Pumped-storage with small hydropower – an option?
This paper contributes towards exploring the technical and institutional feasibility of small hydropower storage and pumped-storage schemes in Switzerland. Within the European and Swiss context of the facilitation of renewable energy technologies, which includes small hydropower (SHP), intermittent sources such as solar and wind increase the need for additional energy storage capacities. Hydropower pumped-storage schemes remain the most efficient and profitable option to “store” electricity. In Switzerland, most of the large scale hydropower potential is already exploited. The potential of SHP (<10 MW) for storage and pumped-storage applications, especially with a decentralised energy supply and grid balancing perspective (“smart grid”), has not yet been evaluated. SHP storage and pumped-storage schemes can use streams and lakes, or existing infrastructures, such as irrigation and snow-making facilities or inoperative galleries (i.e. multipurpose infrastructures). These facilities offer unexplored opportunities using existing reservoirs. The methodology has been applied in Switzerland but can be easily transposed to other countries. The research evaluates the small storage and pumped-storage hydropower potential in a qualitative and explorative manner. It includes a concrete case study in Torgon (Valais, Switzerland). Based on an existing high head run-of-river SHP study with a net annual production of 9 GWh, the storage and pumped-storage are added as possible extensions of the initial project. The proximity of the ski lift station of Torgon offers the possibility to use snow-making lakes as upstream/downstream reservoirs. Finally, this paper formulates some institutional recommendations in order to facilitate such a development (e.g., remuneration instruments).