Miscanthus, a perennial grass originating from Asia, is being examined as a biomass crop in Europe for production of ethanol. In this research energy input-output analyses were executed for Miscanthus production systems in the German province Brandenburg, taking into account the whole ethanol production chain. Simulated Miscanthus yields were used to calculate energy inputs (8.7 - 21.9 GJ ha-1 year-1), energy ratios (7-13) and net energy values (95.6 - 136.7 GJ ha-1 year-1). These calculations were made for conventional, organic and mechanized production system scenarios under various irrigation and fertilization regimes. Irrigation increased yield and net energy value and also lowered GHG emissions per produced unit of biomass. Nutrient application (58 kg N, 12 kg P and 125 kg K ha-1) can be decreased under rainfed conditions, but at high irrigation application rates phosphorus and potassium application rates should be increased. The GHG saving potential of Miscanthus, exclusive soil carbon sequestration, is 68 - 78 % in comparison with conventional diesel. If Miscanthus is grown on all arable land in Brandenburg, this provides enough biomass to achieve the obliged 6.25% biofuel in transportation fuel for the whole German car fleet.