Osmotic energy
A new source of energy in the Rhone Delta!
Osmotic energy is generated naturally by the difference in salinity between the freshwater of rivers and the saltwater of the sea when they meet.
Its advantage is that it produces non-stop 100% natural, renewable and carbon-free electricity. It is controllable 24/7: production can be increased or reduced according to need and programmed with precise forecasting.
The energy transition expertise centre of the European Commission has evaluated the potential of osmotic energy exploitable for the European Union at 50.8 TWh/year.
How does it work?
The salt contained in seawater is composed of two chemical elements: sodium (NA+) with a positive electric charge, and chlorine (CL-) with a negative electric charge. When saltwater and freshwater come into contact, sodium and chlorine ions diffuse naturally and their concentration balances throughout the volume of water.
Placing a semi-permeable membrane between freshwater and saltwater allows controlling this diffusion and generating an ionic current, a phenomenon called osmosis, that can then be transformed into an electric current.
Sweetch Energy has developed the technology called INOD®, a new type of bio-sourced ion exchanger membrane that should lead to the development of large-scale osmotic energy generation.
A modelling phase and technical tests
CNR provides Sweetch Energy with its technical expertise in energies and its knowledge of the river to develop an osmotic energy demonstrator in the Rhone delta.
It is carrying out the first phase of modelling the demonstrator in CESAME, its hydraulics laboratory, and is making available an advantageous site on its concession at the lock of Barcarin to test the technology under real operating conditions.
An environmentally friendly power plant
This small-scale osmotic power plant is integrated in two containers. They house the osmotic generator linked to the Rhone by pipes and pumps to convey the freshwater and saltwater required for its operation. A third conduit is used to evacuate the resulting mixture into the area of the maritime canal where the freshwater and saltwater come into contact downstream of the lock.
In addition, the water entering the demonstrator is filtered before circulating in the osmotic generator. It is then completely restored to the natural environment without any pollutant discharge.
L’énergie osmotique Durée : 2:34 min