Financial economic scenario for the microgeneration of electric energy from swine culture-originated biogas

One of the largest sources of energy available in rural and agro-industrial areas is the biomass, which is found in the form of vegetal and animal residues, such as crop leftovers, animal manure, energetic plantations and agro-industrial effluents. Such residues may be used by rural producers or agro-industries for direct burning, aiming to produce heat or biogas in biodigesters. Swine production generates a large amount of manure that causes environmental issues when not treated properly, due to its high levels of methane. When it is released in the atmosphere, it expressively contributes to the greenhouse effect. The co-generation of electric energy is still one of the ways to utilize biogas generated from food production. Apart from generating energy, it is also possible to sell carbon credits, what provides the producer with higher income. The present work aimed to determine the cost of installation, as well as the feasibility of biogas-based electricity production, by studying the scale economy in several scenarios of swine, biogas and electric energy production, sale or not sale of carbon credits, and investment costs with the estimated amortization period. One can notice that when carbon credits generate profit, production costs decrease and the LPV (Liquid Present Value) increases. Energy production only leads to loss when there is no additional income with carbon credits.