This book presents selected papers from ICOWEFS 2024, addressing contemporary energy challenges. Topics range from energy and urban-industrial systems to governance issues, emphasizing the transformative potential of circular economy frameworks and the decarbonization imperative. It showcases innovative technologies, including energy-saving solutions, biofuels, and waste biorefining, paving the way toward sustainable energy systems. Readers will gain insights into smart technologies and the rise of hybrid local energy generation in this exploration of Energy 4.0's paradigm-shifting landscape.