Marine energies are all the types of energy used in the ocean or along the coast. Different marine energies are generated by solar energy and gravity.
Types of marine energy include:
- tidal power energy, which uses the tides;
- the energy of the swell and waves (wave energy), which uses the vertical movement of the swell;
- ocean current energy (swell current, thermohaline current, etc.), which activates different types of turbines;
- off-shore wind energy, which uses the more powerful and regular ocean winds;
- ocean thermal energy (OTE), which uses the thermal gradient between surface water and deep water;
- osmotic energy, which uses the differences in salinity to produce a water flow;
- marine biomass, especially to produce biofuels from algae.
Marine energies are not, therefore, just hydraulic energy. These energies also include wind, hydrothermal, etc. elements. The use of one or another of these forms of renewable energy particularly depends on local characteristics: some places are more conducive to off-shore wind energy, others to marine current power, etc.
The large amount of ocean mass on the Earth and the diversity of methods for using these energies gives these forms of marine energy a very high energy potential.
The Rance tidal power plant (France). © Le Chant du Hibou CC by-nc-sa 2.0