Excursion to the Hohenwarte II pumped storage power plant

On 16 January 2024, we visited the Hohenwarte II pumped storage power plant and the Hohenwarte I dam together with the VDE university group.

The excursion began with an interesting tour of the pumped storage power plant's visitor center. Here we learned from a former employee that the hydropower plants along the Saale cascade are not only used to generate energy, but also for flood protection. While the normal volume flow of the Saale is around 15 m³/s, it can increase to several 100 m³/s in the event of a flood. To protect the towns further downstream from flooding, the reservoirs of the hydropower plants can be used as retention basins.

After the theoretical introduction to the use of hydropower along the Saale, we visited the machine hall of the pumped storage power plant. Here, the water flows from the upper reservoir through pipes up to 2.5 m thick into the eight turbines of the pumped storage power plant. The drop height of the water is 300 m, which is why Francis turbines are used to convert the energy. When all turbines are running at maximum output, the power plant can feed 320 MW into the electricity grid and thus contribute to its reliable operation. If there is too much electricity in the grid, the turbines can be switched to pumping mode and surplus electrical energy can be stored in the form of potential energy. This makes pumped storage power plants one of the few long-term storage options for electrical energy.

After visiting the powerhouse, we drove to the Hohenwarte I dam wall. The impressive concrete wall is up to 60 m high, which means it is subject to enormous water pressure. The tour inside the wall was characterized by a mixture of awe and a little nervousness as to whether the wall would hold. Our guide was quickly able to counteract these concerns, as he told us that the wall is monitored so closely that any defects are noticed immediately. Nevertheless, we were all relieved when we returned to daylight.

We ended the excursion with a wonderful view of the Saale valley from the dam wall and set off on our journey home.

The Student Council EI and the VDE university group are looking forward to welcoming new members to help organize excursions or provide general support.

Hohenwarte pumped storage power plantCarsten Gatermann
Hohenwarte pumped storage power plant