Comparison of the environmental impacts of a plug-in hybrid and a full electric car using life cycle assessment

Full electric (FEV) and plug-in hybrid (PHEV) vehicles are promising, forward-looking technologies to reduce greenhouse gas (GHG) emissions and other pollution related to road transport. The powertrain of a FEV is composed of a battery, control electronics and the electric motors. A PHEV has much lower battery capacity but it contains an extra internal combustion engine and gearbox. Many argue that FEVs are more energy-efficient than internal combustion engines. However, this energy needs to be stored in heavy, large-capacity battery packs that require plenty of energy and resources to produce as well as highly polluting rare earth elements mining. In this article, an environmental comparison of FEVs and PHEVs is shown using life cycle assessment (LCA). To make the comparison realistic, two models similar in size and power have been selected: Volkswagen E-Golf FEV and Volkswagen GTE PHEV. Results show that the production of FEVs need more energy and it means more burden on the environment however during the use phase it causes less emissions. Since the local electricity production mix and, in case of PHEVs, the user behaviour highly affects the results, three different countries (Hungary, Poland and Norway) and two different use types are considered. The quantified environmental footprints as well as the break-even distances are presented. Sensitivity of the results towards the assumed conditions during the whole design lifetime of the vehicles is discussed.