Full title (too long): The Osmotic Pump: In principle, but probably not in practice, fresh water can be extracted from our oceans for no expenditure of energy.

Full title (too long): The Osmotic Pump: In principle, but probably not in practice, fresh water can be extracted from our oceans for no expenditure of energy. Emphasise is mine. Still an interesting concept that is not widely discussed, and not a perpetual engine fallacy.