Renewable marine energies, state of the art, technological bottlenecks and perspectives

The ocean is a huge reservoir of energy that is very little worked. This article reviews the different ways to use the energy stored in the ocean: -) thermal energy, -) the energy of the ocean streams, -) the energy of the tides, -) the energy of the waves, and -) the off-coast wind energy. This article reviews the different projects throughout the world, the potentialities of such energies and the technical challenges to overcome. (A.C.)