How Eco-Friendly Are Electric Cars? A Holistic View · 8 How Eco-Friendly Are Electric Cars? Are electric cars quieter than conventional cars? Many people in Germany are affected

How Eco-Friendly Are Electric Cars?A Holistic View

2 How Eco-Friendly Are Electric Cars?

Imprint

Published byFederal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) Division P II 2 · 11055 Berlin · GermanyEmail: [email protected] · Website: www.bmu.de/english

Edited byBMU, Division IG I 5 – Environment, Traffic and Transport, Electric Mobility

DesignVDI/VDE Innovation + Technology GmbH, Berlin

DateOctober 2019

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3How Eco-Friendly Are Electric Cars?

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


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?”

Introduction


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/

A life cycle analysis provides a summary all environmental impacts – in this case, the impacts associated with electric cars. These analyses take into account the whole life cycle of the vehicle, including the production of each component, the energy the car needs in order to operate, the level of maintenance required and finally, its disposal. For each stage of the life cycle, consideration is also given to the environmental impact made by the extraction and processing of the raw materials and energy sources.

https://www.bmu.de/en/topics/air-mobility-noise/mobility/electric-mobility/


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

Climate Impact


transition, the impact that electric vehicles have on the climate is lessened. By contrast, sustainable biofuels for petrol and diesel vehicles have limited potential.

Source: Own representation using data from the German Environment Agency (Umweltbundesamt, UBA)

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 CO2 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 convention al 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.

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200

Figure 1: CO2 emissions in grams per kilometre driven during the whole life cycle of a small family car

Production, maintenance, disposalOperation, energy supply

0

50

100

150

Petrol Diesel Electric

2017 20252017 2025

183168

159148

134

101


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.

Noise


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.

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.

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.

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HealthWhat 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


Source: Own representation using data from the German Environment Agency (UBA)

Note: Particulate matter emissions from tire and brake abrasion that are caused by all vehicle types are not shown.

now no direct emissions

no direct emissions

Petrol PetrolPetrol hybrid

Petrol hybrid

Diesel DieselElectric Electric0

10

20

30

40

50

60

70

80

90

100 2030

Figure 2: Emissions of particulate matter over the whole life cycle of vehicles with various drive systems, in milligrams per kilometre

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

Vehicle production Supplying fuel Generating electricity

Direct exhaust emissionsMaintenance


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

Source: Own representation using data from the German Environment Agency (UBA)

Figure 3: Emissions of nitrogen oxides over the whole life cycle of vehicles with various drive systems, in milligrams per kilometre

Vehicle production Supplying fuel Generating electricity Direct emissions Maintenance Vehicle disposal

Note: Direct emission values for the year 2030 according to the model Handbook for Emission Factors (HBEFA) 4.1; September 2019

now

Petrol PetrolPetrol hybrid

Petrol hybrid

Diesel DieselElectric Electric0

50

100

150

200

250

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350 2030

no direct emissions

no direct emissions


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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 popula tion.

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.


ResourcesWhat 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 high er 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.


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 pos ition 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 improve ments to this aspect of the evaluation.

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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.


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.

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

Figure 4: Electricity requirement from renewable energy sources in kilowatt hours for various combinations of drive type and fuel type, per 100 kilometres

15 kWh

Battery-powered e-vehicle + direct use of electricity

Fuel cell vehicle + hydrogen

Internal com-bustion vehicle +

power-to-gas

Internal com-bustion vehicle + power-to-liquid

31 kWh 93 kWh 103 kWh


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/

https://www.bmu.de/en/topics/air-mobility-noise/mobility/electric-mobility/


Picture credits

Cover page: © Tomwang112/iStockPage 4: © Michael Flippo/FotoliaPage 6: © Miredi/FotoliaPage 8: © Matthias Buehner/FotoliaPage 10: © a-wrangler/iStockPage 14: © Tom Bayer/Fotolia


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How Eco-Friendly Are Electric Cars? A Holistic View · 8 How Eco-Friendly Are Electric Cars? Are electric cars quieter than conventional cars? Many people in Germany are affected

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