| Someone with more engineering sense than I can debunk this: The Baltic is dramatically less saline than the Atlantic. That's why the Vasa [1] was so well-preserved after 300 years at the bottom. So could we not take advantage of that salinity difference, somehow? [1] https://www.vasamuseet.se/en Edit: Every engineering student sees the movie of the Tacoma Narrows bridge collapsing. To me, the Vasa is a much better career lesson: Marketing dictating a stupid Engineering decision. "Hey, let's put another gun deck on that thing! It'll be so much more imposing." |
The salinity of the Baltic varies but is generally below 13 g/kg, which is a lot less than the salinity of the Atlantic (around 35 g/kg). This corresponds to an osmotic pressure differential around 1.8 kJ/L (1.8 MPa). If you were to build a dam which had a gravity pressure which matched this pressure differential it would be about 180 m high. So, yes, there is plenty of energy in that salinity difference, but getting it out in a cost effective manner is an open problem.