Economic and Environmental Assessment of Biogas

The paper presents the findings from a case study of a biogas facility in Solrød, Denmark. The facility is designed to run on a combination of cast seaweed (app. 20,000 tons year¬1), waste from pectin production (app. 80,000 tons year¬1) and manure (app. 50,000 tons year¬1) and other materials in lesser amounts. The purpose of the case study is to develop a model for early stage economic assessment and to identify a methodology for calculation of GHG emissions. The paper explains the outline of the case study and elaborates on two main elements: the economy respectively and the environmental impacts. The feasibility assessment concludes that the economy of the biogas facility is depending on revenues generated by both electricity and heat production and sale. The economy of the biogas facility is discusses in the light of a model that illustrates breakeven costs at different gas yields ¬with and without a heat sales. The analysis of the GHG reduction was based on a baseline methodology in which the effects of the biogas facility was analyzed and quantified against a baseline (the reference scenario). The assessment concludes that the biogas plant potentially could reduce greenhouse gas emissions between 25,000 tons CO2e year¬1 and 40,000 tons CO2e year¬1 depending on the type of energy utilization (as transport fuel, industrial process fuel or CHP respectively). The study also indicated that the removal of coastal seaweed would result in a significant reduction of the nutrient load in the bay area and contributing significantly to the compliance with reduction targets enforced as a consequence of the implementation of the EU water frame directive.