Microbial fuel cells (MFCs) are a group of microbial electrochemical cells (bioreactors) that are used to generate energy from organic waste found in wastewater. MFCs represent a promising method of waste disposal and production of electricity. Scaling up the use of MFCs requires extensive analysis and detailed grasp of the required processes. The current work aimed to study a model of an MFC, and find the optimum parameters needed for maximum energy production. The process was simulated and validated on continuous-flow MFCs with a Columbic efficiency of 162% and 35% COD removal. Sensitivity analysis of the model was performed. The studied model was found to be valid for both batch-cycle and continuous-flow MFCs. Parameters with less influence on MFCs were eliminated in order to obtain a simplified model of MFC performance. The new simplified model was then validated. Finally, optimization of operating external resistance was conducted to maximize energy generation.