Dr. Orhan Ekren is Assoc.Prof. in the Solar Energy Institute at Ege University. He received the M.Sc. degree from the Department of Energy Engineering, Izmir Institute of Technology, Turkey, and Ph.D. degree from the Department of Mechanical Engineering(Thermodynamics), Turkey. He has been working at Ege University with the 15 years of work experience. He studied as a Postdoc researcher in Southern Illinois University, USA as well. His main research interests are energy efficiency, energy saving, capacity modulation on refrigeration and HVAC&R systems, renewable heating and cooling, magnetic cooling, integration of renewable energy systems into buildings, optimum sizing of hybrid renewable energy sources(wind/solar etc.), also sustainability in energy and buildings. Dr. Ekren has authored and co-authored 25 international journal papers, 25 international conference papers, 5 books and book chapters and also 2 utility models on efficient operation of HVAC&R systems. Therefore, system design and experimental tests and demo studies are in my research scope. He has currently involved several research project funded by national research council (TUBITAK) and EC-FP7 project (ECOSHOPPING).