Based on a comparative method at South European level (France, Italy, Spain, Switzerland) and an approach linking scientific research and project design, this research aims to show how and to which extend the landscape can be a relevant entry in the analysis and design of a "space of energy". Today, the perception of the relations between landscape and energy issues is focused on the potential negative visual impact of infrastructures associated with the use of renewable energy. In this context, the landscape appears above all as an argument that hamper the development of these energies. This work aims to contribute to changing the relation between the landscape and energy issue, showing that the landscape as energy resource can become a driving force behind collaborative projects that respect society, territory and environment in all its dimensions. The question is thus to experiment methods that allows to use the landscape as a mediation tool, that is to say, as a referent that can be shared by the actors of energy policies and the people concerned, by making it accessible for them and allowing them to integrate the complex socio-ecological realities of which the landscapes are the reflection.To provide a basis for this landscape mediation approach, this research aims to build a “lecture énergétique” of the mountain landscapes in the four studied European massifs, that is to say, an update of the relationships between landscape patterns, their changes and their links towards energy resources over the last century. A major interest of the mountains, in this perspective, is that they constitute a space in which the question of values and cultural representations were already very early influenced by the energy issue. The energy issue determined already very early the configuration of the landscape itself, depending on the choices made in this field. The focus of our research will be on hydroelectricity, about which we hypothesize that, from the early twentieth century, it plays a fundamental role in Europe, both in the "mountain tourism development", in the emergency of a call for landscape quality, "landscape conflicts” and landscape policies.The multiplicity of uses now associated to hydropower infrastructures; the many issues (economic, environmental and landscape, and heritage tourism, agriculture ...) linked to the exploitation of hydro-energy resources, make that few aspects of the relation territory / environment are not affected by the hydropower issue. However, they have to be considered in a new context, particularly related to the implementation of the European Directive Framework on water and development plans for renewable energy; context likely to fuel conflicts, but also to renew the foundations of the understanding of the relationship between energy resource, space and territory. Environmental issues and that of sustainable development, which is now required as a preferred viewing angle on the energy issue, embody a call for an overall approach and a reterritorialisation of hydropower issues. It is in this context that the proposed approach makes sense.The project part of the landscape mediation approach is based on operations in progress in each massif, involving known conflicts around uses and perception (renegotiation of dam concessions and hydropower and ecological river development ...). This aspect of the research is the support of an action learning project in which students of the participating schools and universities are involved, allowing an exchange of knowledge and expertise of landscape architects, architects and geographers. At European level it contributes thus to introduce these practices of landscape mediation into the training of landscape designers and geographers - that is to say, to construct, by inviting students to participate , landscape approaches based on a controlled and thoughtful articulation of the position of the researcher and the point of view of the designer / developer.