Which energy users are hard-to-reach? Identification and characterization of key audiences to foster a just energy transition

Climate change and energy poverty are crucial challenges for energy transitions. Hard-to-reach energy users are defined as any residential/non-residential users who are typically not engaged in energy-related interventions. Five groups have been highlighted: vulnerable households, high-income households, renters, commercial, and small and medium enterprises. Nevertheless, key gaps persist in their identification and engagement, and, to our knowledge, the concept has been seldom quantitatively explored in developed countries. Building on previous work, existing literature, and socioeconomic indicators, this research aims are three-fold: to identify/systematize distinct hard-to-reach audiences in Portugal as a case-study, to characterize specific barriers to audience engagement, and to combine the frameworks of hard-to-reach and energy justice for policy insights. In total, 15 potential hard-to-reach profiles are described together with their barriers to participation in energy issues. The analysis of national-scale data suggests that more than half of Portuguese households and up to 96% of businesses may be hard-to-reach with traditional top-down approaches; these estimates may be exacerbated by vulnerability intersectionality. Exploring the hard-to-reach concept through energy justice lens can serve as a decision-making tool that evaluates the effects of policies on distinct audiences. Future research will develop a local-scale support framework for hard-to-reach profiles to foster just transitions.