Chapter 12 explores the extension of the input–output framework to more detailed analysis of energy consumption associated with industrial production, including some of the complications that can arise when measuring input–output transactions in physical units of production rather than in monetary terms of the value of production. The chapter reviews early efforts to develop energy input–output analysis and compares them with contemporary approaches and examines the strengths and limitations of the alternatives commonly used today. Special methodological considerations such as adjusting for energy conversion efficiencies are developed along with several illustrative applications, including estimation of the energy costs of goods and services, impacts of new energy technologies, and energy taxes. Energy input–output analysis is increasingly being applied to global scale issues, such as the energy embodied in international trade of goods and services. Finally, the role of structural change of an input–output economy associated with changing patterns of energy use is illustrated, building on the more general approaches developed in Chapter 8.