Osmotic Power
Osmotic power involves placing a volume of salt water and a volume of fresh water in adjoining chambers, separated by a semipermeable membrane. The fresh water moves towards the salt water through the membrane, increasing the pressure when the salt water chamber is closed or raising the level when the salt water chamber is open. The increased pressure or rising water level can be used to drive a turbine that generates electricity. Several osmotic power plant prototypes have been built around the world.