The Isar power plant group has 26 run-of-river power plants with a capacity of 240 megawatts and the Walchensee storage power plant with 124 megawatts. The average annual electricity generation is 1.6 billion kilowatt hours. This is enough electricity to supply over 500,000 private households. Compared to the current generation mix in Germany, electricity from the Isar‘s hydropower avoids around 900,000 tons of CO2.

The Isar rises in the Karwendel mountains and flows into the Danube below Deggendorf. It flows through Bavaria over a length of 295 kilometers with a difference in altitude of 637 meters. For Deutsche Bahn, hydropower is an important supplier. A total of four power plants on the Isar supply traction current. This is so-called single-phase alternating current with the frequency of 16.7 hertz, which is only used by the railroads. This electricity is fed into the DB Energie grid.

As a storage power plant, the Walchensee power plant contributes around 100 million kilowatt hours a year to cover Deutsche Bahn's peak demand. The Aufkirchen, Eitting and Pfrombach power plants on the Mittlere-Isar canal supply around 370 million kilowatt hours of green electricity to Deutsche Bahn. This is enough electricity to drive an ICE train around the world several times.