Large-SOFC, Towards a Large SOFC Power Plant

In 2007 the European Technology Platform for Hydrogen and Fuel Cells established a target for installed fuel cell power capacity of 8-16 GW cumulative in 2020. At present the European industry is developing and delivering 250-500 kW molten carbonate fuel cell (MCFC) power plants and small residential polymer electrode (PEFC) as well as solid oxide (SOFC) fuel cell systems. Most of the later have power levels of 1-2 kW electric. 10 GW of these small ones would correspond to 5-10 million units. This is a large number and therefore large units will also be needed to make the number. In Europe there are two companies developing large SOFC systems: Rolls-Royce Fuel Cell Systems (RRFCS) Ltd in UK and a consortium of Wärtsilä in Finland and Topsoe Fuel Cells Ltd (TOFC) in Denmark. Wärtsilä is system integrator and TOFC produce the stacks. The Large-SOFC project, funded by the European Union and the project participants, aims to take forward the developments of small SOFC systems to large systems in the range of hundreds of kW to 1 MW. Two lines of development are pursued. One is the RRFCS pressurised FC/GT hybrid system and the second is the non-pressurised CHP unit by Wärtsilä. Concepts for systems, sub-systems and components are first developed. In a second phase components and sub-systems are developed and their performance verified. The final stage is concept verification with a 50 kW CHP unit constructed by Wärtsilä using 50 kW of planar SOFC stack assembly manufactured by TOFC. The work is supported by the research organisations and industrial partners VTT Technical Research Centre of Finland (VTT), Forschungszentrum Jülich GmbH (FZJ), the University of Genoa (UNIGE), Bosal Research nv, Inmatec Technologies GmbH and The Switch. The work related to the pressurised hybrid system includes the development of test rigs to study system and component both at RRFCS and at UNIGE, experimental and modelling work to study system control, components- and system design. Work is also carried out at Inmatec to find new ceramics and their manufacturing technologies for cells and stacks. Construction of test rigs and testing of potential heat exchanger materials for creep and chemical stability takes place at Bosal The work related to the non-pressurised CHP unit follows a consecutive path from concept design to construction and verification of a 50 kW concept verification unit. It starts with steady state modelling to analyse different concepts in order to find a combination of the best efficiency and lowest component count for cost optimisation. In parallel with that work a dynamic system model is developed in order to simulate the system when ready for concept verification. The next step is to use design tools in combination with component data to do the final design of the 50 kW unit on component level, including drawings. Then the components are found from the market or designed, constructed, and tested in order to get final performance data for the dynamic system modelling. The Switch designs power electronics for grid connection. The stack assembly and the interfaces have already been designed and at present the stacks are being manufactured. By the end of the year the 50 kW unit will be constructed and the first verification measurements made. In addition to the above mentioned activities some supporting work dealing with fuel quality, fuel cleaning, reforming, grid connection, safety standards and life cycle analysis are also undertaken in the project. Dissemination of information and training are undertaken trough workshops and summer schools.