The general objective stated for this project was the development of industrially relevant MCFC stacks that would contribute towards commercialisation phase of power plant based on Molten Carbonate Fuel Cell. Starting from the analysis of the critical problems experienced by the Contractors in developing M.C.F.C technology in previous and parallel projects, and after having defined improvements needed for materials and stack design, aimed to reduce costs and to improve performances, the activities of the projects were focused on the following areas: -Development of new stack design solutions and improved stack components, aimed to extend stack life and to reduce stack costs, followed by manufacturing, assembling and testing of 3 M.C.F.C. Stacks incorporating the improved materials and components. -Basic researches aimed to develop new cathode and manifold seal materials, and to improve fuel processing and impurity tolerability in M.C.F.C power plants. -Experimental validation of these new materials and components, through M.C.F.C single cell tests and dedicated test rigs experiments. -Cost analysis for M.C.F.C stacks and power plants components. Very important results have been obtained by developing the project activities. About the modification adopted for cell configuration and for stack design, and tested both in single cell and full-area stacks, significant improvements have been obtained, also in terms of lifetime and performances. A significant effort has been devoted within the project also to improve performances and characteristics of materials for cell and stack components. A simplification and optimisation of assembly procedures for the full-area stack has also been obtained. In fact some of the modification introduced into the design of the full-area stack STAD-3 were also aimed to simplify the assembly operation and to reduce the assembly time. The analysis concerning the M.C.F.C power plants configuration and base unit sizing, based also on the results of full area stack tests, takes into account and gave rise to the following considerations and results: -The power generation market, as a consequence of the deregulation process, is expected to shift away form large, central power plants, to smaller, more distributes ones. Small additions to the grid may better meet local needs, including cogeneration, with lower risks and capital investments than a very large plant: -The well-known fuel cell modularity permits to easily multiply the power of the selected base unit thus allowing covering for the upper part of the expected market with several standard units suitably arranged. -The capacity of fuel cells of maintaining good efficiencies also at part load allows operation up to about 40% of the rated power. On these basis, it has been identified a rated power in the class of 500 kW which is expected to allow efficient operation in a wide range of power from about 200 kW to several MW (several units in parallel). Therefore this will be the size of the planned firs-of-the-kind unit which will be constituted by two modules 250 kW each based on the original configuration “TWINSTACK”.