Ocean waves are the most abundant and renewable energy resource available in the environment. The ocean power energy market is estimated to have an annual growth rate of 10.2% between 2017-2023. According to IRENA, marine technologies will fulfill 4% of the entire future global energy requirements by 2050.
Ocean energy represents a considerable portion of energy in the form of ocean thermal energy, marine current, tidal, and wave current. The ocean covers about 70% of the earth’s surface. Thus, it can play a significant role in satisfying future energy requirements and helping to improve the economic growth in marshy areas by reducing carbon emission. This oceanic energy can be categorized in different forms, such as
1. Ocean Tidal Power
This energy is produced by the active movements of ocean water when the rise and fall of tides occur. The flow of water is used to generate electricity. It is a renewable and environmentally friendly resource. In terms of maintenance and operation, tidal power is quite cost-effective than other renewable energy sources, though the installation cost of the tidal power plants is considerably high. The tidal reservoirs are used to create a recreational environment in lakes and dams. It is a significant source of blue power energy.
The blue energy analysis program is used to replace fossil fuels by harnessing the ocean’s kinetic energy. During the 20th century, the tidal surges were used for electricity production in areas where the tidal ranges are experienced. The tidal energy in the UK is forecasted to rise above 10GW, which amounts to 50% of the tidal energy generation of Europe. In India, the first tidal power plant is set to develop in Gujarat. India possesses the potential to generate tidal energy worth 8,000 MW. Energy generation from tidal movements has advanced significantly in the last few years. Still, various projects are awaiting around the world for tidal mill installation and electricity generation. Tidal power is potent enough to help the world to be self-sustainable by supplying its power.
2. Wave Energy
Wave energy is harnessed from sea waves. It is a strong disposition of ocean, which is used as an energy source. The energy generation process is eco-friendly, renewable, and it does not release greenhouse gases to the surrounding, and thus does not support the rise of severe climatic changes and weather conditions as well.
Further, it does not contribute to soil pollution and avoid damages to the landscape. Wave energy plants have forecasted that energy from ocean waves can make a significant contribution to the field of renewable energy resources. The remote areas, especially the coastal regions can be highly benefitted from it. With the possibility of generating wave energy, these remote regions and coastal borders are experiencing considerable growth in the business and industrial sectors. Wave energy is easy to create and it is cost-effective as well. This lethal combination is expected to make a significant contribution in satisfying future energy needs. It can create employment in the areas where wave devices are installed.
3. Ocean Current Energy
Ocean current energy is generated using turbines that are placed underwater. Ocean currents remain constant in terms of flow and acceleration. Turbines are used to harness the energy from oceans by converting it into kinetic energy. The suitable regions to harness ocean current energy are islands, coastal areas, and the areas containing powerful tidal currents. The advancement in ocean power technology is getting prominence through research and technical advancement. Currently, the research is focusing on streamlining the installation process to make the energy generation cost-effective.
4. Osmotic Energy
Salinity gradient energy can be created from differing salt concentrations. It is the process of electricity generation through saltwater and freshwater. The pressure difference between the two different types of water are used to operate a turbine for electricity production. It is especially useful where a river meets an ocean where both of these have different salt concentration levels. The osmotic energy is also known as Pressure Retarded Osmosis. The freshwater flowing through a membrane to increase the pressure in a tank of saltwater; and through “reverse electrodialysis” the ions of salt pass through alternating tanks of salt- and freshwater.
The osmotic power plant releases minimal harmful and CO2 emissions in the atmosphere and contributes to environment-friendly surroundings. It recycles natural resources and has a minimal environmental footprint. The ocean energy is harnessed where the sea and freshwater are available in large quantities or where the salt concentration is relatively more. It is estimated that osmotic power has the potential to produce around 1700 TW of energy every year. The estimated energy production cost is less than other energy resources, which makes it a viable energy source.
Salinity gradient is another effective and renewable way of creating energy resources, though most of its possibilities are still in its experimental phase.
5. Ocean Thermal Energy Conversion
It is a technology for energy production by using the difference in temperature between the ocean surface and the deep ocean. The heat engine efficiency depends on the temperature difference. The energy generation from ocean thermal energy conversion (OTEC) is stable and predictable. The energy produced is independent of weather conditions, though the quantity of energy production varies according to seasons. It generates energy without releasing any harmful gases to the surroundings. It is fuel-free and provides clean water for commercial areas and agricultural irrigation. It is a renewable, environmentally sustainable, and clean energy source. OTEC has the potential to generate energy in bulk, and yet the maintenance and construction cost is quite low. OTEC works as a collaboration platform for the various energy research centers. These systems are set up in several countries to meet the electricity requirements, supply desalinated water to land and provides nourishment to agriculture.
Geographically spread as one third of the earth, ocean energy is helping the world to trigger the modern power generating process, create job opportunities, and enhances economic growth. The Ocean Energy Collaboration Programme focusses on developing ocean energy and aims to satisfy the 25% of world energy demands by 2050. We have arrived at a situation where the energy requirement is increasing than ever before. To meet the energy requirements, we need to consider it for better development in the future.