Sustainable Propulsion in a Post-Fossil Energy World: Life-Cycle Assessment of Renewable Fuel and Electrified Propulsion Concepts

Faced with one of the greatest challenges of humanity – climate change – the European Union has set out a strategy to achieve climate neutrality by 2050 as part of the European Green Deal. To date, extensive research has been conducted on the CO2 life cycle analysis of mobile propulsion systems. However, achieving absolute net-zero CO2 emissions requires the adjustment of the relevant key performance indicators for the development of mobile propulsion systems. In this context, research is presented that examines the ecological and economic sustainability impacts of a hydrogen-fueled mild hybrid vehicle, a hydrogen-fueled 48V hybrid vehicle, a methanol-fueled 400V hybrid vehicle, a methanol-to-gasoline-fueled plug-in hybrid vehicle, a battery electric vehicle, and a fuel cell electric vehicle. For this purpose, a combined Life-Cycle Assessment (LCA) and Life-Cycle Cost Assessment was performed for the different propulsion concepts. This assessment follows the methodology of DIN EN ISO 14040/44 and the EU Product Environmental Footprint framework. In contrast to other studies, an integrated approach was used to aggregate the Life-Cycle Inventory data. This approach combines model-based system design including physical-empirical simulation models with internally and publicly available LCA databases. Aiming at a holistic and adequate comparison of these propulsion concepts that meet identical, pre-defined customer requirements regarding system design, a unique scalable and modular modeling approach is used along the entire process to derive individual, precisely tailored mobile propulsion concepts. To deal with uncertainties, a comprehensive sensitivity analysis is conducted and discussed to outline the interdependencies, co-benefits, and trade-offs of different boundary conditions.