Abstract:
Energy lies at the heart of urgent transformations. Climate change and energy poverty are uttered global priorities. However, despite well-known solutions, energy transitions are not yet at the needed pace. Citizens have been pushed to the frontline with high hopes for their uptake of energy efficiency and renewable energy. Still, multi-faceted barriers stand in the way of participation. These are particularly stark for hard-to-reach energy users which can be broadly defined as those who are difficult to reach or hard to engage or motivate by policies and interventions. While this concept has attracted attention, it still lacks systematisation and operationalisation. Moreover, how to activate hard-to-reach groups remains a key research gap. Without faster, deeper, and broader adoption of energy efficiency and renewable energy, and more effective citizen engagement, energy transitions will remain off track.
In this context, this research has the goal of increasing knowledge on how to engage hard-to-reach energy users in just energy transitions. First, it systematises and characterises profiles that may be classified as hard-to-reach and estimates their size at multiple scales from the European to the national and local levels. Second, it operationalises the concept for the ex-ante assessment of energy policies and for the ex-post evaluation of on-the-ground projects. Third, action research is applied to three case-studies in Portugal, namely a digital one-stop shop for home renovation, a physical energy support one-stop shop, and a renewable energy community, for a closer look on approaches that seek to activate hard-to-reach groups. Fourth, recognising their common but ambiguous presence, it engages with local organisations to critically assess their roles as middle actors in energy transitions.
This research shows that hard-to-reach groups are significant at multiple scales, highlighting, for instance, low-income households, multi-family buildings, people with ill-health and disabilities, tenants, and micro-enterprises. It demonstrates that intersectionality compounds vulnerabilities and that variations exist across nations and regions. Data gaps are found for the most marginalised and the wealthiest profiles. This work argues that policymakers can still do much more to recognise hard-to-reach groups and to deploy targeted and tailored measures. Local action seems more effective at engaging hard-to-reach audiences, for instance, through trusted messengers, but has limitations on impact assessment and persistency.
Digital platforms can be useful tools in the energy transition toolbox but do not address hard-to-reach groups. Instead, greater potential is found in local actions; for instance, one-stop shops can deploy face-to-face support and energy communities can produce and share solar power. Local stakeholders can play diverse roles, such as communicating with vulnerable households. However, many organisations face challenges and, if successful partnerships are to be established, dedicated funding and capacity building are a must. Local action relies heavily on the efforts of dedicated individuals and organisations, making their sustainability, upscaling, and replication challenging without stronger institutional backing at all levels of government.
Finally, this research's outputs are useful for policymakers, researchers, and practitioners working on energy transitions at multiple scales. A more sustainable, just, and democratic energy system is within reach, but it requires unprecedented commitment by all actors.

Supervision: Dr. João Pedro Gouveia, Dr. João Joanaz de Melo