Regional energy and environmental efficiency measurement is a noteworthy research topic regarding regional development. Data Envelopment Analysis is a suitable technique in the studies of energy and environmental efficiency. This study investigates the efficiency and total-factor energy efficiency scores of the manufacturing industry in 26 regions of Turkey between the years 2003 and 2012, using four data envelopment analysis models supported by a total-factor framework. The first and the second models are based on absence and presence of undesirable outputs, respectively; the third model and the proposed new model aims to maximize energy saving potential considering undesirable outputs. The empirical results show that TR10-Istanbul region is the best performer and acts as a model for inefficient regions with its production composition. Total electricity saving potential is investigated per each region and for the manufacturing industry per each year between years 2003-2012. It is observed that Turkish manufacturing industry has an average electricity saving potential of 39.7%, which reaches its highest in 2004 and lowest in 2012. Another important finding of this study is the existence of a U-shaped relationship between gross value added per capita as regional development indicator and efficiency as well as total-factor energy efficiency index. (C) 2015 Elsevier Ltd. All rights reserved.