This PhD research intends to develop of a full energy- and carbon balance of a bioenergy plantation with fast-growing poplars (Populus). A large scale operational bioenergy plantation provides the researcher with experimental data with regard to both the energy use and -production and the carbon inputs and ¿outputs. An elaborate life cycle analysis of the full three year rotation of the plantation is performed and all environmental costs are expressed in terms of both monetary costs and carbon costs. The information obtained from the carbon- and energy balance is included in the GORCAM-model, in order to test the carbon efficiency and the energetic performance against the economic potential of short rotation coppices.