Sustainability assessment of wood-based bioenergy A methodological framework and a case-study

The sustainability of the utilization of wood biomass for energy and other purposes has been widely assessed in different studies. Especially discrete methods from the family of Multi-Criteria Decision Analysis (MCDA), such as Outranking methods, Multi-Attribute Utility Theory, and Analytic Hierarchy Process (AHP) are often applied. AHP is considered one of the most promising options to be used in sustainability assessments, because it is comprehensible to apply and it incorporates the preferences of decision-makers in an advanced manner. In this study, we present a theoretical multi-dimensional framework based on a modified version of AHP for assessing sustainability and apply it in a case of wood-based bioenergy production in eastern Finland. The framework includes four dimensions of sustainability and life cycle phases from the acquisition of raw material to manufacturing the final product. The production systems used in the empirical sustainability assessments are a local heat production plant, a combined heat and power production plant, and a wood pellet processing plant. Local sustainability experts identified indicators relevant at the regional scale. The impact assessment data were obtained from literature, by interviewing the managers of the bioenergy plants, and from a postal survey administered to local people. The local heat provider received the highest sustainability index; however, there were no considerable differences between the sustainability indexes. None of the bioenergy production systems can be considered the most sustainable regardless of the assumptions employed in the framework. The framework provided the basis for a quantitative, interdisciplinary approach to assess sustainability.