Electric energy is the movement of electrons. In general, we define electrical energy or electricity as the form of energy that results from the existence of a potential difference between two points. When these two points are brought into contact by an electrical conductor, we obtain an electric current.
Electricity has many technical applications. In electrical engineering, the theory of electricity is further explored and developed. Unlike many other physical phenomena, many of the phenomena related to electricity can be measured and pre-calculated with great precision.
What is electrical potential energy?
In physics, electrical potential energy is the potential energy of the electrostatic field. Electric potential energy is also called electrostatic potential energy. This is an energy that has an electric charge distribution, and is linked to the force exerted by the field generated by the distribution itself. Along with magnetic energy, electrical potential energy constitutes the energy of the electromagnetic field .
Electrostatic potential energy can be defined as the work done to create a charge distribution from an initial configuration in which each component of the distribution does not interact with the others.
For example , for a discrete charging system, it matches the work done to bring individual charges from a position where they have zero electrical potential to their final disposal. The electrostatic potential energy can also be defined from the electrostatic field generated by the distribution itself, and in this case its expression is independent of the source of the field.
This is an amount that can be negative or positive, depending on whether the work done to bring it into the assumed configuration is positive or negative. Two interactive charges of the same sign have positive energy, since the work done to bring them closer together must overcome their repulsion, while, for the same reason, two charges of the opposite sign have negative energy.
What are the characteristics of electrical energy?
Electrical energy are negative electrical charges (electrons) that move through the electrical conductor due to the potential difference between its ends. Normally the conductor is made of a metallic metallic material because they have a greater amount of free electrons.
The electrical charges that move through the conductor are part of the atoms of the substances in the conductor itself.
Electricity is a natural phenomenon , just like fire. The best known is the appearance of lightning in a storm , which is caused by a potential difference in the atmosphere. Some fish, like electric eels, are also capable of generating electricity. Furthermore, the animal and human nervous system works with electrical signals.
How is electrical energy generated?
Electric power just can't be found freely in nature in a way that can be exploited. It can be seen in electrical storms but the difficulty of storing and controlling such amount of energy makes them practically unusable.
There are several ways to generate electrical energy that we can classify into:
- Renewable energy sources.
- Non-renewable energy sources.
Renewable energy sources
The ways of generating renewable electrical energy are those in which fuel is not used or the fuel is inexhaustible. Some examples of renewable energy are:
- Photovoltaic solar energy, which converts solar radiation into electricity.
- Wind energy, which uses the force of the wind
- Hydroelectric energy, which transforms, gives potential energy from water to electricity through a system of turbines.
- Geothermal energy, which benefits from the heat inside the Earth.
Non-renewable energy sources
The ways of generating non-renewable electrical energy require a fuel that, however abundant it is, tends to run out. Some examples of non-renewable are:
- Nuclear energy, since we cannot generate more uranium than can be mined in uranium mines.
- Thermal energy, which harnesses the calorific value of fossil fuels such as coal, oil, and natural gas.
What is a power plant?
A power plant is a set of facilities, equipment and apparatus used directly for the production of electrical energy, as well as the necessary facilities and buildings located in a certain territory. The purpose of a power plant is to convert some primary energy into electrical energy, which is a form of secondary energy.
There are many types of power plants that can run on both renewable and non-renewable energy. Nuclear power plants, for example, are a type of power plant.
Why is electrical energy important?
Electric energy can be transformed into many other types of energy such as:
- mechanical energy (electric motors, machines ...)
- thermal energy (heaters, stoves ...)
- light energy (light).
The great advantage that electrical energy gives us is the ease of transporting it.
The use of electricity is very widespread in modern society and current through connection to the electricity grid or through batteries or accumulators. Some examples of its use are found on a daily basis:
- Building lighting (public and private)
- Road lighting.
- Transportation (electric trains and electric vehicles)
- Home appliances.
- Industrial machines and in industrial production processes.
- Electric machines.
- Electric motors.
Therefore, the discovery of electrical energy has represented a very strong real technological, economic and social evolution . Its use has caused a strong and irreversible need due to its benefits compared to mechanical energy produced by thermal engines (combustion engines).
What advantages and disadvantages does electrical energy have?
Some of the advantages of electrical energy compared to other energy sources include:
- The fact of being able to be transported over a distance
- Low operating noise of electrical equipment
- The absence of exhaust gases at the place of use and the smallest footprint of an electric machine. This allows reducing the presence of greenhouse gases in the atmosphere.
Among the disadvantages are:
- The fact of not being a primary source.
- The use of electrical energy implies the need for a conversion infrastructure that inevitably introduces a loss of efficiency in the conversion process and upstream transportation along power lines.
How do electric power plants work?
Electricity is considered as a secondary energy source . For this reason, it has to be produced by transformation of a primary energy source. In the transformation process, the yield, always less than 100%, occurs within power plants.
- A turbine . Which can be a hydraulic turbine or a steam turbine, which is the one that is usually used in nuclear power plants.
- An alternator to convert mechanical energy into electrical energy.
- A transformer to modulate the electric current obtained to an alternating current with the desired potential difference.
Importance of water in electricity
Another important element to produce electricity is water in liquid form or in the form of high pressure steam . Liquid water is used in as in hydroelectric plants, on the other hand water vapor is more appropriate in thermal power plants, geothermal power plants, in nuclear fission and in solar thermal power plants
In both cases, the objective of the water is to turn the turbines to produce alternating current as constantly as possible by means of the alternator.
The use of water presents the following problems derived from the need to heat it:
- Water availability.
- Thermal pollution of water, if not recovered, is dispersed in the atmosphere in the form of water vapor or is fed back into lakes, rivers and the sea.
In the case of wind power plants, no water is required, since the turbines are powered by the force of the wind.
Transport and distribution of electrical energy
Once the production of electricity is finished, there is a need to transport it on a large scale. The large-scale transportation and distribution of electricity produced by the plants to the end users is carried out through the transmission network and the distribution network.
Why is Joule's law important?
The first Joule law (also known as the Joule effect ) is a physical law that establishes the relationship between the electric current that passes through a conductor and the heat it generates .
Actually, they are two different laws, which associate the heat generated by the electric current and the dependence of the internal energy of an ideal gas with respect to its pressure, volume and temperature.
The name is dedicated to James Prescott Joule, who worked on this concept in the 1840s and it is expressed as follows:
In the formula Q is the heat generated by the constant current I, which passes over a conductor t with resistance R over time. When the current (measured in amps), resistance (measured in ohms), and time (measured in seconds), the unit of Q will be joules.
The first Joule law is also sometimes known as the Joule-Lenz law , because it was later found independent by Heinrich Lenz.
Joule's second law means that the internal energy of an ideal gas depends solely on its temperature, regardless of its volume and pressure.
Last review: April 1, 2020