Ocean- the ocean water possesses energy into two forms- ocean thermal energy & oceanic wave energy.
$$Ocean\ thermal\ energy$$ - it is the energy that is available as a result of the differences in temperature of water at the surface and at deeper levels of the ocean. Ocean thermal energy is harnessed to produce electricity with the help of a device known as ocean thermal energy conversion plant ( OCTEC power plant)
$$Oceanic\ wave\ energy$$ - The kinetic energy possessed by fast moving oceanic waves is known as wave energy.