What is the marine power?

The marine power or marine energy is the exploitation, use or application of the energy carried by waters (oceans, seas, rivers, tides, marine currents, salinity, etc.). Sometimes is also named ocean energy or ocean power. This energy is transformed into electricity that can be used to power homes, business and industries. The idea of using the power of the ocean and sea to produce energy is not new. Up to now the profitable use of this type of energy is very low, with only a few TW installed all over the world, only few countries as Canada, France, USA, UK, China, India, Indonesia, South Korea, Australia, New Zealand are paying close attention to that type of energy. 

Atlantic Ocean in the spanish coast. Picture from Paulo Brandão (Flickr)

Atlantic Ocean in the spanish coast. Picture from Paulo Brandão (Flickr)

A feature of the marine power is their density, higher than in other renewable energies, however their exploitation presents big difficulties due to the adversity of the sea. The first attempts to extract energy from the sea and ocean go back to similar dates as for other sustainable energies sources.

It can be considered that the marine energy or marine power is in a divergence technological phase in which there are many concepts under development and no one has been proved to have a commercial leading capacity. Marine energy is a major growth area in renewable power, many R&D and pilot projects are going on since the oceans represent a vast and largely untapped source of energy in the form of surface waves, fluid currents, salinity gradients, and thermal. The five renewable sources within the marine energies are:

  1. Tidal power; is the energy from moving masses of water. Tidal power generation comprises three main forms, namely: tidal stream power, tidal barrage power, and dynamic tidal power.
  2. Marine current power; is the energy obtained from ocean currents.
  3. OTEC (Ocean thermal Energy Conversion); is the power from temperature differences at varying depths.
  4. Osmotic power; is the energy from salinity gradients.
  5. Wave power; is the he power from surface waves.

According to IEA (International Energy Agency) the marine energy has an enormous potential to grow in the coming years. Only the electricity generation from tidal and wave power will increase from less than 1 TWh (2010) to almost 60 TWh in 2035, with capacity growing from less than 1 GW (2010) to 15 GW in 2035. Tidal power is limited to select sites due to economic considerations, requiring a large tidal range and proximity to existing transmission lines to be considered viable. Wave power has notable potential to contribute to meeting electricity demand, but the relevant technologies are still in their infancy, requiring significant improvements to reduce costs. This situation is being seen by many stakeholders of the energy field as an opportunity to create value, companies,  projects, jobs and business in the coming years.