Turbines and generators:
A Kaplan turbine with horizontal shaft and a nominal output of 11,050 kW was installed in the powerhouse in 1965. 16 guide blades direct the generating water to the 7 blades of the 1.49 metre diameter impeller and process a maximum of 16.5 m³/sec. The 12,500 kVA three-phase asynchronous generator connected at the side has a nominal output of 6.3 kV. At the time of its construction, it was one of the biggest asynchronous generators in Austria.
The generated energy is raised from 6.3 kV to 110 kV via a 12,500 kVA machine transformer and transmitted via a 110 kV line to Arnstein. In parallel, STEWEAG operates its own 110/20 kV transformer in the switchgear to be able to feed the energy into the 20 kV regional grid as an alternative.
Hierzmann annual storage:
The Hierzmann annual storage was built between 1947 and 1950 and made a big improvement to the storage capacity of the Teigitsch group. The reservoir has a capacity of 7.1 million m3 and a final level at a height of 708.0 metres. The reservoir is enclosed by a 58.6 metre-high curved wall that is the highest of its kind in Styria. The headrace comprises the 985 km-long pressure tunnel, the surge chamber and the 121 metre-long armoured pressure pipeline.