Technical-economic viability of tubular biodigester and photovoltaic energy for rural property

Dairy cattle farming is an activity of great economic importance for Brazil, and the state of Parana has a relevant participation in national milk production. In order to reduce production costs, the generation of the electric energy in the distributed generation model appears as an alternative for the milk cattle farmer. Therefore, there are two possible options: The use of the property's animal waste for turning biomass into a biogas source, or the installation of photovoltaic panels. The objective of this work was to evaluate and compare through the use of economic engineering tools such as NPVand Payback, the feasibility of implementing these energy sources in a milk-producing property. The results demonstrated the economic viability of both forms of energy generation for a 25-year project horizon, considering a minimum attractiveness rate of 6,5%. Among the scenarios evaluated, the most financially interesting alternatives were those in which the cost of implementing the system was financed, since the considered interest rate of 3% per year is lower than the average inflation of 5,92% per year on the investment balances.