Question

What is the principle behind ocean thermal energy?

Answer 1

Ocean thermal energy:

1. The Sun heats the water at the sea's or ocean's surface, while the water in deeper sections is relatively cold.
2. This temperature difference is used to generate energy in ocean-thermal-energy conversion plants.
3. These plants can operate if the temperature difference between surface water and water at depths of up to $2\mathrm{km}$ is $20\mathrm{K}(20°\mathrm{C})$.
4. The hot surface water is used to boil a volatile liquid such as ammonia.
5. The liquid vapors are then used to power the turbine of the generator. Cold water from the depths of the ocean is pumped up and condensed the vapor into liquid again.