This report presents the business case for investment in manufacturing sector energy efficiency. In order to provide practical and actionable information for policymakers, manufacturers, and related stakeholders, we focus on energy efficiency opportunities in Midwest pulp and paper mills. As the U.S. region with the largest industry share of overall economic activity, the Midwest is of central importance for industrial energy efficiency and forging a new low-carbon economy. Pulp and paper manufacturing is the third-largest energy-using manufacturing subsector in the U.S. Energy cost reduction, improved competitiveness, and reduced environmental compliance costs provide a compelling business case for Midwest pulp and paper mills to invest in facility-appropriate energy efficiency improvements, as well as energy management programs. The report uses mill-level data to assess the energy efficiency of Midwest pulp and paper manufacturing and presents technology and policy options for increasing regional energy productivity.