Benefit from In-service Life Optimized for Minimum CO2 – Comparison of ICEVs, PHEVs, BEVs and FCEVs 2024-01-2443

The 2023 FISITA White Paper (for which the author was a contributor) on managing in-service emissions and transportation options, to reduce CO2 (CO_2-e or carbon footprint) from the existing vehicle fleet, proposed 6 levers which could be activated to complement the rapid transition to vehicles using only renewable energy sources. Another management opportunity reported here is optimizing the vehicle’s life in-service to minimize the life-cycle CO2 impact of a range of present and upcoming vehicles. This study of the US vehicle fleet has quite different travel and composition characteristics to European (EU27) vehicles. In addition, the embodied CO2 is based on ANL’s GREET data rather than EU27 SimaPro methodology. It is demonstrated that in-service, whole-of-life mileage has a significant influence on the optimum life cycle CO2 for BEVs and H2 fuelled FCEVs, as well as ICEs and PHEVs. Thus, the object is to show how much present, typical in-service life-mileage differs from the optimums against a back drop of steadily improving energy efficiency, as new vehicle designs enter the market along with the greening of electric power supply and conventional fuel supply. The life cycle analysis is more than ‘well-to-wheel’ as the energy content and manufacture of consumables and recycling/reuse of vehicles (as embodied CO2) is included as new vehicles replace older, scrapped ones in the market, with improvements in energy efficiency (and reductions CO2 emissions). It is found that depending on the vehicle size and configuration, the optimum vehicle life ranges from 10 years to more than 20; significantly different from the present fleet median of 17 years. For all forms of EVs the greater the installed battery kWh or H2 tank size and hence range capability, the longer is the optimum service life. As the energy efficiency for new vehicles entering the market improves, vehicles need to stay in use for longer to amortize the embodied energy in manufacturing. It is concluded from the projection results, that PHEVs provide the best path to minimizing CO2 emissions. Across the fleet of technology types, benefits of up to 50% increase in the reduction of life cycle emissions come from optimal age recycling of the vehicle. Under these conditions of optimum age use, the switch to EVs is not so urgent when policies are in place that encourage best use of all vehicles according to their technology.