A model was developed for determining the current-temperature profiles of a solid oxide fuel cell. The model was integrated by an electrochemical module and a thermal module. The electrochemical module included the three principal modes of polarization (i.e., ohmic, activation and concentration). The thermal module solved the energy and mass conservation equation using a unit cell approach. The integrated model (electrochemical-thermal) was used to analyze the performance of the cell with respect to different operating conditions. In addition, the model was used to analyze the response of the fuel cell under different gasifier compositions. These compositions are expected from the thermal integration of a downdraft gasifier with a solid oxide fuel cell. The results showed the effect of the initial concentration of carbon monoxide, water and hydrogen, with respect to the performance of the cell. (c) 2005 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.