Stegenwald power plant: impellers successfully lifted into place

Before the lifting could begin, a logistical challenge had to be overcome. The 72-tonne, 23-metre-long transport had to be guided through the bottleneck at the entrance to the construction site with millimetre precision.

The delicate operation of lifting it into place was then mastered by the construction team and their routine. The two turbine parts, each weighing more than 32 tonnes, had to be lifted into the turbine shaft using a mobile crane and then the impellers had to be horizontally inserted through the distributor into the impeller casing. The two turbines, each with a diameter of 3.6 metres, will in future drive the generator.

The two Kaplan turbines have a combined output of 14.3 megawatts and will, as planned, efficiently generate around 73 million kilowatt hours of domestic renewable electricity from hydropower for around 20,000 households from mid-2025. This will make an important contribution to achieving Austria’s and Salzburg’s energy and climate targets.

Innovative concept implemented at the Stegenwald power plant

For the first time, an innovative plant concept developed in collaboration with Graz University of Technology is being implemented at the Salzach power plant in Stegenwald. This concept could set the standard for future medium-sized run-of-river power plants. For the first time, two vertical Kaplan turbines are being installed horizontally, i.e. lying down. The water is thus directed to the turbine not from the front, but from above. This means that the generator is not located on top of the turbine, as is usual in run-of-river power plants, but in front of it. In this way, the powerhouse can also be flooded during operation and used for flood discharge. The result is that the power plant can discharge 20 per cent more water in the event of flooding than would have been possible with a third weir field. The modern facility is therefore well equipped for future challenges in times of climate change. Another advantage of this construction method is that only the weir bridge is visible and the rest of the plant is under water.