Potential of small hydro power plants for delivering control energy in Germany

A power system that mainly bases on renewable energy sources leads to a higher demand on ancillary services. To ensure the stability of the network, new approaches need to be developed. This paper analyses the potential of small run-of-the-river hydro power plants for participation in the German balancing power market. For this, the necessary technical properties for the units are described as well as the needed additional technical features. The deliverable control energy of small hydro power plants is estimated and evaluated concerning economic and technical aspects. The current German renewable energy act from 2012 simplifies the direct distribution of energy from renewable energy resources. Accordingly, the impact of the provision of control energy is investigated. Also, a combination with other renewable energy sources like photovoltaic or wind energy to a virtual power plant is considered as well.