Wallsee-Mitterkirchen: Turbine replacement begins with divers

To get to the turbine, you have to dive. Not to work under the water, but to get rid of it. The turbine chamber must be drained before work can begin on removing the old Kaplan impeller. Divers ensure that the dam remains sealed.

To withstand the force of the Danube, extremely heavy steel elements are needed: the stoplogs. The gantry crane stacks these in front of the turbine. But this only works if the stoplogs (the heaviest weighs 15 tons alone) are completely watertight. That is the job of the industrial divers. 

At a depth of 16 metres, the divers’ visibility is just a few centimetres. The task is to clean sand and debris off the contact surface of the stoplog at the bottom of the Danube. The Danube is cloudy after last week’s rainfall, but there is also an advantage to the low water supply of the past year: not much material has been washed up. A few branches and a root stump have become entangled in the screen, but floating debris like this is a routine occurrence for the divers. 

Wallsee-Mitterkirchen rehabilitation project

The planned modernisation package will increase the maximum electrical capacity of the Danube power plant, which was built between 1965 and 1968, by around 10 megawatts to a total of 220 megawatts. It will also increase average output by around 54 million kilowatt hours to almost 1.4 billion kilowatt hours. This will allow the Wallsee-Mitterkirchen power plant to generate electricity for 390,000 households in the future. Investment costs of around EUR 62.5 million have been earmarked for the project by 2030.

The second of the six generator sets will be replaced this winter. There is still some delicate lifting work to be done on the heavy generator set components. 

Wallsee-Mitterkirchen as a centre of innovation

The Wallsee-Mitterkirchen site is home to several innovative energy projects, all of which are part of the energy transition. In 2022, a 1.7-megawatt photovoltaic system was added to the largest battery storage system on the Danube, the 10-megawatt Blue Battery. On an area of around three hectares, the facility generates as much electricity per year as around 600 households consume. The factory building itself is also equipped with an efficient facade PV, and the in-house e-car charging station has a highly innovative PV system.