Write two different ways of harnessing energy from ocean.

The two different ways of harnessing energy from ocean are:

1. Tidal energy: Due to the gravitational pull of Moon on Earth results in rise in the level of the ocean which causes high and low tides. The difference in the ocean-level results in tidal energy. This energy can be harnessed by construction of dams across the Sea.

2. Ocean Thermal Energy: The ocean thermal energy arises due to heating of water at the surface of sea or ocean by the radiations of Sun which results in heating of upper surface of ocean but the lower surface remains cold. This temperature difference is used to obtain ocean thermal energy.