This chapter identifies, from a sociological point of view, the main obstacles and levers for the networking of stakeholders involved in the development of renewable energies and cross-border cooperation within the Upper Rhine Region. This issue can be examined on four levels: (i) The roles and profiles of the key players working in the field of renewable energies: they are all endowed with expertise and belong to professional networks specialised in energy issues. ii) The interactions between these key players: there are different types of possible cooperation between private and public players, from financial backing, administrative and regulatory support, assistance during project development … ; (iii) The regulatory levers and obstacles to the development of RE local projects; and (iv) The specific opportunities and challenges for cross-border cooperation in the Upper Rhine Region, based on the example of the “Zusamme Solar Colmar“ project elaborated between a German (Fesa Energie Geno) and a French citizen energy cooperative (Énergies Partagées en Alsace). From a methodological point of view, the chapter is based on an empirical sociological study conducted in the Upper Rhine Region, between France, Germany and Switzerland. The analysis rests on 11 on-site observations, about a hundred interviews and participatory workshops with different key actors of the energy market.