Energy sufficiency is one of the three energy sustainability strategies, next to energy efficiency and renewable energies. We analyse to what extent European governments follow this strategy, by conducting a systematic document analysis of all available European National Energy and Climate Plans (NECPs) and Long-Term Strategies (LTSs). We collect and categorise a total of 230 sufficiency-related policy measures, finding large differences between countries. We find most sufficiency policies in the transport sector, when classifying also modal shift policies to change the service quality of transport as sufficiency policies. Types of sufficiency policy instruments vary considerably from sector to sector, for instance the focus on financial incentives and fiscal instruments in the mobility sector, information in the building sector, and financial incentive/tax instruments in cross-sectoral application. Regulatory instruments currently play a minor role for sufficiency policy in the national energy and climate plans of EU member states. Similar to energy efficiency in recent decades, sufficiency still largely referred to as micro-level individual behaviour change or necessary exogenous trends that will need to take place. It is not treated yet as a genuine field of policy action to provide the necessary framework for enabling societal change.
The concept of sufficiency - reducing energy uses beyond technical efficiency - is far-reaching and requires a reflection on human needs, energy services, urban structures, social norms, and the role of policies to support the shift towards lower-energy societies. In recent years, a growing body of literature has been published on energy sufficiency in various disciplines. However, there has been limited exchanges and cooperation among researchers so far, hindering the visibility and impact of this research. This paper presents an assessment of where sufficiency research stands, especially in the perspective of policy-making. It is the first overview paper issued in the context of the newly-founded ENOUGH network - International network for sufficiency research & policy, established in 2017. In the first part, we provide a condensed literature review on energy sufficiency, based on dozens of recent references collected through the network. Through four main themes (the nature of sufficiency, the challenges of modelling it, the barriers to its diffusion, and the approaches to foster it), we summarise the key issues and approaches. We then present what the scholars themselves see as the priorities for future research, promising sufficiency policy options, and key barriers that research should help overcome. We collected their views through a questionnaire completed by more than 40 knowledgeable authors and experts from various disciplines. We finally build on the previous parts to draw some recommendations on how sufficiency research could increase its impact, notably in relation to policy-making.