ReHydro’s fourth Consortium Meeting brought together partners from across Europe for four days of presentations, excursions, and collaboration in and around Sion, Switzerland. It was by far our most eventful one yet!
A look at EPFL's test facilities
The day before the official opening, the consortium visited EPFL’s facilities in Lausanne, guided by Elena Vagnoni, leader of Work Package 2 – Flexibility Solutions. She walked the group through four test rigs, with the final one reserved for ReHydro’s own work.
In it, a Kaplan turbine hybridized with a battery was spinning at 1,500 rounds per minute. The only way to properly see it in action was under a flashing strobe light- and by quite literally going underneath the rig.
It was a fitting first in-person look at the work done in WP2. One of the central challenges hydropower faces today is the growing demand for flexibility: turbines are increasingly required to turn on and off rapidly in response to sudden spikes in energy demand, which accelerates wear and tear well beyond what they’d normally experience. When a turbine is hybridized with a battery, the battery can serve as an instantaneous energy source, absorbing the pressure of those sharp demand peaks and allowing the turbine to run at a steadier pace. This reduces wear while still delivering the flexibility the modern grid requires. By varying environmental parameters in the test rig, such as head heights and river water levels, this can be tested in detail and under realistic conditions.
Getting a tour of the laboratory was a great start to the week, but by far not the only excursion planned for it.
Day One: Work Packages
The official opening day took place at our partner HES-SO Valais-Wallis in Sion, with a warm welcome from host partner Alpiq before diving into a packed agenda.
A special moment came when Work Package 3 – Fit for Market took the floor. As well as sharing updates, they closed their own chapter: the planned work is now complete. While not an official project milestone, it’s a reason to celebrate no less.
The day wrapped up with an inspiring presentation from Matthias Gäumann, CEO of HYDRO Exploitation SA, followed by a social dinner giving the consortium members the opportunity to gather and catch up.
Day Two: Excursion to Forces Motrices de la Gougra
While day one was about presentations, day two was about perspective.
The consortium split into two groups early in the morning and headed to the Mottec hydropower plant in Vissoie and the Navizence intake respectively, later switching so everyone got to see both. Guided by project partner HYDRO Exploitation SA, the group learned about the history and operation of the entire Forces Motrices de la Gougra (FMG) system: how the facilities work together, the reasoning behind key decisions over the years, and planned future refurbishments. People were engaged, and many questions were asked.
Some highlights from what the group learned: more than half of Switzerland’s energy production comes from hydropower. The FMG system is already well into a series of modernisation and refurbishment measures, including a planned heightening of the Moiry Dam, which already stands at an impressive 148 meters and sits roughly 2,250 meters above sea level.
After regrouping for lunch in the picturesque village of Grimentz, the full consortium headed to the Moiry dam and reservoir; the largest in the FMG system. Sturdy clothes and hiking boots were the dresscode, despite walking around a lake, the path turned out to be quite steep in places.
At this time of year, the water level is expected to be relatively low. Glacial meltwater from Moiry and other sources will gradually fill the reservoir through the summer until around September, when demand for energy rises, daylight shortens, and photovoltaic output drops. That’s the moment hydropower steps up as a renewable source unaffected by the change in daylight hours.
That said, hydropower is far from immune to the pressures of a changing climate. The Moiry Glacier has been retreating for years, and this year’s yield from glacial melt and general snowmelt was slightly lower than usual. Climate change is affecting hydropower directly, and many of the modernisation efforts underway in systems like FMG are specifically aimed at ensuring hydropower remains a reliable energy source in the decades ahead. It’s a challenge ReHydro takes seriously, so visits like this one serve as a great visual reminder of exactly what the project is working towards.
Day Three: Demonstration Sites and group work
With all Work Package updates already covered on the opening day, the final day of presentations focused on updates from ReHydro’s demonstration sites. Overall, things are going very well. Some adjustments to earlier plans have been made to better align with ongoing refurbishment efforts at the sites, and the first publishable results are expected soon.
This also freed up time for something that tends to generate some of the most valuable conversations of any consortium meeting: structured group work. With people from all partner organisations and work packages deliberately mixed together, the groups tackled ReHydro’s core themes: flexibility in pumped storage and hybridization with batteries, fish migration and turbine passage, societal services, economic sustainability and markets, and climate change resilience. The last of these sparked particularly lively discussion, fresh off the visit to Moiry Dam and the visible impact of glacial retreat on water availability. Bringing together people from different workstreams was intentional, and the energy in those groups showed it was worth it.
The meeting closed with final words from project coordinator Atle Harby and advisor Klaus Jorde, before the group headed into summer with new ideas and renewed energy.
Excursion to the Forces Motrices Hongrin-Léman (FMHL) pumped storage scheme
For those who could stay, the meeting wasn’t quite over. A sizable group made a final trip to Veytaux to tour the Forces Motrices Hongrin-Léman (FMHL) pumped storage scheme. With temperatures in Switzerland well above 30°C that day, stepping into a power station built inside a cave was, to put it mildly, a welcome bonus.
ReHydro would like to thank HES-SO Valais-Wallis for hosting the meeting, HYDRO Exploitation SA and Alpiq for the extraordinary excursions, and all consortium partners for their continued dedication to the project.