Whenever we speak of renewable energy the first few things which come to our mind are solar panels or towering wind turbines. There is one major drawback associated with solar or wind power which we usually tend to ignore and that is They’re not always available to us. The sun only shines during the day and the wind comes and goes. So, is there any other form of renewable energy from which we can derive power at all times? Well, the answer is yes and the solution is marine renewable energy.
Marine renewable energy is also known as marine power, ocean energy, or ocean power is a type of renewable energy that utilizes sea, ocean, or river water and requires access to offshore grid and distribution systems. Offshore grid includes offshore wind, tidal stream, tidal range, and other technologies operated by wave energy. The tides which are formed due to ocean waves and river currents all have kinetic and potential energy that can be used to drive turbines and produce electricity. This will result in reducing our dependence on fossil fuels for energy.
Three main different types of energies can be derived from oceans or seas which are:
- Tidal current energy
- Wave energy
- River Hydrokinetic energy
Tidal current energy
Tidal energy is the energy that utilizes the kinetic energy of tides which comes into play when the water rises and then falls during tides. Tidal power surrounds gravitational hydropower, which uses the movement of water to push a turbine to produce electricity. The turbines are similar to wind turbines, except they are positioned underwater.
Tidal power can be generated using three different ways; tidal streams, barrages, and lagoons. Currently, the Sihwa Lake project is the world’s largest tidal power station in operation, which is located on the west coast of South Korea. The 254 MW Sihwa project, consists of 10 water turbine generators and produces enough power to support the domestic needs of a city with a population of 500,000 people.
One of the main advantages of tidal current energy is that output can be expected – tides are predictable and constant by the virtue of gravitational forces. All engineers need to is analyse or assess the low or high tide to design efficient systems.
Wave energy is a form of renewable energy that can be harnessed from the motion of the waves. There are various methods of generating wave energy that involves placing electricity generators on the surface of the ocean.
Similar to tidal current electricity, wave energy is known to produce lesser carbon emissions as compared to energy derived from traditional fossil fuels, such as coal or oil, making it an eco-friendlier option.
River hydrokinetic energy
The hydrokinetic energy conversion systems are the devices that are made to convert the kinetic energy of river streams, tidal currents, or any other man-made water channels into useful energy. The systems also require no special head and any physical structure to operate.
River Hydrokinetic energy is harnessed by utilizing the kinetic energy from flowing water in rivers. River hydrokinetic energy technology is similar to tidal energy; However, the difference lies in the flowing pattern. Rivers only flow in one direction and river hydrokinetic energy is available at all times, while there is water flowing.