'a valuable resource for scholars, practitioners, and policymakers seeking an informed overview of both established and emerging energy systems. Its interdisciplinary approach makes it particularly suitable for use in graduate-level coursework or as a reference for energy research and planning. The book is a comprehensive and well-structured guide to the modern energy landscape.'Dr Azzeddine AOUNE, PhD, Senior Thermal Design Engineer, Smardt Inc., Canada'The book's multidisciplinary scope covering fossil fuels, renewable systems, hydrogen, and low-temperature technologies provides readers with both a strong theoretical foundation and practical, case-based insights. The writing is clear, academically structured, and suitable for students, professionals, and policymakers alike. Importantly, the manuscript situates technical discussions within the broader context of sustainability and energy transition, making it highly relevant to today's global challenges.'Prof Dr Kareema Al-Shammari, LEMTA (Laboratory of Energies Theoretical and Applied Mechanics), Université de Lorraine, France 'The comprehensive scope of the book, ranging from fossil fuels and renewables to hydrogen and geothermal technologies, ensures that readers acquire both breadth and depth of knowledge. With clear explanations, well-chosen references, and practical insights, this book is positioned to become a key resource in energy science and engineering education. By combining rigorous thermodynamic principles with practical case studies, it bridges the gap between theoretical foundations and real-world applications. The author's multidisciplinary approach makes the text particularly valuable: it speaks equally to students seeking fundamental understanding, to engineers designing advanced systems, and to policymakers shaping the future of sustainable energy infrastructure.'Yerzhan Belyayev, Associate Professor, Al-Farabi Kazakh National University, Kazakhstan'The book covers fossil fuels, renewable energy, hydrogen, and low-temperature technologies, providing a strong theoretical foundation along with practical insights. The author has established a common platform for energy technologies and their applications in modern life by using practical mathematical analysis, case studies, and solved exercises. The references are credible and relevant, and the writing is clear and academically structured, making it suitable for students, professionals, and policymakers. It effectively places technical discussions within the broader context of sustainability and energy transition, addressing today's global challenges. This work will be an essential reference for researchers, engineers, and decision-makers in the energy sector. I strongly endorse it for publication.'Prof Dr Dhamyaa S. Khudhur, Al-Mustansiriyah University, Iraq'The book provides a comprehensive and insightful overview of energy systems, bridging conventional and renewable technologies through a multidisciplinary approach. It effectively integrates thermodynamic fundamentals with practical applications, offering readers a clear understanding of how traditional and clean energy systems coexist and evolve toward sustainability. The author skillfully presents complex concepts in an accessible manner, supported by diagrams, equations, and real-life case studies that highlight the global energy transition. The book's structure makes it suitable for students, engineers, and researchers alike, encouraging critical thinking about the relationships between energy, technology, and environmental responsibility. It is particularly valuable for developing countries seeking to balance energy access with emissions reduction. Overall, this book represents a timely and essential contribution to the field of sustainable energy, combining depth, clarity, and vision. I highly recommend it for anyone committed to advancing understanding and innovation in clean and efficient energy systems.'Dr Mariama Said Mohamed,Consultant in Renewable Energy and Hydrogen Storage, Independent Researcher, Africa