The clean energy transition is a pressing global challenge. For a solution we do not only need technological advancement, but also societal change. This transition is more than a change from a brown economy to a green economy. It is embedded in a broader transition from a neoliberal, consumer-oriented regime towards an alternative citizen-focused regime, from a centralized model of the energy market to a decentralized one. It is built on the transformation of passive energy consumers into energy citizens. Civic engagement therefore stands at the core of the clean energy transition. In EC2 we will provide answers on how to facilitate and strengthen energy citizenship, as a means of achieving the EU’s energy and decarbonisation goals. At the core of the project is the empirical, quantitative assessment of energy citizenship and its relation to energy communities. However, this core is embedded within an interdisciplinary theoretical analysis and transdisciplinary co-creation processes. We will also work transdisciplinarily by integrating perspectives and expertise from academia, stakeholders in the energy sector (energy providers, municipalities, distributors, aggregators), energy communities, and citizens. EC2 will gather data from citizens and energy communities across Europe and conduct several co-creation workshops along the different stages of the project in four in-depth regions in the Netherlands, Spain, Italy and Poland, but also in Germany and Austria. The involved citizens will be drawn from diverse socio-economic, socio-cultural and socio-political backgrounds, and vary in gender and age. EC² will translate research into evidence-based innovative actions by co-creating (digital) tools for energy communities, by producing a digital training program, and by supplying actionable policy recommendations and practical advice.