Sustainability refers to the concept that all people should be able to meet their basic needs indefinitely, without compromising future generations. Sustainability, in terms of energy, embraces the same principles. One day the world will run out of fossil fuels. We need to realize how important sustainable energy is and its significance when it comes to the future of our planet. Sustainable energy includes any energy source that cannot be depleted and can remain viable forever. It does not need to be renewed or replenished; sustainable energy meets our demand for energy without any risk of failing or running out. This is why sustainable energy is the answer to our energy needs. Furthermore, sustainable energy doesn’t harm the environment (or at most, there is a minimal risk), increase climate change, or cost a heavy price. Although there is a cost associated with creating and building ways to capture sustainable energy, the energy sources themselves are typically free. The main objective of this book is to provide an up-to-date review of conduction mechanisms, structure construction, operation, performance evaluation, and applications of various renewable energies and fuels. The current trend in innovation is likely to explore the potential to connect novel materials, design methods, and new techniques, which would allow us to maintain existing resources and develop new methods by employing smart technologies. This book provides a complete insight into recent advancements in nanomaterials, renewable energy design, and applications. The purpose of this book is to provide relevant theoretical frameworks that include materials, modeling, circuit design, and the latest developments in experimental work in the field of renewable energy and fuels.