Prof John (Ioannis) K. Kaldellis: PhD, Mechanical Engineer (National Technical University of Athens), Business Administration Diploma (University of Piraeus). He obtained his PhD in 1988 from NTUA sponsored by Snecma–Dassault, France and Bodosssakis Foundation, Greece. Since 1993, Professor at Mechanical Engineering Department, University of West Attica (UNIWA, former TEI of Piraeus), Director of the Soft Energy Applications & Environmental Protection Laboratory and Scientific Director of MSc in Energy Systems (collaboration with Heriot-Watt University) and Deputy Director of MSc in Energy and Environmental Investments and of MSc in Oil and Gas Process Systems Engineering. Since September 2019, he has been elected as Vice-Rector of University of West Attica, responsible for Research and Lifelong Education. Since November 2020 is Vice President of Sectorial Scientific Council for Energy, Environment & Sustainable Mobility, General Secretariat for Research and Innovation, Ministry of Development. His research interests include feasibility analysis of energy sector applications and projects, technological progress in wind, hydro and solar energy market, hybrid energy systems, energy storage issues, social attitude towards renewable energy applications and environmental technology-air pollution. In this context he has been the Scientific Responsible and/or member of the Research Team for many (more than 60) international and national research projects. Prof Kaldellis has published six books concerning Renewable Energy Applications (4) and Protection of the Environment (2). On top of these, he is the Editor of the book entitled “Stand-alone and hybrid wind energy systems: Technology, energy storage and applications” and he is also the Editor of the “Wind Energy” Volume of the Comprehensive Renewable Energy Encyclopaedia by Elsevier (1st edition 2012 with 21 Chapters and 2nd edition 2022 with 25 Chapters). He is currently Subject Editor of the Renewable Energy International Journal (IF=8+), member of the Editorial Board of several International Journals (Applied Energy (IF=8+), Sustainability (IF=2.5), etc.) and reviewer in more than 60 International Journals in the Energy and Environment Sector. He is the author of more than 180 scientific papers in peer reviewed Journals and more than 520 papers in Scientific Conferences and has more than 6000 citations in his research work (h-index (Scopus) -48). According to the 2020 Jeroen Baas (Elsevier, B.V.), Kevin Boyack (SciTech Strategies, USA) & John P.A. Ioannidis (Stanford) annual (2020) list he belongs to the top 1% of most cited researchers and ranks amongst the world’s top 200 (and 2nd in Greece) researchers in the Energy Sector. Since 2015, he is the Scientific Responsible of the well-recognized TILOS-Horizon 2020 research program.