Schwarza reservoir

Reservoir and link between two power plants

Schwarza reservoir serves as the lower reservoir for Häusern pumped-storage power plant and the upper reservoir for Witznau power plant. It is 950 metres long at its longest point, up to 270 metres wide and has an active storage capacity of around 1.3 million cubic metres of water when full. The surface area covers around 15 hectares.

The Schwarza dam was built between 1929 and 1931 as a gravity dam with a structure volume of 44,000 cubic metres. The dam has an overall height of 43 metres, of which 34 metres are visible.

Energy transition

Being able to store electricity in large quantities and generate it within seconds when needed is now more important than ever. The sun and the wind have long been playing their part in generating electricity in Germany and are producing an ever increasing share. Yet these generation sources fluctuate depending on the weather and are unreliable. Pumped-storage power plants come into play when too much electricity overloads the grid or a lack of electricity threatens the supply. They work within seconds, produce zero emissions and generate outputs that rank them among the best of all available storage technologies.

How pumped-storage power plants work

Pumped-storage plants consist of an upper and lower basin. Between them are power plants, which pump water uphill if there is excess electricity and allow it to flow down again through turbines to generate electricity when power is needed. They are precisely tailored to meet the needs of the grid at all times. As such, they help to secure the supply – cleanly, effectively and reliably.

Schluchseewerk AG

With its five pumped-storage power plants, Schluchseewerk AG is one of Germany’s largest suppliers and leading experts. As a partner to its shareholders, it oversees the safe and reliable operation of all its facilities, thereby helping to stabilise the power grid and playing its part in safeguarding the energy supply for today and tomorrow. Schluchseewerk AG – peak power permanently!

Schluchsee Power Plant Group

The three pumped-storage power plants managed by the Schluchsee Power Plant Group – Häusern upstream plant, Witznau intermediate plant and Waldshut downstream plant – store and generate electricity with water that is moved between Schluchsee and the High Rhine. This water, along with the water from the natural tributaries of the eastern Feldberg region, is primarily used to generate eco-friendly reserve electricity for the European power grid.

Schwarza reservoir facts and figures:

• The reservoir has an active storage capacity of around 1.30 million cubic metres of water
• It is the lower reservoir of Häusern power plant and the upper reservoir of Witznau power plant
• The top water level is 723 metres above mean sea level, while the drawdown level is 711 metres above mean sea level.
• The dam’s barrier structure is a gravity wall with a crest length of 158 metres.