The text provides in-depth knowledge about recent advances in solar collector system, photovoltaic system, role of thermal energy systems in buildings, phase change materials, geothermal energy, biofuels, thermal management systems for EV in social and industrial applications. It further aims toward the inclusion of innovation and implementation of strategies for CO2 emission reduction through the reduction of energy consumption using conventional sources. This book: Presents the latest advances in the field of thermal energy storage, solar energy development, geothermal energy, and hybrid energy applications for green development. Highlights the importance of innovation and implementation of strategies for CO2 emission reduction through the reduction of energy consumption using sustainable technologies and methods. Discusses design development, life cycle assessment, modeling, and simulation of thermal energy systems in detail. Synergize exploration related to the various properties and functionalities through extensive theoretical and numerical modeling present in the energy sector. Explores opportunities, challenges, future perspectives, and approaches toward gaining sustainability through renewable energy resources. The text discusses the fundamentals of thermal energy and its applications in a comprehensive manner. It further covers advancements in solar thermal, and photovoltaic systems. The text highlights the contribution of geothermal energy conversion systems to sustainable development. It showcases the design and optimization of ground source heat pumps for space conditioning and presents modeling and simulation of the thermal energy systems for design optimization. It will serve as an ideal reference text for senior undergraduate, graduate students, and academic researchers in the fields including mechanical engineering, environmental engineering, and energy engineering.