Today there are only a few thousand small hydroelectric power stations in Germany. A hundred years ago there were an estimated 70,000. Why is the freely available power of water no longer used to generate clean energy? Hydroelectric power supplies electricity at a relatively constant level all year round, both day and night. Especially in winter, when PV power generation reaches its limits due to a lack of sunshine, hydroelectric power stations reliably supply electricity during this particularly water-rich season. The Black Forest's topography and numerous streams make it ideal for this type of power generation.