La marine energy comes from the Energy potential, kinetic, thermal and chemical properties of seawater, which can be used to produce electricity, thermal energy or even drinking water. Thanks to the abundance of water on the planet, this renewable energy source offers great potential to reduce our dependence on fossil fuels.
Tidal energy and ocean currents
The technologies for harnessing marine energy are very varied. There are specialized structures, such as tidal power plants, which harness the energy of tidal movement. These power plants operate using large dams and turbines that trap water during high tide and release it during low tide, generating electricity during both phases.
In addition to the tides, the ocean currents represent another important way to capture ocean energy. A typical system for harnessing the energy of ocean currents involves submerged turbines that convert the kinetic energy of water into electricity.
Thermal energy in the oceans
Another innovative technology is the ocean thermal energy (known as tidal wave). It is based on the difference in temperature between surface waters, heated by the sun, and the colder deep waters. Tidal power plants use this temperature difference to generate electricity continuously through thermodynamic cycles.
Wave energy: a promising source
La wave energy (also known as wave energy) is the energy generated by the wave motion of the sea surface. This energy is produced by the wind blowing over the surface of the water, creating waves that contain kinetic energy. This energy can be captured by various floating devices, oscillating water columns or platforms anchored to the seabed that transform the movement of the waves into electricity.
There are currently several experimental wave energy projects, such as the Motrico plant in the Basque Country, which uses turbines to generate up to 296 kW. One of the major challenges of this technology is to harness wave energy efficiently despite its irregular and climate-dependent nature.
The energy of salinity: blue energy
La salt gradient energy, Also known as blue energy, is based on taking advantage of the differences in salinity between sea water and fresh water in rivers. This contrast causes an osmotic pressure that can be converted into electrical energy through reverse osmosis processes. Although this technology is still under development, it has great potential in coastal areas where there are large rivers.
Advantages and challenges of marine energy
Marine energy has several key advantages. Firstly, It is renewable and as a nearly inexhaustible natural resource, a sustainable option for the future. Unlike other renewable sources such as solar or wind, ocean power is predictable and constant, making it more reliable for ensuring continuous electricity production.
Another important advantage is its low environmental impact. Since most technologies are installed underwater, the visual and noise impact is minimized, in addition to not producing emissions of polluting gases.
- Compatibility with other renewables: Marine energy can be combined with other technologies such as offshore wind and floating solar, forming highly efficient hybrid systems.
- Reduced environmental impact: It does not produce greenhouse gases and has almost no visual impact, since most of the infrastructure is underwater.
However, its development presents some challenges. Among these, the following stands out: high initial cost of the facilities, the technical challenges arising from the marine environment, and the need for greater investment in research and development to optimise their efficiency. For example, saltwater corrosion and harsh sea conditions can damage facilities, increasing maintenance costs.
Featured marine energy projects
Europe is leading the development of marine energy, especially in the area of ​​wave and tidal energy. The oldest and best-known plant is La Rance in France, which has been in operation since 1966 and remains a benchmark in tidal power generation. There are also notable projects in the United Kingdom, where large-scale energy parks such as MeyGen, the largest tidal energy facility in the world, are being built.
Outside Europe, South Korea and Canada are countries that have invested in the development of marine energy with pioneering projects. In the case of Chile, its extensive coastline positions it as a key country in the research of these energies, while in Mexico the first wave energy project has been approved in Colima.
Globally, it is estimated that by 2050 marine energy could supply up to 10 % of Europe's electricity consumption, which will not only help reduce carbon emissions but also create thousands of jobs in the maritime and energy industries.
The future of marine energy
The potential of marine energy is vast and its development is essential to help complement other renewable energy sources such as solar and wind. As technical challenges are overcome and installation costs fall, marine energy could become one of the key sources to achieve a cleaner and more sustainable energy matrix. Institutions and governments around the world are betting on this technology, and its integration will be crucial to achieve long-term sustainability goals.
Energy storage and transport are also evolving to meet the needs of the sector, with new infrastructure that will facilitate the connection between offshore projects and onshore power grids. This represents a major opportunity for countries with long coastlines and abundant marine resources.
Marine energy as a renewable energy source has enormous potential thanks to the vastness of the oceans that cover more than 70% of the Earth's surface. Although technologies are still under development, growing interest and projects underway indicate that in the coming decades it will become a key alternative in the global energy transition.