Exergetic and thermoeconomic analysis were performed for a 200-kW phosphoric acid fuel cell plant which offers many advantages for co-generation in the aspect of high electrical efficiency and low emission. This analytical study was based on the data obtained by in-field measurement of PC25C fuel cell plant to find whether this system is viable economically. For 100% load condition, the electrical efficiency obtained, 43.7% turned out to be much better than that for the 1000-kW gas turbine co-generation plant. However, the calculated unit cost of electricity with the initial investment cost per power of fuel cell plant of 3000 $/kW, 0.068 $/kWh turned out to be 125% higher than the cost obtained for the 1000-kW gas turbine co-generation plant. This fuel cell system may be viable economically when the initial investment cost per power is reduced to the level of the gas turbine co-generation plant of 1500 $/kW. (C) 2004 Elsevier Ltd. All rights reserved.