Project description: COMETS aims to fill the knowledge and participatory gaps surrounding the low carbon energy system transition to ensure citizens are at the center of the transformation and empower their creative potential. COMETS will advance the scientific knowledge on the motives, potential, objectives and barriers of socially innovative Collective Action Initiatives (CAIs) and their historical and future role in the energy transition. This will be achieved by quantifying the European-wide aggregate contribution of CAIs (e.g. energy communities, cooperatives, purchasing groups) to the energy transition at national and European levels. The information gathered and tested throughout the project will help to co-develop and test supportive tools together with CAI members, policy makers and the scientific community. These stakeholders will then be able to exploit the main outputs of COMETS in order to mobilize people and to guarantee acceptance for and participation in the energy transition process.