This book quantifies the potential for increased energy efficiency in industry through technology- and sector-specific analyses. Starting from the methodological foundations, the first part discusses electricity- and heat-based core technologies and cross-sectional processes using numerous practical examples. In addition to classic topics such as lighting and heat recovery, it also addresses previously less considered processes like drying and coating. The second part is dedicated to energy-intensive industries, particularly metal production and processing, the manufacturing of non-metallic materials such as cement and glass, as well as the chemical, paper, plastics, and food industries. Both parts are ultimately placed in a broader energy and economic context. The findings are frequently presented as checklists.