energies Review Closing the Energy Efﬁciency Gap—A Systematic Review of Empirical Articles on Drivers to Energy Efﬁciency in Manufacturing Firms Mette Talseth Solnørdal * ID and Lene Foss School of Business and Economics, UiT The Arctic University of Norway, Pb 6050 Langnes, 9037 Tromsø, Norway; lene.foss@uit.no * Correspondence: mette.solnordal@uit.no; Tel.: +47-77-64-6016 Received: 7 February 2018; Accepted: 26 February 2018; Published: 28 February 2018 Abstract: Research has identiﬁed an extensive potential for energy efﬁciency within the manufacturing sector, which is responsible for a substantial share of global energy consumption and greenhouse gas emissions. The purpose of this study is to enhance the knowledge of vital drivers for energy efﬁciency in this sector by providing a critical and systematic review of the empirical literature on drivers to energy efﬁciency in manufacturing ﬁrms at the ﬁrm level. The systematic literature review (SLR) is based on peer-reviewed articles published between 1998 and 2016. The ﬁndings reveal that organizational and economic drivers are, from the ﬁrms’ perspective, the most prominent stimulus for energy efﬁciency and that they consider policy instruments and market drivers to be less important. Secondly, ﬁrm size has a positive effect on the ﬁrms’ energy efﬁciency, while the literature is inconclusive considering sectorial impact. Third, the studies are mainly conducted in the US and Western European countries, despite the fact that future increase in energy demand is expected outside these regions. These ﬁndings imply a potential mismatch between energy policy-makers’ and ﬁrm mangers’ understanding of which factors are most important for achieving increased energy efﬁciency in manufacturing ﬁrms. Energy policies should target the stimulation of management, competence, and organizational structure in addition to the provision of economic incentives. Further understanding about which and how internal resources, organizational capabilities, and management practices impact energy efﬁciency in manufacturing ﬁrms is needed. Future energy efﬁciency scholars should advance our theoretical understanding of the relationship between energy efﬁciency improvements in ﬁrms, the related change processes, and the drivers that affect these processes. Keywords: energy efﬁciency; drivers; manufacturing sector; systematic literature review; ﬁrm-level analysis 1. Introduction Climate change is one of the most imperative topics of the 21st century. It challenges the very structure of our global society, and encompasses issues such as economics, politics, business management, and individual choice of lifestyle. The commonly acknowledged relationship between energy consumption, emissions of greenhouses gases (GHG), and climate change [1] has brought energy efﬁciency into political agendas worldwide [2,3]. Energy efﬁciency is the use of technologies that require less energy to perform the same function [4]. The manufacturing sector accounts for about 50% of the world’s energy use [1]. Industrial energy efﬁciency is thus a key factor for mitigating climate change. Moreover, reduced energy costs are crucial for industrial companies in maintaining a competitive advantage [5,6]. Increased energy efﬁciency can arrive from technological improvements [7], improved supply chain management [8], and the implementation of environmental management systems (EMS) [9], environmental regulation [10], and economic motives [6]. Energies 2018, 11, 518; doi:10.3390/en11030518 www.mdpi.com/journal/energies