Electrical Generation

We explain what electrical energy generation is, its types and how it is produced. Also, stages of the electrical sector.

What is electrical energy generation?

The generation of electrical energy includes set of different processes through which electricity can be produced or what is the same, transform other forms of energy available in nature (chemical, kinetic, thermal, light, nuclear, etc.) into usable electrical energy.

The ability to produce electricity is one of the main concerns of contemporary humanity, given that its consumption has become widespread and normalized since its discovery in the 19th century, to the point of becoming indispensable in our daily lives. Our homes, industries, public lighting, even our personal appliances, depend on a constant and stable supply of electrical energy.

So, global energy consumption is sharply increasing . While in 1900 global energy consumption was only 0.7 Terawatts (0.7 x 10¹² W), already in 2005 it was estimated at about 500 Exajoules (5 x 10²⁰ J), equivalent to 138,900 Terawatts.

The industrial sector is the largest consumer of all and therefore the developed world (the so-called First World) is responsible for the highest percentages of consumption. The United States, for example, consumes 25% of the energy generated worldwide.

Therefore, the search for new and more efficient ways to obtain it is an area in which enormous scientific and technological resources are invested, especially at a time in which the climatic effects of industrialization and the burning of fossil fuels have become not only obvious, but alarming.

How is electrical energy produced?

Electricity, in general, It is produced in large facilities called power plants or power plants, which, taking advantage of different types of raw materials or natural processes, “manufacture” electricity.

For this purpose, for the most part, the power plants have alternators, which are great devices that generate alternating current . They are in turn composed of a coil, which is a large, rotating roll of electrically conductive material arranged in threads, and a magnet that remains stationary.

By spinning the coil inside the magnet at high speeds, a phenomenon called electromagnetic induction occurs : The resulting magnetic field mobilizes the electrons of the conductive material, creating a flow of energy that must then be “prepared” for distribution through a series of transformers.

The issue, then, is how to make the coil rotate at high speeds and constantly. In 19th century experiments with electricity, it was generated by pedaling a bicycle, which produced only a minimal amount, of course.

In the case of power plants, something much more sophisticated is required: a turbine, which is a rotating device capable of transmitting mechanical energy to the coil making it rotate, from the use of another force.

For example, you can use the fall of water in a waterfall, or the constant blow of the wind, or in most cases, the rising steam of a good amount of boiling water, for which it is necessary to generate a quantity constant heat, through the combustion of various types of materials.

As will be seen, the complete process of generating electrical energy is nothing more than the transformation of chemical energy into caloric energy (combustion), and then converting it into kinetic and mechanical energy (by mobilizing the turbine), and later into electromagnetic energy, that is, , in electricity.

Stages of the electrical sector

The electrical sector is the one that is in charge of the entire electricity production circuit, from its inception to its consumption in each of our homes, for example. The entire energy production cycle in this sector involves the following stages:

• Generation . The first stage, logically, consists of obtaining electricity through the available means, in any of the types of power plants that exist.
• Transformation . Once the electricity is obtained, it is usually subjected to a transformation process that prepares it for its transportation along a power grid, since electricity, unlike other products and goods, cannot be stored for consumption. later, but must be transmitted immediately.

The so-called substations or transformer plants are responsible for this, located near the power plants, and also the transformation centers, close to the consumer populations, since their mission is to modulate the electrical voltage to make electricity transportable (high voltage) and consumable (low voltage).

• Distribution . Electricity must ultimately be supplied to our homes or to the industries that consume it through a wiring network known as power lines, and which is usually handled by different energy distribution and marketing companies.
• Consumption . Finally, each consumer home or industrial plant has a link installation, which links the distribution networks with the interior facilities, allowing the energy to be present wherever we need it.

Types of electricity generation

Electrical generation is normally classified by the type of power plant in which it is produced, or what is the same, according to what specific procedure is used to, as we explained before, mobilize the turbine to rotate the coil that in turn time generates electricity. Thus, we have:

• Fossil fuel thermoelectric energy . Thermoelectric plants are those that produce electricity from heat energy, boiling large quantities of water, or similarly heating other gases, thanks to the combustion of various organic materials (coal, oil, natural gas or other fossil fuels) in a internal boiler. In these cases, the expanding gas is responsible for mobilizing the turbine, and then it is cooled to repeat the cycle.
• thermonuclear energy . The principle of operation of thermonuclear energy is not different from that of thermoelectric energy, with the exception that the heat necessary to rotate the turbines is obtained through various chemical processes of fission of heavy atoms, that is, by bombarding the atoms with particles. atomic nuclei of certain elements, to force them to become other lighter elements and release an immense amount of energy. In these plants, known as reactors, the same logic as the atomic bomb is followed, but applied for peaceful purposes. The disadvantage is that it produces radioactive waste that is difficult to handle and highly toxic.
• Geothermal energy . Again, in this case the operation of the power plant obeys the thermoelectric model, but without the need for fuel or boilers, since the internal heat of the Earth's crust is used. To do this, a convenient tectonic location is required, that is, an area with tectonic activity that allows water to be poured into the earth's depths and take advantage of the resulting steam to mobilize electric turbines.
• solar thermal energy . Similar to the previous cases, this type of power plants take advantage of sunlight, focusing and concentrating it through a complex system of mirrors, in order to heat liquids to temperatures between 300 and 1000 °C, and thus initiate the thermoelectric generation process.
• photovoltaic energy . This type of energy is also obtained by taking advantage of sunlight, but in a different sense: through large fields of photovoltaic cells, composed of diodes sensitive to sunlight, which generate small potential differentials at their ends. Large locations of these solar panels are required to generate electricity, but at the same time it is done without requiring raw materials and without polluting the environment too much.
• Hydroelectric power . In this case, the electric turbines of the generation plant are not moved by the action of heat, but rather by taking advantage of the mechanical energy of a fall of water. For this reason, a specific topography is required for this, such as waterfalls, waterfalls, mighty rivers or bodies of water in which dams or dams can be installed. Beyond the brutal modification of these bodies of water and their own ecosystems, it is a form of clean, cheap and safe energy.
• Tidal or wave energy . This is the name given to plants that obtain electrical energy from the tides or sea waves, through coastal installations that, through floating devices, take advantage of the thrust of the water to mobilize the turbines. However, these are not very powerful and unprofitable ways of obtaining energy, at least for the moment.
• Wind energy. If in the previous cases the natural movement of water was used, in wind plants the push of the wind is used, especially in regions where it blows constantly, such as coastal areas, large plains, or similar. To do this, there are entire fields of giant propellers, sensitive to the passage of the wind, which when moving transmit mechanical energy to an electric turbine. It is a relatively economical and safe way of producing electricity, but unfortunately very little powerful and with a significant cost in terms of landscaping.

Renewable energies

Obtaining electricity is a complex process with a very high environmental impact, especially in its traditional variants, such as fossil fuel. Furthermore, in these latter cases, the available fuel has limited reserves, since coal and oil have a very slow and prolonged geological origin, which does not allow planetary stocks to be replaced at the same rate at which we are consuming them.

Therefore, Many of the efforts of the energy sector are invested in the search for possible renewable sources or in the improvement of those that already exist, such as solar, hydroelectric and geothermal energy.

However, The great hopes of humanity in energy matters point to the possibility of atomic fusion as a safe, reliable, non-polluting and renewable source of energy: hydrogen atoms, the most abundant element in the universe, are taken and fused to generate enormous amounts of energy, just as happens in the hearts of stars in space.

Unfortunately, such technology is still far from our reach, so humanity will have to make greater efforts to adapt its energy consumption to the possibilities of the world, or risk ruining it completely in our desire for infinite electrical energy.

References

• “Electric power generation” on Wikipedia.
• “Electrical supply system” in Wikipedia.
• “How electrical energy is generated” at Endesa.
• “How is the electrical energy you consume generated?” (video) at the Technological Institute of Monterrey (Mexico).
• “Types of energy generation” in Seisa Energía.