**Summary:** *Principles of Solar Engineering, Fourth Edition* by D. Yogi Goswami provides an updated and comprehensive overview of solar energy technologies, including photovoltaics, solar thermal systems, energy storage, and applications in heating, cooling, and desalination. The book addresses the growing need for solar resource assessment and highlights advancements in solar technologies, such as organic, dye-sensitized, and perovskite solar cells, as well as concentrating solar power (CSP) with supercritical CO₂ cycles. It also covers battery storage, thermal energy storage, and the economic analysis of solar energy systems. Key features include new forecasting models for solar radiation, expanded coverage of high-temperature thermal storage for CSP, a new chapter on solar seawater desalination, and updated end-of-chapter problems. The book is intended for senior undergraduate and graduate students in energy engineering and solar energy courses. It includes a solutions manual for instructors and is supported by online resources. The book discusses the global energy situation, the role of renewable energy in achieving net-zero carbon emissions, and the importance of solar energy in the transition to a sustainable future. It covers solar radiation fundamentals, solar thermal collectors, energy storage and transport, solar heating and industrial process heat, solar cooling and dehumidification, passive solar heating and cooling, and solar thermal power systems. It also includes chapters on photovoltaics, solar photochemical applications, and solar desalination. The book emphasizes the importance of solar energy in addressing global energy needs, with a focus on its potential to provide clean, renewable energy. It discusses the economic and technical aspects of solar energy systems, including the design of solar power plants, the use of solar energy for heating and cooling, and the application of solar energy in industrial processes. The book also highlights the role of solar energy in reducing carbon emissions and the need for energy storage solutions to address the intermittency of solar power. It provides a detailed analysis of various solar technologies and their applications, making it a valuable resource for students, researchers, and professionals in the field of solar energy.**Summary:** *Principles of Solar Engineering, Fourth Edition* by D. Yogi Goswami provides an updated and comprehensive overview of solar energy technologies, including photovoltaics, solar thermal systems, energy storage, and applications in heating, cooling, and desalination. The book addresses the growing need for solar resource assessment and highlights advancements in solar technologies, such as organic, dye-sensitized, and perovskite solar cells, as well as concentrating solar power (CSP) with supercritical CO₂ cycles. It also covers battery storage, thermal energy storage, and the economic analysis of solar energy systems. Key features include new forecasting models for solar radiation, expanded coverage of high-temperature thermal storage for CSP, a new chapter on solar seawater desalination, and updated end-of-chapter problems. The book is intended for senior undergraduate and graduate students in energy engineering and solar energy courses. It includes a solutions manual for instructors and is supported by online resources. The book discusses the global energy situation, the role of renewable energy in achieving net-zero carbon emissions, and the importance of solar energy in the transition to a sustainable future. It covers solar radiation fundamentals, solar thermal collectors, energy storage and transport, solar heating and industrial process heat, solar cooling and dehumidification, passive solar heating and cooling, and solar thermal power systems. It also includes chapters on photovoltaics, solar photochemical applications, and solar desalination. The book emphasizes the importance of solar energy in addressing global energy needs, with a focus on its potential to provide clean, renewable energy. It discusses the economic and technical aspects of solar energy systems, including the design of solar power plants, the use of solar energy for heating and cooling, and the application of solar energy in industrial processes. The book also highlights the role of solar energy in reducing carbon emissions and the need for energy storage solutions to address the intermittency of solar power. It provides a detailed analysis of various solar technologies and their applications, making it a valuable resource for students, researchers, and professionals in the field of solar energy.