After the groundbreaking ceremony in October 2023, construction work on Energie AG’s (EAG) Ebensee pumped storage power plant is progressing. The 460-meter-long access tunnel is now complete. As reported, the project is the largest single investment in the utility’s history at 450 million euros.
The cavern power plant at the foot of the Sonnstein is expected to have an output of around 170 megawatts, generate ten hours of electricity at full load and go into operation in 2027. It is also part of a strategic realignment of EAG.
In recent months, the Salzkammergut federal highway and the ÖBB tunnel were crossed for the access tunnel. Two to three blasting operations were carried out per day. The tunnel was driven forward with around 130 boreholes per tunnel. “Due to the required gradient of the access tunnel to the power plant cavern, we are now 460 meters into the mountain and around 40 meters below the water level of Lake Traunsee,” explains project manager Klaus Höller.
Image: EAG/Hörmandinger
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Image: EAG/Hörmandinger
The next big step is the excavation of the cavern inside the mountain, which is 53 meters long, 26 meters wide and around 41 meters high, roughly the size of the Ebensee church. Work is underway at the same time to build the dam at the headwater reservoir. Work on the 560-meter-long pressure tunnel, which carries the water from the headwater reservoir to the cavern, is also well advanced, says EAG.
