St. Martin Storage Power Plant

VERBUND's St. Martin power plant is a storage power plant situated in the municipality of St. Martin am Wöllmissberg in Styria. It was constructed from 1964 until 1965.

*Source: ENTSO-E Production 2017

The Hierzmann annual storage was built between 1947 and 1950 and made a big improvement to the storage capacity of the Teigitsch group. The St. Martin cavern power plant has a bottleneck capacity of 9,800 kW and was put into operation in 1965 with one machine set.
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.

Transformers: 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.