How is electricity generated?

How is Electricity Generated?

Electricity can be generated by conventional means like hydro-electricity and thermal electricity. It is also produced through the use of renewable sources of other forms of energy. Here, we will study the way it is conventionally produced.

Electricity is a form of energy. When electrons flow in a wire we say that we have electricity.  All matter is made up of atoms. The atoms of different matter are structured differently. Each atom has a center, called a nucleus which contains positively charged particles called protons and uncharged particles called neutrons. It is surrounded by negatively charged particles called electrons. The total charge in an atom is well balanced most of the times if the atom is stable. When this balancing force is upset by an outside force (may be a chemical force or mechanical force or heat), an atom may gain or lose an electron. When electrons are "lost" from an atom, the free movement of these electrons creates a current if directed through a wire. (When there is no wire to conduct such electrons, the free electrons pile up on the matter and create a negative charge. Sometimes free protons also charge up a material positively).

In the early 19th century a similarity was observed between two oppositely charged particles and two magnets. The similarity was that 1) both created "forces" that could operate in a vacuum and 2) charge had a positive and negative component whereas the magnets had a north and south pole. There was a further observation that 3) the positive and negative charges attracted one another while North and South poles displayed similar attraction. Similarly, charged particles repulsed one another and the same type of magnetic poles showed similar behavior. Thus, 4) force could then be either attractive or repulsive. 5) It was also observed that the force of attraction decreased when the distance between these attracting charges or poles increased.

In 1820 Oersted discovered that current passing through an electric wire produced a magnetic field. He further observed that when the direction of current through the wire changed, the magnetic field changed its direction.It was also noticed that when a coil was placed in a magnetic field (next to or between magnets) and when the magnets moved (rotated), it generated a current in the coil (wire). This resulted in the methods of generating electricity.







Today, large quantum of electricity is produced by making a coil turn through a magnetic field. Greater the rate of turning of the coil, greater is the rate of cutting of magnetic flux (lines of attraction) and greater is the quantity of current produced. To turn the coil at greater speed, the coil is attached to a turbine and the turbine is made to rotate by using water current (hydro-electricity) or by a jet of steam produced from heating water in a thermal furnace or nuclear reaction or even by wind (wind energy). A sample generator is shown below:




Electricity that is produced is brought to our homes through transmission and distribution system. In India we have 220 V of potential and 5 or 15 ampere of current.

Imagine what would happen if we do not produce electricity! We will have no television, we would not be able to charge our mobile phones, our computers will not work and there would be no industrial production. We need to thank the scientists like Faraday, Kirchhoff, Oersted, Volt and many others.