We explain what tidal energy is, its main characteristics and uses. Also, its advantages, disadvantages and examples.
What is tidal energy?
It is known as tidal energy. to which It is obtained from the use of the tides. Through tidal power plants, sea water is used in different ways to generate, through a system of alternators, an electrical charge that can be used in numerous ways.
The operation of these plants is simple: When the tide rises, the plant's floodgates open and water is allowed to enter which will then be retained when the tide goes out, to be released through a mechanism of turbines that will transform the kinetic or potential energy of the water into electricity.
The use of tidal energy can occur in three different ways:
- Tidal current generators Also called TSG (from English tidal stream Generators), they take advantage of the movement of water to convert kinetic energy into electrical energy, just as wind plants do with the wind.
- Tidal dams. They operate as described above, taking advantage of the potential energy of the dammed water to mobilize the generating turbines.
- Dynamic tidal energy. Also called DTP (from English dynamic tidal power), combines the two previous ones: it consists of a system of large dams that induce different tidal phases in the water, and then mobilize their generating turbines.
In the case of plants that take advantage of ocean waves instead of tides, it will be called wave energy and not tidal energy.
See also: Clean energies
Characteristics of tidal energy
Tidal energy is a type of renewable energy (since the tides never run out) and clean (since it does not underproduce elements that pollute the environment).
However, the relationship between the cost of construction of tidal plants, the environmental and landscape impact they have, and the amount of electrical energy produced, makes it an expensive and ineffective technology which has prevented its popularization in the world.
Uses of tidal energy
Tidal energy is used as source of electrical energy to power small towns or industrial facilities. This electricity can be used to illuminate, heat or activate mechanisms of all kinds.
Advantages of tidal energy
The advantages of this type of energy lie in the total absence of consumable raw materials, since the tides are infinite and inexhaustible in human terms, which makes tidal energy a form of renewable, inexhaustible and economical energy, which does not fluctuate according to the prices of an input in the international market as happens with oil.
On the other hand, does not underproduce chemical or toxic elements whose disposal requires additional effort as occurs with radioactive plutonium from nuclear energy or with the greenhouse gases released by the combustion of fossil hydrocarbons.
Disadvantages of tidal energy
The main drawback of this form of energy is how ineffective it is; in ideal cases it can provide electricity to hundreds of thousands of homes, but through colossal investments that have a quite negative landscape and environmental effect since we must intervene directly in the marine ecosystem. This makes the relationship between the cost of manufacturing the plant, the ecological damage and the amount of energy obtained not very profitable.
Examples of tidal energy
Some examples of tidal plants are:
- La Rance tidal power plant Located in France and inaugurated in 1996, it produces electricity for 225,000 inhabitants, which is nothing to sneeze at (9% of Brittany's electricity). Its facilities are 390 m long and 33 m wide, and a 22 km² reservoir.
- Sihwa Lake Tidal Power Plant Built in South Korea on Lake Sihwa, about 4 km from the city of the same name, it generates around 254 MW of electricity and has the largest tidal facilities in the world: a 12.5 km long sea wall and a of 30 km².
- Tidal Lagoon tidal power plant Planned in Great Britain, in the United Kingdom, in Swansea Bay, it will equal La Rance in its capacities and will generate about 240 MW of electricity. A budget of around £850 million is allocated for the project and construction began in 2013.
