This paper reports on research being conducted as part of the H2020 ENTRUST project, an interdisciplinary research project exploring the human factor in the energy system. The challenges of climate change and finite fossil fuel resources mean that the current energy paradigm is unsustainable, and such challenges are important drivers of the transition to a more sustainable, low-carbon energy system. Many contributions at envisioning this low-carbon energy future focus on technology to the exclusion of human and societal aspects, however the sustainable energy transition required for this decarbonisation cannot be achieved without the involvement of communities. This paper describes research which seeks to engage and empower citizens to become active participants in shaping their sustainable energy future. The research explores how human behaviour around energy is shaped by both technical and socio-demographic factors, including in particular: age, gender, and socio-economic status. An intersectional approach is being taken to explore how multiple identities and social positions combine to shape energy-related practices and attitudes. In order to explore the socio-technical issues involve, six varied communities in five different European countries are being engaged: an Irish rural community; a cohort of university students; residents of an eco-village in a large French city; the urban customer base of a Spanish utility company; a disadvantaged suburban neighbourhood in the UK; and the residents of an Italian port town. These communities provide a diverse range of socio-demographic characteristics, life experiences, and policy contexts. As such, they provide great insight into the different obstacles faced by communities to transition to a more sustainable energy system. This paper will look at how and why the communities were chosen and the value they bring to the research. It will detail the participatory research methods being undertaken