Reversed electrodialysis (RED) is a method of extracting electrical power out of salinity gradient energy between seawater and freshwater. It functions similar to any other electrochemical method, effectively it is a fuel cell that uses ions from seasalt as fuel. Ions are exchanged through selective membranes, so that cations and anions flow in opposite directions, effectively creating an electrical current that is balanced by opposite-equal flow of electrons through the electrical circuit it feeds.
How much energy is available for harvesting this way?
>In the Netherlands, for example, more than 3,300 m³ fresh water runs into the sea per second on average. The membrane halves the pressure differences which results in a water column of approximately 135 meters. The energy potential is therefore e=mgΔh=3.3*106 kg/s*10 m/s2*135 meters ca.= 4.5*109 Joule per second, Power=4.5 gigawatts.
What's Ernst's opinion on this readily available source of energy?