Sustainable Storage Hydropower for a Resilient Future Energy System

For decades, hydropower has been an important pillar of the electric power system in Alpine regions, providing both generation of electric energy and storage of energy by high-altitude impoundments of water; and it is still today. Simultaneously to the future deployment of new renewables including solar and wind as part of the energy transition, hydropower facilities will require a transformation to maintain their role as the backbone of an increasingly volatile and extended electric power system in Switzerland. Moreover, the increasing risk of winter electricity shortage should be addressed by the seasonal water storage in hydropower reservoirs, which is evident from the provision of “Hydropower Reserve” in the last two winter seasons.

In 2019, the Swiss Federal Office of Energy published an updated edition of its hydropower potential study, stating that considerable efforts are necessary to maintain and extend today’s hydropower capacities to meet the requirements set out in the Swiss Energy Strategy 2050. Among other factors, the study specifies reservoir sedimentation as a negative impact on hydropower storage capacities in Switzerland. An estimated loss of 7% of the seasonal storage capacity in Swiss reservoirs is anticipated from 2019 to 2050. In many reservoirs, the sedimentation rate is much more acute, creating operational and dam safety problems. The project aims at reducing the uncertainties related to the assessment of long-term reservoir sedimentation under the effect of climate change. This will lead to better information of the future availability of Swiss hydropower’s storage capacities. Incorporated in upcoming editions of the hydropower potential study, these results may directly influence policy decisions shaping the development of prospective Swiss energy systems. Therefore, the hydropower section of the Swiss Federal Office of Energy is involved as a partner organization.

Numerical modelling is applied to simulate the long-term effects of different sediment management strategies in selected cases of Switzerland. The result is then generalized to derive recommendations for sediment management in Alpine reservoirs under the impact of climate change.

This fellowship is hosted by the Energy Science Center.