What is the principle behind ocean thermal energy?
Statement1: The warm water at surface is used to boil ammonia , which vaporizes and then used to rotate turbine.
Statement 2: The ammonia is vaporized as only then it gains sufficient kinetic energy for power generation.
Statement 1 and Statement 2 are correct, But statement 2 is not the reason for statement 1
The water at the surface of the sea or ocean is heated by the Sun while the water in deeper sections is relatively cold. This difference in temperature is exploited to obtain energy in ocean-thermal-energy conversion plants. These plants can operate if the temperature difference between the water at the surface and water at depths up to 2 km is 20 K (20°C) or more. The warm surface-water is used to boil a volatile liquid like ammonia. The vapours of the liquid are then used to run the turbine of generator. The cold water from the depth of the ocean is pumped up and condense vapour again to liquid.