Development of Hybrid Electric Vehicles in the Context of Life Cycle Assessment

Apart from the tank-to-wheel approach, which is currently used for passenger car homologation, the importance of emissions in other life cycle phases is more and more acknowledged. This includes the production and disposal of the vehicle as well as the upstream emissions of the energy carriers. In order to evaluate the eco-friendliness of passenger cars, life cycle assessment (LCA) gained large popularity over the last few years. Within this work, an overview of different life cycle-based methods is given, including methodological background such as the ISO 14040/44 standards and combined technical LCA (TLCA) approaches. Hereby, a research gap regarding the TLCA of HEVs could be identified, with related publications lacking detail in LCA modelling. On this basis, the authors present a toolchain consisting of a vehicle co-simulation platform and a full LCA tool. The proposed environment allows for a large variety of influencing factors, such as powertrain configuration, operating strategy, driver behavior as well as the materials and manufacturing processes involved in the vehicle production. Exemplarily, a conventional gasoline-fueled vehicle is compared to a mild hybrid and full hybrid electric vehicle in a cradle-to-grave context. ... mehrIn the considered use cases, fuel savings of up to 8.5 % can be achieved by full hybridization in a real driving scenario. When tested in a WLTC, the considered full hybrid only achieves a fuel consumption reduction of 5 %. In both cases, an even larger savings potential is hampered by the additional mass introduced through an increased hybridization degree. Moreover, the additional environmental impact caused by hybrid components cannot always be compensated through improved fuel consumption. Particularly in case of impact categories other than the global warming potential, such as mineral resource scarcity potential, hybridization can result in increased environmental burdens. This work provides a methodology to assess such interactions between technical features and environmental impact.