Full assessment - WTW + LCA
The scope of greenhouse gas (and air pollutant) emissions estimation and the associated terminology can be confusing. For instance, ‘well-to-wheel’ (WTW) greenhouse gas emissions include all emissions related to fuel production – often referred to as the fuel-cycle – in other words, processing, distribution (fossil transport fuels, electricity, hydrogen) and on-road use.
An even more comprehensive scope is included in a life-cycle assessment (LCA), which estimates ‘cradle-to-grave’ emissions and accounts for both fuel-cycle emissions (WTW) and vehicle-cycle emissions (material and vehicle production as well as end of life, recycling or scrapping).
Another commonly used way is to refer to Scope 1, 2 or 3 emissions. Scope 1 accounts for “direct emissions”, Scope 2 for “indirect emissions related to the generation of purchased energy” and Scope 3 for “indirect emissions from other upstream and downstream activitities” (suppliers, extraction, production, etc.).
TER has recently conducted LCAs for the Australian passenger cars and this work is ongoing for other vehicle types such as trucks. We have developed an innovative, fast and cost-effective LCA approach to compare the emissions performance of different vehicle types such as fossil-fuelled internal combustion engine vehicles (ICEVs) and battery electric vehicles (BEVs).
TER used a statistical approach to quantify the uncertainty in the results, which is important when comparing different technology options. The work has been published in an open access paper that can be found here.
Previous TER research has shown that the use phase dominates total life-cycle GHG emissions per kilometre for Australian passenger vehicles, accounting for about 70% for both fossil-fuelled internal combustion engine vehicles (ICEVs) and battery electric vehicles (BEVs).
In June 2023 TER published an independent study into greenhouse gas emissions from Australian road transport in 2019 (baseline) and 2050. The research question is will we achieve net zero in 2050? This is a WTW assessment, which captures the bulk of emissions for future transport and is - in TER's view - a minimum requirement for future emissions forecasting.