How Eco-Friendly Are
Electric Cars?
A Holistic View
2 How Eco-Friendly Are Electric Cars?
Imprint
Published by
Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU)
Division P II 2 · 11055 Berlin · Germany
Email: buergerinfo@bmu.bund.de · Website: www.bmu.de/english
Edited by
BMU, Division IG I 5 – Environment, Traffic and Transport, Electric Mobility
Design
VDI/VDE Innovation + Technology GmbH, Berlin
Date
October 2019
Download of this publication
Website: www.bmu.de/en/publications
Note
This publication of the Federal Ministry for the Environment, Nature Conservation and
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www.bmu.de/en/publications
How Eco-Friendly Are Electric Cars? 3
Contents
Introduction 4
Are electric vehicles more eco-friendly than internal combustion vehicles? 4
Climate Impact 6
How high are the greenhouse gas emissions of electric cars? 6
Noise 8
Are electric cars quieter than conventional cars? 8
Health 10
What are the other environmental impacts of electro mobility? 10
Resources 14
What are the resource requirements of electric cars? 14
Are there alternatives to electric cars? 16
Summary 18
4 How Eco-Friendly Are Electric Cars?
Introduction
Are electric vehicles more eco-friendly than internal
combustion vehicles?
Electric cars can lessen the negative environmental consequences of automobile
traffic – especially carbon dioxide (CO2) emissions. Alongside the issue of green-
house gas emissions, road traffic is also associated with air pollutants. Particulate
matter and nitrogen oxides are the most problematic of these pollutants. The
current debate surrounding diesel engines has increased public awareness of
nitrogen oxides and many people are asking themselves, “So which vehicles are
actually eco-friendly?”
How Eco-Friendly Are Electric Cars? 5
How do the environmental credentials of electric cars compare if we look
beyond the measurements taken when the vehicle is running? What if we also
examine the way the electricity is generated and the way the cars are
manufactu- red, including their batteries and electric motors? How does the
evaluation shape up if the data is obtained from everyday driving, rather than
from information provided by the manufacturer or found in brochures?
This kind of comprehensive assessment can be undertaken by using life cycle
analyses. These analyses do not use the values provided by the manufacturer or
listed in the vehicle’s documents. Instead, they use real life figures. What is the real-
world range of an electric car? How much electricity is lost during char- ging?
What are the real levels of pollutants in the exhaust fumes of vehicles with
internal combustion motors? These are the questions addressed by a life cycle
analysis.
The environmental impacts outlined over the following pages compare a con-
temporary electric car with modern, small family cars with internal combustion
engines. For details on the underlying data and assumptions as well as further
information on electric mobility visit:
www.bmu.de/en/topics/air-mobility-noise/mobility/electric-mobility/
t the whole life cycle of the vehicle, including the production of each component, the energy the c
6 How Eco-Friendly Are Electric Cars?
Climate Impact
How high are the greenhouse gas emissions of electric
cars?
On the roads, electric cars do not emit any CO2 or any other greenhouse gases.
When considering climate change, however, the location where the emissions
are generated is of no relevance – it is the overall levels that matter. It is
therefore vital to take into account the way the electricity is generated (the
power plant
emissions) and other sources of emissions when assessing the impact that
electric vehicles have on the climate. This also applies to the vehicle
manufacturing pro- cess and, for cars with internal combustion engines, to the
fuel supply process – from the borehole to the filling station. Figure 1 shows a
comparison of the total climate impact of the various types of car. As the chart
shows, electric cars are in the lead.
By 2025, the increased proportion of renewable energy in the energy mix will
push electric vehicles even further ahead, even though the other types of vehicles
will also have become more efficient. With each year of progress with the energy
How Eco-Friendly Are Electric Cars? 7
e 1: CO2 emissions in grams per kilometre driven during the whole life cycle of a small fam
200 183
168
159
148
150 134
101
100
50
0
Petrol Diesel Electric
Production, maintenance, disposal 2017 2025
Operation, energy supply 2017 2025
Source: Own representation using data from the German Environment
Agency (Umweltbundesamt, UBA)
transition, the impact that electric vehicles have on the climate is lessened. By
contrast, sustainable biofuels for petrol and diesel vehicles have limited potential.
! The electric cars that are currently available on the market place less
of a burden on the climate than internal combustion vehicles – even
with Germany’s current energy mix. In terms of CO 2 emissions, an electric car
is 16 percent cleaner than a very efficient diesel vehicle and 27 percent cleaner
than a modern petrol car. Furthermore, the way the energy for today’s
electric cars is being sourced is affected by the energy transition, which is not
affecting conventional cars. Calculations by the UBA show that by 2025, the
CO2 emis- sions levels of newly registered electric vehicles will be 32 percent
lower than those of modern diesel vehicles. Compared to petrol vehicles, the
difference is as much as 40 percent.
8 How Eco-Friendly Are Electric Cars?
Noise
Are electric cars quieter than conventional cars?
Many people in Germany are affected by traffic noise. Electric motors are signi-
ficantly quieter than internal combustion engines. Nevertheless, the majority
of the noise pollution from automobile traffic does not originate from the
motor. It is caused by the movement of tyres on the road and, at high speeds,
by aero- dynamic noise. In these respects, there are no differences between
electric cars and conventional vehicles.
The rolling noise of tyres is only a significant factor at speeds of 25 kilometres
per hour or faster. At lower speeds, the engine or motor is the main source of noise.
This means that electric cars are quieter in areas where people drive at slower
speeds, such as residential areas, or in areas where drivers set off from stationary,
such as at junctions and traffic lights.
How Eco-Friendly Are Electric Cars? 9
The benefits are greater for utility vehicles such as buses, snow ploughs or refuse
collection vehicles. Electric versions of these kinds of vehicles are significantly
quieter – across the whole spectrum of speeds used on urban roads. The same
applies for mopeds and motorbikes. In motorised two-wheel vehicles, the inter-
nal combustion engine and its associated components are generally so loud that
electric versions are quieter at all speeds.
! In terms of passenger vehicles, the extent to which electric cars may
be able to decrease noise pollution at low speeds is limited. The
main
types of vehicle that could be made significantly quieter through the use of
electric motors are motorbikes, mopeds, and utility vehicles that stop and
start frequently and mainly travel within a single urban region.
Compulsory AVAS for electric cars
The European Union (EU) is stipulating that from 2019, all new electric vehicles
must have an AVAS (Acoustic Vehicle Alerting System). This will mean that
electric cars will have to emit sounds to alert vulnerable road users – especially
those who are blind or partially sighted – to their presence. The EU regulations
state that the noise should be easily indicative of vehicle behaviour. It may
sound similar to a vehicle of the same category that has an internal combustion
engine. The sounds should also communicate the vehicle’s actions, such as
setting off, stopping and accelerating.
The sounds made by AVAS will be significantly more pleasant than the noises
made by a conventional engine. It is likely that in future, electric cars will
use sensors so that they will only make a sound if there is actually a hazard
and if pedestrians or cyclists need to be warned.
10 How Eco-Friendly Are Electric Cars?
Health
What are the other environmental impacts of electro
mobility?
Nitrogen oxides and particulate matter are pollutants that are known to be
harmful to human health and the environment. The extent of the health risk
posed by these substances is partly determined by where the emission is genera-
ted. For example, air quality monitoring stations on very busy roads sometimes
record levels that significantly exceed the emission limit values for various
harmful substances. This is because in these areas, the local road traffic emissions
are added to the background level of pollution, which is caused by emissions
from industry, power plants, domestic heating systems and fireplaces. The people
affected most by these emissions are local residents, pedestrians and cyclists.
Drivers are also affected by the poor air quality in the surroundings. This is
because outside air enters the car through the air intake vent.
Pure electric vehicles are battery operated and they have no exhaust. Locally
speaking, they are zero emissions vehicles. By contrast, cars with internal
com- bustion engines additionally emit propulsion-generated air pollutants
such as
How Eco-Friendly Are Electric Cars? 11
particulate matter over the whole life cycle of vehicles with various drive systems, in mi
100
now no direct emissions 2030
90
80
70 no direct emissions
60
50
40
30
20
10
0
Petrol Petrol Diesel Electric Petrol Petrol Diesel Electric
hybrid hybrid
Vehicle production Supplying fuel Maintenance
Direct exhaust emissions
Generating electricity
te: Particulate matter emissions from tire and brake abrasion that are caused by all vehicle types are not
Source: Own representation using data from the German Environment Agency (UBA)
nitrogen and particulate matter, aside of emissions from tire and brake
abrasi- on produced by all types of vehicles. Diesel Cars tend to have much
higher air pollutant emissions than petrol vehicles.
This means that in localities where exhaust fumes are responsible for
polluting the air to an extent that poses a health risk, electric cars are very
advantageous. They help to improve the air quality in these areas.
So how does the picture change if we also take into account the emissions of
pollutants that are not caused directly by the running of the vehicle? And where
do these other emissions come from? Some of the air pollutants are associated
with the fossil fuels that are used in order to generate a proportion of the car’s
electricity. Contrary to what is commonly assumed, however, the emissions
12 How Eco-Friendly Are Electric Cars?
ogen oxides over the whole life cycle of vehicles with various drive systems, in milligrams
350
now 2030
300
no direct emissions
250
no direct
200emissions
150
100
50
Petrol Petrol 0
Petrol Petrol
Diesel Electric Diesel Electric
hybrid hybrid
Vehicle production Supplying fuel Generating electricity
Direct emissions Maintenance Vehicle disposal
ssion values for the year 2030 according to the model Handbook for Emission Factors (HBEFA) 4.1; Septem
Source: Own representation using data from the German Environment Agency (UBA)
levels of particulate matter and nitrogen oxides are not especially high for this
aspect. This is because coal-fired power stations are now equipped with modern
waste gas purification technologies. In relation to the kilowatt hours of electricity
consumed by electric cars, the proportion of air pollutants emitted is therefore
modest compared to the overall values.
The vehicle production process, however, makes a significant contribution to air
pollution. It is by far the larger of the two main additional sources of pollutant
emissions, both for electric cars and for internal combustion vehicles. For ex-
ample, steel production generates large quantities of particulate matter. The total
How Eco-Friendly Are Electric Cars? 13
air pollutant emissions are significant for each of the vehicle types, as shown in
Figures 2 and 3. The fact that the directly generated emissions tend to be generated
in remote areas, however, means that they pose less of a health risk to the majority
of the population.
! Although electric cars are already in pole position in terms of
emissions that have an impact on the climate, a more differentiated
picture emer-
ges when considering particulate matter and nitrogen oxides1. Across the
entire vehicle life cycle, emissions of harmful substances are generated by
both elec- tric vehicles and conventional cars. Owing to the higher complexity
of the ma- nufacturing processes, more particulate matter is emitted when
making electric cars. By contrast, electric cars compare favourably for
emissions of nitrogen oxides, especially when compared to diesel vehicles. If
consideration were only given to direct exhaust emissions, which can pose a
health risk, particularly in high-traffic areas, electric cars are at an advantage
for both types of pollutants.
1 As yet, owing to a lack of measurement data, there are only approximate estimates for the direct
emissions of natural gas-driven vehicles. It is assumed that the emissions of particulate matter
and nitrogen oxides are similar to those of petrol vehicles. The pollutant emissions for petrol-
electric hybrids are likely to be similar.
14 How Eco-Friendly Are Electric Cars?
Resources
What are the resource requirements of electric cars?
In addition to the analysis concerning noise and the emissions of pollutants that
affect human health and the environment, comprehensive life cycle analyses
often include an assessment of the scarce resources that are utilised. Two mea-
sures that are often used in these resource evaluations are cumulative energy
demand and cumulative raw material demand.
What do the values for these measures look like in our evaluation? The cumula-
tive energy demand is lower for electric cars than for internal combustion
vehicles. This is mainly because they have highly efficient electric motors, which
means that driving requires less energy. This more than compensates for the
higher levels of energy required for manufacturing. If the proportion of renewa-
ble energy in the energy mix continues to increase, electric cars will edge
further and further ahead in this respect.
How Eco-Friendly Are Electric Cars? 15
By contrast, the cumulative raw material demand is higher for today’s electric
vehicles than for internal combustion vehicles. The vehicle components require
more raw materials during the production process. Advances in manufacturing,
higher levels of material efficiency, recycling and greater proportions of renew-
able energy may help to reduce the raw material demand. A trend in this direc-
tion is already evident for the batteries that power electric vehicles. It is import-
ant to keep monitoring the extent to which this trend continues and to keep
supporting its continuation. For this reason, the BMU has funded the develop-
ment of recycling processes for new components. Furthermore, regulations are
already in place for the recycling of batteries and vehicles. The industrial sector
can also help to ensure that raw material supply chains become more sustain-
able. This is already taking place through ‘responsible mining’ and ‘due diligence’
initiatives.
! The high efficiency of electric vehicles means that they hold the top
position for total energy demand over the entire life cycle. In terms
of
total raw material consumption, vehicles with internal combustion engines
are in the lead. There is scope for improvement here, especially concerning
energy storage systems. In all likelihood, continued improvements to
manufactur- ing, material efficiency and energy storage technology will bring
significant improvements to this aspect of the evaluation.
16 How Eco-Friendly Are Electric Cars?
Are there alternatives to electric cars?
Electric vehicles are not the only possible solution being raised in discussions
about how to minimise the impact that road traffic has on the climate. Fuel cell
vehicles, most of which use hydrogen, are also powered by electricity. This means
that locally speaking, they are also zero emissions vehicles. Furthermore, syn-
thetic fuels made using renewable energy, often known as e-fuels or power-
to-liquid/power-to-gas, could make it possible for petrol and diesel vehicles
to become CO2 neutral. Several important questions must be asked in order
to assess the potential of these technologies for mitigating climate change.
When using these technologies, how much energy is required for
mobility? There is a systemic disadvantage to e-fuels in particular because they
only work in vehicles with internal combustion engines, which are significantly
less effi- cient than electric motors. The production of e-fuels also requires a great
deal of energy. This is because several conversion steps are required in order for
electri- city, water and CO2 to become a liquid or gaseous fuel. There is a
significant loss of energy at each step. To some extent, the same applies to
hydrogen vehicles and fuel cell vehicles. Although the drive mechanism itself is
as efficient as that of an electric car, the steps of generating the hydrogen and of
generating electricity in the fuel cells are both associated with energy losses.
Ultimately, compared to an electric vehicle, all of these alternatives require
more renewable energy for one kilometre of mobility, as shown in Figure 4.
Is this energy renewable and therefore climate neutral?
Hydrogen and e-fuels require more energy than an electric car. Since the energy
mix is now so clean, electric cars compare favourably. Nevertheless, coal-fired,
lignite-fired and natural gas-fired power plants will continue to contribute to
the energy mix for a long time. If e-fuels are produced using this energy mix,
this burden increases all the more. As such, cars that use these kinds of fuels will
not only compare less favourably than electric cars but will also be doing
significant- ly more damage to the climate than petrol or diesel vehicles.
How Eco-Friendly Are Electric Cars? 17
nt from renewable energy sources in kilowatt hours for various combinations of drive type
15 kWh 31 kWh 93 kWh 103 kWh
Battery-poweredFuel cell Internal
vehicle +com-Internal
e-vehicle + directhydrogen
com- bustion vehicle +bustion vehicle + power-to-gas
use of electricity
Source: Agora Verkehrswende, based on a short study on mobility and fuel strategy entitled ‘Renew-
able Energy in Transport’ (Erneuerbare Energien im Verkehr), which was conducted on behalf of
Germany’s Ministry of Transport
What if these fuels were produced using exclusively renewable energy?
In that case, they would be climate-friendly. Nevertheless, the differences in
energy requirements have an impact on costs as well as on the environment. If
lots of new wind turbines need to be erected in order to produce a fuel, that fuel
would be much more expensive to produce – more expensive than petrol and
diesel but also more expensive than electricity for charging batteries. This is true
even if it is possible to generate the renewable energy for e-fuels in very cheap
locations.
Consideration should also be given to the fact that the plants where water is
broken down into hydrogen and oxygen (known as electrolysers) and the
plants where fuels are synthesised, place a very high level of demand on raw
materials and resources. Even with the use of e-fuels, the local environmental
impact of the pollutants emitted by internal combustion engines is very
similar.
18 How Eco-Friendly Are Electric Cars?
Summary
Electric vehicles are not a silver bullet solution for mitigating the impact that
road traffic has on the environment and the climate. In order for cities to be
liveable, it is also necessary to improve public transport provision, increase the
number of people cycling and have short distances between the workplace, the
home and shops and services. In all likelihood, however, motorised vehicles will
continue to be used for a significant proportion of journeys in the future.
It is therefore important to lessen the impact that automobile traffic has on
the climate and the environment. The contribution that electric cars can make
to reaching this goal is significant and, crucially, is becoming more significant
over time. This is particularly true in terms of mitigating climate change – an
area where electric cars are already taking the lead. This lead will continue to
widen because the proportion of renewable energy being generated is
constantly growing. In ten years’ time at the latest – by which time today’s
newly registered vehicles will generally still be in service – renewable energy
should already be catering for the majority of Germany’s electricity
requirements.
The picture is more differentiated for the other environmental impacts. More
raw materials are used for electric cars than for conventional vehicles and more
particulate matter is emitted as well. By contrast, electric cars compare
favourab- ly in terms of nitrogen oxides, which are a hot topic at the moment. It
should be noted here that the nature of the environmental impact also depends
on where the emissions are generated.
All in all, the picture given by the overall assessment depends on how these
factors are weighed and weighted. It also depends on the time period being
taken into account. Should protecting the climate be given a heavier weighting
than the quantity of raw materials used? How much value should be placed on
pro- tecting human health and how does this affect the weighting given to
emissions that are generated outside of city centres? And which climate-friendly
alterna- tives are actually available – if driving cars is not to be abolished
completely?
For more information about electro mobility and a more detailed life cycle
analysis, which includes references to the studies on which it is based, visit:
www.bmu.de/en/topics/air-mobility-noise/mobility/electric-mobility/
How Eco-Friendly Are Electric Cars? 19
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Cover page: © Tomwang112/iStock
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