This book highlights recent advances in energy research. The chapters included in this volume include research on nuclear power reactors, specifically small modular reactors (SMRs) for electricity generation; stakeholder participation in local energy-planning and the possible ways of integrating stakeholder participation in current energy planning practices; a comprehensive review of energy sources, and the development of sustainable technologies to explore these energy sources; the modeling and analysis of a liquefied natural gas (LNG) fired CCHP system, compared to the conventional method of generating useful energy, which is assumed to be a centralized electricity-only power plant; electrospray deposition method for fabricating organic photovoltaic cells; the application of energy-saving, passive strategies in occupied school building spaces; an evaluation of energy consumption in buildings with complex topology equipped with a HVAC system; and an evaluation of solar thermal technologies and applications.