This book delves into the basics of energy conservation as well as its practical applications in a variety of sectors. This book is divided into thirteen chapters, each of which is devoted to a different aspect of energy efficiency and conservation. Everything from the fundamentals of energy to the notion of green energy is covered. In these chapters, we take a look at different innovative technologies that may help us reduce our energy use while still providing us with the comforts we’ve come to expect from our heating systems. The contents of this book include lighting systems and improving its efficiency in many aspects, understanding saving our valuable resources like water systems with purifying and distributing, electrical power has how become very important and understanding its various types, solar energy system, temperature, humidity, pressure in measurement instrumentation & measurement system are very major role in this book. The book provide overview of energy management for going green and developing energy management program; the alternative energy system more green possibilities have geothermal, wind, tidal, biomass power and etc., in the last chapter includes about energy cost reduction concepts. This Book is also useful for the understanding of energy fundamentals, design and applications.