Highlights from the second phase

To round off the second phase of the SCCER-SoE from 2016 to 2020, we invite you again to learn more about a collection of our research highlights. We will publish the articles throughout 2020.

100% renewable – 100% doable

The knowledge that wind power is very productive in winter and that photovoltaic (PV) installations can produce more electricity in alpine environments than in the valleys is not completely new. Yet these insights have remained little appreciated or acted upon. But with the energy transition pushing forward into a renewable future, this knowledge is of critical importance. As Switzerland is facing a substantial winter energy deficit with its nuclear power plants going offline, SCCER-SoE modelling results provide vital information as to how smart choices of installation location can help to fill this deficit with solar and wind power from the mountains.

A digital clone monitors penstock ageing

The electrical market prices fluctuations are driving the ageing rate of hydropower infrastructures. Starts and stops, as well as pressure oscillations, mechanically stress the penstocks and pipelines. In contrast to valves or turbines, penstocks are very difficult and costly to refurbish or replace. Therefore, hydropower infrastructure operators seek to optimize the maintenance to extend the operation life and safety of their infrastructure. In this work, scientists from the HES-SO show how the use of a numerical clone helps to achieve this by assessing the degradation of the penstocks and other components.

The HEATSTORE project: assessing the implementation potential of High Temperature Underground Thermal Heat Storage

HEATSTORE aims at developing High Temperature (~25°C to ~90°C) Underground Thermal Energy Storage (HT-UTES) technologies, which are crucial for the energy system transformation to be successful. Storing heat underground will allow to manage variations in heat supply and demand and store energy for future use. In Switzerland, HEATSTORE focuses on two demonstration projects for High Temperature Aquifer Thermal Energy Storage (HT-ATES). Scientists from the Universities of Geneva, Bern, Neuchâtel and the Swiss Federal Institute of Technology in Zurich (ETHZ) are working on this project in collaboration with industrial operators (Services Industriels de Geneva SIG and Energie Wasser Bern EWB) within the framework of the SCCER-SoE to assess the feasibility of HT-ATES systems in Switzerland.

Price-driven dispatch of hydropower

On the wholesale electricity markets, Swiss hydropower is mainly a price-taker. In the last decade, market prices in Switzerland decreased, which lead to drops in market revenues. The energy economics group of the Paul Scherrer Institute evaluated the possible prospects of market revenues under future price scenarios to assess possible profitability ranges of Swiss hydropower.

The GECOS project: reducing subsurface uncertainties by the smart use of field-based integrated geophysical investigations

The economics of deep and medium depth geothermal projects rely to a great extent on cost-effective geophysical exploration techniques. How can these be designed and deployed with a fit-for-purpose approach to achieve more effectively a satisfactory image of the subsurface and its uncertainties? These are the questions at the core of the GECOS project.

Towards more flexible hdropower: preventing turbine instability during multiple start/stop procedures

This study performed within the FlexStor-WP6 project allowed us to identify the critical operating conditions that had led to the premature fatigue of the turbine runner from Grimsel 2 power plant. We concluded that those conditions had developed due to a drastic increase in the number of daily starts and stops in recent years. In the end, we synthesized our findings in a protocol of experimental diagnosis for hydropower units showing premature fatigue signs. This smart diagnostic tool is also useful for other machines with similar problems.

The extension of existing hydropower reservoirs substantially contributes to the Energy Strategy 2050

The extension of existing hydropower reservoirs substantially contributes to the Energy Strategy 2050

With the implementation of the Energy Strategy 2050, the demand for seasonal storage of electricity increases. One option is to extend existing reservoirs of storage hydropower plants by heightening their dams. Researchers from the Laboratory of Hydraulics, Hydrology and Glaciology (VAW) at ETH Zurich evaluated the possibilities and potential benefits of heightening 38 dams in the Swiss Alps. They concluded: If 17 to 26 dams were heightened by up to 20 %, a total of 2.2 to 2.9 TWh of electric energy per year could be additionally shifted from summer to winter. This corresponds to the household electricity consumption of 1.7 to 2.2 million inhabitants during winter.

Scale matters – providing the missing validation of air-water flow research in hydraulic infrastructures

Scale matters – providing the missing validation of air-water flow research in hydraulic infrastructures

High-velocity air-water flows commonly occur in human-made hydraulic infrastructures such as spillways and low-level outlets at reservoir dams. Air entrainment significantly affects the flow properties of the resulting water-air-mixture and must be considered in the design of these safety-relevant structures. However, existing design guidelines primarily take into account physical model tests, which may be subject to scale effects. An SCCER-SoE project at the Laboratory of Hydraulics, Hydrology and Glaciology (VAW) at ETH Zurich aims at providing prototype data necessary to assess the extent of these scale effects.