Having negative impacts on environment and the scarcity of resources of conventional fossil fuels, fuel cell technology draws more attention as an alternative for providing the electrical energy in parallel with thermal energy. In this study, a single tubular solid oxide fuel cell (SOFC) with an electrolyte of Yttria-Stabilized Zirconia 8 mol% ceramic powder was experimentally investigated. The investigation illustrated the effects of three different fuel flow-rates (175 ml/min, 250 ml/min and 325 ml/min) and two operating temperatures (650 degrees C and 750 degrees C) on the output electrical and thermal powers. The highest electrical voltage (open circuit) and overall output power of the cell were found to be 1.1 V and 5.30 W respectively for the fuel flow-rate of 250 ml/min at the operating temperature of 750 degrees C. The electrical power and efficiency were increased about 18.80% and 1.27% respectively for the increase of operating temperature from 650 degrees C to 750 degrees C for a constant fuel flow-rate of 250 ml/min, where; thermal power and efficiency were increased about 33.33% and 10.51% respectively for the same condition. The overall efficiencies of the fuel cell were obtained about 80.42%, 77.49% and 60.73% for the fuel flow-rates of 175 ml/min, 250 ml/min and 325 ml/min respectively for the operating temperatures of 650 degrees C. On the other hand, the overall efficiency of the cell was found to be 83.38% at the operating temperature of 750 degrees C and fuel flow-rate of 250 ml/min. The investigation recommends that for achieving higher efficiency, fuel flow-rate should be lower and operating temperature should be higher. (C) 2015 Elsevier Ltd. All rights reserved.