The U.S. industrial sector accounts for the largest share of energy consumption in the country, and energy efficiency improvements in this sector can significantly reduce the nation's demand for energy. Fortunately, the industrial sector has shown steady progress in improving energy efficiency over the past few decades, and energy efficiency improvements are expected to continue. There are barriers, however, that impede the adoption of energy efficient technologies and practices in the industrial sector. This book and the accompanying study examine those barriers and identify successful examples and opportunities to overcome them. Three groups of energy efficiency technologies and measures were examined: industrial end-use energy efficiency, industrial demand response, and industrial combined heat and power.