This study investigates the performance of a combined industrial molten carbonate fuel cell (MCFC) system, including a turbo expander, which was recently installed by Enbridge Inc. in Toronto, Canada. it entails a comprehensive thermodynamic analysis regarding energy and exergy calculations, subject to varying operating conditions. Furthermore, a simplified and novel method is used for a cost analysis to assess the amortization of the system. The results from the base case study suggest that an overall energy efficiency as high as 60% is achievable while fuel cell stack energy and exergy efficiencies of 50.6% and 49.3%, respectively, are reached. The cost analysis indicates that the amortization of the system may take up to 15 years of operational time, depending on the price of electricity and natural gas. However, carbon offsets may make a paramount contribution to the overall savings and economic viability of future combined MCFC systems. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.