The sheer thought of a world without electricity seems impossible. It is one of the greatest gifts that science has given to humanity. Almost everything in our world today depends on electrical power.
And electrical dependence is only expected to grow over time. Estimates show that in 2018, the global electricity demand grew to 23,000 TWh, and this number is likely to increase with each passing year. This skyrocketing demand is responsible for half of the growth in energy needs and takes a 20% share in the total energy consumption globally.
These statistics clearly show that electricity is the generator of the future. That said, what are the ways through which we can generate such a staggering amount of electricity to meet the ever-increasing demands? Let us find out!
Electricity can be defined as a form of energy that is produced as a result of the flow of electrons from positive and negative points within a conductor. We consider electricity as a secondary energy source.
This is because it doesn't come as a ready-made product, but it needs to be generated through primary sources such as wind, sunlight, coal, natural gas, nuclear fission reactions, and hydropower.
Here are some fundamental ways through which we can generate electricity and how it can be done!
1. Electricity by rubbing
The first observations about electrical phenomena were made in ancient Greece. This happened when the philosopher Thales of Miletus (640-546 BC) found that when amber bars are rubbed against tanned skin, they produce attractive characteristics that they did not previously possess.
It is the same experiment that can now be done by rubbing a plastic bar with a cloth. By bringing it closer to small pieces of paper, it attracts them, as is characteristic of electrified bodies.
We are all familiar with the effects of static electricity. Some people are more susceptible than others to the influence of static electricity. Certain car users feel its effects when using a key or touching the car's plate.
We create static electricity when we rub a pen with our clothes. The same happens when we rub a piece of glass with silk or amber with wool.
Therefore, the concepts of charge and mobility are essential in the study of electricity, and without them, the electric current could not exist.
2. Electricity by chemical action
All batteries consist of an electrolyte (which can be liquid, solid, or semi-solid), a positive electrode, and a negative electrode. An electrolyte is an ionic conductor.
One of the electrodes produces electrons, and the other electrode receives them. When the electrodes are connected to the circuit to be fed, they produce an electric current.
The batteries in which the chemical cannot return to its original form once the chemical energy has been transformed into electrical energy are called primary or voltaic batteries.
The secondary batteries or accumulators are reversible. In these types of batteries, the chemical that reacts in the electrodes to produce electrical energy can be reconstituted by passing an electric current through it in the opposite direction to the normal operation of the battery.
3. Electricity by the action of light
As sunlight becomes more intense, the voltage generated between the two layers of photovoltaic cell increases. But how does a photovoltaic cell work?
In the absence of light, the system does not generate energy. When sunlight hits the plate, the cell begins to function. The photons of sunlight interact with the available electrons and increase their energy levels.
In this manner, electricity is generated through solar energy.
4. Thermal electricity by heat action
A thermal generation plant is a type of plant where a turbine that is powered by steam under pressure is used to move the axis of electric generators. Conventional thermal power plants and nuclear thermal power plants use the energy contained in pressurized steam.
The simplest example is to connect a kettle full of boiling water to a paddle wheel, which, in turn, is linked to a generator. The steam jet from the kettle moves the rotor.
Hence, we can get steam in many ways, such as by burning coal, oil, gas, urban waste, or taking advantage of a large amount of heat generated by nuclear fission reactions. You can even produce steam by concentrating the sun's energy.
It would not be wrong to say that thermal energy is one of the most common ways of generating electricity.
5. Electricity by magnetism
In 1819, Hans Christian Oersted, a Danish physicist, made an extraordinary discovery by observing that you could deflect a magnetic needle by an electric current. This discovery, which showed a connection between electricity and magnetism, was developed by the French scientist André Marie Ampère.
Ampère studied the forces between wires through which electric currents circulate. In the same vein, the French physicist Dominique François Arago is known to have magnetized iron by placing it near a cable running with current.
Thereafter, in 1831, the British scientist Michael Faraday discovered that the movement of a magnet in the vicinity of a cable induces an electric current in it. This effect was the opposite of that found by Oersted.
Thus, Oersted demonstrated that an electric current could create a magnetic field. On the other hand, Faraday demonstrated that we could use a magnetic field to create an electric current. Both discoveries are ground-breaking.
In this context, the complete blend of the theories of magnetism and electricity happened thanks to the British physicist James Clerk Maxwell. Maxwell predicted the existence of electromagnetic waves and identified light as an electromagnetic phenomenon.
As is evident, it took a lot of scientists and researchers to deduce that electricity can also be generated through magnetism.
6. Electricity generated by pressure
The pressure exerted by underground water currents is the process used in large ships as alternative energy to the main system. In dams, electricity is generated by releasing a controlled flow of high-pressure water through a forced conduit.
The water drives turbines that move the generators and, thus, produce an electric current. This high low-voltage current then passes through a voltage booster that transforms it into electricity.
7. Hydraulic electricity by water action
Of all the ways used to generate energy listed above, magnetic energy is most commonly used to produce electricity in large quantities. Its production is based on the fact that when moving a conductor in the presence of a magnet, an orderly movement of electrons occurs in the conductor.
This happens as a consequence of the attractive forces and repulsion caused by the magnetic field. The operation of alternators, motors, and dynamos is based on this form of electricity production.
It is noteworthy that hydroelectricity generates around 9% of the electricity in the US. Moreover, it is renewable and can be produced with very few emissions.
The production of electricity has a rich history and an even brighter future. According to predictions made by the Institute of Energy Research, fossil fuels will continue to maintain their status as the leading source of electricity production in the US until 2040.