Using the Rapid Impact Assessment Matrix to synthesize biofuel and bioenergy impact assessment results: the example of medium scale bioenergy heat options

Despite the potential opportunities, there remain widespread concerns about bioenergy and biofuel feedstock sustainability, assessment and policy. This paper illustrates the value of the Rapid Impact Assessment Matrix (RIAM) for transparently presenting evidence and judgements relating to four biomass options that are potentially suitable for supplying heat to a university-sized facility. The RIAM approach provides comparable scores for: soybean biodiesel, waste cooking oil biodiesel, anaerobically co-digested food waste and manure; and timber pellets made from sawmill by-product. The high-level nature of the RIAM allows the user to structure a broader range of considerations and contingencies than the life-cycle approach embodied in EU biofuel legislation. We advocate the RIAM not as a substitute for LCA or any other form of assessment in a bioenergy context, but as a means of synthesising the results of different types of impact assessment and for making broader debates and uncertainties explicit, such that non-specialist knowledge users are both guided and made aware of differing scientific and stakeholder opinion.