Tierfehd, Switzerland

Located in the canton of Glarus in central Switzerland, the main production equipment of this large hydro scheme was first installed in the early 1960s.

ANDRITZ HYDRO was awarded a turnkey contract for the supply of the complete electro-mechanical package for HPP Tierfehd, including automation, EPS, and auxiliary systems. The heart of the project is a reversible pump turbine unit with a net head of more than 1,000 m. Due to the extraordinary high head for a Francis pump turbine, a design with four stages and fixed guide vanes was applied - a layout found only in very few pump turbines around the world.

In pump mode, the unit is started by means of a six-jet-Pelton turbine before the motor-generator is synchronized to the grid. The entire system is installed in a vertical pit more than 70 m deep to provide a sufficient suction head for the pump. It is connected to the original penstock by a system of three spherical valves, which were also supplied by ANDRITZ HYDRO. The project was executed by cooperating ANDRITZ HYDRO teams from Switzerland, Germany, and Austria.

HPP Tierfehd was first commissioned in 2009. Later the motor-generator underwent some improvements so that the plant in its final configuration was put into operation in 2012. It is predominantly used in pump mode, but is also capable of switching from pump to turbine mode and vice versa in a remarkably short time. This feature proved very valuable to the customer in an increasingly volatile electricity market.

TECHNICAL DATA