The research work of Forschungszentrum Julich covers many areas ranging from materials development over manufacturing of cells, stack design, mechanical and electrochemical characterization, to systems design and demonstration, always supported by feedback from post-test characterization. Optimized anode supported cells with two different cathode materials have been standardized with a maximum power density of more than 4 A cm(-2) (extrapolated) at 800 degrees C and 0.7 V with hydrogen/air. The use of improved steels, cathodes, contact and protective layers as well as optimized materials processing have resulted in a significant reduction of the voltage degradation rate to about 0.1% per 1000 h at 700 degrees C demonstrated in an ongoing test for a short stack, which has reached more than 15,000 h of operation. In addition, the benchmark stack of the Real SOFC project has concluded 40,000 h at the beginning of March 2012, and is still in operation. This behavior has to be verified for larger stacks with cells of a size of 20 x 20 cm(2) with most emphasis on design optimization and reduced internal thermo-mechanical stress to ensure gas tight operation. This was shown for four 5 kW stacks to be integrated into a 20 kW system. (C) 2013 Elsevier B.V. All rights reserved.