In April 2019, Hans-Werner Sinn and his co-authors started a lively discussion about battery-electric vehicles and their CO2 emissions compared to conventional diesel vehicles. At thinkstep, we welcome such public discourse, because it’s important to present different perspectives on such complex challenges and to think critically about the transition to more efficient and effective energy and mobility. With a strong background in and continuous experience with the topic, we would like to contribute a few additional comments to the discussion.

1. E-Vehicle Production Volume Influences Comparisons

On the one hand, holistic technology comparisons, which take into account the manufacturing, use and disposal of vehicles, are nothing new. thinkstep has made many such comparisons, some of which have been published [1-3]. In those considerations, we repeatedly emphasized that an electric vehicle first has to reach a certain mileage to compensate for the emissions resulting from the production of its large battery. Increasing the volume of green energy in a grid mix in relationship to non-renewable energy sources will reduce the overall emissions associated with that grid mix. So, increasing the number of electric vehicles in production should ideally cause us to generate more renewable energy so as to improve the environmental footprint of electric vehicles in contrast to conventional vehicles.  

The current debate about this topic has included arguments from all sides. Among other things, the arguments concern the lack of comparability between diesel and electric vehicles. Of course, there are some significant differences between those two types of vehicles, such as range, maximum drive power and the torque curve. While diesel vehicles have an advantage with range, the electric vehicle is ahead in the other two categories. There is a certain number of people who doubt the importance of making such comparisons, but such comparisons are necessary even though unavoidable differences between the products are part of equation. 

 

2. Emissions from Battery Production Are Key

However, much more important is the quantification of emissions from battery production, which is a particularly critical parameter in the comparison of the two vehicle types. The battery production study [4], cited by Sinn and his co-authors, shows the immense range of values ​​published to make such comparisons and the relevance of the energy demand and the corresponding CO2 emissions. A closer look at this parameter reveals how important the production volume is for energy consumption per battery capacity and, accordingly, that the CO2 emissions resulting from battery production fall sharply with larger production volumes (Figure 1). Therefore, the CO2 emissions determined by the authors do not represent large-scale battery production, but rather are based on early, smaller production quantities.

3. The Source Of Your Electricity Matters

In addition, the corresponding electricity procurement is of immense importance. The use of electricity with low CO2 emissions—in particular, through the company's own production of electricity from renewable energy—significantly reduces the carbon footprint of the battery. The same applies to the constantly advancing optimization of battery technologies, such as through higher storage capacities and more efficient production processes (e.g., due to the economies of scale already discussed). Electric vehicle manufacturers continue to keep a close eye on all of these developments. However, the same efficient production measures do not lead to the same improvements for a combustion vehicle, because the majority of a combustion engine’s CO2 emissions are generated during the use phase (when the vehicle is driven).

5 Sustainability Insights into the Electric Vehicle Debate

Figure 1: Differences in energy consumption of battery production (Sources: [5, 6])

Nonetheless, the assumption that electricity use in both electrical and plug-in hybrids does not cause CO2 emissions, especially considering displacement effects as underpinned by European regulations, is absolutely false. This assumption is a premise of the European regulatory framework. But it would be significantly more expedient if the EU would take into account at least the average European emissions generated by electricity generation. Here, the focus should be on the so-called “tank-to-wheel analysis,” in which we only analyze the emissions from the vehicle, and extend it a well-to-wheel consideration, taking into account the emissions generated from the provision of fuel and electricity. 

4. Use a Holistic Approach 

But even here, analysis would not consider the production and disposal of vehicles and batteries. Such analysis is only possible in a cradle-to-grave view or life cycle assessment. The automotive industry carries out all necessary approaches and thinkstep provides databases and software tools for such considerations [7]. With these holistic assessments, negative developments become visible, for example when higher CO2 emissions from battery production shift the break-even point with conventional vehicles to higher life-cycle mileage (see Figure 2). In order to achieve desirable outcomes, such considerations must also ground the regulatory framework for the future. Fortunately, the idea of ​​communicating results based on standardized life-cycle considerations has already been discussed at European political level [8].

5 Sustainability Insights into the Electric Vehicle Debate

Figure 2: Schematic diagram for shifting the break-even point between the combustion engine and the electric vehicle as the emissions from battery production increase

5. The Future Is Electric—Approach It Critically

Electric vehicles have a higher potential for the future than conventional combustion vehicles due to their long-term CO2 reduction potential, expected technological developments and the full potential and impact of using renewable energy in vehicle production and use. The burning of fossil fuels will never be a sustainable solution. It is important for policy makers and businesses to think together about energy and transportation transformation, and life cycle assessment is the ideal way to do it holistically. All the necessary tools, data and methodological approaches exist for doing this, and there are professionals who can give accurate answers to these relevant questions. I encourage you to approach your LCA work holistically—a lot of people like to jump onto the sustainability band wagon and offer tips about the sustainability of electric vehicles without fully understanding the complexity involved.

 


 

[1] Fraunhofer IBP, thinkstep AG „Abschlussbericht: Bewertung der Praxistauglichkeit und Umweltwirkungen von Elektrofahrzeugen“ BMVI (Hrsg.), Berlin, 2016, Link 

[2] thinkstep AG (ehemals: PE International AG), Gingo21 „Élaboration selon les principes ACV des bilans énergétiques, des émissions de gaz à effet de serre et desautres impacts environnementaux induits par l’ensemble des filières de véhicules électriques et de véhicules thermiques, VP desegment B (citadine polyvalente) et VUL à l’horizon 2012 et 2020“, 2013, Link

[3] thinkstep AG, prognos “Nullemissionsnutzfahrzeuge – Vom ökologischen Hoffnungsträger zur ökonomischen Alternative“, e-mobil BW, 2017, Link

[4] Romare, Dahllöf „The Life Cycle Energy  Consumption and  Greenhouse Gas Emissions from Lithium-Ion Batteries”, 2017, Link

[5] Ellingsen et al. „Life Cycle Assessment of a Lithium-Ion Battery Vehicle Pack“, Journal of Industrial Ecology, 2013.

[6] Dai et al. “Update of Life Cycle Analysis of Lithium-ion Batteries in the GREET Model”, September 2017

[7] Philipp Vetter „Erst nach 100.000 Kilometern ist der E-Golf wirklich „grün““, Welt online,  26.04.2019, Link

[8] Europäisches Parlament „Strengere Klimaziele für Autos bis 2030“, Pressemitteilung, Oktober 2018, Link