By Hollie Moffett
Ocean energy, otherwise known as “blue energy”, encompasses the different technologies that are used for energy production, usually from various marine resources, to generate electricity. As of 2023, the total capacity of global marine energy reached 527 megawatts (MW): South Korea (KOR) performing the highest with 255.6 MW, followed by France with 212 MW, and the United Kingdom with 23.8 MW. From the visuals below, the top 3 leading nations of 2023 have generated considerable amounts of electricity through marine engineering, especially from 2013 and onwards, and has maintained a steady progression a decade later.
Ocean energy falls under the intersections of Energy, Marine, and Water. Within the energy sector, ocean energy is a clean and sustainable source of electricity generation as it aligns with the global shift towards renewable energy sources and reducing GHG emissions. Regarding the marine sector, ocean energy technologies are deployed in marine environments, requiring marine engineering and oceanography expertise.
Concerning the water sector, ocean energy technologies interact with water bodies, which demands careful consideration of marine biodiversity and coastal zone management. E Co. has substantial project experience across these three sectors. Beverley Salmon, E Co’s Head of Consulting, affirms that in ‘harnessing our team’s considerable expertise in these areas to support in unlocking the potential of ocean energy is an opportunity for considerable impact’.
In every aspect of E Co’s project design, we adopt a relevant lens to enhance the understanding of the project’s context. And so, by selecting a mitigation lens, this article explores the various forms of ocean energy, including wave, tidal, thermal, current and osmotic, and discusses their current state of development and future prospects.
Wave energy
Wave energy relates to the solar energy contained in ocean waves that can be used to generate electricity. Types of wave energy technologies include oscillating water columns otherwise called ‘converters’ that drive turbines through trapped air. Such converters include the floating ‘Mighty Whale’ found in Mie Prefecture, Japan, the submerged ‘WaveRoller’ that can be found in near-shore areas, and the ‘Sea Slot-cone Generator’ which utilises wave overtopping.
Tidal Energy
Tidal energy is potential energy that can derive from the height changes in sea level as a result of the gravitational pull of the moon. Such technologies include barrages that can be built on estuaries, tidal array optimisation, and subsea hubs such as the MeyGen energy plant found in the north of Scotland.
Thermal Energy
Ocean thermal energy (OTE) converts the temperature difference between warm surface seawater and cold seawater (800-1000 meters) into power. Its technologies are still in its experimental stage; however, they typically include modular systems or hybrid thermal energy storage systems. It is estimated that Asia-Pacific will lead the expansion of OTE as several development plans have been introduced in China, Japan and the Maldives.
Current Energy
Ocean current energy channels the kinetic energy of currents using tidal horizontal-axis turbines or propellers, either attached to the seabed or float in water. The rotors oscillate based on the tidal currents, which in turn generate tidal electricity. Minesto, a Swedish tidal energy company with branches in Northern Ireland, Wales, the Faroe Islands and Taiwan, uses tidal kites to generate electricity from current and tidal streams.
Osmotic Energy
Osmotic energy arises from the differing salt concentrations where a river empties into an ocean. Norway implemented the world’s first osmotic power plant called ‘Statkraft’ back in 2009 and since then other osmotic plants have been created in the Rhone delta, France and in Friesland, Denmark.
Advantages and Future Prospects
In recent decades, developments in technology and increasing global demand for sustainable energy sources is driving the progress of ocean energy forward. The following advantages are as follows:
- Provides power to coastal, remote and inland communities
- A resilient energy source
- Creates opportunities for further marine research and development
- More predictable than solar or wind energy
- Fosters economic growth through job creation for coastal communities
- Smaller carbon footprint than fossil fuel use
From the support ocean energy can provide, this article also links to two of E Co’s core principles: ‘Empowering communities, shaping futures’ and ‘People, planet, and profit’ as this type of renewable energy can protect and economically enhance vulnerable and coastal communities as well as being substantially cleaner than carbon-based fuels reducing its severity on the planet.
Concerning its future potential, in terms of wave power, Horizon Europe has allocated 78m EUR (82m USD) of its funding to pilot farm demonstrations which will lead to the deployment and testing of future ocean energy projects. Research has shown that by capturing just 1% of the energy in global waves, it could power 50m households. Miodrag Grujić, Principal Consultant at E Co, elaborates, “Ocean energy could contribute between 5% to 10% of the world’s energy needs by 2050, reducing GHG emissions by 1.5 to 3 billion tons annually. In the energy sector, any emission reduction of at least 0.1% is enormous.” However, there needs to be continuous environmental assessments concerning the construction of ocean energy materials to ensure the protection of marine life and ecosystems.
To summarise, ocean energy is still in its infancy with vast possibilities for further innovation. For the benefit of our predominately blue planet, ocean energy can complement other renewable sources like solar and wind power, creating a more reliable and resilient energy system.
References
- Planete Energies. 2021.
- Statista. 2024.
- International Renewable Energy Agency. 2024.
- Office of Energy Efficiency and Renewable Energy. 2024.
- Economist Impact.
