Energy storage
Riedl

Essential for a successful energy transition

The Riedl energy store (ESR) is an important element for climate protection and a sustainable energy future. As owner of Donaukraftwerk Jochenstein AG, VERBUND is planning an ultra-modern pumped storage power plant at Untergriesbach in the area along the Austrian-Bavarian border.

The Riedl energy store is becoming an important pillar for the storage of solar electricity generated in the region. It is thus essential for a successful energy transition and a secure supply of green electricity. As required, the Riedl energy store will feed environmentally friendly electricity from stored renewable energy sources into the electricity grid. With the construction of the 300 MW Riedl energy store, Bavaria's pumped storage capacity will increase by more than 50% and the state's electricity storage capacities by more than 70%. The energy store is one of the most important infrastructure projects in Lower Bavaria and makes an essential contribution to the security of supply.

A view of the Jochenstein hydropower plant on the Danube.

Between Gottsdorf and Riedl, in the municipality of Untergriesbach, a reservoir (upper pool) with a naturally shaped dam is being created in a natural depression in the terrain. The water tunnel between the upper pool and the Jochenstein power plant site on the banks of the Danube, the so-called headrace, run invisibly inside the mountain. Two machine sets, each with a capacity of 150 megawatts (MW), will be installed as a shaft power plant in a powerhouse on the existing power plant site. The inlet and outlet structure of the Riedl energy store is being built between the Danube and the shipping lane on the dividing dam, which also belongs to the site of the Jochenstein power plant.

Technical details

Power plant location: Municipality of Untergriesbach/district of Jochenstein
Location of reservoir: Municipality of Untergriesbach/district of Gottsdorf
Mean Danube flow: 1,420 m³/s
Highest navigable Danube flow (HSQ): 4,150 m³/s
Reservoir capacity: 4.2 million m³
Upper pool surface area: 24 ha
Average head: 331.5 m
Flow rate of turbines in operation: 108 m³/s
Flow rate of pumps in operation: 83 m³/s
Machine capacity: 2 x 150 megawatts
Investment volume: approx. €400 million

The map shows the Jochenstein power plant, the Danube and the surrounding area.

Stimuli for the region

This infrastructure project is expected to have a positive impact on the regional development of Passau district and the market town of Untergriesbach. The investment volume of around 400 million euros is helping to strengthen the regional economy. Experience shows that about 30 percent of value added remains in the region. The operation and maintenance of the power plant secure existing and create new jobs, including through contracts for regionally based companies.

Ecology

Planning and implementation take place with the greatest possible avoidance of impacts on the population and the environment as well as in accordance with the state of the technology and the highest safety standards.

So, for example, the water pipes and power lines are entirely underground. Nothing about the present form of the Jochenstein power plant and the reservoir of the Aschach power plant is being changed. Planning and construction are being carried out in direct dialogue with the local population. Protective construction methods and offsetting measures will retain the ecological assets of this sensitive project area.

The picture shows a stylistically beautiful close-up of a lush green meadow with different grasses.

Suitable location

The location of the Riedl energy store was carefully chosen. The natural depression in the terrain between Gottsdorf and Riedl in the municipality of Untergriesbach, which is currently used for intensive agriculture, is ideally suited for the construction of the necessary reservoir. In this way, the upper pool can nestle harmoniously in this natural depression. Both the headrace tunnel towards the valley and the inlet/outlet structure will be constructed underground. The machine house with the turbines, pumps and generators will also be situated on the site of the Danube power plant in the form of an also largely underground shaft power plant.

The location for the energy store offers many advantages. These include the fact that the reservoir can make use of the available infrastructure as an extension of the existing Danube power plant Jochenstein. This infrastructure includes not only the structural facilities like offices, workshops and switchgear, but also the highly-qualified and operationally experienced personnel. Existing roads and the possibility of transporting the material by boat offer the opportunity to construct and operate the facility in an especially environmentally friendly way. The existing 220 kV line can be used to transport the energy, meaning there is no need to build a new line.

About the Riedl energy storage project

Find out more about the Riedl energy storage project near Jochenstein on the Danube. (German only)

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Geology

Initial geological investigations date back to 1954, with further investigations carried out in 1977 and 1984. Exploratory drilling in the Jochenstein valley floor in July 2010 and an extensive drilling programme with laboratory and field tests contributed to the further consolidation of the investigation network. The geological, geotechnical and hydrogeological conditions of the subsoil are being investigated. The results of the investigations to date all showed that the subsoil is ideally suited for the project.

The hard rock (gneiss) of the local mountain massif, the natural basin in Riedl-Gottsdorf in the immediate vicinity of the Danube and the Jochenstein power plant, and the usable height difference enable the energy storage facility to be operated safely.

Explanation

Geology: Investigation of the composition, structure and composition of the subsoil
Geotechnics: influence of structures on the subsoil
Hydrogeology: water in the subsoil (rock)

The picture shows an aerial view of Kraft Jochenstein in the sunshine.

Surroundings

Jochenstein, on the Danube, with its adjacent former factory housing estate, stands on the "sunny side" of the Danube valley. At one time situated in the somewhat isolated corner of eastern Bavaria, the town has been a popular rest stop and departure point for cycling and hiking excursions into the Danube valley ever since the opening of Europe's internal borders. The "Haus am Strom" built on the power plant site right by the entrance to the power plant offers both education and information, as a means to invigorate tourism in the region.

As an extension of the existing Danube power plant Jochenstein, the new energy store not only enjoys ideal topographical conditions, but also the available infrastructure. This includes the existing open-air switchgear and grid connection as well as the highly-qualified and operationally experienced personnel. That creates efficient co-existence, which protects resources.

The arrangement of the new power plant on the banks of the Danube and the construction of the inlet and outlet structure in the form of an underground tunnel will retain the landscape's beauty and additionally enrich the tourism offering.