Owing to its strategic nature, the Spanish energy policy is primarily the responsibility of the central state. In spite of this, the Spanish legal code does in fact also confer certain powers to territorial governments in Spain, the Autonomous Communities. The objective of this work is specifically to investigate the differences between the energy performance of Spanish regions, which may be a consequence of specific features of their productive structures and resource endowments, in addition to the specific decisions adopted by each of them within the scope for action that they have in this area. With this aim in mind, we intend to calculate the inefficiency levels of Spanish regions as regards their use of various energy sources during the period 2003-2008, by estimating an environmental directional distance function. The results obtained confirm the existence of significant differences in the behaviour and evolution of regional energy efficiency and point to the need to pay more attention to energy planning in this territorial sphere. (C) 2016 Elsevier Ltd. All rights reserved.