K2 mounting system on the world's first floating solar system in the mountains

Installation information

  • Location: ‘Lac des Toules’ alpine lake, Switzerland
  • Altitude: 1,810 m.a.s.l.
  • Wind conditions: wind with 120 km/h
  • Weather conditions: up to -30°C and 60 cm of ice in winter
  • Start of construction: spring 2019
  • Completion: December 2019
  • Perspective (2021): 10 MW solar park
  • Yield: 800 MWh / annual consumption of around 220 households
  • System: customized construction
  • Number of modules: 1,400 bifacial modules
  • Module field (total): 2,240 m²
  • Number of floater: 36 floater
  • Investment: CHF 2.4 million
  • Partners: Romande Energie, Swiss Federal Office of Energy, ABB

‘The project will prove that the output is 50% higher than in the valley’

‘We started planning the project seven years ago and installed a pilot plant near the reservoir. There we tested suitable solar modules, the right inclination and checked the technical and financial feasibility. With this project at 'Lac des Toules' we want to prove that it is possible to realize a floating PV project on alpine area, where the output is 50% higher than in the valley,’ says Guillaume Fuchs, project manager at Romande Energie (interview).


‘The project will prove that a reservoir can be used twice. On the one hand for the production of water power and on the other hand as a carrier for large-area PV systems,’ says Lars Kreemke, project manager at K2 Systems.

Impressions of Romande Energie SA

Tailor-made substructure

Tailor-made substructure

The substructure has been developed together with Romande Energie especially for this project and consists of high-density polyethylene floaters and aluminium rails that can carry heavy loads.

In addition, the floaters are anchored in the ground with weights to be able to sink or rise depending on the water level.

Floating PV in the Switzerland, Lac du Toules, Romande Energie
The project is the world's first floating solar power plant in the mountains on a reservoir. The lake is completely emptied once a year.

‘The project has a 50 percent higher efficiency’

‘The project has a 50 percent higher efficiency than a comparable land-based plant. On the one hand, we use bifacial modules, and on the other hand there is higher UV radiation and lower temperatures at over 1,800 meters, which makes the modules more efficient. Moreover the efficiency of the bifacial modules is increased by the stronger reflection of the snow in winter,’ says Guillaume Fuchs.


In addition, the project and the construction of the floating park will benefit from the existing infrastructure on the reservoir, as it has already been used to produce electricity for several years. ‘We find it exciting and useful that someone is trying this out and gaining experience with it for the first time anywhere in the world,’ says Frank Rutschmann, Head of Renewable Energies at the Swiss Federal Office of Energy.

Perspective: 10 MW solar park

Perspective: 10 MW solar park

If the tests are successful, the project will be expanded to a total of approx. 10 MW from 2021. This corresponds to an area of about 30 football pitches (218,000 m2).

The floating plant will then cover 35 percent of the lake and supply electricity for 6,600 households.


Our team would be happy to help you with the planning of your next project. Give us a call!


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