Future scenarios of greenhouse gas emissions from electric and conventional vehicles in Australia

Demand for reductions in greenhouse gas (GHG) emissions is leading automakers to develop various types of low-emission vehicles, including electric vehicles and efficient combustion vehicles. Although electric vehicles avoid tailpipe GHG emissions, their use results in only small net life-cycle benefits in countries where electricity generation is GHG intensive. In the near future, this benefit might reduce to a net cost as automakers aim to achieve strict vehicle emission targets for combustion vehicles. Demand for reductions in GHG emissions is, however, also driving some shift towards low-GHG electricity generation such that the net emissions of electric vehicles would decrease. The present study explores the effect of these changes in GHG intensities of vehicles and electricity generation. It quantifies and compares the GHG emissions of two functionally-similar vehicles, an electric vehicle (EV) and a conventional combustion vehicle (CV), driven in Australia. The results suggest that an EV will have fewer GHG emissions than a CV from driving but that the benefit declines steadily with later models. Therefore, to maintain the net life-cycle GHG emissions benefits of EVs, EV automakers may still include some GHG-intensive processes and components during manufacture, but they should plan to improve or replace such processes and components. A detailed model that accounts for further variations in influential parameters would help to increase the accuracy of the calculations.