Sölk Storage Power Plant

VERBUND's power plant of Sölk is a storage power plant and situated east of the town of Stein in the municipality of Großsölk in Styria. It was constructed from 1975 until 1978.

*Source: ENTSO-E Production 2017

With their large catchment areas and high annual water loads, the Sölk Valleys (Sölktäler) made the construction of a hydropower plant particularly economical. At a geological site also favourable for its terrain, a daily storage was constructed in the Großsölktal which terminates in a 39 metre-tall vaulted wall. The water from the Kleinsölkbach, the Donnersbach and the Walchenbach is fed into the reservoir. These water volumes are used for electricity generation by a Francis turbine in the Stein power house. On average, around 47,500 households can be supplied each year with electricity generated entirely from hydropower.
 
Turbines and generators: The power plant has a vertically installed Francis turbine with a nominal output of 61,000 kW. The impeller has a diameter of 2.5 metres for an intake capacity of 34 m³/sec. The directly coupled 70,000 kVA three-phase synchronous generator has a nominal voltage of 10.5 kV.

Transformers: A 70,000 kVA machine transformer raises the generated energy to 110 kV. For supplying the plant’s own requirements, there is a transformer bank consisting of three 83.4 kVA single-phase transformers which convert the generated energy from 6 kV to 230 V.