Nowadays, carbon-rich fuels are the principal energy supply utilized for powering human society, and it will be continued for the next few decades. Connecting with this, modern energy technologies are very essential to convert the available limited carbon-rich fuels and other green alternative energies into useful energy efficiently with an insignificant environmental impression. Amongst all kinds of power generation systems, SOFCs running with high temperatures are emerging as a frontrunner in chemical to electrical transformation efficiency, allows the engagement of all-embracing fuel varieties with negligible environmental impact. This study investigates the effect of ammonia usage in tubular SOFC performance. Firstly, the use of ammonia and hydrogen in the electrolyte supported SOFC (ES-SOFC) has investigated. Then, the effect of using ammonia in anode supported SOFC (AS-SOFC), ES-SOFC and cathode-supported SOFC (CS-SOFC) on performance has been examined by using COMSOL software. As a result of the study performed, it is found that the ammonia can be used in tubular SOFC's as a carbon-free fuel and CSSOFC shows better performance compared with ES-SOFC and AS-SOFC. Besides, the findings of this study indicate that the use of ammonia as a fuel for SOFCs is comparable to the use of hydrogen. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.