Focusing on a critical aspect of the future clean energy system - renewable fuels - this book will be your complete guide on how these fuels are manufactured, the considerations associated with utilising them, and their real-world applications. Written by experts across the field, the book presents many professional perspectives, providing an in-depth understanding of this crucial topic. Clearly explained and organised into four key parts, this book explores the technical aspects written in an accessible way. First, it discusses the dominant energy conversion approaches and the impact that fuel properties have on system operability. Part II outlines the chemical carrier options available for these conversion devices, including gaseous, liquid, and solid fuels. In the third part, it describes the physics and chemistry of combustion, revealing the issues associated with utilizing these fuels. Finally, Part IV presents real-world case studies, demonstrating the successful pathways towards a net-zero carbon future.