A while back in the Netherlands, there was a plan to use the saline gradient between salt and fresh water as a battery. It was briefly in the news, and then I n

A while back in the Netherlands, there was a plan to use the saline gradient between salt and fresh water as a battery. It was briefly in the news, and then I never heard anything, but perhaps that is the idea? The energy from desalination goes into creating a fresh-salt gradient. It stands to reason that some of that energy could be recovered from the gradient between the brine and the sea water.