Image Credits: https://www.city-journal.org/electric-vehicle-batteries
The sustainability of vehicle electrification has been assessed by many researchers and compared to that of conventional vehicles (i.e. internal combustion engine vehicles) that run on gasoline. There seems to be a consensus that electric vehicles outperform conventional vehicles in terms of the potential life cycle environmental and economic impacts. However, most of these assessments fail to provide insights into the materiality aspect of vehicle electrification. This may be an important limitation to our understanding of the sustainability implications of electric vehicles to the full extent since they are substantially different from conventional vehicles in terms of their drivetrains and infrastructural needs (i.e., electricity refueling station vs. gasoline station). Hence, in this column, I will attempt to cover this aspect.
Given its significance in terms of global sustainability, improving the environmental and socioeconomic performances of the transportation sector has been given a high priority towards the mitigation and management of climate crisis, globally. The dependence of the transportation sector on fossil fuels has increased the reliance on fuel imports for countries that do not possess the needed resources, which, in turn, raised concerns over energy security and fuel supply risks. The economic consequences of such a reliance were experienced around the world during the oil crisis of the 1970s, which led many countries to redesign their energy and transportation policies.
Most importantly, the combustion of fossil fuels consumed by vehicles has caused adverse environmental impacts while posing serious risks for public health, as well as the health of urban ecosystems, especially in countries without proper air and environmental quality control measures. In addition, the estimated increase in the number of registered vehicles around the world — especially in countries like the United States, Europe, China, and India — is likely to cause greater environmental and socioeconomic impacts due to increased vehicle use. These concerns and potential consequences have led scientists and decision-makers in both public and private organizations to reconsider the electrification of transportation, even more seriously than ever before.
In practice, electrifying the transportation sector means transforming the way we build and maintain the related infrastructure, as well as the way we generate and supply fuel (i.e. electricity). There is a growing consensus — even acknowledged by fossil-minded politicians — on the findings of many scientific studies, concluding that the world has already run out of its carbon budget, and cannot afford to use fossil fuels in any manner. Therefore, we also need to reconsider the role of energy infrastructure in transforming the transportation sector, since the electricity needed to power our vehicles must come from renewable energy sources utilized in the most sustainable way.
At this junction, it is critical to take into account the materiality aspect of this transformation, since both the electric vehicle and clean energy technologies that will be used to power these vehicles rely on the stable supply of materials that are critical for such a transformation. Additionally, the majority of countries are dependent on the imports of such materials. The question of how criticality in this context is defined can be naturally raised; however, that is a topic for another time. An indicator that can provide insights into the materiality aspect of electric vehicles is the material footprint. The material footprint of a product can be defined as the amount of materials involved in the production of the given product along its entire supply chain, from raw material extraction to final consumption. Material footprint analysis aids in effectively managing natural resources, which is crucial to the deployment of electric vehicles around the world.
Using this indicator, I have investigated the material footprints of U.S. electric vehicles and observed that when the materiality aspect is of concern, the results draw a different picture compared to other sustainability indicators (e.g., global warming potential) used to assess the benefits and costs of these vehicles. Given their additional needs such as relatively larger batteries to store and provide power and recharging stations, electric vehicles underperform conventional vehicles in terms of their material requirements, leading to large differences between their material footprints and those of a conventional vehicle.
For example, the material footprint of a battery electric vehicle is 60% higher than that of a conventional vehicle. Plug-in hybrid electric vehicles also have a similar material footprint profile as battery electric vehicles, with their material footprint being 40% to 55% higher than that of a conventional vehicle. In both cases, battery manufacturing is a critical factor driving up their life cycle material footprints. My investigation has also confirmed the concerns over the supply risks of critical materials, as the U.S. is moderately to heavily dependent on the imports of many such materials embedded in the production of U.S. electric vehicles. The expected increase in the demand for electric vehicles, as pushed by environmental constraints and government regulations, is likely to result in an increase in the demand for these critical materials.
All in all, there are at least four important takeaways related to the materiality of electrifying the transportation sector, and they apply to all countries.
Firstly, the material efficiency of electric vehicles should be paid due attention from a life cycle perspective.
Secondly, the share of electricity generated from renewable energy sources should be increased at the margin as much as possible, preferably by 100%, and urgently.
Thirdly, batteries are critical to the material footprints of electric vehicles, and the importance of batteries becomes clearer as the material footprint attributed to the use phase of a conventional vehicle is larger than electric vehicles.
Last but not least, countries should heavily invest in material recycling in order to diversify their material supplies while increasing domestic supply capacity.