A power plant is a facility that transforms energy into electricity.
Most of the power generation plants work using a heat source, thermal energy. This heat source can come from the combustion of fossil fuels or uranium in nuclear power plants.
However, there are other types of plants that work in a very different way. It is the case of wind farms, photovoltaic plants, or tidal power stations.
Depending on the energy source, they can be classified into:
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Renewable energy plants which its source to generate electricity is inexhaustible. Solar energy plants is an example of a renewable power plant.
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Non-renewable energy plants in which the regeneration capacity of the energy source is less than the consumption. For example, coal-fired power plants are non-renewable power stations.
How does a thermoelectric plant work?
Thermoelectric power plants are thermal power stations whose objective is to transform thermal energy into electrical energy. Generally, they use their heat source to boil water and then generate electricity.
This conversion is done by the thermodynamic water/steam turbine cycle (Rankine cycle). In this case, the steam source is to generate the steam that drives the turbine.
In thermoelectric plants, there are three essential elements to produce electrical energy:
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A steam turbine. The turbine converts thermal energy into kinetic energy.
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An alternator to convert mechanical energy into electrical energy.
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A transformer to modulate the electrical current obtained to alternating current with the desired potential difference.
There are different types of thermal power plants:
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Classic: they obtain energy from the combustion of fossil fuels.
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The biomass obtains the energy from forest and agricultural residues’ combustion or the famous energy crops.
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From the incineration of urban solid waste: they obtain energy through the combustion of treated garbage.
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Nuclear power plants: they generate energy thanks to the fission reactions of uranium atoms.
What is a combined cycle power plant?
Combined cycle power plants transform the thermal energy of natural gas into electricity through the joint work of a gas turbine and a steam turbine.
There is a type of industrial facility that is a combined cycle. In combined cycle plants, there are two thermodynamic cycles:
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Brayton cycle. This cycle works with a gas turbine, generally natural gas, by combustion.
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Rankine cycle. It is a conventional water and steam turbine cycle.
What are the advantages of a combined power station?
Combined cycle power plants are more flexible than conventional ones. It means that it can operate at full load or partial loads, down to a minimum of about 45% of maximum power.
Also, they are more efficient, their emissions are lower, the consumption of cooling water is lower, and they save energy in the fuel.
Lastly, they are built more quickly than other plants and require less surface area per MW installed, which reduces the visual impact.
Types of power plants
The different types of power plants are as follows:
1.- Nuclear power plants
Nuclear power plants are a type of thermoelectric power plants. All the amount of energy comes from the nuclear fission of uranium atoms.
Fission reactions take place inside the nuclear reactor with extreme safety measures. A nuclear accident can have devastating environmental impacts.
2.- Wind power plants
These types of power plants take advantage of the force of the wind to turn a turbine. In this way, the turbine converts wind’s kinetic energy into electrical energy.
It is a renewable energy that does not generate greenhouse gas emissions.
3.- Solar power plants
Solar power plants are gigantic installations of solar panels interconnected. Its sole purpose is to capture vast amounts of sunlight to convert it into electrical energy and cope with industries, urban complexes, and even cities.
This type of plants can belong to two types:
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Photovoltaic plants. They are farms of photovoltaic panels that convert sunlight directly into electric power. They need a significant surface extension.
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Solar thermal power plants work through mirrors. These mirrors concentrate solar radiation to raise the temperature of this point and heat water to generate steam. It is a type of thermoelectric plant.
4.- Hydroelectric plants
Hydroelectric plants work by the force of water in height. By dropping water from a certain height, it is possible to convert potential energy into kinetic energy. The speed of the water enables the hydraulic turbines connected to an electric generator to generate electricity.
Hydraulic energy is a type of renewable energy, thanks to the water cycle.
5.- Geothermal power plants
Geothermal facilities are thermoelectric plants. The heat source for these plants comes from the underground layers of the earth. Volcanic areas are ideal for this type of technology.
The generation process begins with the extraction of the steam and water mixture from the geothermal reservoir. Once brought to the plant, the steam is separated from the geothermal water using a cyclone separator. When the moisture is extracted, the water is returned to the surface again to the reservoir to be reheated.
6.- Tidal power plants
A tidal power station consists of a lockable dam. During high tide, the dam is open, and water flows into the basin behind the dam. When the water reaches the highest level, the gates close, and the water remains in the bay.
If the water difference in front of and behind the dam is high enough, the gates open. Then, the water flows back to the sea through the turbines. Turbines drive electrical generators.
Summary
Power plants are facilities for transforming some type of energy into electricity. The plants that use a heat source as a resource are thermoelectric plants.
Depending on the energy source, they can be:
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Renewable They usually have fewer impacts on the environment. Its source of energy is inexhaustible.
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Non-renewable, which usually uses fossil fuels (coal, oil, or natural gas) or are nuclear power plants.