VERBUND's Inn power plant at Rosenheim is a run-of-river plant situated on the river Inn in the midst of the Rosenheim basin. The Inn power plant is in the municipality of Rohrdorf near Rosenheim in Upper Bavaria.
Rosenheim power plant was constructed on the Inn between 1957 and 1960 and commissioned on 23 June 1960. Typical for power plants on the Inn, it has a flat design and was constructed as a bay power plant without a machine hall. The power house and the weir were built next to each other and the superstructures were kept low. The arrangement results from the flow from the slight left turn in the Inn. The inlet spiral and the turbines have an anticlockwise arrangement.
The power plant lies in the middle of the Rosenheim basin. Two dams, Thansau on the right bank and Pfraundorf on the left bank, were built as a flood protection measure. The retaining dams along the left bank of the Grießenbach and on both sides of Litzldorfer Bach and Mooseckerbach serve to protect against flooding. The pump stations Grießenbach, Reischenhart and Thalreut were erected to drain the neighbouring communities Reischenhart and Kirchdorf.
Rosenheim power plant comprises: a three-field weir system, the power house with Kaplan turbines and a 110 kV switchyard. Two gantry cranes, each with a load capacity of 50 t, are used for assembly work and to position the bulkheads. Three machine units with a vertical shaft and a combined nominal capacity of 39,000 MW are installed at the power house. Each of the units comprises a Kaplan turbine and an umbrella-type generator. The electricity that is generated is fed into the Inn works distribution system via a 110 kV switchyard.
The water is conducted to the wheel via a spiral inlet with twelve stay vanes and the cylindrical control device with 24 guide vanes and is channelled into the downstream water via a concrete hose.
The covers over the generator shaft openings comprise two moveable sections. A 2.50 m wide thrash rack cleaning machine ensures the removal of flotsam such as wood, plastic bottles etc. This material is transported away with a plant-owned diesel locomotive. An average of 4.000 tons of rakings are removed from the Rosenheim reservoir every year.