Forecasting of energy and diesel consumption and the cost of energy production in isolated electrical systems in the Amazon using a fuzzification process in time series models

► A decision support system has been developed using SARIMA with fuzzy systems and optimizations tools. ► It assists the decision-making process for planning the expansion in isolated thermoelectric systems. ► The α-cut concept facilitated the evaluation of risks for the cost of electricity production. ► Provides decisions using various forecasted interval for this cost with different membership values.