For an equitable transition towards a decentralized and clean energy future, the involvement and active participation of citizens is needed, exemplified by new organizational forms such as Energy Communities (ECs). While determinants of citizen engagement in renewable energy projects have received some attention in the literature, research mostly focuses on continental Europe, with limited understanding of the perceptions and motivations of citizens living in the Global South or in contexts of poverty and marginalization. Using novel survey data (n = 392) and insights from 16 key informant interviews from the French overseas territory Mayotte, we investigate citizens' perception of renewable energies and ECs and their willingness to participate in such initiatives, confirming high support of the local population for a community-based energy transition. Through exploratory factor analysis and subsequent multivariate regressions, we identify the factors Environmental Awareness, Access to Services and Social Inclusion as important determinants of citizen engagement, with Environmental Awareness exhibiting particularly strong and robust effects on both general support and the willingness to actively participate in an EC. Establishing the housing situation of respondents as a proxy for socio-economic status (SES), we find positive effects of SES on EC support, which is mediated by the identified factors and thereby represents a fourth, underlying determinant of support. Our research underscores the vital importance of considering the multifaceted, diverse perceptions and motivations of the local population to achieve the vision of an equitable transition. Inclusion of needs and priorities of various socio-economic groups, particularly the most vulnerable community members, is essential.