This chapter analyses a very specific kind of renewable energy participatory projects in France: co-developed citizen, public, and private partnership projects. From an institutional economics perspective, they represent a structural change in the energy sector that shows promise in encouraging the ecological transition through energy democracy. This chapter highlights findings from an empirical investigation that drew on several analytical frameworks useful for understanding these still marginal social innovation practices, which are in the process of being institutionalized. First, co-developed citizen, public, and private partnership projects are defined as emerging participatory renewable energy projects. It then analyses how institutional changes create a context favourable to their spread. It examines what distinguishes them from other projects in the renewable energy sector, comparing them to participatory projects more generally. It concludes by describing certain tensions arising from the heterogeneous nature of the partners and explains how the partners attempt to compromise to make the project succeed.