Oberems Argessa

Oberems Argessa pumped hydro overview.

Oberems is the pumped-storage stage of Argessa’s Illsee–Oberems–Turtmann hydropower system in Valais. Water from the Illsee reservoir generates electricity at Oberems, while pumping supports storage in the upper reservoir. The downstream Turtmann station is a separate generating installation.In OperationSwitzerland

At a Glance

Turbine nameplate capacity

8.2 MW

Energy storage

Data coming soon

Operator

Data coming soon

Country

Switzerland

Location

46.283°, 7.689°

Website

Official project page

Ownership

1 record

Share	Organisation	Role	Details	Period
Unknown		Owner Operator	Argessa is identified as the owner of the Oberems pumped-storage installation in the BFH energy storage database and operates the wider Illsee–Oberems–Turtmann system.	Current / not dated

Organisations

5 records

Organisations recorded as working on this asset or its project, and their role.

Organisation	Role	Details
	Pumped-storage owner and operatorOwner Operator	Argessa operates the Illsee–Oberems–Turtmann hydropower system. The BFH energy storage database identifies Argessa as the owner of the Oberems installation.
	Historical Pelton turbine manufacturerEquipment Supply	Stellba’s Oberems reference identifies two single-jet Pelton turbines manufactured by Escher Wyss in 1942.
	Balancing reservoir waterproofing technologyEquipment Supply	Sika documents waterproofing and concrete technology for the 2015 refurbishment of the balancing reservoir between the Oberems and Turtmann power stations.
	Hydraulic governor modernisation in 2012 and 2013Equipment Supply	Stellba modernised the Oberems MG1 hydraulic governor in 2012 and the MG2 governor in 2013. Its work on the separate Turtmann machines is outside this installation’s scope.
	Business and operational managementOperations And Maintenance	Argessa identifies VARELLION Teams AG as its provider of business and operational management, including personnel and administration.

Supplier registration

Contact page only

How suppliers get onto this project's radar: its standing register, supplier portal or contact route.

Businesses can contact the operator through its published company contact page. The page provides a general enquiry route for engagement about the hydropower system.

General company enquiries for the wider Illsee–Oberems–Turtmann hydropower system.

Contact page

SourceChecked 29 Oct 2026

Capacity history

Recorded project capacity figures. Future-dated changes are shown but are not used as current capacity.

Effective	Capacity type	Capacity	Source
Current	Technical capacity	5.9 MW	Swiss Federal Office of Energy – pump motor input power, 2025 snapshot
Current	Turbine nameplate capacity	8.2 MW	Swiss Federal Office of Energy – maximum mechanical turbine power, 2025 snapshot

Wind [m/s]

Wave [m]