Professor Detlef Stolten is head of the Institute for Techno-Economic Systems Analysis (IEK-3) at the Forschungszentrum Jülich, and has held the Chair for Fuel Cells at RWTH Aachen University since 2000. He spent 12 years in private industry at Bosch and Daimler Benz/Dornier, respectively. Amongst other positions, he is Chairman of the Executive Committee of the Technology Collaboration Program, ‘Advanced Fuel Cells,’ of the International Energy Agency (IEA) and Vice President of the International Association of Hydrogen Energy (IAHE). After many years of research in the field of electrochemistry and process engineering for different types of fuel cells and electrolyzers, his focus is now on techno-economic energy system analysis and strategies for facilitating the transformation of the energy system.