It was in the 1960s that tidal energy emerged. Today, this energy has continued to be developed and there are different mechanisms to harness it, although it can only be generated in very small quantities. This is because there are no sufficiently advanced technologies available to be able to make optimal use of it and replace traditional energies.
If you want to learn more about this type of energy, as well as how tidal power plants use the tide to generate energy, keep reading this interesting article from EcologíaVerde because here we talk about what tidal energy is and how it works .
What is tidal energy?
We call tidal energy, ocean energy or marine energy the energy that is obtained by taking advantage of the movement produced by the tides , that is, when they rise and fall. The energy that is generated naturally in this way is used by the turbines that, when activated, move the mechanical assembly of the alternator and, thus, electrical energy is produced .
It is important to mention that this energy is sometimes confused with wave energy , also called wave energy . Wave energy is produced by the movement of waves and tidal energy by the movement of tides, so they are not the same even though both are produced in the sea. Here you can learn more about What is wave energy .
To continue learning about marine energy that uses tides, the next section will explain in detail how tidal energy is produced and we will continue to talk about its characteristics and some examples of power plants.
How tidal energy works
The best places to install a tidal power plant are in an estuary, bay or ria where sea water penetrates and where there is a difference of at least 5 meters between high tide (maximum sea level) and low tide (minimum sea level). Once the location for the plant has been chosen, this is how tidal energy works :
- The construction of a dam is necessary to control the movement of water.
- When the tide rises, the dam gates open and water flows into the reservoir.
- When the water reaches the maximum level of the reservoir, the gates close.
- At low tide the sea level drops and a difference is achieved between the water level of the reservoir and the sea.
- At this point, the floodgates of the loading channels are opened so that the water passes from the reservoir to the sea through the turbines.
- The force of the water causes the turbine’s propeller to spin, and as a result, this movement reaches a generator that produces the electricity.
Characteristics of tidal energy
There are many characteristics of tidal energy , among them we find:
- The main characteristic is that with this type of energy, electricity is obtained thanks to the rise and fall of the tides.
- It is a type of renewable energy and can be produced at any time of the year. We recommend that you learn more about renewable and non-renewable energies: examples and summary with this other article from Green Ecology.
- This is an energy considered clean, since its production does not emit GHG or greenhouse gases. Find out more about What are clean or green energies with this other post.
- Knowing when tides will occur is possible thanks to advances in science and technology, which means that the design of systems can be focused on making them ideal for the potential that is to be obtained.
- It is an energy that we can consider efficient due to the density of water, since energy can be produced even by making the turbines move at a low speed, thus adjusting their production to the need.
- Its facilities are easy to maintain.
- Its facilities are silent, which means that noise pollution is not produced. Obtaining energy is economically affordable.
In the following article you can learn about the advantages and disadvantages of tidal energy .
Examples of tidal energy
The location of the dams is a crucial element for the viability of using this type of energy. Some examples of tidal power plants are:
Sihwa Lake Tidal Power Plant, South Korea
It is located on Sihwa Lake, 4 km from the city of Siheung, installed on the edge of an artificial lake facing the sea. It was put into service in 2011. It is currently the largest tidal power plant in the world and generates unidirectional energy twice a day. It has 10 turbines that have the capacity to produce 552.7 GWh/year, being able to supply 500,000 inhabitants for domestic activities.
La Rance Tidal Power Plant, France
The power station is located in the Rance estuary in Brittany. It has a dam and a breakwater, covering more than 22 square kilometres. It is the first tidal power station to be installed in the world, having been put into operation in 1996. It is still generating energy and is the second largest in the world, able to cover 60% of the energy needs of the Brittany region during the year. The tides of this power station average 8 metres, and it has 24 turbines, producing 540 GWh/year.
Annapolis Royal Tidal Power Plant, Canada
It was commissioned in 1984 and the tides have an average range of 10.8 metres. It only has one turbine installed, which produces 30 GWh/year. The turbine it uses has been in experimental use since 1984, being 18 MW with a consumption of 400 m3/s and, like the Sihwa power plant, it operates in a unidirectional direction.
