In this paper, a parametric study of the performance of a SOFC system for several types of supplied fuels is carried out. A SOFC system which is assisted by some energy resources, namely biomass, solar energy and natural gas, i.e. methane, is designed in order to realize this study. This system consists of four main components which are Solid Oxide Fuel Cell (SOFC), Proton Exchange Membrane Electrolyser (PEME), Photovoltaic system (PV), and Anaerobic Digester for biogas production (AD). The system is designed by considering three fundamental operation modes which are day-time (Ml), night-time (M2), and winter-time (M3), in accordance with the duration of solar irradiation period. In order to evaluate the performance of the system, comprehensive energy and exergy analyses are performed, as major system parameters are changed for the operation modes considered. In this study, maximum total energy and exergy efficiency values of 0.60 and 0.49, respectively, are achieved when the overall energy and exergy performance of the system is evaluated, at 5500 A/m(2) current density for M3 operation mode among the three operation modes considered. Finally, the maximum net electrical energy and exergy efficiencies are achieved for 633 degrees C SOFC fuel inlet temperature and 8000 A/m(2) current density, in this study. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.