Association for Public Policy Analysis & Management

Whether energy efficiency retrofits save energy in the field is an ongoing debate. Accurately estimating the empirical savings of retrofits is important to policymakers and building owners. This paper quantifies the energy savings of retrofits of commercial and residential buildings in the large publicly funded Energize Phoenix program in Phoenix, Arizona (2010-2013). There were six types of retrofits for commercial buildings and five types for residential buildings. Impacts of energy retrofits are analyzed using before-and-after treatment billing data from January 2008 to April 2013, including 201 residential buildings and 636 commercial buildings, with 45,916 observations in total. We apply fixed effects panel regression which utilizes both the variation in the types of treatments and the timing of the treatments, and employ a robustness check using flexible fixed effects. The overall treatment resulted in energy savings of 14071.3 kWh per month (12.1%) for commercial buildings and 89.4 kWh per month (7.6%) for residential buildings. We also disentangle the energy savings provided by each of the individual retrofits. Building type and attributes do impact the efficacy of individual retrofits. The heterogeneity in the effectiveness of different energy retrofits for different types of buildings should be considered when making energy efficiency decisions.