A new Life Cycle Assessment (LCA) study by Ricardo for the Low Carbon Vehicle Partnership (LowCVP) across a broad range of vehicle sectors finds that the relative contribution of each vehicle life cycle stage is highly dependent on the vehicle type and powertrain technology as well as what assumptions are made about a vehicle’s operational life, mileage and duty cycle.

Source: Ricardo, LowCVP.

For electric and plug-in hybrid vehicles the carbon intensity of the power grid is also a key factor in terms of the vehicle’s full life cycle emissions.

Well-to-wheel CO₂e emissions of current electric vehicles are already significantly lower (40-60%) as a proportion of full lifetime emissions than those of typical current passenger cars (70-85%) and this difference can increase as the electricity grid becomes increasingly decarbonized.

However, if a race for bigger and bigger batteries is left unchecked, EVs doing low mileages could undermine some of the potential benefits, the report finds.

The environmental impacts associated with the production phase, in particular, for road vehicles will become increasingly important in the context of the full life cycle and, therefore, the focus of more policy attention as governments around the world strive to meet greenhouse gas (GHG) emissions reduction targets.

The Ricardo study focuses on providing insights into how life cycle CO₂e emissions vary by vehicle segment and powertrain technology. It considers ‘L-category’ (micro) vehicles, passenger cars, heavy duty trucks and buses across four life cycle stages: vehicle production, fuel production, vehicle use and vehicle end-of-life.

For larger, heavy duty trucks, life cycle CO₂e emissions are overwhelmingly from vehicle use (>95%); unsurprising given the high utilization and lifetime mileages of these types of vehicles. In this sector using lower carbon fuels and energy sources will deliver the greatest carbon reductions in the near term.

For passenger cars, embedded GHG emissions from vehicle production and end-of-life account for 10-30% of total life cycle GHG emissions for conventional ICEVs and 20-95% of total life cycle GHG emissions for BEVs (depending on electricity carbon intensity).

For smaller vehicles, such as passenger cars and micro vehicles, there is much greater sensitivity in each life cycle stage; often more than 50% of the overall impact comes in the manufacturing stage.

Source: Ricardo, LowCVP.

For a medium-sized passenger car, embedded emissions are typically 5-8 tCO₂e for gasoline ICE, and 6-16 tCO₂e for BEV, depending on size of battery pack and assumed production emissions factor.

This new analysis – “Understanding the life cycle GHG emissions for different vehicle types and powertrain technologies” builds on earlier work for the LowCVP. In 2011 the LowCVP commissioned “Preparing for a life cycle CO₂ measure”, also by Ricardo. A follow-up project—“Life cycle CO₂e assessment of low carbon cars 2020-30”—was completed in 2013 by PE International.