Electric vehicle battery manufacturing emissions have been studied extensively. … the studies indicate that battery production is associated with 56 to 494 kilograms of carbon dioxide per kilowatt-hour of battery capacity (kg CO₂/kWh) for electric vehicles. Several of the studies also provide estimates for the equivalent amount of emissions per kilometer driven over the vehicle lifetimes. These generally find 1–2 g c O₂per kilometer per kWh of battery capacity.

… The wide range of values found in these studies indicates the degree of uncertainty in assessing life-cycle emissions and the variety of methods and materials used in manufacturing batteries. The methodology used for a life-cycle assessment (LCA) can greatly influence its conclusions about the carbon intensity of batteries.

—Hall and Lutsey (2018)

Potential changes in battery manufacturing greenhouse gas emissions (compared to reference 2017 electric vehicle) resulting from increased pack size and improvements in battery manufacturing and use. Hall and Lutsey 2018. Click to enlarge.

Among the general findings from the analysis:

• Electric cars are much cleaner than internal combustion engine cars over their lifetime. The ICCT team found that a typical electric car today produces just half of the greenhouse gas emissions of an average European passenger car. Furthermore, an electric car using average European electricity is almost 30% cleaner over its life cycle compared to even the most efficient internal combustion engine vehicle on the market today.

  Plug-in hybrid vehicles, when driven on electric power for most trips, have lifecycle emissions similar to battery electric vehicles. In markets with very low-carbon electricity, such as Norway or France, electric vehicles produce less than a third of the life-cycle emissions of an average combustion-engine vehicle. This finding bolsters governments’ goals to promote electric cars as part of their decarbonization strategies.

• The battery manufacturing life-cycle emissions debt is quickly paid off. An electric vehicle’s higher emissions during the manufacturing stage are paid off after only 2 years compared to driving an average conventional vehicle, a time frame that drops to about one and a half years if the car is charged using renewable energy.

  Approximately half of a battery’s emissions come from electricity used in the manufacturing process. Battery manufacturing emissions appear to be of similar magnitude to the manufacturing of an average internal combustion engine vehicle, or approximately a quarter of an electric car’s lifetime emissions. However, recent estimates of battery manufacturing emissions vary by a factor of 10, indicating the need for additional research in this field.

• Grid decarbonization offers a significant opportunity to reduce the impact of battery manufacturing. The emissions from battery manufacturing are likely to decline significantly in coming decades, especially with the use of cleaner electricity throughout the production cycle.

  A 30% decrease in grid carbon intensity would reduce emissions from the battery production chain by about 17%, in addition to even greater savings in the use phase. Use of recycled materials and alternative battery chemistries could also reduce emissions in the manufacturing phase. Even as electric vehicles use larger batteries to allow longer electric-range travel, these and other improvements will further increase electric cars’ life-cycle advantage over internal combustion engine vehicles.

• Incorporating electric vehicle life-cycle manufacturing emissions into vehicle regulations would be misguided. The ICCT team foresees “deep problems” with introducing aggregated manufacturing emissions data into vehicle CO₂ and efficiency regulation.

  Calculating life-cycle emissions for all vehicle models would be onerous and not at all rigorous, the ICCT stipulates. Any such policy would need to include manufacturing emissions for all conventional vehicle components, in addition to batteries, so as not to unfairly penalize electric vehicles. (An outcome that would be supported by a number of stakeholders, such as the steel industry, which is using the lifecycle emissions argument to bolster its position against the aluminum industry.)

  Slowing down electric vehicle uptake to wait for a near-zero-emission grid would be incompatible with global goals to decarbonize the transport sector by 2050, the ICCT team concludes.

Resources

• Dale Hall and Nic Lutsey (2018) “Effects of battery manufacturing on electric vehicle life-cycle greenhouse gas emissions”