Sotirios Karellas is an Associate Professor at the School of Mechanical Engineering of National Technical University of Athens (NTUA), visiting Professor at the Technische Universität München and at the Universität Bayreuth in Germany, specialist on energy systems, energy storage, solar-thermal energy, biomass, ORC technology, decentralized energy systems, heat pumps, and tri-generation systems. He has over 100 relevant publications in scientific Journals and Conferences. He is currently supervising 6 Ph.D. students at NTUA working in the field of energy production/conversion. He has participated in a high number of projects in NTUA (2006-present) and in Technische Universität München (2001-2006), having both technical and coordination responsibilities. He has significant industrial experience in power production plants, co/tri-generation systems, heat pumps and chillers. He is full member of the editorial board of 5 scientific journals dealing with energy systems and renewable energy sources. Tryfon C. Roumpedakis is a M.Sc. Mechanical Engineer. He graduated from the School of Mechanical Engineering of the National Technical University of Athens, Greece, in 2014. In 2016 completed his Master studies in Power Production and Management, in School of Electrical Engineering of National Technical University of Athens. At the time, is on due to pursue his second master degree in Mechanical Engineering (specialization of Sustainable Processes and Energy Technologies) in TU Delft, Netherlands. During 2014-2015 he had been working in the laboratory of Steam Boilers and Thermal Plants of the National Technical University of Athens as a research engineer, where at the moment is collaborating as an external associate in projects relevant to his specialization. His main fields of expertise are Organic Rankine Cycle and Refrigeration technologies. Nikolaos Tzouganatos received his M.Eng. degree from the Dept. of Mechanical Engineering of the National Technical University of Athens in 2010 and his M.Sc. degree in Energy Science & Technology from ETH Zurich in 2012. In October 2016, he received his Ph.D. degree from the Dept. of Mechanical and Process Engineering of ETH Zurich. He performed his doctoral research at the Solar Technology Laboratory of the Paul Scherrer Institute, Switzerland in the field of solar thermochemistry and, particularly, on solar reactor development for zinc recycling and other metallurgical processes. Part of his work has been performed in close collaboration with the Commonwealth Scientific & Industrial Research Organisation (CSIRO) during his research visit at the National Solar Energy Centre in Newcastle, Australia in 2014.
