What is marine energy?
The Netherlands live with water
To protect the lowlands from the sea, the Dutch have accumulated lots of knowledge and expertise on water management. Today, however, the Netherlands is re-defining its relationship with the ocean. The ocean can be used to generate sustainable energy and combat climate change. Tidal energy, wave energy, ocean thermal energy and salinity gradient energy offer a win-win situation for the security of our energy system and our planet.
Tidal energy is based on the concept of using the natural tides of oceans to produce energy. Low tide and high tide create a water flow and sea level differences that can be turned into electricity. Contrary to solar and wind energy, which depend on the irregular presence of sun and wind, tidal energy is fully predictable. Tidal energy is a 100% reliable source of energy. The efficiency of tidal energy depends on the velocity of the seawater flow, hence on the difference of sea levels between ebb and flood. Areas with high sea level differences are mostly located close to the ocean and relatively far from the equator.
Sea and ocean waves contain energy that can be turned into electricity. The amount and intensity of waves can be predicted a few days in advance, similar to wind energy. Areas with the highest potential for wave energy are located in the open ocean and far from the equator, as waves are highest there.
Ocean Thermal Energy Conversion
In tropical oceans, the natural difference in temperature between the surface and deeper water layers can be used to generate clean, reliable electricity, day and night, year-round. This is called Ocean Thermal Energy Conversion (OTEC). OTEC is best suited for areas near the equator, as large differences in temperature are present there.
Salinity gradient energy
Salinity gradient energy is produced by making use of the difference in salinity between salt water and fresh water. The technology can be applied in any location where both salt water and fresh water are available. Consequently this is promising in combination with coastal water defences such as dikes and dams.