The energy resources other than fossil fuels and traditional sources of energy are known as alternative sources of energy. This energy is naturally replenished on a human timescale. Unlike fossil fuels, this energy can be rapidly deployed which results in energy security, economic benefits and mitigating climate change. Solar energy, geothermal energy, hydropower and wind energy are some of the common forms of alternative energy. This field finds application in primarily four areas. These are air and water heating/cooling, electricity generation, transportation, and rural energy. Another important type of alternative energy is bioenergy. Alternative energy aims to reduce carbon emissions, lower pollution and conserve water. Different approaches, evaluations and methodologies and advanced studies on renewable energy have been included in this book. The book also studies, analyses and upholds the pillars of alternative energy and its utmost significance in modern times. Those in search of information to further their knowledge will be greatly assisted by this book.