As part of ECN＇s in-house R&D programme on molten carbonate fuel cells (MCFC), assessment studies for small systems (500 kW(c)) in decentralised applications, e.g. commercial and industrial combined heat and power (CHP) and for large systems (600 MWc) in centralised power generation applications have been performed. For a 500 kW, internal reforming MCFC CHP plant, different system designs are evaluated with respect to the possibilities for production of process heat at different temperature levels. This includes the calculations of the electrical and thermal efficiencies and estimations of the investment costs. System designs are characterised by the operating pressure and method of steam handling (anode gas recycling or separated steam injection). To determine the future market potential of coal-fuelled MCFC power plants, the promise of this fuel cell technology was assessed against the performance and development of the competing technologies normally used for these applications. Coal-fuelled fuel cell power plants will have to face severe competition from advanced pulverised coal and integrated gasification combined cycle (IGCC) power plants, despite their higher electrical efficiency.