This book comprises the proceedings of the International Symposium on Sustainable Energy and Power Engineering (SUSE) 2021. The contents of this volume focus on recent technological advances in the field of energy efficiency and green buildings, new construction materials and related technology, hydrogen and renewable energy, environmental aspects of the modern power industry, etc. The contents cover latest advances especially in digital transformation of society and economy of the energy sector, turbomachines and combined plants, intelligent energy systems. This volume will prove a valuable resource for those in academia and industry.