CO2-balance for the cultivation and combustion of Miscanthus

Miscanthus ‘Giganteus’ is a perennial C4-grass from East Asia. The biomass yield-potential of Miscanthus has been investigated in Germany since 1987. The combustion of biomass offers a possibility for lowering emissions of the greenhouse gas CO2. The CO2 which is set free during combustion has previously been fixed by the plants. The study analyses the demand for energy and the CO2-emissions which are involved in the production of Miscanthus, beginning with propagating the plants to transporting the biomass to the power station. Energy demand and CO2-emissions are compared with those of the provision and combustion of hard coal. The energy content of Miscanthus biomass harvested from one hectare, about 20 t of dry matter, corresponds to the energy content of 12 t hard coal. For each gigajoule of hard coal, 96.6 kg CO2 are emitted during provision and combustion. By combusting Miscanthus instead of hard coal 90% of CO2-emissions can be saved.