Los océanos ofrecen un enorme potencial energético que, mediante diferentes tecnologías, puede ser transformado en electricidad y contribuir a satisfacer las necesidades energéticas actuales.
Atlas of the resource potential from wave energy of the Spanish coastline, inclusive of the Peninsula and both the Canary and Balearic archipielagos.
The atlas, implemented by the Environmental Hydraulic Institute at Cantabria University upon request of IDAE, takes into account the spatial features of the energy average flux (magnitude and direction) from undefinite depths to the coast. It is a high resolution atlas, which takes into account time variability on different scales: monthly, seasonal, annual and interannual.
There are clear-cut technologies within Sea Energies, depending on the energy use: tidal power, ocean current energy, ocean thermal energy, wave power and salinity gradient power (osmotic).
Tidal power: it consists in the energy exploitation of tides, on the basis of the rise and fall of sea water due to the Sun and the Moon gravitational action – nevertheless, it is only profitable to install a tidal power plant on the points of the coast with a difference over 5 metres in level between high and ebb tides. A tidal power project is based on the water storage in a dam, once having built a dike with floodgates in a bay, creek, river or estuary to generate electric power. The said floodgates enable the water inlet or flow volume to be processed by turbines.
Ocean current energy: it consists in the exploitation of the kinetic energy on sea currents. This capture process is based on the kinetic energy converters, similar to wind generators – in this case, using underwater installations.
Ocean thermal energy: it runs on the exploitation of thermal sea energy, based on the difference in temperature between the sea surface and deep waters.
The exploitation of energy of this kind requires that the thermal gradient should be at least 20ºC. Ocean thermal energy plants transform thermal energy into electric energy, using the thermodynamic circle called Rankine cycle, to produce electric power with a hot focus on the sea surface and the cold one in the sea depths.
Wave power: it is the energy exploitation resulting from wave movement. The sea swell results from the air friction on the sea surface, so it is very irregular. This fact has led to building several kinds of machinery to make its exploitation possible.
Osmotic power: Osmotic power or blue energy is the one obtained through the difference in the salt concentration between sea water and river water by means of osmosis processes.