46 In general, components for vehicle body
and auxiliary systems do not differ, and manufacturers can take advantage of existing production
lines to benefit from economies of scale; however, some models incorporate lightweight materials
to counteract the effects of heavier batteries.47 The production of batteries, other BEV-specific
components, and the use of alternative materials have differing environmental effects than
traditional ICEV manufacturing. During the production process, much of the differing

39 There are 17 rare earth elements (REEs), 15 within the chemical group called lanthanides, plus yttrium and
scandium. The lanthanides, which are all REEs, consist of the following: lanthanum, cerium, praseodymium,
neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium,
ytterbium, and lutetium.
40 For more information on REEs, see CRS Report R41347, Rare Earth Elements: The Global Supply Chain, by Marc
Humphries.
41 Rim et al., 2013.
42 Rim et al., 2013.
43 Rim et al., 2013.
44 Risks can be exacerbated by poor working conditions, inadequate ventilation, lack of awareness of safety precautions
among workers and improper use of protective equipment.
45 Monazites contain thorium, a naturally occurring radioactive metal, and its associated decay products, which can
include radium. Waste generated from REE mining activities can be referred to as technologically enhanced naturally
occurring radioactive materials (TENORM) and are subject to state and federal standards. For more information, see
EPA, “TENORM: Rare Earths Mining Wastes,” April 10, 2019, https://www.epa.gov/radiation/tenorm-rare-earths-
mining-wastes.
46 ICEVs have a fuel tank, engine, gearbox, and exhaust; BEVs have a traction battery pack, electric motor, including
regenerative braking, and power electronics.
47 See BMW i3 or Tesla vehicles, for example. EEA Report No. 13/2018, p. 22.
Congressional Research Service
10

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

environmental effects profile of BEV technologies is attributable to the greater demand for
electricity and other forms of energy required for battery production.48
Factors Affecting the BEV Production Stage
A number of characteristics, additional to the electricity generation mix used during production,
can affect LCA results for vehicle production. These include vehicle mass, powertrain, material
composition of components, fuel consumption, and lifetime driving distance. Generally the larger
the vehicle, the more materials required for the vehicle, and the more energy required across the
various life cycle stages. Changes to material composition may increase the energy consumption
during manufacturing but may reduce vehicle weight and reduce fuel consumption during the in-
use phase.49 The longer the lifetime mileage of the vehicle and the battery, the less influence that
production-related emissions have and the greater influence that the in-use stage emissions have
over the total life cycle effects.50
Some additional characteristics affecting LCAs of BEV production include the size of the battery,
the battery chemistry and configuration, and the manufacturing efficiencies. Different battery
chemistries have different performance characteristics, with some batteries requiring more
energy-intensive production processes or materials. Manufacturers that can take advantage of
economies of scale and use the full capacity of production plants may reduce energy consumption
per vehicle or battery produced.
As the industry is currently structured, the life cycle environmental effects of battery production
are largely beyond the borders of the United States and outside of the jurisdiction of the U.S.
legislative and regulatory framework.
Environmental Assessment of Battery Manufacturing
Many LCAs of BEV technologies find that battery production is potentially responsible for the
largest proportion of energy use and subsequent environmental effects that occur during the
manufacturing stage. Estimates range between 10% to 75% of manufacturing energy and 10% to
70% of manufacturing GHG emissions, depending on the approach taken and the electricity
generation source (e.g., coal-fired, natural gas-fired, or renewable).51 As for other BEV
components, LCAs estimate contributions from the electric motor production to be 7% to 8% of
total production-related emissions (including raw material extraction and processing) due to a
high copper and aluminum content; and from the power train production to be 16% to 18% due to
a high aluminum content.52

48 Ellingsen et al., 2018, p. 24.
49 Sullivan et al., 2018, pp.1-2.
50 To allow comparison across different vehicle types, LCA practitioners typically express production impacts per
distance driven and assume a lifetime mileage of the vehicle (or battery). LCA practitioners may assume different
lifetime mileages in their analyses; these differences can lead to different estimates in lifetime impacts (e.g., GHG
emissions). For more information, see EEA Report No. 13/2018, p. 27.
51 A. Nordelöf, M. Messagie, A. Tillman, M. L. Söderman, J. Van Mierlo, “Environmental Impacts of Hybrid, Plug-In
Hybrid, and Battery Electric Vehicles—What Can We Learn from Life Cycle Assessment?” International Journal of
Life Cycle Assessment, vol. 19 (2014), pp. 1866–1890; R. Nealer and T. Hendrickson, “Review of Recent Lifecycle
Assessments of Energy and Greenhouse Gas Emissions for Electric Vehicles,” Current Sustainable/ Renewable Energy
Reports, vol. 2 (2015), pp. 66-73; and EEA Report No. 13/2018, p. 24.
52 Hawkins et al., 2013; and EEA Report No. 13/2018, pp. 24-27.
Congressional Research Service
11

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Figure 2. Components of a Battery Electric Vehicle

Source: Reproduced from U.S. Department of Energy, Alternative Fuels Data Center, https://afdc.energy.gov/
vehicles/how-do-all-electric-cars-work.

Figure 3. Components of an Internal Combustion Engine Vehicle

Source: Reproduced from U.S. Department of Energy, Alternative Fuels Data Center, https://afdc.energy.gov/
vehicles/how-do-gasoline-cars-work.
Congressional Research Service
12

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Steps in the production of lithium-ion batteries (the technology of focus for this report) include
the preparation of anode and cathode materials, cell manufacture, and assemblage of multiple
cells into a battery pack.53 Cell manufacture largely occurs in Asia (e.g., Japan and South Korea
are net exporters of battery packs).54 Pack assembly is less complex and energy-intensive than
cell manufacture. Packs are either assembled by a cell manufacturer and then delivered to
automobile manufacturers, or are assembled by automobile manufacturers themselves.55
When comparing the GHG emissions from the production of BEVs and ICEVs (including those
emissions from raw material extraction and processing), LCA practitioners generally find the
impact of BEV production is greater than that of ICEV production. When GHG emissions of
similarly sized BEVs and ICEVs are compared in the production phase, the GHG emissions of
BEV production are commonly estimated to be between 1.3 and 2 times those of ICEV
production.56 Further, many LCAs report that emissions of NOx, SO2, and PM from BEV
production are approximately 1.5-2.5 times higher than ICEV production.57 This is largely due to
the energy-intensive process of battery manufacturing and the current mix of sources for
electricity generation in the manufacturing sector. This higher energy use has broader associated
human health and ecosystem effects (depending upon fuel source and pollution controls).
The life cycle environmental effects associated with battery manufacturing vary greatly based
upon the manufacturing location.58
C. Vehicle In-Use (Including the Fuel Life Cycle)
The environmental effects associated with the “in-use” stage of a vehicle correspond primarily to
the life cycle environmental effects arising from the vehicle’s source of energy (i.e., the fuel life
cycle). For ICEVs, the source of energy is most commonly petroleum-based fuel (e.g., gasoline or
diesel), which is extracted, processed, distributed, and then combusted in the vehicle’s engine.
For BEVs, the source of energy is electricity, which is generated at a power station (potentially
from a variety of energy sources), transmitted, stored in a battery pack, and then used by the
vehicle’s motor. Beyond the fuel life cycle, some emissions may occur during the vehicle’s
operation stage, specifically in the form of PM pollution from brake and tire wear.59

53 Cell manufacture combines the prepared anode and cathode, electrolyte, collector, and separator materials into a
container. Battery pack assembly includes the cells, battery casing, electrical system, thermal management system, and
electric battery management systems.
54 According to EEA Report No. 13/2018, p. 23, in addition to Japan and South Korea, China also produces battery
packs. As China has a relatively large BEV market compared with other countries, China’s battery packs may be
directed to China’s domestic BEV market.
55 Ellingsen et al., 2018.
56 Ellingsen et al., 2018; Kim et al., 2016; and EEA Report No. 13/2018, pp. 24-27.
57 S. Rangaraju, et al., “Impacts of Electricity Mix, Charging Profile, and Driving Behavior on the Emissions
Performance of Battery Electric Vehicles: A Belgian Case Study,” Applied Energy, vol. 148 (2015), pp. 496-505. NOx
and SO2 emissions are linked with acidification and eutrophication as well as human health impacts.
58 Battery manufacturing for BEVs is an energy-intensive process that consumes more energy from electricity
generation than similar production stages for ICEVs. While electricity may be used during the production stages of
both vehicle life cycles, the GHG emissions associated with the electricity generation in a region have a larger impact
on the battery manufacturing stage than other production stages. GHG emissions can vary depending upon the fuel mix
of the electricity generation in a region. For example, according the U.S. Department of Energy, Argonne National
Laboratory (ANL), Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET®) Model,
2018, the U.S. grid emits, on average, 505 gCO2e/kWh (148,000 gCO2e/MMBtu, including life cycle emissions) while
the Chinese national grid is estimated to emit, on average, 760 gCO2e/kWh.
59 “Vehicles emit inhalable particulates from two major sources: the exhaust system, which has been extensively
Congressional Research Service
13

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

BEVs do not emit GHG or other air pollutants during operation of the vehicle motor. However,
emissions often occur from electricity generation upstream of the vehicle charging stage,
including the upstream extraction, refining, and transportation of fuels used for electricity
generation. In LCA, “upstream” refers to those life cycle stages that occur prior to the in-use
stage—in the case of the fuel cycle, its extraction, processing, transport, and, if necessary,
generation. “Downstream” typically refers to those life cycle stages that include in-use and end-
of-life management—in the case of the fuel cycle, its combustion or use (see text box
“Terminology in Transportation Sector LCAs”).
ICEVs emit GHG and other pollutants downstream during vehicle operation through fuel
combustion and upstream during the extraction, refining, and transportation of crude oil for the
production of liquid transportation fuel, as well as distribution of the refined fuel.
Terminology in Transportation Sector LCAs
In addition to the “upstream” and “downstream” terms used in this report, LCA practitioners use certain
terminology to enable comparisons between vehicle types with different power sources, fuel use, and associated
effects. These terms are based on the concept of the fossil fuel life cycles for ICEVs, and they have been adopted
for BEVs.

Well-to-Tank (WtT) refers to any environmental effects from the processes needed to extract and transform
crude oil into useable fuel for ICEVs. For BEVs, WtT refers to any environmental effects from electricity
production occurring upstream of vehicle charging. WtT corresponds to the term “upstream.”

Tank-to-Wheels (TtW) refers to any environmental effects from the combustion of the fuel in the vehicle’s
engine for ICEVs. For BEVs, TtW refers to the direct environmental effects of driving the vehicle. TtW
corresponds to the term “downstream.”

Well-to-Wheels (WtW) refers to the WtT and TtW stages col ectively for both ICEVs and BEVs.
Factors Affecting the ICEV In-Use Stage
For ICEVs, the amount of GHG and other pollutants emitted during upstream processes are
related to the characteristics of the crude oil resource; the methods and efficiencies of the
extraction and refining processes; and the methods of fuel transportation and distribution. The
amount of GHG and other pollutants emitted during downstream processes (i.e., vehicle
operation) are related to the type and quality of the fuel combusted; the fuel efficiency of the
vehicle and its engine; and the distance that the vehicle travels during its lifetime.60

characterized and regulated; and non-exhaust sources including brake wear, tire and road wear, clutch wear and road
dust resuspension. The non-exhaust sources have not been regulated because they are difficult to measure and control.
However, with increasingly stringent standards for exhaust emissions, the non-exhaust fraction has become
increasingly important.” For more information, see California Air Resources Board, “Vehicle Non-Exhaust Particulate
Matter Sources,” at https://ww2.arb.ca.gov/resources/documents/brake-tire-wear-emissions. See also European
Commission, “Non-Exhaust Traffic Related Emissions—Brake and Tyre Wear PM,” at https://ec.europa.eu/jrc/en/
publication/eur-scientific-and-technical-research-reports/non-exhaust-traffic-related-emissions-brake-and-tyre-wear-
pm; and V. R. J. H. Timmers and P. Achten, “Non-Exhaust PM Emissions from Electric Vehicles,” Atmospheric
Environment, vol. 134 (2016), pp. 10-17.
60 A number of CRS reports focus on the environmental effects and the statutory and regulatory requirements affecting
transportation fuel production and vehicle use. See, for example, CRS Report R40506, Cars, Trucks, Aircraft, and EPA
Climate Regulations, by James E. McCarthy and Richard K. Lattanzio; CRS Report R42986, Methane and Other Air
Pollution Issues in Natural Gas Systems, by Richard K. Lattanzio; CRS Report R43497, Tier 3 Motor Vehicle Emission
and Fuel Standards, by Richard K. Lattanzio and James E. McCarthy; and CRS Report R45204, Vehicle Fuel Economy
and Greenhouse Gas Standards: Frequently Asked Questions, by Richard K. Lattanzio, Linda Tsang, and Bill Canis.
Congressional Research Service
14

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

In the United States, environmental laws mitigate some of the environmental effects from the
ICEV in-use stage. For example, the Clean Air Act (CAA) seeks to reduce air pollution in the
United States, specifically requiring fuels and vehicles to produce fewer emissions. To meet the
requirements of the CAA, EPA has taken several actions, including setting ambient air quality
standards; requiring the use of emissions control devices and practices for industrial sources of
pollution (e.g., crude oil and natural gas production, processing, and refining operations);
requiring emissions control devices and cleaner burning engines in vehicles; removing lead from
gasoline; requiring the use of reformulated gasoline; and requiring the supply of ultra-low sulfur
gasoline and diesel fuel.61
Further, the Clean Water Act regulates surface discharges of water associated with crude oil and
natural gas drilling and production as well as contaminated storm water runoff from production
sites. The Safe Drinking Water Act regulates the underground injection of wastewater from crude
oil and natural gas production and the underground injection of fluids used in hydraulic fracturing
if the fluids contain diesel fuel. The Resource Conservation and Recovery Act regulates
underground storage tanks. States and localities may also have environmental requirements.
Similarly, environmental laws and regulations in other countries may mitigate some of the
environmental effects from the ICEV in-use stage. An analysis of other countries’ activities is
beyond the scope of this report.
Environmental Assessment of ICEV In-Use
The environmental effects of ICEVs occur upstream during the extraction, refining, and
transportation of crude oil and refined products and downstream (i.e., locally) during vehicle
operation.
With respect to the upstream stages, transportation fuels like gasoline and diesel are the product
of a long process beginning with the exploration and extraction of the resource and leading to its
treatment in refineries, transportation to distributors, and eventual delivery to consumers. Crude
oil is commonly recovered from geologic formations in the ground through drilling and extraction
activities by the oil and gas industry. Potential environmental effects associated with these
activities include water quality issues (e.g., the potential contamination of groundwater and
surface water from production activities); water management practices (both consumption and
discharge); land use changes; induced seismicity; and air pollution. Pollutants emitted from crude
oil and natural gas systems include, most prominently, methane (a potent GHG) and VOCs—of
which the sector is one of the highest-emitting industrial sectors in the United States62—as well as
NOx, SO2, and various forms of toxics. Further, the type and the extent of emissions from crude
oil and natural gas systems depend heavily on the quality of the crude resource, the characteristics
of the resource basin from which the fuel resource is extracted, and the subsequent refinery
processes. For example, some crude oils and their production processes (e.g., Canadian oil sands

61 For more information on CAA requirements, see CRS Report RL30853, Clean Air Act: A Summary of the Act and Its
Major Requirements, by Kate C. Shouse and Richard K. Lattanzio.
62 The U.S. Environmental Protection Agency’s 2014 National Emissions Inventory estimated VOC emissions from
“oil and gas” stationary sources to be 3.23 million tons, from all stationary sources to be 8.26 million tons, and from all
anthropogenic sources to be 16.48 million tons. Data for VOCs, as well as the other criteria pollutants and hazardous
air pollutants (HAPs), which are pollutants known or suspected to cause cancer or other serious health effects, are
derived from EPA’s National Emissions Inventory, https://www.epa.gov/sites/production/files/2017-04/documents/
2014neiv1_profile_final_april182017.pdf.
Congressional Research Service
15

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

mining) may have on the order of seven times the GHG emissions that other crude oils and their
production processes have (e.g., light, sweet oils from the U.S. Bakken region).63
Regarding the downstream (or vehicle operation) stage, gasoline and diesel transportation fuels
are toxic and highly flammable liquids. The vapors given off when they evaporate and the
substances produced when they are combusted (CO, NOx, PM, and VOCs) contribute to air
pollution. Burning gasoline and diesel also produces CO2. The combustion of a gallon of gasoline
and a gallon of diesel produce about 8.89 and 10.16 kilograms of CO2 respectively.64 According
to EPA’s Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990–2018,65 the national
inventory that the United States prepares annually under the United Nations Framework
Convention on Climate Change,66 the transportation sector is currently the largest contributor to
anthropogenic GHG emissions in the United States. The agency estimates that transportation
accounted for 28% of total U.S. GHG emissions in 2018, for a total of over 1,883 million metric
tons of carbon dioxide equivalent (MMTCO2e). The category of light duty vehicles (i.e.,
passenger cars and light trucks) contributed 1,055 MMTCO2e. Thus, the combustion of fuel
during the in-use stage is a major contributor to the life cycle environmental effects of ICEVs.
Factors Affecting the BEV In-Use Stage
For BEVs, the amount of GHG and other pollutants emitted during upstream processes are related
to the fuel type and the energy efficiency of the power plant and transmission infrastructure used
to power the vehicle. The amount of GHG and other pollutants emitted during downstream
processes (i.e., vehicle operation) are related to the energy efficiency and other characteristics of
the vehicle.
Upstream factors include the following:67
 Electricity generation mix: Different types of electricity generation are
currently associated with very different environmental effects profiles per unit of
electricity generated. These profiles include potential environmental effects
during electricity generation and potential environmental effects during the
extraction, processing, and transportation of the fuel used for electricity
generation. Coal-fired power plants have the highest life cycle GHG, SOx, and
PM emission intensities. Nuclear, hydroelectric, and non-biomass renewable
energy sources have lower GHG and other air pollutant emissions intensities,
although their lifecycle emissions are not zero due to the construction and
maintenance of the facilities, as well as potential fuel production and end of life
management issues. Further, each type of power source has different energy,
resource, and water consumption and use patterns. When assessing the life cycle
environmental effects from an attributional standpoint, the average electricity
generation grid mix for a country, region, or locality represents the total amount
of electrical energy fed into the grid from each generation source over the course

63 For a comprehensive investigation into the WtW GHG emissions intensities of a variety of global crude oil types, see
D. Gordon, A. Brandt, J. Bergerson, J. Koomey, “Oil-Climate Index,” Carnegie Endowment for International Peace,
2015, https://oci.carnegieendowment.org/.
64 U.S. Energy Information Administration, https://www.eia.gov/energyexplained/index.php?page=
gasoline_environment.
65 U.S. Environmental Protection Agency, Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990–2018, EPA-
430-R-20-002, April 13, 2020.
66 United Nations Framework Convention on Climate Change (U.S. Treaty Number: 102-38, October 7, 1992).
67 For more discussion, see, for example, EEA Report No. 13/2018, pp. 38-43.
Congressional Research Service
16

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

of the entire year, 24 hours per day. This calculation can determine the average
environmental effects of the electricity supply.
 Charging patterns: While the average annual electricity generation mix is a
useful approximation for the likely environmental effects of BEV charging, it
does not account for the dynamics of electricity supply and demand. For a more
accurate assessment, the environmental effects for any given charging event
depend on the instantaneous electricity generation mix, which varies according to
time of year, time of day, and the level of electricity demand. Thus, when
assessing the life cycle environmental effects from a consequential standpoint,
additional demand created by BEV charging may cause a shift in the electricity
generation mix, resulting in either an increase or a decrease in the power sector’s
environmental effects, depending on the type of generation available to meet the
additional demand. For example: BEV charging during times of higher renewable
electricity supplies (e.g., during the middle of the day when solar photovoltaic
(PV) generation is available) may help to integrate these supplies in the
electricity generation mix, resulting in a less carbon-intensive mix with lower
GHG and other air pollutant emissions on average. However, BEV charging at
times that coincide with peaks in other energy use may produce higher GHG and
other air pollutant emissions on average, as the extra demand may be met using
carbon-intensive sources of electricity.
 Transmission efficiencies: Conversion losses during electricity generation and
losses during transmission and charging can offset some of the in-use efficiency
advantages of BEVs (see BEV engine efficiency discussion below). Because the
average U.S. electricity mix includes low emission sources (e.g., nuclear,
hydroelectric, solar, and wind), the improved in-use efficiency advantage of
BEVs currently outweighs the conversion losses in the United States.68 Locally,
however, this balance is strongly dependent on the regional electricity generation
mix.69
Downstream factors include the following:70
 Engine efficiency: The energy consumption of BEVs is dependent upon the
energy efficiency of their motors, as is the case for ICEVs. In general, BEVs
have higher in-use energy efficiency than ICEVs. BEVs convert over 77% of the
electrical energy delivered from the grid for propulsion. ICEVs convert about
12%–30% of the energy stored in gasoline for propulsion.71 The efficiency
advantage of BEVs arises partly because of the higher efficiency of individual
powertrain components (battery, motor, and transmission) and partly because of

68 See section “Review of the Findings from Dunn et al., 2015 (Updated).”
69 See Lawrence Livermore National Laboratory, “Energy Flow Charts,” at https://flowcharts.llnl.gov/commodities/
energy.
70 For more discussion, these factors are outlined in EEA Report No. 13/2018, pp 37-38.
71 U.S. Department of Energy, “All-Electric Vehicles,” https://www.fueleconomy.gov/feg/evtech.shtml, accessed
February 5, 2020.
Congressional Research Service
17

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

regenerative braking,72 which can recapture roughly 10% to 20% of total energy
used depending on driving style and conditions.73
 Vehicle size and weight: The energy consumption of BEVs is strongly correlated
with vehicle size and weight, as is the case for ICEVs. Heavier and larger BEVs
require more energy to accelerate, and they have greater rolling resistance and air
resistance than smaller and lighter BEVs.74 Further, BEVs are between 14% and
29% heavier than an equivalent-sized ICEV from the same manufacturer.75 The
extra weight of BEVs is largely due to the weight of the battery and the
associated secondary weight increases required to strengthen the vehicle body.
This extra weight diminishes the overall efficiency advantage of BEVs in
comparison to ICEVs.
 Driving style: A key factor affecting energy consumption of BEVs is the extent
to which regenerative braking can recuperate energy. Regenerative braking is
most effective during gradual deceleration and descending hills. During sharp
braking, a lower proportion of the energy can be recuperated and the use of
mechanical brake pads is required. Therefore, under more aggressive driving
conditions, the efficiency advantage of BEVs over ICEVs is diminished.
 Auxiliary systems: Another factor affecting the energy efficiency of BEVs is the
degree of electricity consumption by auxiliary systems (e.g., heating and air
conditioning). For most auxiliary systems (including air conditioning for cooling)
the effect on energy consumption in BEVs and ICEVs is similar. However, for in-
cabin heating, BEVs must draw energy from the battery, whereas ICEVs can
make use of waste heat from the engine. Therefore, in cold conditions, the
efficiency advantage of BEVs over ICEVs is diminished.
In the United States, environmental laws mitigate some of the environmental effects from the
BEV in-use stage. For example, electric power generation, transmission, and distribution are part
of the utility sector. As with the various sectors related to ICEV’s in-use stage, EPA has taken
several actions to reduce pollution from the utility sector.76 States and localities may also have

72 Regenerative braking is unique to BEVs and enables the vehicle’s kinetic energy to be converted back to electrical
energy during braking (deceleration or downhill running). The converted electrical energy is stored in energy storage
devices such as batteries, ultracapacitors, and ultrahigh-speed flywheels. See A. Doyle and T. Muneer, “Traction
Energy and Battery Performance Modelling,” in Electric Vehicles: Prospects and Challenges (Elsevier Inc. 2017), pp.
93-124.
73 See EEA Report No. 13/2018, and S. Rangaraju, et al., “Impacts of Electricity Mix, Charging Profile, and Driving
Behavior on the Emissions Performance of Battery Electric Vehicles: A Belgian Case Study,” Applied Energy, vol. 148
(2015), pp. 496-505.
74 P. Egede, Environmental Assessment of Lightweight Electric Vehicles (Springer International Publishing: Basel,
Switzerland, 2017).
75 V. R. J. H. Timmers and P. Achten, “Non-Exhaust PM Emissions from Electric Vehicles,” Atmospheric
Environment, vol. 134 (2016), pp. 10-17.
76 These include regulating NOx, PM, and SOx at power plants under CAA New Source Performance Standards;
regulating mercury and other air toxics at power plants under the CAA National Emissions Standards for Hazardous
Air Pollutants (NESHAP); controlling for interstate air pollution transport; controlling for benzene waste operations;
requiring emission standards for stationary internal combustion engines, including reciprocating internal combustion
engines (RICE); requiring emission standards for stationary combustion turbines; requiring reporting under a
Greenhouse Gas Reporting Program; promulgating rules for cooling water intake structures under Clean Water Act
§316(b) National Pollutant Discharge Elimination System (NPDES); and providing for effluent guidelines for steam
electric power generation. A number of CRS reports focus on the environmental effects and the statutory and regulatory
requirements affecting the utility sector. See, for example, CRS Report R45451, Clean Air Act Issues in the 116th
Congress, by James E. McCarthy, Kate C. Shouse, and Richard K. Lattanzio; CRS Report R45299, The Clean Air Act’s
Congressional Research Service
18

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

more stringent environmental requirements, including regional GHG initiatives and renewable
energy portfolio standards.
Similarly, environmental laws and regulations in other countries may mitigate some of the
environmental effects from the BEV in-use stage. An analysis of other countries’ activities is
beyond the scope of this report.
Environmental Assessment of BEVs In-Use
The life cycle environmental effects attributable to the BEV in-use stage are minimal during
downstream vehicle operation because BEVs do not emit CO2 or other air pollutants through
tailpipe exhaust. However, a variety of environmental effects may occur from electricity
generation occurring upstream of vehicle charging, including the upstream extraction, refining,
transportation and combustion of fuels used for electricity generation.
Most LCA practitioners report that emissions of many common air pollutants (including GHG,
VOCs, CO, and NOx) from BEVs tend to be lower than ICEVs on a per kilometer basis during
the in-use phase of the vehicle life cycle (including the fuel life cycle). This is due to the energy
efficiency advantages of electric motors and the incorporation of electricity sources with low
emissions intensities in the electricity generation mix. A scenario in which BEVs emit more
GHGs and other air pollutants than ICEVs is if a vehicle uses electricity derived primarily from
coal as a fuel source. Some other common air pollutant emissions, however, specifically those
more prevalent in coal combustion than petroleum combustion (e.g., SOx, PM, toxics), are
generally estimated to be greater in most scenarios for BEVs than ICEVs due to the inclusion of
some percentage of coal-fired power in most modeled electricity generation mixes.
Further, the comparative impact of BEVs’ and ICEVs’ in-use air pollutant emissions on human
health is dependent upon the location of emissions. In urban centers, street-level emissions of
NOx, PM, hydrocarbons, and other pollutants from ICEVs can lead to high local concentrations in
densely populated areas. In contrast, emissions from power plants, on average, tend to occur
away from densely populated areas, contributing to lower levels of background concentrations
over larger areas.77
Environmental effects of BEVs also include potential effects on terrestrial and aquatic
ecosystems. While LCAs of BEVs on ecosystems are less common than LCAs of GHG and other
air pollutant emissions in the literature, these effects are nonetheless important. Generalized
results from the selection of articles reviewed for this report suggest that the in-use environmental
effects of BEVs are similar to that of ICEVs for terrestrial acidification, because the NOx and SOx
emissions from coal-fired electricity generation counterbalance the NOx emissions savings from
the absence of tailpipe emissions. BEVs and ICEVs effects for terrestrial ecotoxicity are likely to
be similar, as the primary cause is the release of zinc, copper, and titanium from tire and brake
wear for which data on differences are limited.78 In contrast, freshwater eutrophication and

Good Neighbor Provision: Overview of Interstate Air Pollution Control, by Kate C. Shouse; CRS In Focus IF11078,
EPA Reconsiders Benefits of Mercury and Air Toxics Limits, by Kate C. Shouse; CRS Report R45453, U.S. Carbon
Dioxide Emissions in the Electricity Sector: Factors, Trends, and Projections, by Jonathan L. Ramseur; CRS In Focus
IF10778, Overview of the Steam Electric Power Generator Effluent Limitation Guidelines and Standards, by Laura
Gatz; and CRS Report R41836, The Regional Greenhouse Gas Initiative: Background, Impacts, and Selected Issues, by
Jonathan L. Ramseur.
77 For more discussion, see, for example, EEA Report No. 13/2018, pp 33-34.
78 Estimates of local PM emissions from BEVs, and the comparison with those of ICEVs, vary considerably because of
the difficulty of measuring them reliably in real-life conditions.
Congressional Research Service
19

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

ecotoxicity effects of in-use BEVs are typically higher than those for ICEVs due to the emissions
to water from the mining of coal required for electricity generation.
D. Vehicle End-of-Life
The final stage of a vehicle’s life cycle is end-of-life. This stage can include reuse and recycling
of vehicle components in addition to disposal. In terms of process, end-of-life vehicle treatment
starts with deregistration and collection. The vehicle is then dismantled. Components containing
hazardous materials, such as batteries and refrigerant gases, are collected, followed by recyclables
and valuable materials for secondary use, including engines and tires. The vehicle shells left after
the dismantling process are put into shredders. The shredded materials are separated and
subsequently iron is separated from non-ferrous materials.79
Factors Affecting the End-of-Life Stage
Factors that can affect LCA results for the end-of-life stage include the manner in which the
materials are disposed and whether or not materials are reused or recycled. Designing
components or selecting battery chemistry to facilitate disassembly, reuse, or recycling could
generally reduce potential impacts. However, for modeling purposes, LCA practitioners
commonly allocate the effects of such changes to the subsequent vehicle that received reused or
recycled components.
Environmental Assessment of End-of-Life Management
The environmental effects from the end-of-life stage—for both BEVs and ICEVs—contribute a
smaller percentage to total life cycle environmental effects than other stages.80 There is
uncertainty with the data for end-of-life emissions, and the potential for reuse and recycling of
components, including batteries, could further alter life cycle contributions. As BEVs increase in
market share, the overall life cycle of the vehicles market is shifting away from a fuel-intensive
portfolio to a materials-intensive portfolio. Some believe that this shift makes it increasingly
important to have efficient recycling processes to recover materials.81 Others are reportedly
looking for “second-life” stationary energy storage applications for BEV batteries past their
useful life in vehicle applications.82
Recycling can reduce the resource intensity of the raw material supply chain. For example,
primary aluminum production is 20 times as energy intensive as scrap aluminum production.83

79 As described in EEA Report No. 13/2018, p. 47.
80 EEA Report No. 13/2018, p. 7; Hawkins et al., 2012; and C. Tagliaferri, et al., “Life Cycle Assessment of Future
Electric and Hybrid Vehicles: a Cradle-to-Grave Systems Engineering Approach,” Chemical Engineering Research
and Design, vol. 112 (2016).
81 L. A-W. Ellingsen and C.R. Hung, Research for TRAN Committee—Resources, Energy, and Lifecycle Greenhouse
Gas Emission Aspects of Electric Vehicles, European Parliament, Policy Department for Structural and Cohesion
Policies, IP/B/TRAN/IC/2017-068 (Brussels, 2018).
82 David Stringer and Jie Ma, “Where 3 Million Electric Vehicle Batteries Will Go When They Retire,” Bloomberg
Businessweek, June 27, 2018, https://www.bloomberg.com/news/features/2018-06-27/where-3-million-electric-vehicle-
batteries-will-go-when-they-retire.
83 International Energy Agency, Greenhouse Gas Emissions from Major Industrial Sources—IV the Aluminum
Industry, Report No. PH3/23, Paris, 2000.
Congressional Research Service
20

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

While some of the materials in BEVs have mature recycling industries, others do not. For
example, the recycling of REEs from magnets used in BEVs is limited.84
Environmental Assessment of Battery Recycling
End-of-life batteries may affect the environment if improperly disposed.85 A lead-acid battery86
recycling market exists in the United States. According to EPA, in 2014 the rate of lead-acid
battery recycling was approximately 99%,87 making them one of the most recycled products in
the United States.88 Some see the lead-acid battery recycling market as a model for lithium-ion
battery recycling; however, the typical automotive lead-acid battery is a mature technology that
serves a different function than the lithium-ion battery for a BEV. The lead-acid battery has been
the standard battery technology for most of the past century. Compared with a lithium-ion battery
for a BEV, a typical automatic lead-acid battery is smaller, weighs less, and has a shorter
lifetime.89
The recycling industry for lithium-ion batteries is less developed than for lead-acid in the United
States. Reports estimate recycling rates for lithium-ion batteries to be less than 5% in the United
States.90 According to the U.S. Geological Survey, “one domestic company has recycled lithium
metal and lithium-ion batteries since 1992 at its facility in British Columbia, Canada,” and the
same company established the first U.S. lithium-ion vehicle battery recycling facility in
Lancaster, OH, in 2015.91
DOE has also announced a lithium-ion battery recycling prize and an associated battery recycling
research and development center.92 According to DOE, the Lithium Battery Recycling Prize is a
“competition with a series of progressive down selections to incentivize the nation’s innovators
and entrepreneurs to develop and demonstrate processes that, when scaled, have the potential to

84 A. Tsamis and M. Coyne, Recovery of Rare Earths from Electronic Wastes: An Opportunity for High-Tech SMEs,
Report on a study for the ITRE committee IP/A/ITRE/2014-09 (European Parliament, 2015).
85 Waste management is subject to state and federal standards. Concerns over improper disposal also extends to internal
combustion vehicles, which have fluids and materials—including batteries—that are subject to state and federal
standards.
86 The type of battery used in ICEVs to start the engine.
87 U.S. Environmental Protection Agency, Advancing Sustainable Materials Management: 2014 Fact Sheet, EPA530-
R-17-01, November 2016, p. 5.
88 See A. D. Ballantyne, J. P. Hallett, and D. J. Riley, et al., “Lead Acid Battery Recycling for the Twenty-First
Century,” Royal Society Open Science, vol. 5 (2018), https://doi.org/10.1098/rsos.171368; U.S. Environmental
Protection Agency, Advancing Sustainable Materials Management: 2014 Fact Sheet, EPA530-R-17-01, November
2016, p. 9.
89 While an automotive lead-acid battery is smaller and lighter than a lithium-ion battery, the lead-acid battery is poorly
suited for electric vehicles due to a lower energy density than a lithium-ion battery. Automotive lead-acid batteries are
typically designed to deliver 12 volts of electricity to start a gasoline combustion engine within a vehicle and run other
automotive components. For more information on how automotive batteries work, see CRS Report R41709, Battery
Manufacturing for Hybrid and Electric Vehicles: Policy Issues, by Bill Canis.
90 Mitch Jacoby, “It’s Time to Get Serious About Recycling Lithium-Ion Batteries,” Chemical and Engineering News,
vol. 97 (July 14, 2019), https://cen.acs.org/materials/energy-storage/time-serious-recycling-lithium/97/i28.
91 U.S. Geological Survey, “Lithium,” Mineral Commodity Summaries, February 2019, p. 98, https://minerals.usgs.gov/
minerals/pubs/commodity/lithium/. DOE awarded $9.5 million to the company in 2009 to construct the Ohio facility
for lithium-ion vehicle batteries; see U.S. Geological Survey, “Lithium,” Mineral Commodity Summaries, January
2018, p. 98, https://minerals.usgs.gov/minerals/pubs/commodity/lithium/.
92 U.S. Department of Energy, “Energy Department Announces Battery Recycling Prize and Battery Recycling R&D
Center,” press release, January 17, 2019, https://www.energy.gov/eere/articles/energy-department-announces-battery-
recycling-prize-and-battery-recycling-rd-center.
Congressional Research Service
21

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

profitably capture 90 percent of all lithium-based battery technologies in the United States.”93
DOE’s first lithium-ion recycling R&D center, the ReCell Center, will focus on research topics to
enable profitable recycling for industry adoption. One goal of the center is closed-loop recycling,
where materials from spent batteries are recycled directly into the vehicle battery manufacturing
process, which would minimize energy use and material waste by eliminating mining and
processing steps.94 In addition to reducing concerns about the generation and disposal of
hazardous waste, the availability of material supply, and environmental effects associated with
production, some research shows that recycling batteries and recovering multiple minerals has
been found to maximize both energy savings and emission reductions during material
production.95 Studies have shown that the recycling and reuse of materials within BEV batteries
could reduce primary energy use and result in reductions in GHG emissions of up to 50% across
the battery production process.96
Studies also indicate that the impact of battery recycling and reuse depends upon the type of
battery technology and the materials used in the battery. For lithium-ion batteries, one study
found that recycling could reduce the ecological impact of the battery by more than 20%.97
Reports found the reduction or substitution of select materials (such as gallium in lithium-ion
batteries) within the batteries influenced the ecological impact of the battery system.98
Different recycling methods have different potential environmental effects. Two recycling
methods considered for lithium-ion battery recycling are hydrometallurgical and
pyrometallurgical recycling. Hydrometallurgical recycling extracts materials from the battery by
dissolving the battery in a liquid. This chemical leaching process has the capability of capturing
metals and lithium. Pyrometallurgical recycling first chemically transforms the materials through
a kiln firing process and then leaches the material to recover slag and metals. Pyrometallurgurical
recycling is considered to be a cost-effective material recovery process and is less water intensive
than hydrometallurigical recycling; however, pyrometallurgurical recycling is typically more
energy intensive and can emit more air pollutants than hydrometallurgical recycling.99

93 U.S. Department of Energy, FY2020 Congressional Budget Request, vol. 3, part 2, March 2019, pp. 26-27.
94 For further information on ReCell research priorities, see Argonne National Laboratory, “DOE Launches Its First
Lithium-Ion Battery Recycling R&D Center: ReCell,” press release, February 15, 2019, https://www.anl.gov/article/
doe-launches-its-first-lithiumion-battery-recycling-rd-center-recell.
95 J. B. Dunn, L. Gaines, J. Sullivan, M. Q. Wang, “The Impact of Recycling on Cradle-to-Gate Energy Consumption
and Greenhouse Gas Emissions of Automotive Lithium-Ion Batteries,” Environmental Science and Technology, vol. 46
(2012), pp. 12704-12710.
96 Dunn et al., 2015; T. P. Hendrickson, O. Kavvada, N. Shah, R. Sathre, C. D. Scown, “Life-Cycle Implications and
Supply Chain Logistics of Electric Vehicle Battery Recycling in California,” Environmental Research Letters, vol. 10
(2015), 014011.
97 L. Unterreiner, V. Jülch, and S. Reith, “Recycling of Battery Technologies—Ecological Impact Analysis Using Life
Cycle Assessment (LCA),” Energy Procedia, vol. 99 (2016), pp. 229-234 (hereinafter Unterreiner et al., 2016). For
more information on stationary energy storage technologies, see CRS Report R45980, Electricity Storage:
Applications, Issues, and Technologies, by Richard J. Campbell.
98 Unterreiner et al., 2016.
99 T. P. Hendrickson, O. Kavvada, N. Shah, R. Sathre, C. D. Scown, “Life-Cycle Implications and Supply Chain
Logistics of Electric Vehicle Battery Recycling in California,” Environmental Research Letters, vol. 10 (2015),
014011.
Congressional Research Service
22

link to page 38 Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

A Discussion of the Published LCA Literature
Literature analyzing the life cycle environmental effects of BEV technology—both in isolation
and in comparison to ICEV technology—is extensive and growing. However, as the literature
grows, so does the range of results. From this literature, CRS selected 38 peer-reviewed articles to
assess, published from 2008 to 2019 (see the Appendix). The criteria used to select the articles
included (1) the article’s inclusion in Scopus and Web of Science databases, (2) the impact factor
of the journal that published the article,100 and (3) the extent to which the LCA focused on the full
life cycle of BEVs in comparison to ICEVs. A great number of detailed studies exist that focus on
specific stages and/or technologies (e.g., a specific battery type or vehicle type or stage of life);
these studies were not included in this review.
Review of the Findings from Selected LCAs
The selected articles diverged greatly in their results. The divergence is due to the differing
system parameters of each study, including the selected goals, scopes, models, scales, time
horizons, and datasets. Differences among the scopes of the studies included, inter alia, (1) the
number and types of environmental effects categories modeled; (2) the specific vehicle and
battery technologies modeled; (3) the choice of vehicle and battery lifetimes modeled; and (4) the
geographic locations modeled, including the particular electricity infrastructure. Further, the
studies employed different modeling assumptions (e.g., attributional, consequential),101 GHG
emissions datasets (e.g., EcoInvent; the Greenhouse gases, Regulated Emissions, and Energy use
in Transportation Model [GREET®]), electricity grid databases (e.g., eGRID, EPA’s CEMS,
National TSO/DSO), and energy forecasts (e.g., International Energy Agency, U.S. Energy
Information Administration). While each article may be internally consistent based upon the
assumptions within it, analysis across the articles is difficult. Because of these divergences and
complexities, CRS sees significant challenges to quantifying a life cycle assessment of BEV and
ICEV technologies that incorporates all of the findings in the published literature. A review of the
literature, however, can speak broadly to some of the trends in the life cycle environmental effects
as well as the relative importance of certain modeling selections.
Regarding the global warming potential effects of BEV technology, the quantitative results from
the selected articles have a wide variability. Excluding results obtained from stylized LCAs (i.e.,
those whose role is to denote an extreme state rather than a real-world situation), the findings of
the articles reviewed for this report span from approximately 50 grams of carbon dioxide
equivalent emissions per vehicle kilometer traveled (gCO2e/km) (Van Mierlo, et al., 2017,
presenting the full LCA results of a BEV in the Belgium environment) to 292 gCO2e/km (Bohnes,
et al., 2017, assessing the full LCA results of a BEV introduced in the Danish market in 2016,
using short-term marginal electricity mix).102 As stated previously, this divergence is due to the

100 An “impact factor” measures the number of citations that an average article in a journal receives in a particular year.
The impact factor applies to the journal where an article is published and does not measure the impact of an individual
article.
101 Attributional methodology typically utilizes average data for each unit process within the life cycle. Consequential
methodology, on the other hand, aims to describe how physical flows can change as a consequence of an increase or
decrease in demand for the product system under study. Unlike attributional, consequential methodology includes unit
processes inside and outside of the product’s immediate system boundaries. It utilizes economic data to measure
physical flows of indirectly affected processes.
102 CRS was unable to produce a comparably reliable range of values for ICEVs from the journal articles.
Congressional Research Service
23

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

differing system parameters of each study, including the selected goals, scopes, models, scales,
time horizons, and datasets.
Many authors, however, have noted the role of a specific factor, the CO2e intensity of the
modeled electricity generation mix, as a statistically significant modeling selection. Marmiroli et
al., 2018, investigates this hypothesis through an analysis of results correlating a BEV’s life cycle
emissions to the carbon intensity of the electricity generation mix from which the vehicle draws
its power. In this study, the authors find that “despite the wide-ranging scopes and the numerous
variables present in the assessments, the electricity mix’s carbon intensity can explain 70% of the
variability of the results.”103
Review of the Findings from Dunn et al., 2015 (Updated in 2019)
As stated in the previous section, although a number of LCAs are available, CRS sees significant
challenges to quantifying a life cycle assessment of BEV and ICEV technologies that incorporates
all of the findings in the published literature. Therefore, to provide an internally consistent
summary in graphical form, this report presents the results from one study: Dunn, J. B., Gaines,
L., Kelly, J. C., James, C., and Gallagher, K. G., “The Significance of Li-ion Batteries in Electric
Vehicle Life-Cycle Energy and Emissions and Recycling’s Role in Its Reduction,” Energy and
Environmental Science, 2015, as updated by the authors using the DOE, Argonne National
Laboratory (ANL), GREET® 2018 dataset.104
Dunn et al., 2015 (updated) analyzes a broad range of environmental effects, with vehicle types,
life stages, and geographic coverage well matched to the scope of this CRS report. While
comprehensive, Dunn et al., 2015 (updated) and the GREET® database have limitations and
analytical uncertainties based upon the modeling assumptions, as discussed below.105
Dunn et al., 2015 (Updated) Modeling Assumptions
Dunn et al., 2015 (updated) examines the environmental effects categories modeled by the DOE,
ANL GREET® 2018 LCA database. It is a “complete” LCA using attributional modeling for
average annual U.S. and California electricity grid data and average ICEV, PHEV, and BEV data.
Input assumptions are listed below (as well as in the initial study, Dunn et al., 2015):
 Year: 2017 simulation year; this corresponds to a 2017 electricity generation grid
with model year (MY) 2012 vehicle technology to account for the average age of
vehicles on the road.
 Grids examined: U.S. and California average (505 and 283 gCO2e/kWh,
respectively).
 Vehicle lifetime: 278,659 km (173,151 miles). Vehicle lifetime is based on
ANL’s VISION model, which in turn derives from a statistical evaluation of
annual vehicle miles traveled (VMT) for vehicles over their lifetime and the

103 B. Marmiroli, M. Messagie, G. Dotelli, J. Van Mierlo, J., “Electricity Generation in LCA of Electric Vehicles: A
Review,” Applied Sciences, vol. 8 (2018), p. 1384 (hereinafter Marmiroli et al., 2018).
104 The LCA dataset used by the U.S. Department of Energy, Argonne National Laboratory, for presentation in this
report is the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET®) Model, 2018,
https://greet.es.anl.gov/. J. C. Kelly and his team at Argonne National Laboratory provided updated inputs and data to
CRS.
105 The GREET® model and database is widely used, in part because of its accessibility and usability; however,
GREET® does not conform fully to the principles and framework in ISO 14040 for LCA. (See
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4643755/.)
Congressional Research Service
24

link to page 30 link to page 35 link to page 30 link to page 35 link to page 30 link to page 31 link to page 31 link to page 32 link to page 33 link to page 32 link to page 33 link to page 34 link to page 34 link to page 35 Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

survivability of those vehicles. ANL uses the same VMT for each vehicle. The
rationale is as follows: PHEV has no range limitation so should be equivalent to
ICEV; a BEV with a 300 mile range is treated here as equivalent to an ICEV.
 PHEV all electric range: 64 km (40 miles).
 BEV range: 482 km (300 miles). The BEV in the Dunn et al., 2015 study had a
range of 110 km, and its efficiency was higher than that of the 300 mile range
vehicle in the updated dataset.
 ICEV fuel economy: 9.02 liters (L)/100 km (26.08 miles per gallon [MPG]).
 PHEV fuel economy: 3.42 L/100 km (68.84 MPG). The PHEV’s charge
depleting (CD) and charge sustaining (CS) modes are 2.4 L/100 km, and 6.1
L/100 km (38.3 and 99.5 miles per gallon gasoline equivalent [MPGGE],106
respectively). The blend between them is 49.9% CD and 50.1% CS.
 BEV fuel economy: 2.81 L/100 km (83.56 MPGGE). The fuel economies are
based on ANL’s research in association with the vehicle simulation team (the
Autonomie team).
Selected Environmental Effects Categories
Figure 4 through Figure 13 present the Dunn et al., 2015 (updated) LCA findings for several
environmental effects categories compared across model year (MY) 2012 ICEV, PHEV, and BEV
powered by the U.S. and California electricity grids (2017 average) and divided into stages for
the vehicle cycle (battery), vehicle cycle (other than battery), upstream fuel cycle (“Well-to-
Tank”), and in-use fuel cycle (“Tank-to-Wheel”). In Figure 4 through Figure 13, the scale of the
environmental effects (i.e., the y-axis) varies greatly given the range of different pollutant types.
The effects of those emissions are not proportional by mass (to the extent that they are at all
comparable).
Dunn et al., 2015 (updated) finds that in comparison to the life cycle of ICEVs in the United
States, the life cycle of lithium-ion BEVs (inclusive of two selected battery chemistries) emits, on
average, an estimated 33% less GHGs (Figure 4), 61% less VOCs (Figure 5), 93% less CO
(Figure 6), 28% less NOx (Figure 7), and 32% less black carbon (Figure 10) when analyzed
using an averaged U.S. electricity grid mix. However, the life cycle of lithium-ion BEVs emits,
on average, an estimated 273% more SOx (Figure 8) and 15% more fine PM (Figure 9). Further,
in comparison to the life cycle of ICEVs, the life cycle of lithium-ion BEVs consumes, on
average, an estimated 29% less total energy resources (Figure 11) and 37% less fossil fuel
resources (Figure 12). However, the life cycle of lithium-ion BEVs consumes, on average, an
estimated 58% more water resources (Figure 13). These results are global effects, based on the
system boundaries and input assumptions of the study. The study does not assess human health or
ecosystem effects.

106 The U.S. Environmental Protection Agency uses a fuel economy value, “miles per gallon gasoline equivalent,” for
vehicles that do not use liquid fuels. According to the agency, the value “represents the number of miles the vehicle can
go using a quantity of fuel with the same energy content as a gallon of gasoline. This allows a reasonable comparison
between vehicles using different fuels.” See https://www.epa.gov/fueleconomy/text-version-electric-vehicle-label.
Congressional Research Service
25

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Figure 4. Life Cycle Assessment: Global Warming Potential
(Comparison of MY 2012 ICEV, PHEV, and BEV for U.S. and California Electricity Grid, 2017 Average)

Source: J. B. Dunn, L. Gaines, J. C. Kelly, C. James, C., and K. G. Gallagher, “The Significance of Li-ion Batteries
in Electric Vehicle Life-Cycle Energy and Emissions and Recycling’s Role in Its Reduction,” Energy and
Environmental Sciences, 2015, as updated by the authors using the most recent U.S. Department of Energy,
Argonne National Laboratory (ANL), Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation
(GREET®) Model, 2018, https://greet.es.anl.gov/.
Notes: Global warming potential measured in grams carbon dioxide equivalent emissions per vehicle kilometer
traveled averaged over the lifetime of the vehicle (gCO2e/km); model year (MY) 2012 internal combustion engine
vehicle (ICEV); MY 2012 plug-in hybrid electric vehicle (PHEV); MY 2012 battery electric vehicle (BEV); United
States electricity grid, 2017 average (US Grid); California electricity grid, 2017 average (CA grid); lithium-ion
battery with LiNi0.4Co0.2Mn0.4O2 cathode materials paired with graphite anodes (NMC111); lithium-ion battery
with a LiMn2O4 cathode material paired with graphite anodes (LMO). See Dunn et al., 2015 (updated) system
parameters and input assumptions listed below.
Dunn et al., 2015 (updated) examines all environmental effects categories modeled by the DOE, ANL GREET®
2018 LCA database. It is a “complete” LCA using attributional modeling for average U.S. and California
electricity grid data and average ICEV, PHEV, and BEV data. Input assumption are as fol ows, as well as in the
initial Dunn et al., 2015. Year: 2017 simulation year; this corresponds to a 2017 electricity generation grid with
model year (MY) 2012 vehicle technology to account for system lag. Grids examined: U.S. and California average
(505 and 283 gCO2e/kWh, respectively). Vehicle lifetime: 278,659 km (173,151 miles). Vehicle lifetime is based
on ANL’s VISION model, which in turn derives from a statistical evaluation of annual vehicle miles traveled
(VMT) for vehicles over their lifetime and the survivability of those vehicles. ANL uses the same VMT for each
vehicle. The rationale is as fol ows: PHEV has no range limitation so should be equivalent to ICEV; a BEV with a
300 mile range is treated here as equivalent to an ICEV. PHEV all electric range: 64 km (40 miles). BEV range:
482 km (300 miles). The BEV in the initial Dunn et al., 2015 study had a range of 110 km, and its efficiency was
higher than that of the 300 mile range vehicle in the updated dataset. ICEV fuel economy: 9.02 liters (L)/100 km
(26.08 miles per gallon [MPG]). PHEV fuel economy: 3.42 L/100 km (68.84 MPG). The PHEV’s charge depleting
(CD) and charge sustaining (CS) modes are 2.4 L/100 km, and 6.1 L/100 km (38.3 and 99.5 miles per gallon
gasoline equivalent [MPGGE], respectively). The blend between them is 49.9% CD and 50.1% CS. BEV fuel
economy: 2.81 L/100 km (83.56 MPGGE). The fuel economies are based on ANL’s research team associated
with vehicle simulation (the Autonomie team). These results are global effects.
J. C. Kelly and his team at Argonne National Laboratory provided updated inputs and data to CRS.
Congressional Research Service
26

link to page 30 link to page 30

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Figure 5. Life Cycle Assessment: Volatile Organic Compounds
(Comparison of MY 2012 ICEV, PHEV, and BEV for U.S. and California Electricity Grid, 2017 Average)

Source: Dunn et al., 2015 (updated).
Notes: Volatile organic compound emissions (VOC) in grams per vehicle kilometer traveled averaged over the
lifetime of the vehicle (g/km); see Figure 4 for additional notes.
Figure 6. Life Cycle Assessment: Carbon Monoxide
(Comparison of MY 2012 ICEV, PHEV, and BEV for U.S. and California Electricity Grid, 2017 Average)

Source: Dunn et al., 2015 (updated).
Notes: Carbon monoxide emissions (CO) in grams per vehicle kilometer traveled averaged over the lifetime of
the vehicle (g/km); see Figure 4 for additional notes.
Congressional Research Service
27

link to page 30 link to page 30

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Figure 7. Life Cycle Assessment: Nitrogen Oxides
(Comparison of MY 2012 ICEV, PHEV, and BEV for U.S. and California Electricity Grid, 2017 Average)

Source: Dunn et al., 2015 (updated).
Notes: Nitrogen oxides emissions (NOx) in grams per vehicle kilometer traveled averaged over the lifetime of
the vehicle (g/km); see Figure 4 for additional notes.
Figure 8. Life Cycle Assessment: Sulfur Oxides
(Comparison of MY 2012 ICEV, PHEV, and BEV for U.S. and California Electricity Grid, 2017 Average)

Source: Dunn et al., 2015 (updated).
Notes: Sulfur oxides emissions (SOx) in grams per vehicle kilometer traveled averaged over the lifetime of the
vehicle (g/km); see Figure 4 for additional notes.
Congressional Research Service
28

link to page 30 link to page 30

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Figure 9. Life Cycle Assessment: Fine Particulates
(Comparison of MY 2012 ICEV, PHEV, and BEV for U.S. and California Electricity Grid, 2017 Average)

Source: Dunn et al., 2015 (updated).
Notes: Fine particulates emissions (PM2.5) in grams per vehicle kilometer traveled averaged over the lifetime of
the vehicle (g/km); see Figure 4 for additional notes. PM2.5 is particulate matter with a diameter of less than 2.5
microns.
Figure 10. Life Cycle Assessment: Black Carbon
(Comparison of MY 2012 ICEV, PHEV, and BEV for U.S. and California Electricity Grid, 2017 Average)

Source: Dunn et al., 2015 (updated).
Notes: Black carbon emissions (BC) in grams per vehicle kilometer traveled averaged over the lifetime of the
vehicle (g/km); see Figure 4 for additional notes.
Congressional Research Service
29

link to page 30 link to page 30

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Figure 11. Life Cycle Assessment: Total Energy Consumption
(Comparison of MY 2012 ICEV, PHEV, and BEV for U.S. and California Electricity Grid, 2017 Average)

Source: Dunn et al., 2015 (updated).
Notes: Total energy consumption in megajoules (a gallon of gasoline contains roughly 120 megajoules) per
vehicle kilometer traveled averaged over the lifetime of the vehicle (MJ/km); see Figure 4 for additional notes.
Figure 12. Life Cycle Assessment: Total Fossil Fuel Consumption
(Comparison of MY 2012 ICEV, PHEV, and BEV for U.S. and California Electricity Grid, 2017 Average)

Source: Dunn et al., 2015 (updated).
Notes: Total fossil fuel consumption in megajoules (a gallon of gasoline contains roughly 120 megajoules) per
vehicle kilometer traveled averaged over the lifetime of the vehicle (MJ/km); see Figure 4 for additional notes.
Congressional Research Service
30

link to page 30
Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Figure 13. Life Cycle Assessment: Water Consumption
(Comparison of MY 2012 ICEV, PHEV, and BEV for U.S. and California Electricity Grid, 2017 Average)

Source: Dunn et al., 2015 (updated).
Notes: Water consumption in liters per vehicle kilometer traveled averaged over the lifetime of the vehicle
(L/km); see Figure 4 for additional notes.
Issues for Consideration
Summary of Findings
Broadly speaking, the 38 LCAs reviewed for this report show that in most cases BEVs have
lower life cycle GHG emissions than ICEVs. In general, GHG emissions associated with the raw
materials and production stage of BEVs are between 1.3 and 2.0 times higher than for ICEVs.
This can be offset by lower in-use stage emissions, depending on the electricity generation source
and the lifetime vehicle miles traveled. BEVs offer greater local air quality benefits than ICEVs,
due to the absence of tailpipe exhaust emissions. Both BEVs and ICEVs are responsible for
upstream air pollutants emissions during the production and in-use stages.
The volume of literature on human toxicity and ecosystem effects is limited in comparison with
that on GHG and other air pollutant emissions. These effects are based on second-order modeling
assumptions (i.e., they are effects that potentially affect human health and ecosystems because of
a given level of emissions and exposures). Many LCA practitioners assign greater difficulty to
analyzing and quantifying them. They mention data variance and analytic uncertainties as reasons
to find estimates in these categories less reliable. Further, the scale of these effects may vary, and
their impacts may differ locally and globally depending upon regional variabilities, population
size and characteristics, exposure rates, and the environmental regulations and management
practices of the exposed areas.
Studies generally suggest that BEVs could be responsible for greater human toxicity and
ecosystems effects than their ICEV equivalents, based on current mining and recycling
technologies. These potentially different effects from BEVs result from the additional mining and
Congressional Research Service
31

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

processing of metals to produce batteries and from the mining and combustion of coal to produce
electricity. Increased freshwater ecotoxicity effects from BEVs may likewise result from the
additional mining requirements. Other impacts are more complicated to compare. Acidification
depends largely on the assumptions made regarding the tradeoff in BEVs between increased
emissions from battery production and electricity generation versus the absence of tailpipe
emissions. In addition, the limited literature on terrestrial ecotoxicity suggests that BEVs and
ICEVs have similar effects across their life cycle, dominated by emissions of metal particles from
tire and brake wear during the in-use stage.
Considerations Affecting Life Cycle Performance
A range of key variables associated with vehicle design, vehicle choice and use patterns, vehicle
end-of-life options, and the electricity generation mix employed during production and use can
influence the life cycle environmental effects of BEVs, and their advantages or disadvantages
relative to ICEVs. Overall, CRS notes that the most discussed variables associated with the life
cycle environmental effects of BEVs in the literature reviewed for this report are as follows:
 Electricity generation mix. Power systems that supply electricity to the different
life cycle stages of BEVs (processing, production, use, and end-of-life) have
different emission intensities per kWh of electricity generated. These emission
factors depend upon the fuel source of the electricity generators and the upstream
processes that went into producing the fuel. Differences in the emission factors
for the electricity grids employed during the various life cycle stages of BEV
production and use will change the total life cycle emissions of BEVs. Future
changes to the fuel source of electricity generators could change the emission
factors of the electricity grids and potentially change the total life cycle emissions
of BEVs.
 Vehicle size and other characteristics. Generally the larger the vehicle, the
more materials required for vehicle and battery, and the more energy required
across the various life cycle stages. Charging and use patterns (e.g., in-cabin
heating) may also contribute to greater energy requirements.
 Modeled vehicle lifetime mileage. The longer the modeled lifetime mileage, the
less influence that production-related emissions have and the greater influence
that in-use emissions have over the total life cycle effects.
 Battery chemistry. Different battery chemistries have different performance
characteristics. For example, higher specific energy density batteries would
require less material to deliver the same level of vehicle range than other
batteries. Batteries with higher life expectancy could extend lifetime mileage
beyond other batteries. Some battery chemistries are better suited for recycling
than others. New chemistries could further change the total life cycle effects. In
addition to federal research and development efforts into new chemistries, some
industry stakeholders are reportedly exploring approaches to reduce potential
effects of batteries.107

107 For example, Samsung SDI has reportedly developed lithium-ion batteries that have reduced the amount of cobalt
relative to nickel and is working toward removing cobalt entirely. Material ratios vary for a lithium nickel manganese
cobalt oxide battery. Common cathode combinations are often one-third nickel, one-third manganese, and one-third
cobalt. Other combinations increase nickel such as 60% nickel, 20% manganese, and 20% cobalt for the cathode.
Samsung SDI reports combinations above 90% nickel, with 5% cobalt and 5% manganese. Samsung SDI is also
Congressional Research Service
32

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Issues Regarding LCA and Policy Development
The International Organization for Standardization (ISO) released a systemized framework for
conducting LCAs during the period 1997–2000, and updated it in 2006. As noted in ISO’s 2006
update (ISO 14040),108 LCA is one of several environmental management techniques (e.g., risk
assessment, environmental performance evaluation, environmental auditing, environmental
impact assessment, and benefit cost analysis) and may not be the most appropriate technique to
use in all situations. Because all techniques have limitations, it is important for policymakers to
understand those that are present in LCA. The limitations include the following:
 LCA typically does not address the economic or social aspects of a product.
 The nature of choices and assumptions made by the practitioner of an LCA (e.g.,
system boundary setting, selection of data sources and impact categories) may be
subjective.
 Models used to analyze inventory or to assess environmental effects are limited
by their assumptions, and may not be available for all potential effects or
applications.
 Results of LCA studies focused on global and regional issues may not be
appropriate for local applications, and vice-versa (i.e., local conditions might not
be adequately represented by regional or global conditions).
 The accessibility or availability of relevant data or data quality (e.g., gaps, types
of data, aggregation, averaging, and site-specificity) may limit the accuracy of
LCA studies.
 The lack of spatial and temporal dimensions in the inventory data used for
assessment introduces uncertainty in the results. This uncertainty varies with the
spatial and temporal characteristics of each environmental effect category.
The ISO recommends that the information developed in an LCA study is best used as part of a
much more comprehensive decisionmaking process or used to understand the broad or general
trade-offs of different product or policy choices.

recycling lithium-ion batteries to recover cobalt and other components. Additionally, a cooperative pilot project was
created by BMW, BASF, Samsung SDI, and a development agency to examine how to improve living and working
conditions for artisanal cobalt miners. See Kang Seung-woo, “Samsung SDI to Make Cobalt-Free EV Batteries,” The
Korea Times, February 12, 2018, http://m.koreatimes.co.kr/phone/news/view.jsp?req_newsidx=244074; Ceclia
Jamasmie, “Electric Car Dreams May Be Dashed by 2050 on Lack of Cobalt, Lithium Supplies,” Mining, March 16,
2018, http://www.mining.com/electric-cars-dreams-may-shattered-2050-lack-cobalt-lithium-supplies/; and Edward
Taylor, “BMW Joins Project to Improve Conditions for Cobalt Mining in Congo,” Reuters, November 29, 2018,
https://www.reuters.com/article/us-bmw-cobalt-congo/bmw-joins-project-to-improve-conditions-for-cobalt-mining-in-
congo-idUSKCN1NY1UQ.
108 See International Organization for Standardization, “ISO 14040: Environmental Management—Life Cycle
Assessment—Principles and Framework,” 2006.
Congressional Research Service
33

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

LCA Bibliography

1. J. Archsmith, A. Kendall, and D. Rapson, “From Cradle to Junkyard: Assessing
the Life Cycle Greenhouse Gas Benefits of Electric Vehicles,” Research in
Transportation Economics, vol. 52 (2015), pp. 72–90.
2. L. Athanasopouloua, H. Bikasa, and P. Stavropoulosa, “Comparative Well-to-
Wheel Emissions Assessment of Internal Combustion Engine and Battery
Electric Vehicles,” Procedia CIRP 78 (2018), pp. 25–30.
3. I. Bartolozzi, F. Rizzi, and M. Frey, “Comparison Between Hydrogen and
Electric Vehicles by Life Cycle Assessment: A Case Study in Tuscany, Italy,”
Applied Energy, vol. 101 (2013), pp. 103–111.
4. C. Bauer, J. Hofer, H. Althaus, A. Del Duce, and A. Simons, “The Environmental
Performance of Current and Future Passenger Vehicles: Life Cycle Assessment
Based on a Novel Scenario Analysis Framework,” Applied Energy, vol. 157
(2015), pp. 871–883.
5. F. Bohnes, J. Gregg, and A. Laurent, “Environmental Impacts of Future Urban
Deployment of Electric Vehicles: Assessment Framework and Case Study of
Copenhagen for 2016–2030,” Environmental Science and Technology, vol. 51
(2017), pp. 13995–14005.
6. E. Crossin, and P. J. B. Doherty, “The Effect of Charging Time on the
Comparative Environmental Performance of Different Vehicle Types,” Applied
Energy, vol. 179 (2016), pp. 716–726.
7. J. B. Dunn, L. Gaines, J. C. Kelly, C. James, and K. G. Gallagher, “The
Significance of Li-Ion Batteries in Electric Vehicle Life-Cycle Energy and
Emissions and Recycling’s Role in Its Reduction,” Energy and Environmental
Science, vol. 8 (2015), p. 158.
8. J. B. Dunn, L. Gaines, J. C. Kelly, C. James, and K. G. Gallagher, “The
Significance of Li-Ion Batteries in Electric Vehicle Life-Cycle Energy and
Emissions and Recycling’s Role in Its Reduction,” Energy and Environmental
Science, vol. 8 (2015), p. 158, as updated by the authors in 2019 using the U.S.
Department of Energy, Argonne National Laboratory (ANL), GREET® 2018
dataset.
9. L. A-W. Ellingsen, C. R. Hung, and A. H. Strømman, “Research for TRAN
Committee: Resources, Energy, and Lifecycle Greenhouse Gas Emission Aspects
of Electric Vehicles,” European Parliament, Policy Department for Structural and
Cohesion Policies (Brussels, 2018).
10. R. Faria, P. Moura, J. Delgado, and A. T. de Almeida, “A Sustainability
Assessment of Electric Vehicles as a Personal Mobility System,” Energy
Conversion and Management, vol. 61 (2012), pp. 19–30.
11. R. Faria, P. Marques, P. Moura, F. Freire, J. Delgado, and A. de Almeida, “Impact
of the Electricity Mix and Use Profile in the Life-Cycle Assessment of Electric
Vehicles,” Renewable and Sustainable Energy Reviews, vol. 24 (2013), pp. 271–
287.
12. F. Freire, and P. Marques, “Electric Vehicles in Portugal: An Integrated Energy,
Greenhouse Gas and Cost Life-Cycle Analysis,” in Proceedings of the 2012
Congressional Research Service
34

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

IEEE International Symposium on Sustainable Systems and Technology (ISSST),
(Boston, MA, USA, 16–18 May 2012; IEEE: Piscataway, NJ, USA, 2012).
13. L. Gao and Z. C. Winfield, “Life Cycle Assessment of Environmental and
Economic Impacts of Advanced Vehicles,” Energies, vol. 5 (2012), pp. 605–620.
14. R. Garcia and F. Freire, F., “Marginal Life-Cycle Greenhouse Gas Emissions of
Electricity Generation in Portugal and Implications for Electric Vehicles,”
Resources, vol. 5 (2016), p. 41.
15. P. Girardi, A. Gargiulo, and P. Brambilla, “A Comparative LCA of an Electric
Vehicle and an Internal Combustion Engine Vehicle Using the Appropriate Power
Mix: The Italian Case Study,” International Journal of Life Cycle Assessment,
vol. 20 (2015), pp. 1127–1142.
16. T. Hawkins, B. Singh, G. Majeau Bettez, and A. Stromman, “Comparative
Environmental Life Cycle Assessment of Conventional and Electric Vehicles,”
Journal of Industrial Ecology, vol. 17 (2012), pp. 53–64.
17. E. Helmers, J. Dietz, and S. Hartard, “Electric Car Life Cycle Assessment Based
on Real-World Mileage and the Electric Conversion Scenario,” International
Journal of Life Cycle Assessment, vol. 22 (2017), pp. 15–30.
18. E. Helmers, and P. Marx, “Electric Cars: Technical Characteristics and
Environmental Impacts,” Environmental Sciences Europe, vol. 24 (2012), p. 14.
19. H. Huo, H. Cai, Q. Zhang, F. Liu, and K. He, “Life-Cycle Assessment of
Greenhouse Gas and Air Emissions of Electric Vehicles: A Comparison Between
China and the U.S.,” Atmospheric Environment, vol. 108 (2015), pp. 107–116.
20. L. Lombardi, L. Tribioli, R. Cozzolino, and G. Bella, “Comparative
Environmental Assessment of Conventional, Electric, Hybrid, and Fuel Cell
Powertrains Based on LCA,” International Journal of Life Cycle Assessment,
vol. 22 (2017), pp. 1989–2006.
21. A. Lucas, C. Alexandra Silva, and R. Costa Neto, “Life Cycle Analysis of Energy
Supply Infrastructure for Conventional and Electric Vehicles,” Energy Policy,
vol. 41 (2012), pp. 537–547.
22. H. Ma, F. Balthasar, N. Tait, X. Riera Palou, and A. Harrison, “A New
Comparison Between the Life Cycle Greenhouse Gas Emissions of Battery
Electric Vehicles and Internal Combustion Vehicles,” Energy Policy, vol. 44
(2012), pp. 160–173.
23. B. M. Marshall, J. C. Kelly, T. Lee, G. A. Keoleian, and Z. Filipi, “Environmental
Assessment of Plug-In Hybrid Electric Vehicles Using Naturalistic Drive Cycles
and Vehicle Travel Patterns: A Michigan Case Study,” Energy Policy, vol. 58
(2013), pp. 358–370.
24. M. Messagie, T. Coosemans, and J. Van Mierlo, “The Influence of Electricity
Allocation Rules in Environmental Assessments of Electric Vehicles,” in
Proceedings of the 28th International Electric Vehicle Symposium and Exhibition
(Goyang, Korea, 3–6 May 2015; Korean Society of Automotive Engineers:
Seoul, Korea, 2015), p. 1252.
25. R. McCarthy and C. Yang, “Determining Marginal Electricity for Near-Term
Plug-In and Fuel Cell Vehicle Demands in California: Impacts on Vehicle
Greenhouse Gas Emissions,” Journal of Power Sources, vol. 195 (2010), pp.
2099–2109.
Congressional Research Service
35

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

26. A. Noshadravan, L. Cheah, R. Roth, F. Freire, L. Dias, and J. Gregory,
“Stochastic Comparative Assessment of Life-Cycle Greenhouse Gas Emissions
from Conventional and Electric Vehicles,” International Journal of Life Cycle
Assessment, vol. 20 (2015), pp. 854–864.
27. D. Notter, M. Gauch, R. Widmer, P. Wäger, A. Stamp, R. Zah, and H. Althaus,
“Contribution of Li-Ion Batteries to the Environmental Impact of Electric
Vehicles,” Environmental Science and Technology, vol. 44 (2010), pp. 6550–
6556.
28. N. Onat, M. Kucukvar, and O. Tatari, “Conventional, Hybrid, Plug-In Hybrid or
Electric Vehicles? State-Based Comparative Carbon and Energy Footprint
Analysis in the United States,” Applied Energy, vol. 150 (2015), pp. 36–49.
29. Qinyu Qiao, Fuquan Zhao, Zongwei Liu, Shuhua Jiang, and Han Hao, “Cradle-
to-Gate Greenhouse Gas Emissions of Battery Electric and Internal Combustion
Engine Vehicles in China,” Applied Energy, vol. 204 (2017), pp. 1399–1411.
30. C. Stephan and J. Sullivan, “Environmental and Energy Implications of Plug-In
Hybrid-Electric Vehicles,” Environmental Science and Technology, vol. 42
(2008), pp. 1185–1190.
31. C. Tagliaferri, S. Evangelisti, F. Acconcia, T. Domenech, P. Ekins, D. Barletta,
and P. Lettieri, “Life Cycle Assessment of Future Electric and Hybrid Vehicles: A
Cradle-to-Grave Systems Engineering Approach,” Chemical Engineering
Research and Design, vol. 112 (2016), pp. 298–309.
32. M. Tamayao, J. Michalek, C. Hendrickson, and I. M. L. Azevedo, “Regional
Variability and Uncertainty of Electric Vehicle Life Cycle CO2 Emissions Across
the United States,” Environmental Science and Technology, vol. 49 (2015), pp.
8844–8855.
33. C. E. Thomas, “U.S. Marginal Electricity Grid Mixes and EV Greenhouse Gas
Emissions,” International Journal of Hydrogen Energy, vol. 37 (2012), pp.
19231–19240.
34. J. Van Mierlo, M. Messagie, and S. Rangaraju, “Comparative Environmental
Assessment of Alternative Fueled Vehicles Using a Life Cycle Assessment,”
Transportation Research Procedia, vol. 25 (2017), pp. 3435–3445.
35. O. Van Vliet, A. Brouwer, T. Kuramochi, M. van den Broek, and A. Faaij,
“Energy Use, Cost and CO2 Emissions of Electric Cars,” Journal of Power
Sources, vol. 196 (2011), pp. 2298–2310.
36. A. Weis, P. Jaramillo, and J. Michalek, “Consequential Life Cycle Air Emissions
Externalities for Plug-In Electric Vehicles in the PJM Interconnection,”
Environmental Research Letters, vol. 11 (2016), 024009.
37. J. Woo, H. Choi, and J. Ahn, “Well-to-Wheel Analysis of Greenhouse Gas
Emissions for Electric Vehicles Based on Electricity Generation Mix: A Global
Perspective,” Transportation Research Part D, vol. 51 (2017), pp. 340–350.
38. T. Yuksel, M. Tamayao, C. Hendrickson, I. M. L. Azevedo, and J. Michalek,
“Effect of Regional Grid Mix, Driving Patterns and Climate on the Comparative
Carbon Footprint of Gasoline and Plug-In Electric Vehicles in the United States,”
Environmental Research Letters, vol. 11 (2016), 044007.

Congressional Research Service
36

Environmental Effects of Battery Electric and Internal Combustion Engine Vehicles

Author Information

Richard K. Lattanzio
Corrie E. Clark
Specialist in Environmental Policy
Analyst in Energy Policy

Acknowledgments
Kezee Procita, CRS Senior Research Librarian, assisted with this report.

Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan
shared staff to congressional committees and Members of Congress. It operates solely at the behest of and
under the direction of Congress. Information in a CRS Report should not be relied upon for purposes other
than public understanding of information that has been provided by CRS to Members of Congress in
connection with CRS’s institutional role. CRS Reports, as a work of the United States Government, are not
subject to copyright protection in the United States. Any CRS Report may be reproduced and distributed in
its entirety without permission from CRS. However, as a CRS Report may include copyrighted images or
material from a third party, you may need to obtain the permission of the copyright holder if you wish to
copy or otherwise use copyrighted material.

Congressional Research Service
R46420 · VERSION 1 · NEW
37