What are the problems with the use of hydropower



Hydropower was already used in pre-industrial times to drive mills, sawmills and hammer mills. The kinetic and potential energy of a water flow is converted into mechanical rotational energy via a turbine wheel, which can be used to drive machines or generators. Today in Germany almost exclusively electricity is generated with hydropower.

Hydropower is a mature technology that generates the largest share of renewable energy worldwide, second only to the traditional use of biomass.

The role of hydropower in the future

The greatest potential for the use of hydropower lies in the southern federal states, as the foothills of the Alps ensure a favorable gradient here. The main potential of hydropower lies in the replacement, modernization and reactivation of existing systems and in the construction of new transverse structures. All environmental concerns must be considered in a balanced way. The aim of the federal government is to increase performance combined with an improvement in the water-ecological situation.

Differentiation of the hydropower plants

Waterworks are divided into small (less than 1 MW) and large systems (greater than 1 MW). Of the large hydropower plants in Germany, 20% are storage power plants and 80% are run-of-river power plants.

  • Small hydropower plants

    There is a certain potential for expansion in small hydropower plants, in particular through the modernization and reactivation of existing systems or through the occasional new construction of existing transverse structures. The concerns of nature conservation and aquatic ecology must be taken into account. The systems are used both in stand-alone operation and connected to the grid. Technically, these are also storage or run-of-river power plants, which, however, only deliver lower performance due to lower heads and water volumes. The costs for the construction of hydropower plants are generally tied to the amount of installed capacity, but also depend on the height of the fall, the other site conditions and in particular the necessary ecological measures.

  • Storage power plants

    Storage power plants use the high gradient and the storage capacity of dams and mountain lakes to generate electricity. In the dam power plant, the turbines are located at the foot of the dam. In the mountain storage power plant, a lake lying high up is connected to the power plant in the valley via penstocks. Storage power plants can be used both to cover the electrical base load and in peak load operation. Pumped storage power plants are not filled with natural water, but with water pumped from the valley. This means that electrical power generated in off-peak times is temporarily stored as potential water energy and can be called up again via a turbine during peak load times.

  • Run-of-river power plants

    Run-of-river power plants use the flow of a river or canal to generate electricity. Characteristic is a low height of fall with a relatively large amount of water, which often varies more or less depending on the season. For economic reasons, the systems are often built in connection with locks.

Hydropower potentials are described in more detail in a study by the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety.

Additional information

Additional information