The actual transition to non-carbon energies is changing our territories. Energy and the territory are in fact strictly linked, since production, transportation, consumption of energy happen in the space and heavily influence landscape transformation. Nevertheless on one side energy policies did not adopt any territorial approach in designing this transition, and on the other side landscape policies and planning rarely include energy dimension. There is then a need of bridging the gap between energy and the territory. This can be done developing research at the crossroads of landscapes and energies (Nadai and Van den Horst, 2010). This article presents some results of the international research “Ressources paysagères et ressources énergétiques dans les montagnes sud-européennes. Histoire, comparaison, expérimentation » (Landscape resources and energy resources on the south European mountains. History, comparison, experiments), that worked on the landscapes of hydropower, under a geo-historical point of view. Its main objective is to analyse the “landscapes of energy” and the social representations connected, today and in the past, with the development of energy infrastructure. The project focused on hydropower development from the end of the XIX century until nowadays, in four different European mountainous study areas. On this basis, the research tried to identify some tools for a “mediation paysagère”, a mediation by the means of landscape, that can help actors in conceiving together energy project and territorial project. Landscape seems able to bridge the gap between energy development and the territory. The question is how to make its role of interface emerge, activating its underlying character of intermediator. As the article shows, studying mountain landscape helps to reveal and to highlight the complex interrelations among hydropower development and the territory. Since landscape links people and the territory, it can be used as a tool to recognise territorial potential of energy development, giving back to energy its spatial and social dimension. In the energy field, the discourse on landscape is normally focused on the potentially negative impact of infrastructure associated with the exploitation of renewable energy. This exclusively “visual” landscape appears on one side as an obstacle to the development of new energies, on the other side something to be protected against them. Our research aims to contribute to the current debate, testing the landscape as a tool to ensure that the choices on energy become a strategic element of territorial concerted projects, able to take charge of the complex relationship between society / territory / environment. The research identifies and tests some methods to use the landscape as an instrument of intermediation, as a reference to be shared among the actors involved. This would happen making the geo- historical and socio-ecological complexity of landscape accessible to them. The landscape brings deep traces of the relationship between man and energy. This awareness allows us to read landscape through energy, showing how energy is inherent in the forms and transformations of the landscapes itself. To achieve this, it is necessary to question landscape as a witness, showing how the energy sector have influenced its transformations. Stakeholders must be able to access information and data included in the landscape-archive. To reading landscape through energy we need a new specific knowledge, a geo- historical research collecting materials useful to build what we called “scénarios paysagers de l’énergie” (landscape scenarios of energy). This is a tool, both discursive and visual, allowing to highlight the sequence of events at the crossroads between people and the territory, that leave their traces on the landscape. Landscape records somehow this sequence, its inflection points, its lulls. Like a backdrop (scenario in Italian) landscape modifies following the storyline (scénario en Français) and commenting it with its own language. Like a backdrop changes in the crucial moments of the comedy, so the landscape can change dramatically when it changes the relationship between resources and society. In the mountains the relationship between society, the visible forms of the territory and the exploitation of its energy potential appears particularly easy to read. For example the exploitation of solar energy has largely determined, anywhere, settlements, agriculture, pastoral and forest activity, etc. – in a word – the configuration of mountain landscapes itself. The slope, the altitude gap, is another typically mountainous energy factor: it allows for example to exploit running water, transforming kinetic in mechanical energy. This last case is the one exploited by hydropower energy. Hydropower appeared on the European mountains between the end of the XIX and the beginning of XX century. This was the last energy transition before the present one. Showing how hydroelectricity changed the mountain landscapes helps us to better understand what is at stake in the current energy transition. Observing the interaction between energy production and the generation and transformation of the landscape we can distinguish two levels. The first is direct, for example when hydropower infrastructures generates their “technological” landscape, sometimes very visible, even exhibited, sometime the hydropower landscape is completely invisible, hidden underground. But there is a second, indirect level of interaction: when a new energy system settles in, it is always accompanied by deep changes. Every change establishes important interactions between hydropower development and forests resources, agro-pastoral resources, tourism, the protection of nature and the use of water. The article presents some examples of these interactions in the research study areas, where the interface character of the landscape becomes explicit and active. Reading landscape through energy appears to be the way towards the building of a collective sensibility: not only to observe the elements of the territory and give them a value and a sense, but also a way to make shareable gaze emerge, to enter the game with a co-constructed representations, to build something that can be placed at the intersection of subjectivities. In this sense the “lecture énergétique du paysage” works with landscape as intermediator. It is at the base of what we call a process of “mediation”, whose characteristic is to build the territorial project on a shareable knowledge and negotiated the distribution of values and meanings.< Réduire