Towards a common intervention framework: A taxonomy of theory and techniques for digital energy behaviour change

Since 2010, a proliferation of digital tools, such as smartphone apps, have been tested to encourage energy-related behaviour change in European research projects. However, there has been little analysis on the intervention design and the alignment with behaviour change theory. The paper proposes a framework for a standardized taxonomy for better cross-comparison and knowledge transfer between projects, and as a tool for design and replication of interventions. The taxonomy is applied to 29 digital tools from EU-funded research projects and identifies the behaviour change techniques employed and the proposed theory-based mechanisms of action driving behaviour change. The analysis finds a wide diversity in the mechanisms of action, with clustering around motivation, intention, knowledge, feedback processes, social influences, beliefs about capabilities, and behavioural regulation. The techniques for behaviour change used in the analysed cases are found to both align to underlying theories of behaviour change, but also deviate from theory, potentially due to context, resources, or personal experience. While it appears that EU funders have an appetite for digital-based interventions for energy behaviour change, there is little consensus on effective design. Looking forward, a more systematic use of techniques in order to evaluate and improve the impact, cost-effectiveness, and longevity of these approaches seems pertinent to capture the potential value of digital tools for behaviour change. • Taxonomy developed to standardize design and learnings of digital energy behaviour interventions. • Taxonomy was mapped onto 29 European energy-related behaviour change intervention cases from 2010 to 2025. • The use of techniques to activate specific behaviour change mechanisms broadly lacked theory-practice alignment. • Inconsistent taxonomy hinders knowledge transfer and effectiveness evaluation between and beyond EU-funded projects.