Development and Comparison of Sustainable Energy Supply Chains Using the P-Graph Methodology With Integration of Ecological Footprint and Emergy Analysis Criteria

A computer-aided methodology using the P-graph framework with sustainability metric criteria was developed to analyze and contrast sustainable energy supply chains. These supply chains generate heat and electricity using alternative renewable resources such as wood, corn, and grass products. These were compared to traditional fossil-fuel-based energy supply chains (electricity and natural gas). Assessments of twenty-one different supply chain structures, (annual capacity of 18 TJ heat and 7.2 TJ electricity), were based upon cost and multiple sustainability metric criteria: ecological footprint (land use burden) and emergy analysis (energy resource burden). Compared to the traditional “business as usual” energy supply chain, cost variation ranged from +12% to -17%; ecological footprints differed by +72% to -78%, and emergy results comparatively varied by -11% to -93%. These results point to the feasibility of designing more cost-effective and sustainable renewable energy supply chains compared to traditional fossil fuel-based supply chains.