Almost every individual, organisational, and societal activity is linked to, and dependent on, the use of one or more forms of energy. The development of a nation and the quality of life of its population are closely related to the amount and types of energy consumption. In the face of an increasing world population, improving the standard of living in developing countries, and maintaining the levels that have been reached in advanced industrialised countries, will require a considerable increase in the world's use of energy. The challenge is to make this use compatible with sustainability. Providing a broad introduction, this book discusses some of the fundamental considerations associated with energy sustainability. The text is written for advanced undergraduates and first year postgraduates in energy resources, technology and planning and related areas. It should also appeal to the many professionals in industries concerned with energy technology, management and energy systems sustainability. These include specialists in energy project management, energy information systems, systems analysis and simulation of energy systems.