(a) The water at the surface of the sea is heated by the sun, while the water in the deeper sections is relatively cold. This difference in temperature (heat from the sun) is exploited at ocean thermal power plant to produce electricity.
(b) Tidal energy
Wave energy
Ocean thermal energy
The source of tidal energy is tides, the rise and fall in the level of sea, produced by gravitational pull of moon, on the spinning earth
The source of wave energy is the kinetic energy of waves
The source of ocean thermal energy is the difference in temperature of water, at the surface and in the deeper sections.
