Hydropower makes use of the natural flow of water - generally in rivers or dams - to generate electricity. In the marine sector, both the tides (the periodic rising and falling of the sea level) and the energy content of currents and waves can be used to generate electricity.
The advantage of hydropower and marine energy compared with wind energy and photovoltaics is that the energy can be provided very steadily over time, or can be reliably predicted. Hydropower is a tried-and-tested source of energy, but in Germany it is already being deployed at virtually all the suitable sites. In contrast, the use of marine energy is still at a demonstration stage around the world, and is not suited for use in Germany.
The research funding by the Federal Ministry for Economic Affairs and Energy supports research projects to generate power from water and marine energy where the environmental conditions are in place (cf. ).