Upgrading of Power Station Grimsel 1, Pressure Shaft and Cavern

Widening of the power house of the Grimsel 1 hydroelectric facility and installation of a new supply turbine for the water diversion from Grimsel lake to Rätrichsboden reservoir with the following features:

  • connection to the existing intake and to the access shaft of the valve chamber
  • armoured penstock gallerie, crossing the Aare river
  • adaptation of valve chamber and pressure shaft
  • new turbine shaft
  • unlined tail race gallerie

Main Data

  • Geology: Central Aare Granite
  • Penstock gallery/ Pressure shaft
    • length: 431 m
    • diameter: 2.2 m / 2.0 m
    • lining: steel plates
  • Turbine
    • design discharge: 25 m3/s
    • gross head: 184 m
    • typ: Francis

Client

KWO Oberhasli Hydropower Ltd.

Consultant

IUB Engineering Ltd (for pressure gallerie and pressure shaft) / BKW FMB Energy Ltd. (for machinery and tail race tunnel)

Construction period

2003–2006

Construction costs

33 Mio. CHF

Scope of services

  • Basic project
  • Bill of quantities and tender evaluation
  • Detail project
  • Site supervision, commissioning, as-built documents
Upgrading of Power Station Grimsel 1, Pressure Shaft and Cavern
Upgrading of Power Station Grimsel 1, Pressure Shaft and Cavern
Upgrading of Power Station Grimsel 1, Pressure Shaft and Cavern