Energy use, and its impact on the environment, is one of the most important technical, social, and public-policy issues that face mankind today. There is a great deal of research, and many publications, which address these issues, some of which paint a very pessimistic picture for future generations, while others point to a bright future through the use of new technologies or the implementation of new policies. Although a lot of excellent work is being conducted, much of the research necessarily tends to be quite narrowly discipline-based. Solutions to the problems caused by current patterns of energy use therefore often appear to be somewhat piecemeal in nature, and it is difficult for decision-makers and energy consumers to see the “big picture” which is really needed to understand and design truly sustainable energy processes. This book takes a systems approach to energy use, so that the complete consequences of choosing a particular energy source, or energy conversion system, can be seen. The concept of the complete energy conversion chain, which is a simple but powerful tool for analyzing any energy consuming process, is introduced to link primary energy resources through to the ultimate end-use. Looking at the complete consequences of any proposed energy technology in this way enables the reader to see why some proposed solutions are more sustainable than others, and how the link between energy consumption and greenhouse gas emissions can be broken.