By means of energetic life cycle assessment, innovative fuel cell (FC) powertrain systems and the respective fuels are examined and compared with conventional systems. The basis for this research is process chain analyses for the supply of conventional and alternative fuels at the point of consumption in Germany, e.g. compressed natural gas, methanol or hydrogen. To complete the integrated view, the use of these fuels in vehicles with internal combustion engines and FCs is examined. Within the scope of this study, special attention is paid to a system breakdown and energetic assessment of the FC powertrain. For the purpose of a full life cycle assessment, energy requirements and CO2-emissions for the production, maintenance and disposal of the vehicles are included. (c) 2005 Elsevier Ltd. All rights reserved.