Society relies mainly on fossil fuels for energy generation, which results in risks due to geopolitical conflicts, environmental damage, and climate change. By opting for renewable energy sources, including bioenergy derived from microorganisms, there is a potential solution to this predicament. By harnessing the energy-producing abilities of microorganisms, it is possible to generate renewable energy on a large scale without harming the environment or human activities. Thereby, the present work has as a neuralgic objective to develop a decision-making method for microbial energy generation. Using as a method the fuzzy logic of the Mamdani type for absorbing the uncertainties and inaccuracies, characteristic of this work theme. A structure with 4 levels of indicators was developed, using triangular and trapezoidal functions at the ends. In the development of the fuzzy rules, were used 5 input fuzzy sets and 5 output fuzzy sets when there were two indicators in the fuzzy machinery and three input fuzzy sets and 5 output fuzzy sets with 3 or more indicators in the fuzzy machinery. Five scenarios were developed, considering a scale of 0 to 10: High criticality (10-8), Tolerable (8-6), Adequate (6-4), Desirable (4-1.5) and Low criticality (1.5-0). Thus, it is expected that this model can optimize decision-making processes and promote renewable energy alternatives, potentially reducing the dependence on fossil fuels in the future.