Plantselectric are industrial facilities designated for the generation of electricity. Power plants use generators that are capable of converting the mechanical energy from some external driving force into electrical energy.
You generators present in power plants are machines capable of rotating at high speeds. Inside, there are big magnets is spiral (a winding of wires with a large number of turns). when there is movementrelative between the magnetic field of the magnets and the coil, a electric current. This electrical current is collected and then distributed to industries, rural areas and homes, through high voltage conductor wires.
The term power plants covers all types of power plants that produce electricity, such as power plants hydroelectric plants, thermoelectric, solar, wind, nuclear, among others.
How do power plants work?
Although there are different types of power plants, almost all of them produce electricity according to the same physical principle: electromagnetic induction, also known as Faraday-Lenz law.
This law establishes that, whenever there is a variation in the flowinfieldmagnetic, an induced electrical current must arise to compensate for this variation. In practical terms, the rotational movement of a coil surrounded by powerful magnets causes the magnetic field flux to vary over time, with this, a large electrical current flows through the coil. All power plants that transform motion into electricity work by this principle.
One of the few power plants that produce energy through a physical phenomenon, other than electromagnetic induction, is the solar power plant of the photovoltaic. In this type of plant, the energy of electromagnetic waves emitted by the Sun is directly converted into electrical current by a large number of solar boards.
Lookalso: Understand how the photoelectric effect occurs
Power Plants in Brazil
Brazil has several types of plants focused on the production of electricity. Among them, the plant hydroelectric is by far the most popular, due to the enormous hydraulic potential of the country. This type of plant is powered by the falling water movement of dammed rivers. Then come the plants thermoelectric, whose energy is provided by the burn of natural gasor mineral coal; and, finally, the plants nuclear, which generate electrical energy from the heat released by the fission of heavy atoms, like Uranium.
Types of Power Plants
According to the type of energy matrix, from which a power plant extracts its energy, it is possible to characterize the latter in different types. Check out some of the most important types of energy and their definition, as well as the names given to the plants that exploit them, in order to obtain electricity:
Hydraulic energy: is the gravitational potential energy contained in water masses that have a height, or unevenness. During a waterfall, this energy is converted into kinetic energy, moving the generators of the plants. This type of energy is exploited by the plants hydroelectric plants and tidal waves.
Thermal energy: is directly related to the temperature of a system. The higher the temperature of a system, the greater the force with which its molecules reach the boundaries that surround it. Thus, this form of energy makes it possible to move large generating turbines using water vapor, for example. The plants thermoelectric and geothermal make use of this type of energy through the coal burning and for the use of steam jets emitted by geysers, respectively.
Solar energy: comes from electromagnetic radiation issued by Sun. This energy can be used to produce a large increase in water temperature in order to evaporate it and drive large turbines. Another use of solar energy is to convert it directly into electrical energy using solar panels, through a phenomenon called photoelectric effect. The plants that make use of this type of energy are the solar plants of the types thermosolar and photovoltaic.
wind energy: is the name given to the kinetic energyof the winds. This type of energy produces the rotation of mills, the movement of ships, etc. The plants that make direct use of this type of energy, through large pinwheels, are the plants wind.
Nuclear energy: is obtained through the nuclear fission in heavy atoms and unstable, like Uranium. During nuclear fission, part of the mass of atoms is converted into an immense amount of energy, this energy is used to heat water, which evaporates under high pressures and, when released, produces rotating turbines generators.
Solar plants, like the one in the photo, are one of the technological applications of the photoelectric effect.
Read too: How solar power plants work
How the hydroelectric plant works
The hydroelectric plants operate through the repression on one big volume in Water. Generally, the depth of dammed rivers can reach hundreds of meters. Such a measure makes the water acquire a large gravitational potential energy. When opening the floodgates of these plants, the water acquires kinetic energy rapidly, and its passage, through the generating turbines, produces electricity.
1 — Reservoir
2 — Dam
3 — Turbine
4 — Generator
5 — Transformer
6 — Distribution
The electrical current that is produced by the generators of hydroelectric plants is called alternating current, as its meaning is quickly reversed, often 60 Hz. At the time of its generation, this electric current has very high intensity, so, in order to avoid large losses of the energy produced, it is directed to a set of transformers which lowers it to lower intensities, reducing losses resulting from the joule effect. Therefore, this electrical current has its electrical potential increased to high voltage values.
Lookalso:Discover the 10 largest hydroelectric plants in the world
Hydroelectric Power Plants in Brazil
Brazil is the third country with the greatest water potential in the world. The hydroelectric plants correspond to more than 60% of all electricity generated in Brazilian territory. It is the most common type of plant in the country, due to its abundance of rivers with great hydraulic potential.
Check out a list of the largest hydroelectric plants in Brazil, followed by their energy production, in MW (megaWats):
Itaipu hydroelectric plant — 14000 MW
Belo Monte hydroelectric plant — 11233 MW
São Luiz do Tapajós hydroelectric plant — 8381 MW
Tucuruí hydroelectric power plant — 8370 MW
According to the National Electric Energy Agency (Aneel), hydroelectric plants are those energy generating facilities capable of producing higher powers The 1 MW. In Brazil, there are a total of 217 plants with such specifications. However, it is considered as hydroelectric generating plants, the installations whose potency é smaller what 1 MW. There are about 698 installations of this type in national territory.
The generating turbines of hydroelectric power plants are formed by huge windings of wires and powerful magnets.
How the thermoelectric plant works
At power plantsthermoelectric produce electricity by heating water and the consequent movement of generator blades in boilers, where highly combustible products such as mineral coal, wood, natural gas, diesel oil and others. There are, however, some types of thermoelectric power plants that do not burn fuel, such as power plants thermosolar, which focus sunlight on large water reservoirs using a set of concave mirrors.
Lookalso:Learn more about how solar power plants work
When water evaporates and remains confined in a reservoir, its pressure greatly increases after its release, the water vapor has enough speed to move the large blades of a generator, thus producing energy electric.
Solar thermal power plants use sunlight to produce the evaporation of large bodies of water and drive generator turbines.
Thermoelectric Power Plants of Brazil
Thermoelectric power plants are very common in Brazil due to their low cost. Little more than 24% of all the electricity generated in Brazil comes from this type of plant. until the year of 2019, Brazil has a number of 3008 thermoelectric plants, capable of generating about 40,000 MW of power.
How the nuclear plant works
THE power plantnuclear uses the energy that is produced by fission of atoms in Uranium to heat large bodies of water and move generator turbines, just as thermoelectric plants do. However, unlike thermoelectric plants, nuclear plants cannot simply be turned off, since the nuclear reaction that produces the energy of these plants is a Chain reaction that cannot be stopped.
In fact, what happens is that, periodically, large bars are inserted with tablets of some chemical elements, capable of absorbing the large number of neutrons emitted by nuclear fissions within their reactors. As a result, there is a drastic decrease in the amount of energy released each second.
The large chimneys characteristic of nuclear power plants are part of their cooling system and do not emit pollution.
Lookmore:Learn more about the operation of nuclear power plants
Nuclear Power Plants in Brazil
There are only two nuclear power plants operating in Brazil that, together, produce about 1,2% of all national electricity, generating about 2007 MW of power. Both are located in the state of Rio de Janeiro, in Angra dos Reis. A third unit, known as Angra-3, which is under construction, should have a power of approximately 1350 MW.
By Me. Rafael Helerbrock
Source: Brazil School - https://brasilescola.uol.com.br/fisica/usinas-eletricidade.htm
