What is Ocean Energy?
Ocean energy, also known as marine energy, is a type of renewable energy produced by tidal currents, ocean salinity, ocean waves and ocean thermal gradient that can be used to generate electricity used in homes, industries and for transportation. Ocean energy provides a sustainable, dependable and cost-effective source of energy.
A high level of kinetic energy is obtained from the ocean due to the various movements of water in the ocean. It is this kinetic energy that is obtained and used as a source of renewable energy capable of providing power across the world.
Wave power obtained from ocean surface waves and Tidal power generated from the kinetic energy obtained from the movement of water are both part of the constituents of ocean energy. The two types of ocean energy include mechanical energy and thermal energy. Mechanical energy is obtained from ocean tides and waves and thermal energy is obtained from the heat exerted on the ocean by the sun.
Forms of Ocean Energy Resources
Tidal energy is obtained from the movement of large masses of water due to changing tides. Tides result from the periodical rise and fall of the ocean’s surface. The kinetic energy from the movement is harnessed nearshore where constrictions are located.
Tidal range technology, usually a barrage such as a dam, is used to gather the power situated between the low tides and high tides. There are two types of tidal technology used to harness this energy which include tidal steam generators and tidal barrages.
Waves are created due to the interaction between the wind and the surface of the ocean. Energy is transferred from the wind to the surface of the water to form a wave. The size of the wave depends on the speed of the wind, the depth of the ocean, and the distance and duration in which the wind has been blowing.
Wave energy is created by converting the energy produced by the ocean waves into other kinds of energy like electrical energy. This is achieved with the help of various kinds of converter technologies such as oscillating water columns and oscillating body converters.
Ocean Thermal Energy
There is a temperature difference in the ocean between the surface where the sunlight heats and the depth of the water which gets no sunlight. This temperature difference helps in the creation of ocean thermal energy. Ocean thermal conversion plants convert the temperature difference into other sources of energy used for electricity generation and so on.
Salinity Gradient Energy
At the point where a river mixes with an ocean, there is a flow of fresh water into the salt water thereby causing a difference in salt concentration. The energy generated from this salinity gradient can be obtained using pressure-retarded reverse osmosis or reverse electrodialysis.
In the pressure-retarded reverse osmosis process, a membrane is placed in a tank of salt water and freshwater is made to flow through the membrane leading to an increase in pressure. While in reverse electrodialysis, ions of salts are passed alternatively through tanks of fresh water and salt water to produce electrochemical reactions.
Benefits of Marine Energy
- It is a renewable source of energy as it only requires the natural movement of water to work.
- Ocean Energy can be predictable due to the known cyclical nature of tides, currents and waves.
- It is useful in the provision of electrical power to remote areas by using the water surrounding the area and harnessing energy from it.
- It provides job opportunities in local and rural communities because people would be needed to run the production around the area
- The use of ocean energy produces less carbon footprint in the environment and causes no harm to the soil, unlike other sources of renewable and nonrenewable energy.
The negative effects of Ocean Energy
- Fish and other marine animals can be subjected to the danger of being struck by the tidal turbine blades placed in the water.
- The process can exert negative effects on the marine environment, especially the quality of water.
- The process of harnessing ocean energy can lead to the alteration of the behaviour of marine animals
- The electromotive force and noise created underwater from the operation of ocean energy technologies can lead to unpleasant effects.