Tour of the Gletsch-Oberwald Cavern Power Plant

Construction of the Gletsch-Oberwald Cavern Power Plant

In 2013, the Canton of Valais granted FMV an 80-year concession.

Construction of the power plant began in 2015. In Oberwald, the first 300 m

of the access tunnel were excavated using explosives. The access tunnel was used to transport

and install the 120-meter-long tunnel boring machine. A 2.2 km-long pressure tunnel connects the

water intake in Gletsch with the cavern power plant in Oberwald. Construction of the water intake, including

the sand removal system, was completed in the fall of 2017.

In 2017, work began in the Oberwald cavern on the installation of the two six-nozzle

Pelton turbines. The turbines are designed for a water flow rate of 5.7 m³/s at a head of

288 m. The impellers have a diameter of 1.15 m and rotate at 600 rpm.

The directly coupled synchronous generators each produce a rated apparent power of 8,100

KVA. The electricity generated is stepped up to 16 kV in the cavern and transmitted to the Ulrichen substation

. Since early 2018, the Gletsch-Oberwald power plant has been producing clean electricity for

approximately 9,000 average households. As the project manager and developer, FMV has successfully harnessed the previously

untapped energy potential of the Rhone River between Gletsch and Oberwald.

Date: Saturday, October 10, 2026, at 9:30 a.m.

Meeting point: 9:30 a.m. at the parking lot of the Oberwald Multipurpose Hall, Dorfstrasse 13

On-site parking is very limited: 2–3 cars each on Furkastrasse and at the portal

We will therefore meet at the multi-purpose hall in Oberwald for:

➢ A walk along the Rotte to the portal, approx. 20 min.

➢ A bike ride along Furkastrasse or the Rotte to the portal

➢ Carpooling in private cars to the portal

Equipment: sturdy footwear, weather-appropriate clothing; helmets are provided

Register by September 30, 2026, with: Armando Camenzind, praesident@igzw-goms.ch or 041 780 26 18

Guides: Raoul Albrecht, Mathias Bischoff, Xavier Eggel; Forces Motrices Valaisannes SA, Sion

Stops/Information:

1. Oberwald Cavern Control Center entrance, presentation

2. Oberwald Cavern Control Center, tour

3. Aue Sand, tour within the Oberwald portal perimeter

Schedule:

10:00 a.m.: Welcome at the portal by Raoul Albrecht, Director of Production at FMV

10:15 a.m.: Formation of 3 groups for a rotation of 15–20 minutes at each station

11:30 a.m.: Refreshments at the Central Portal, courtesy of FMV

12:00 p.m.: End of event, farewell, and return trip

Insurance: Participants are responsible for their own insurance

The Board of the IGZW Goms and Raoul Albrecht and his team look forward to a large turnout.

Locals and visitors are also welcome!

Note:

INFORMATION:

Meeting point: 9:30 a.m., Oberwald Multipurpose Hall, Dorfstrasse 13

Price: Free admission

Contact: Armando Camenzind · 041 780 26 18 · praesident@igzw-goms.ch

Registration: by September 30, 2026

Guides: Raoul Albrecht, Mathias Bischoff, Xavier Eggel; Forces Motrices Valaisannes SA, Sion

Note: This text was translated by machine translation software and not by a human translator. It may contain translation errors.