Interreg North-West Europe Project
Whilst Europe is seeking to strengthen its energy sovereignty and increase the share of renewable energy, one resource remains largely untapped: the kinetic energy of water currents.
Unlike conventional hydroelectricity, hydrokinesis technologies generate electricity directly from the speed of the water, without requiring a significant head or the construction of a dam. Submerged turbines can therefore be installed in rivers, tidal streams or certain existing hydraulic infrastructure.
The European project SHINES – Showcasing Hydrokinetic Energy Innovations for Energy Sovereignty in North-West Europe aims to accelerate the roll-out of these technologies in north-western Europe. With a budget of approximately 10 million euros and co-funded by the Interreg North-West Europe programme, it brings together 14 partners from six countries. Three innovative technologies – RivGen, HydroWing and TidalKite – will, in particular, be tested under real-world conditions in France and the Netherlands.
Identifying potential hydrokinetic sites in Switzerland
Within SHINES, the Hydro Alps Lab is responsible for assessing the hydrokinetic potential of the Swiss part of the North-West Europe region, with a focus on the cantons of Valais and Geneva.
The study focuses on two types of site:
- stretches of natural rivers with sufficient flow velocities; ;
- the man-made infrastructure associated with hydroelectric schemes, in particular the intake and outlet channels.
This second category is of particular interest in Switzerland. The country already has a dense hydroelectric network, with facilities where water flows can be relatively steady, accessible and close to existing electricity infrastructure.
From river flow rates to mapping energy potential
One of the challenges of the project is to move from hydrological data available at specific points in time to a spatial and temporal estimate of hydrokinetic potential along several hundred kilometres of watercourses.
A specific methodology has therefore been developed by HAL. It combines topographical and bathymetric data, historical records of flow and water levels, the contributions of natural tributaries and hydroelectric discharge, as well as a hydraulic model developed using HEC-RAS.
For the Valais section of the Rhône, the model is based in particular on several hundred bathymetric sections and on measurements from federal hydrological stations. It makes it possible to establish, for each section of the river, the relationship between discharge, water level and flow velocity.
A representative daily profile for the year is then reconstructed from several years’ worth of measurements. Inflows from natural tributaries, as well as those from discharges from hydroelectric power stations, are factored in to replicate the variation in flow along the Rhône.
The Rhône region accounts for the bulk of the identified potential
Initial results show that the Swiss hydrokinetic potential under study is overwhelmingly concentrated in the Rhône.
At this stage, the identified theoretical annual energy potential amounts to approximately 200 GWh, broken down mainly as follows:
- approximately 160 GWh per year on the Rhône in Valais ;
- approximately 33 GWh per year on the Rhône in the canton of Geneva ;
- approximately 3 GWh per year on the River Arve ;
- to which must be added several GWh from certain man-made hydroelectric facilities.
For the major watercourses analysed, the most promising sections typically have a theoretical potential of around 1 to 2 GWh per kilometre, although these figures will need to be refined further during the next stages of the project.
Existing hydroelectric infrastructure: a particularly promising avenue
The study also confirms an avenue already explored by the Hydro Alps Lab in previous projects: harnessing residual kinetic energy within existing hydroelectric infrastructure.
Two works from Valais stand out in particular from this initial analysis: the intake channel for the Chippis-Rhône development and the outlet channel at the Lavey power station. Both sites offer significant hydrokinesetic potential and will be among those of interest for further investigation.
These man-made sites can offer several advantages over natural rivers: more predictable hydraulic conditions, easier access for installation and maintenance, and proximity to existing electrical infrastructure. Previous trials carried out by HAL in Lavey had already demonstrated the feasibility of such an approach under real-world conditions.
From theoretical potential to sites that can actually be exploited
The approximately 200 GWh/year identified corresponds to a theoretical potential. They therefore do not yet represent a source of electricity that can actually be utilised.
The next stage of the project will involve selecting the most promising sites and then gradually incorporating the technical, environmental and economic constraints: turbine dimensions and performance, water depth, usable speed range, turbine layout, interactions between turbines, accessibility, maintenance and investment costs.
This approach will enable us to move from theoretical potential to a realistic technical and economic potential for the selected sites.
Towards a European hydrokinetic atlas
The data generated as part of the SHINES project will also be used to create a hydrokinetic atlas. This will bring together, in map form, the main hydraulic characteristics and energy potential indicators in order to facilitate the identification of sites suitable for future installations.
The next stages of the project will focus, in particular, on selecting the best sections of the Rhône and Arve rivers, carrying out a technical and economic assessment of the natural and man-made sites identified, and finalising this online atlas.
SHINES will therefore make it possible to determine the extent to which the kinetic energy of watercourses and existing hydroelectric infrastructure can contribute, alongside conventional hydroelectricity, to a local, renewable and reliable electricity generation.
