In this study, LBNL analyzes the current size of the Energy Service Company (ESCO) industry, industry growth projections to 2011, and market trends in order to provide policymakers with a more indepth understanding of energy efficiency activity among private sector firms. We draw heavily on information from interviews with ESCOs conducted from October 2009 to February 2010 and from our review of publicly available financial information regarding individual ESCOs. A significant ramp-up in energy efficiency activities is occurring at the local, state, and federal level. These activities include the establishment in (approx)18 states of statewide energy savings goals to be obtained from adoption of an Energy Efficiency Resource Standard (EERS), legislative or state regulatory directives to obtain all cost-effective demand-side resources (Barbose et al 2009), and a significant increase in federal funding for energy efficiency programs as part of the American Recovery and Reinvestment Act (ARRA). As part of this increased focus on energy efficiency, policymakers are evaluating the role of private sector companies, including ESCOs, in delivering cost-effective energy savings to end-users. The U.S. ESCO industry has long been recognized for its role in successfully delivering comprehensive energy projects in the public sector. This study analyzes the current size of the ESCO industry, industry growth projections, and market trends in order to provide policymakers with a more in-depth understanding of energy efficiency activity among private sector firms. This study may also be of interest to policymakers abroad who are exploring options to encourage development of a private-sector energy services industry in their own countries. This study draws heavily on information from interviews with ESCOs conducted from October 2009 to February 2010 and is part of a series of ESCO industry reports prepared by Lawrence Berkeley National Laboratory (LBNL) in collaboration with the National Association of Energy Services Companies (NAESCO). The analysis builds on previous ESCO industry reports (see Goldman et al. 2005 and Hopper et al. 2007) and provides updated estimates of ESCO industry revenues and ESCO views on perceived trends in costs and savings.