Kosmas A. Kavadias, Ph.D., MSc, Mechanical Engineer, is an Associate Professor in the Energy Sector in the Department of Mechanical Engineering at the University of West Attica. His research interests, experience, and expertise include the design and optimization of solar energy systems, optimization of hybrid energy systems, design of RES-based hybrid energy systems, evaluation of energy storage systems, optimum management of autonomous energy systems, and building integrated renewable energy systems, energy savings in buildings, and industry. He has 20 years of experience teaching courses on renewable energy sources, hybrid energy systems, building energy improvement, and energy saving for undergraduate and postgraduate students. He is the author and co-author of more than 30 papers in International peer-reviewed Journals and more than 100 papers in National and International conferences. He is also a co-author of three books concerning Renewable Energy Sources and he has also contributed a chapter in the books entitled “Stand-Alone and Hybrid Wind Energy Systems”, published by Woodhead Publishing Ltd., “Comprehensive Renewable Energy”, published by Elsevier B.V., and “Advanced Power Engineering” published by CRC Press Taylor & Francis Group.