Ferramenta de apoio a análise de viabilidade econômica para projetos de biogás que utilizem resíduos de animais para geração de energia elétrica

Abstract

Converting biogas into electricity through a generator set is a way of generating clean, renewable electricity. The economic analysis of biogas plant projects is a crucial and determining factor in the investment, thus, this work aims to provide a tool to support economic decision making in biogas projects that use animal waste to generate electricity. The development of the work began by the planning stage, where a literature survey was performed to obtain parameters about biogas generation, electric power generation from this source and which economic engineering tools most used for analysis. Of this kind of project. The construction of the tool was then started by determining the phases and creating buttons for quick movement inside, inserting project input questions to be answered by the user, auxiliary tab for calculations base, economical engineering methods and finally the project summary. The tool was then programmed using macros, formulas, software functions, graphics, data validation and comments to make it interactive, facilitating its completion. With the data properly entered, the tool is able to return to the user the values of economic indicators (NPV, IRR, Simple Payback, Discounted Payback and Financial Payback), a cash flow chart and allows the user to create two scenarios simultaneously. With oscillation of up to four variables at the same time, for comparison with the indicator values originally obtained in the project analysis. Incrementing the study, one can select up to five variables that will be inserted in a graph where it is possible to analyze the sensitivity of each selected parameter. For the test of the tool we used a case study adapted from the literature as a source of input data, where the economic engineering indicators were obtained. Scenario analysis and sensitivity analysis were also performed for a data variation of 20%. This analysis was performed considering three cases, when the investment is made using only own resources and two others when there is a need for financing, where the SAC and PRICE amortization systems were considered for a 20-year horizon. Finally, the tool was available online for free.