Economic sustainability in a biogas CHP plant, in terms of the current trend of incentivization for energy production: a real case analysis

The renewed interest for anaerobic treatment cycle associated with biogas CHP plants, that has recently become more attractive because of its environmental benefits, renders a deep evaluation of the economic sustainability of this solution for green energy necessary. The application of this method is particularly interesting in areas with high livestock density, where an overload coming from animals' manure and slurries is not balanced by the availability of wide agricultural surfaces. Rapid changes in the actual scenario introduce continuous variations in boundary conditions, especially in terms of value for electrical and thermal energy produced in cogeneration, and of incentives possibly achieved. The aim of this study is to focus attention on the feasibility of an anaerobic digestor associated to a CHP plant in the Capaccio di Paestum area, and to provide the necessary parameters to perform a comparative analysis between alternative solutions, according to the Directive 2004/8/EC. The analysis clearly shows that only the incentives achieved under specific conditions make these investment profitable, so that is not strictly necessary to apply any kind of fee to the farmers in the area. On the other hand, the study highlights how much dependant is the financial plan on the admittance to the incentive mechanism and on the assumed price for Green Certificates: the likely decrease of their value will heavily penalize the ratio between costs and revenues