Abstract: Osmotic power plants belong to the ocean renewable energy source exploiting the potential of salinity gradients, which occur in the mixing zone of river and sea water at the mouth of rivers.
The global potential of salinity gradient energy is huge and theoretically only limited by the world’s river water flux into the oceans. In practice, only a small amount of this potential can be exploited. Taking technical constraints of the energy conversion into account, the global technical potential is calculated to approx. 5.200 TWhel/a. Based on the fact that the extractable river water is limited to sustain the ecological stability of the river, the ecological potential for osmotic power plants is introduced. Being a subset of the technical potential it is calculated to 520 TWhel/a.
In theory, every river-mouth is a possible location for an osmotic power plant, but there are several practical constraints. Site criteria to identify suitable regions for osmotic power plants are defined and the potentials for selected regions are calculated.
