CO_2e-emissions of different technologies in passenger cars at real user scenarios in the product life cycle

摘要

Comprehensive objective evaluation of technologies can only be achieved under consideration of the entire product lifecycle. In the present work, the resulting CO_2-equivalent (CO_2e) emissions of different drivetrain technologies are compared and quantified over the total lifecycle, including internal combustion engines (ICE), hybrid- and electric drives. Furthermore, the evaluation considers various vehicle body technologies and materials (steel, aluminium and carbon-fibre-reinforced plastic CFRP), and the provision of electric energy and fuel from fossil and renewable origin. The use phase has a major influence on the life cycle evaluation of vehicles. In the present work, different customer usage scenarios are taken into account. Determination and processing of data is done by a combination of simulation and field tests. The study discusses resulting CO_2e emissions of production and use of the defined systems. Furthermore, it delivers an outlook on comprehensive future assessment strategies, which are able to consider individual user scenarios. In case of plug-in hybrids (PHEV) and electric vehicles with range extenders (REEV), the overall balance is significantly influenced by the ratio of electric- or fuel-supplied operation. A high share of short distances and intermediate charging possibilities supports an increased use of the electric drive unit. This leads to a lower CO_2e footprint, especially when using electric energy from renewable sources. A higher share of long distances without intermediate charging requires the increased use of the ICE. The CO_2e saving potential of material-lightweight construction depends also on the user scenario, especially on the share of acceleration and deceleration phases (urban traffic) of the total travel distance. Other main influences are efficiency of the drivetrain and effort for production. The saving potential of lightweight technologies increases with a higher portion of urban traffic, lower efforts for production and lower efficiency of the propulsion system.