Report: LCA of bioenergy systems - state of the art and future challenges
Francesco Cherubini, Anders Hammer Strømman - Department of Energy and Process Engineering, Norwegian University of Science and Technology (NTNU), Norway
The use of different input data, functional units, allocation methods, reference systems and other assumptions complicates comparisons of LCA bioenergy studies. In addition, uncertainties and use of specific local factors for indirect effects (like land-use change and N-based soil emissions) may give rise to wide ranges of final results. In order to investigate how these key issues have been addressed so far, this work performs a review of the recent bioenergy LCA literature. The abundance of studies dealing with the different biomass resources, conversion technologies, products and environmental impact categories is summarized and discussed. Afterwards, a qualitative interpretation of the LCA results is depicted, focusing on energy balance, GHG balance and other impact categories. With the exception of a few studies, most LCAs found a significant net reduction in GHG emissions and fossil energy consumption when bioenergy replaces fossil energy.
This paper performs a review of a large portion of the existing scientific literature that explicitly used life cycle assessment (LCA) methodology, or a life-cycle approach, to estimate the environmental impacts of biomass energy uses. Authors of this paper assume that the reader already has a basic knowledge of LCA and bioenergy production chains, so that general information on these aspects is not provided here.