To generate electricity but what. Where does electricity come from? Sources of electricity. New on the forum

A generator converts mechanical energy into electrical energy by rotating a wire coil in a magnetic field. An electric current is also generated when the field lines of a moving magnet intersect the turns of a wire coil (picture on the right). Electrons (blue balls) move towards the positive pole of the magnet, and electric current flows from the positive pole to the negative pole. As long as the magnetic field lines cross the coil (conductor), an electric current is induced in the conductor.

A similar principle also works when moving a wire frame relative to a magnet (far figure on the right), i.e., when the frame intersects the magnetic field lines. The induced electric current flows in such a way that its field repels the magnet when the frame approaches it and attracts it when the frame moves away. Each time the frame changes orientation relative to the poles of the magnet, the electric current also changes its direction to the opposite direction. As long as the source of mechanical energy rotates the conductor (or magnetic field), the generator will generate alternating electric current.

Operating principle of an alternator

The simplest alternating current generator consists of a wire frame rotating between the poles of a stationary magnet. Each end of the frame is connected to its own slip ring, which slides along an electrically conductive carbon brush (picture above the text). The induced electric current flows to the inner slip ring when the half of the frame connected to it passes the north pole of the magnet, and vice versa to the outer slip ring when the other half of the frame passes the north pole.

Three Phase Alternator

One of the most cost-effective ways to generate high alternating current is to use a single magnet rotating across multiple windings. In a typical three-phase generator, the three coils are located equidistant from the axis of the magnet. Each coil produces alternating current when a magnet pole passes by it (right picture).

Changing the direction of electric current

When a magnet is pushed into a wire coil, it induces an electric current in it. This current causes the galvanometer needle to deviate away from the zero position. When the magnet is removed from the coil, the electric current reverses its direction and the galvanometer needle moves away from the zero position.

AC

The magnet will not induce electric current until its lines of force begin to cross the wire loop. When a magnet pole is pushed into a wire loop, an electric current is induced in it. If the magnet stops moving, the electric current (blue arrows) also stops (middle diagram). When a magnet is removed from a wire loop, an electric current is induced in it, flowing in the opposite direction.

This is the ordered movement of certain charged particles. In order to competently use the full potential of electricity, it is necessary to clearly understand all the principles of the structure and operation of electric current. So, let's figure out what work and current power are.

Where does electric current even come from?

Despite the apparent simplicity of the question, few are able to give an intelligible answer to it. Of course, these days, when technology is developing at an incredible speed, people don’t think much about such basic things as the principle of operation of electric current. Where does electricity come from? Surely many will answer, “Well, out of the socket, of course,” or simply shrug their shoulders. Meanwhile, it is very important to understand how current works. This should be known not only to scientists, but also to people who are in no way connected with the world of science, for their overall diversified development. But not everyone can competently use the operating principle of current.

So, first you should understand that electricity does not appear out of nowhere: it is produced by special generators that are located at various power plants. Thanks to the rotation of turbine blades, steam produced by heating water with coal or oil produces energy, which is subsequently converted into electricity with the help of a generator. The design of the generator is very simple: in the center of the device there is a huge and very strong magnet, which forces electrical charges to move along copper wires.

How does electric current reach our homes?

After a certain amount of electric current has been generated using energy (thermal or nuclear), it can be supplied to people. This supply of electricity works as follows: in order for electricity to successfully reach all apartments and businesses, it needs to be “push.” And for this you will need to increase the force that will do this. It is called the voltage of the electric current. The principle of operation is as follows: current passes through a transformer, which increases its voltage. Next, the electric current flows through cables installed deep underground or at a height (because the voltage sometimes reaches 10,000 Volts, which is deadly to humans). When the current reaches its destination, it must again pass through the transformer, which will now reduce its voltage. It then travels along wires to installed switchboards in apartment buildings or other buildings.

The electricity carried through the wires can be used thanks to a system of sockets, connecting household appliances to them. There are additional wires in the walls through which electric current flows, and it is thanks to this that the lighting and all the equipment in the house work.

What is current work?

The energy carried by electric current is converted over time into light or heat. For example, when we turn on a lamp, the electrical form of energy turns into light.

To put it in simple language, the work of current is the action that electricity itself produces. Moreover, it can be very easily calculated using the formula. Based on the law of conservation of energy, we can conclude that electrical energy has not been lost, it has completely or partially transferred to another form, giving off a certain amount of heat. This heat is the work done by the current when it passes through the conductor and heats it (heat exchange occurs). This is what the Joule-Lenz formula looks like: A = Q = U*I*t (work is equal to the amount of heat or the product of the current power and the time during which it flows through the conductor).

What does direct current mean?

Electric current is of two types: alternating and direct. They differ in that the latter does not change its direction, it has two clamps (positive “+” and negative “-”) and always begins its movement from “+”. And alternating current has two terminals - phase and zero. It is precisely because of the presence of one phase at the end of the conductor that it is also called single-phase.

The principles of the design of single-phase alternating and direct electric current are completely different: unlike constant, alternating current changes both its direction (forming a flow both from phase towards zero and from zero towards phase) and its magnitude. For example, alternating current periodically changes the value of its charge. It turns out that at a frequency of 50 Hz (50 vibrations per second), electrons change the direction of their movement exactly 100 times.

Where is DC used?

Direct electric current has some characteristics. Due to the fact that it flows strictly in one direction, it is more difficult to transform it. The following elements can be considered DC sources:

batteries (both alkaline and acid);
ordinary batteries used in small devices;
as well as various devices such as converters.

DC operation

What are its main characteristics? This is work and current power, and both of these concepts are very closely related to each other. Power refers to the speed of work per unit of time (per 1 s). According to the Joule-Lenz law, we find that the work done by a direct electric current is equal to the product of the strength of the current itself, the voltage and the time during which the work of the electric field was done to transfer charges along the conductor.

This is the formula for finding the work of current, taking into account Ohm’s law on resistance in conductors: A = I 2 *R*t (work is equal to the square of the current multiplied by the value of the resistance of the conductor and again multiplied by the time during which the work was done).

Dozens of times a day, turning the lights on and off and using household appliances, we don’t even think about where electricity comes from and what its nature is. It is clear, of course, that along the power lines ( power line) it comes from the nearest power station, but this is a very limited view of the world around us. But if electricity generation around the world stops for at least a couple of days, the death toll will be measured in hundreds of millions.

How does current occur?

From the physics course we know that:

All matter is made up of atoms, tiny particles.
Electrons orbit around the nucleus of an atom and have a negative charge.
The nucleus contains positively charged protons.
Normally, this system is in a state of equilibrium.

But if at least one atom loses just one electron:

Its charge will become positive.
A positively charged atom will begin to attract an electron to itself due to the difference in charges.
To get the missing electron for yourself, you will have to “rip it” from someone’s orbit.
As a result, another atom will become positively charged and everything will repeat, starting from the first point.
Such cyclicity will lead to the formation of an electrical circuit and the linear propagation of current.

So from the point of view of nuclear physics everything is extremely simple, the atom is trying to get what it lacks most and thus triggers the start of the reaction .

"Golden Age" of Electricity

Man adapted the laws of the Universe to his needs relatively recently. And this happened about two centuries ago, when an inventor named Volt developed the first battery capable of maintaining a charge of sufficient power for a long time.

Attempts to use current for one's benefit have an ancient history. Archaeological excavations have shown that even in Roman sanctuaries, and then in the first Christian churches, there were handicraft “batteries” made of copper, which provided minimal voltage. Such a system was connected to the altar or its fence, and as soon as the believer touched the structure, he immediately received “ divine spark" This is more likely the invention of one craftsman than a widespread practice, but it is an interesting fact in any case.

The twentieth century became the heyday of electricity:

Not only new types of generators and batteries appeared, but also unique concepts for extracting this very energy were developed.
Over the course of several decades, electrical appliances have become an integral part of the lives of every person on the planet.
There are no countries left, except the least developed, where power plants and carried out power lines.
All further progress was based on the capabilities of electricity and devices that operate from it.
The era of computerization has made people dependent on current, in the truest sense of the word.

How to get electricity?

It’s a little naive to imagine a person as a drug addict who regularly needs a “life-giving dose of electricity,” but try to completely cut off the power in your home and live peacefully for at least a day. Despair can make you remember the original methods of extracting current. In practice, this will be of little use to anyone, but maybe a pair of Volts will save someone’s life or help impress a child:

Dead battery You can rub your phone on clothes; jeans or a wool sweater will do. The static electricity won't last long, but it's at least something.
If there is one nearby sea water, you can pour it into two jars or glasses, connect them with a copper wire, after wrapping both ends with foil. Of course, for all this, in addition to salt water, you will also need containers, copper and foil. Not the best option for extreme situations.
Much more realistic is the presence iron nail and a small copper device. Two pieces of metal should be used as anode and cathode - a nail in the nearest tree, copper in the ground. Pull any thread between them; a simple design will give approximately one Volt.
If you use precious metals- gold and silver, it will be possible to achieve greater tension.

How to save electricity?

Saving energy can have different reasons - a desire to preserve the environment, an attempt to reduce monthly bills, or something else. But the methods are always approximately the same:

You don’t always have to severely limit yourself in something in order to reduce costs. There is another good tip - unplug all appliances while you are not using them.

The refrigerator, of course, does not count. Even when in “standby” mode, the equipment consumes a certain amount of electricity. But if you think about it even for a second, you might come to the conclusion that you don’t need almost all the devices most of the day. And all this time they keep burning your electricity .

Modern technologies also aim to reduce the overall level of electricity consumption. What are they worth at least? energy saving light bulbs, which can reduce the cost of lighting a room by five times. The advice to live by a “sundial” may seem wild and absurd, but it has long been proven that artificial lighting increases the risk of developing depression.

How is electricity generated?

If you go deeper into the scientific details:

The current appears due to the loss of an electron by the atom.
A positively charged atom attracts negatively charged particles.
Another atom loses its electrons from the orbit and history repeats itself again.
This explains the directional movement of the current and the presence of a propagation vector.

In general electricity is generated by power plants. They either burn fuel, or use the energy of splitting atoms, and maybe even use natural elements. We are talking about solar panels, wind turbines and state district power plants.

The resulting mechanical or thermal energy is converted into current using a generator. It accumulates in batteries and travels through power lines to every home.

Today, it is not necessary to know where electricity comes from in order to enjoy all the benefits it provides. People have long moved away from the original essence of things and are slowly beginning to forget about it.

Video: where does our electricity come from?

This video will clearly show the path of electricity from the power plant to us, where it comes from and how it enters our home:

To solve the problem of limited fossil fuels, researchers around the world are working to create and commercialize alternative energy sources. And we’re not just talking about well-known wind turbines and solar panels. Gas and oil may be replaced by energy from algae, volcanoes and human footsteps. Recycle has selected ten of the most interesting and environmentally friendly energy sources of the future.

Joules from turnstiles

Thousands of people pass through the turnstiles at the entrance to railway stations every day. At once, several research centers around the world came up with the idea of using the flow of people as an innovative energy generator. The Japanese company East Japan Railway Company decided to equip every turnstile at railway stations with generators. The installation works at a train station in Tokyo's Shibuya district: piezoelectric elements are built into the floor under the turnstiles, which generate electricity from the pressure and vibration they receive when people step on them.

Another “energy turnstile” technology is already in use in China and the Netherlands. In these countries, engineers decided to use not the effect of pressing piezoelectric elements, but the effect of pushing turnstile handles or turnstile doors. The concept of the Dutch company Boon Edam involves replacing standard doors at the entrance to shopping centers (which usually operate using a photocell system and begin to rotate themselves) with doors that the visitor must push and thus generate electricity.

Such generator doors have already appeared in the Dutch center Natuurcafe La Port. Each of them produces about 4,600 kilowatt-hours of energy per year, which at first glance may seem insignificant, but serves as a good example of an alternative technology for generating electricity.

Modern life cannot be imagined without electricity; this type of energy is used most fully by humanity. However, not all adults are able to remember the definition of electric current from a school physics course (this is a directed flow of elementary particles with a charge), very few people understand what it is.

What is electricity

The presence of electricity as a phenomenon is explained by one of the main properties of physical matter - the ability to have an electric charge. They can be positive and negative, while objects with oppositely polar signs are attracted to each other, and “equivalent” ones, on the contrary, repel. Moving particles are also the source of a magnetic field, which once again proves the connection between electricity and magnetism.

At the atomic level, the existence of electricity can be explained as follows. The molecules that make up all bodies contain atoms made up of nuclei and electrons circulating around them. These electrons can, under certain conditions, break away from the “mother” nuclei and move to other orbits. As a result, some atoms become “understaffed” with electrons, and some have an excess of them.

Since the nature of electrons is such that they flow to where there is a shortage of them, the constant movement of electrons from one substance to another constitutes electric current (from the word “to flow”). It is known that electricity flows from the minus pole to the plus pole. Therefore, a substance with a lack of electrons is considered to be positively charged, and with an excess - negatively, and it is called “ions”. If we are talking about the contacts of electrical wires, then the positively charged one is called “zero”, and the negatively charged one is called “phase”.

In different substances, the distance between atoms is different. If they are very small, the electron shells literally touch each other, so electrons easily and quickly move from one nucleus to another and back, thereby creating the movement of an electric current. Substances such as metals are called conductors.

In other substances, interatomic distances are relatively large, so they are dielectrics, i.e. do not conduct electricity. First of all, it's rubber.

Additional information. When the nuclei of a substance emit electrons and move, energy is generated that heats the conductor. This property of electricity is called “power” and is measured in watts. This energy can also be converted into light or another form.

For the continuous flow of electricity through the network, the potentials at the end points of the conductors (from power lines to house wiring) must be different.

History of the discovery of electricity

What electricity is, where it comes from, and its other characteristics are fundamentally studied by the science of thermodynamics with related sciences: quantum thermodynamics and electronics.

To say that any scientist invented electric current would be wrong, because since ancient times many researchers and scientists have been studying it. The term “electricity” itself was introduced into use by the Greek mathematician Thales; this word means “amber”, since it was in experiments with an amber stick and wool that Thales was able to generate static electricity and describe this phenomenon.

The Roman Pliny also studied the electrical properties of resin, and Aristotle studied electric eels.

At a later time, the first person to thoroughly study the properties of electric current was V. Gilbert, the physician to the Queen of England. The German burgomaster from Magdeburg O.f. Gericke is considered the creator of the first light bulb made from a grated sulfur ball. And the great Newton proved the existence of static electricity.

At the very beginning of the 18th century, the English physicist S. Gray divided substances into conductors and non-conductors, and the Dutch scientist Pieter van Musschenbroek invented a Leyden jar capable of accumulating an electric charge, i.e. it was the first capacitor. The American scientist and politician B. Franklin was the first to develop the theory of electricity in scientific terms.

The entire 18th century was rich in discoveries in the field of electricity: the electrical nature of lightning was established, an artificial magnetic field was constructed, the existence of two types of charges (“plus” and “minus”) and, as a consequence, two poles was revealed (US naturalist R. Simmer) , Coulomb discovered the law of interaction between point electric charges.

In the next century, batteries were invented (by the Italian scientist Volta), an arc lamp (by the Englishman Davey), and also a prototype of the first dynamo. 1820 is considered the year of the birth of electrodynamic science, the Frenchman Ampere did this, for which his name was assigned to the unit for indicating the strength of electric current, and the Scotsman Maxwell deduced the light theory of electromagnetism. Russian Lodygin invented an incandescent lamp with a coal core - the progenitor of modern light bulbs. A little over a hundred years ago, the neon lamp was invented (by the French scientist Georges Claude).

To this day, research and discoveries in the field of electricity continue, for example, the theory of quantum electrodynamics and the interaction of weak electric waves. Among all the scientists who researched electricity, Nikola Tesla holds a special place - many of his inventions and theories about how electricity works are still not fully appreciated.

Natural electricity

For a long time it was believed that electricity “by itself” does not exist in nature. This misconception was dispelled by B. Franklin, who proved the electrical nature of lightning. It was they, according to one version of scientists, that contributed to the synthesis of the first amino acids on Earth.

Electricity is also generated inside living organisms, which generates nerve impulses that provide motor, respiratory and other vital functions.

Interesting. Many scientists consider the human body to be an autonomous electrical system that is endowed with self-regulatory functions.

Representatives of the animal world also have their own electricity. For example, some breeds of fish (eels, lampreys, stingrays, anglerfish and others) use it for protection, hunting, obtaining food and orientation in underwater space. A special organ in the body of these fish generates electricity and stores it, like in a capacitor, its frequency is hundreds of hertz, and its voltage is 4-5 volts.

Getting and using electricity

Electricity in our time is the basis of a comfortable life, so humanity needs its constant production. For these purposes, various types of power plants are being built (hydroelectric power plants, thermal, nuclear, wind, tidal and solar), capable of generating megawatts of electricity with the help of generators. This process is based on the conversion of mechanical (energy of falling water at hydroelectric power plants), thermal (combustion of carbon fuel - hard and brown coal, peat at thermal power plants) or interatomic energy (atomic decay of radioactive uranium and plutonium at nuclear power plants) into electrical energy.

Much scientific research is devoted to the electrical forces of the Earth, all of which seek to harness atmospheric electricity for the benefit of humanity - generating electricity.

Scientists have proposed many interesting current generator devices that make it possible to produce electricity from a magnet. They use the ability of permanent magnets to perform useful work in the form of torque. It arises as a result of repulsion between similarly charged magnetic fields on the stator and rotor devices.

Electricity is more popular than all other energy sources because it has many advantages:

easy movement to the consumer;
rapid conversion to thermal or mechanical energy;
new areas of its application are possible (electric vehicles);
discovery of new properties (superconductivity).

Electricity is the movement of differently charged ions inside a conductor. This is a great gift from nature, which people have been cognizing since ancient times, and this process is not yet completed, although humanity has already learned to extract it in huge quantities. Electricity plays a huge role in the development of modern society. We can say that without it, the lives of most of our contemporaries will simply stop, because it’s not for nothing that when the electricity goes out, people say that they “turned off the lights.”