A grassroots sustainable energy niche? Reflections on community energy case studies

System changing innovations for sustainability transitions are proposed to emerge in radical innovative niches. ‘Strategic Niche Management’ theory predicts that niche level actors and networks will aggregate learning from local projects, distilling and disseminating best practice. This should lower the bar for new projects to form and establish, thereby encouraging the innovation to diffuse through replication. Within this literature, grassroots innovations emerging from civil society are an under researched site of sociotechnical innovation for sustainable energy transitions. We consider the emerging community energy sector in the UK, in order to empirically test this model. Community energy is a diverse grassroots led sector including both demand and supply side initiatives for sustainable energy such as community owned renewable energy generation, village hall refurbishments, behaviour change initiatives and energy efficiency projects. Our analysis draws on in depth qualitative case study research with twelve local projects, and a study of how intermediary organisations aim to support local projects and encourage replication. This rich data allows us to examine the extent and nature of interactions between projects and intermediary actors in order to evaluate the utility of niche theories in the civil society context. In particular, we investigate which types of knowledge, support and resources were needed by our case study projects to become established and thrive, and compare and contrast this with those offered by the emerging community energy niche. Our findings indicate that while networking and intermediary organisations can effectively collate and spread some types of learning and information necessary for replication, this is not sufficient: tacit knowledge, trust and confidence are essential to these projects’ success, but are more difficult to abstract and translate to new settings. We draw out the implications of our findings for niche theory, for community energy and other grassroots practitioners aiming to build robust influential niches, and for policymakers eager to harness civil society’s innovative potential for sustainability.