Less or different environmental impact?

Book chapter, 2013

Electric and hybrid drivetrains are currently regarded as a promising technology for vehicle propulsion. They can reduce greenhouse and other exhaust gas emissions from road transport. Electric drivetrains are more efficient than conventional internal combustion engines fuelled by petrol or diesel (Chapter 5), and fully electrified vehicles does not give any tailpipe emissions. In addition, electric drivetrains can also assist in decoupling the transport sector from its heavy reliance on fossil fuels. On the other hand, electric vehicles will require that more electricity is produced and this can be done from several different energy sources with diverse environmental impacts. Furthermore, electric drivetrains require new advanced components (Chapter 3) that result in additional, or at least different, environmental impacts compared to conventional vehicles. The trade-off between the benefits when operating of the vehicle and possible negative impacts from the production and from energy supply can be analysed using life cycle assessment (LCA). However, LCA studies come in many shapes and diverging arguments on the utility of technology are based on them. Some advocate the technology (using for example the well-to-wheels approach to guide government promotion policies on different types of drivetrains and alternative fuel options)1 and others claim that the prospective for electric cars to reduce the environmental impacts of mobility is “substantially overrated”2 or that there will be “significant increases in human toxicity“.3 This chapter provides an overview of the life cycle impacts of electric vehicles, with general conclusions and examples of results. We review existing research and sort studies found in literature into categories by asking what we can learn from different LCA approaches. More specifically, which answers do we get from well-to-wheels (WTW) studies in comparison to complete LCA studies, and what difference does it make if a study includes a narrow or broad set of environmental impacts. We conclude by summarising these learnings and discuss implications for a set of stakeholders identified in the area of vehicle electrification, such as policy makers and various branches of industry.