Penstock for KLL 2015 - Linth Limmern, Switzerland

DSD NOELL receives major pumpstorage contract: Penstock for KLL 2015 - Linth Limmern, Switzerland

Already the second award by swiss NOK, after Nestil extension project.

In November 2009 DSD NOELL GmbH of Germany received a new contract from Kraftwerke Linth – Limmern AG (KLL). The scope of works comprises two penstocks for the pump storage plant Linthal 2015 in Switzerland.

Linthal 2015 is located in Swiss canton Glarus. It is currently the biggest hydropower and infrastructure project in the Swiss energy industry covering an investment volume of approx. 2.1 billion Swiss Francs.

The contract for DSD NOELL GmbH includes design, supply and erection of penstocks, the major items being:

• Steel linings for two horizontal pressure shafts with an internal diameter of 4.4 m from surge shaft up to the gate chamber
• Steel linings for two inclined pressure shafts (approx. 40°, each 1.000 m long) with an internal diameter of 4.2 m from gate chambers up to bifurcations
• 4 draft tube steel linings at an internal diameter of 4.0 m

After completion of the new facilities the climate-friendly hydropower plant will contribute tremendously to a safe and reliable electricity supply in Switzerland. With its high power production capacity of 1,460 MW Linthal 2015 will significantly help to meet the ever increasing need for base and peak energy.

Linthal 2015 provides for a comprehensive expansion of the KLL plants. The main component is the construction of an underground pumped storage plant between lake Limmern and lake Mutt, above Linthal, thus increasing the performance of the KLL plants by 1,000 MW to finally 1,460 MW. The pumped storage plant is located at an altitude of about 1700 m a.s.l. and is built around 600 meters deep inside the mountain. Four turbine-generator-sets with a capacity of 250 MW each will be installed in the power house cavern.

The project features an adjustable pump and turbine maximum output of 1,000 MW. It will pump water from the existing reservoir Limmernboden at 1860 m a.s.l. into the 600 meters higher Muttsee (lake Mutt) and in reverse will generate electricity during turbine operation mode. To accomplish the required output it is necessary to increase the Muttsee water level by 30 m.

Starting at Tierfehd near the valley’s bottom a new access tunnel will be created for access to the powerhouse cavern. The tunnel will be equipped with a funicular railway.

Major works of the new hydro power plant started in January 2010 whereas extensive preparatory works were already accomplished since early summer 2008.

This represents already the second contract assigned to DSD NOELL GmbH by KLL AG. In the years 2003 up to 2006 the company had completed the pump storage extension project “Nestil” which already was a part of the overall KLL facilities modernization.