The Solid Oxide Fuel Cell (SOFC) is modelled and optimised for the tri-generation hybrid system fed by biogas produced from hospital waste. A 50 kW tubular SOFC combined with a chiller, Heat Recovery Steam Generator (HRSG), combustion chamber and required equipment in this study. The system provides 50% of total electricity required using the produced biogas and also provides the whole cooling load of the hospital using an absorption chiller. Further, an economic optimisation is carried out. The principal goal is to give a comprehensive perspective on the affordability of using the proposed system by considering economic parameters along with thermodynamic principles. The single-objective optimisation is performed by genetic algorithm. The results indicate that under the acquired optimum conditions, the proposed system can be economically affordable in long term and will result in net profit of approximately US $ 874,200 annually. (C) 2015 Elsevier Ltd. All rights reserved.