Illustration of an Deep Green array

Ocean Energy

The ocean forms one of the largest yet least explored renewable energy sources on earth. Ocean energy has the potential for providing a substantial amount of new renewable and reliable energy around the world.

The oceans represent a major source of renewable energy. Different technologies employ different strategies for harvesting that energy. The main sources of ocean energy are:

  • Tidal streams
  • Ocean currents
  • Tidal range (rise and fall)
  • Waves
  • Ocean thermal energy
  • Salinity gradients

Minesto's Deep Green technology is developed to efficiently harvests the energy in tidal streams and ocean currents.

Minesto’s unique technology Deep Green is the only known technology tested and verified in authentic conditions at sites with velocities in the range of 1.2-2.4 m/s. Consequently, Minesto expands the exploitable tidal energy resource by more than 100 percent.

Tidal streams and ocean currents offer safe, reliable and locally produced renewable energy. They have several significant advantages over other renewable energy sources:

  • Predictable and reliable. Unlike wind, solar and other ocean energy sources such as wave power, tides and ocean currents are almost 100 percent predictable. The endless flows create reliability of the future energy availability.
  • Global:  Tidal streams and ocean currents are available on all continents.
  • Energy-rich: Moving water is 832 times denser than moving air, which multiplies the kinetic energy by the same factor. 
  • Limited use of land: In many regions, land is a scarce resource. Therefore, on-shore solutions such as wind and solar compete with other users. Subsea ocean energy technologies such as Minesto’s Deep Green are hidden in the depth of the ocean, out of sight and does not compete for land space.

The large resource of tidal streams and ocean currents can be also exploited with relatively small environmental interaction, thereby offering one of the most lenient methods for large-scale electricity generation.

Tidal streams: closing in on commercialisation

Tides are generated by the gravitational forces between the earth, the moon and the sun. This relative motion creates tidal currents that contain a tremendous amount of energy. Since the positions of the sun and moon can be predicted with complete accuracy, so is the tide’s movement and stream speed.

Together with the fact that tides are not affected by weather or climate makes tidal energy a reliable, predictable source of clean energy, with all prerequisites to become a significant part of the future renewable energy mix. 

Illustration of global tidal currents

Deep Green expands the available tidal energy resource

The tidal energy industry is on the brink of commercialisation, with thousands of megawatts announced for installation or under development. For the last years, major breakthroughs have been made as several MW turbines has been successfully commissioned.

The conventional tidal energy technologies are designed for high-speed locations (above 2.4 m/s of stream velocity). These sites are energy dense, but scarce. Minesto’s unique technology Deep Green is the only known technology tested and verified in authentic conditions at sites with velocities in the range of 1.2-2.4 m/s.

Consequently, Minesto expands the exploitable tidal energy resource by more than 100 percent. The company’s assessment is that the low-velocity tidal stream market exceeds 200GW in installed capacity, corresponding to more than 400,000 Deep Green power plants.

Ocean currents: renewable base-load power

Ocean currents are created by regional differences in temperature and salinity and the Coriolis effect due to the rotation of the earth. Ocean currents exist in open oceans and flow continuously in the same direction with low variability. This means ocean current energy represents a completely reliable non-intermittent energy source.

    Illstration of global ocean currents

    In addition to the earlier mentioned benefits of tidal and ocean currents, the characteristics of the latter brings further advantages such as:

    • High load factors. Since ocean currents are continuous, they enable capacity factors of 70 to 95 percent, which doubles the energy output per installed megawatt and therefore lowers the cost of energy. 
    • Renewable base-load power. The continuous streams mean feasibility for providing sustainable, renewable base-load power to the grid.

    According to the Intergovernmental Panel on Climate Change (IPCC), given the scale of open ocean currents, there is a promise of significant project scale when technologies harness lower-velocity currents. For example, capturing just 1/1000 of available energy in the Florida Current would supply Florida with 35% of its electricity needs.

    Deep Green is the only technology known on the market that is able to utilise the ocean current resource. The company’s assessment is that the ocean current market has a potential of more than 70GW in installed capacity, corresponding to more than 140,000 Deep Green power plants.

    More information on ocean energy

    Useful information on ocean energy can be found on the web sites of the trade orgainsations Ocean Energy Europe and RenewableUK.