An electrolyte-supported hybrid direct carbon fuel cell (DCFC) was used to evaluate the performance of different carbon fuels in this study. The direct carbon fuel cell consists of a samarium doped ceria (SDC) electrolyte, a Ni/SDC anode and a Ba0.5Sr0.5Co0.8Fe0.2O3-delta cathode. Three types of carbon (graphite, coal and activated carbon) and three particle sizes of activated carbon (70, 250 and 500 mu m) were investigated at 650-750 degrees C. The electrochemical reactivity of these three types of carbon fuels was in the order of activated carbon > German creek coal > graphite. Sulphur in German creek coal has poisoning effect on Ni catalyst resulting in lower power density of the fuel cells. The activated carbon (250 mu m) fuelled hybrid DCFC achieved a peak power density of 158.3 mW cm(-2) at 750 degrees C along with the maximum current density of 561.5 mA cm(-2). However, the stability of the hybrid DCFC is poor and need to be improved at the present. (c) 2013 Elsevier Ltd. All rights reserved.