Review of Recent Lifecycle Assessments of Energy and Greenhouse Gas Emissions for Electric Vehicles

Abstract

This paper synthesizes the most recent studies on the lifecycle of electric vehicles (EVs), summarizes the critical assumptions and inputs of the lifecycle assessments (LCAs), and discusses policy context affecting these assessments. The use phase represents the majority of environmental impacts for EVs, particularly in areas with more fossil fuel use in the electricity grid mix. Assumptions made in LCAs about electricity generation, vehicle lifetime, vehicle weight, and driving behavior greatly impact the resulting lifecycle energy consumption and greenhouse gas (GHG) emissions of EVs. However, vehicle and battery considerations outside of vehicle use affect the lifecycle environmental performance of EVs as well. The battery manufacturing and end-of-life (EOL) technologies and processes are still being developed and researched, and manufacturing batteries has some uncertainties but is a large contributor to the manufacturing emissions of EVs. Recycling and second-life applications present an opportunity for increasing the value and lowering environmental impacts of EV batteries. Policies today help to get EVs on the road by reducing costs to own EVs, but more research and policies can be developed to improve the state of battery technology. Future policies focusing on battery manufacturing and EOL and a cleaner electricity grid can have the potential to reduce the environmental burden of EVs by encouraging recycling batteries, producing batteries more efficiently, and reducing emissions from the electricity grid.