Electricity Definition and Basic Terms Associated with Electricity
What is electricity? The answer to this question is key to understanding how the energy is generated, how it works, and its importance to the human race.
Electricity is the flow of charged particles known as electrons through a conducting material. Electrons alongside protons and neutrons are the building blocks of an atom, which make up everything in this world.
Electricity is a form of energy. However, it is considered a secondary energy source since it can only be obtained by converting other sources of energy. These other sources can either be renewables such as solar energy or non-renewables such as coal.
Several basic terms are associated with electricity. They include current, voltage, resistance, and power. Analyzing these four terms is key to understanding the energy and how it works
Current refers to the rate of flow of electric charge that is electrons through a given material. Current is measured in amperes.
Voltage is the electromotive force that pushes or causes charges to flow through a conductor and is measured in volts.
Resistance is the opposition to the flow of current caused by a given material measured in ohms.
Power, which is measured in watts, is the rate at which electrical energy is transferred in a given electrical circuit.
Invention of Electricity
There are two commonly asked questions about this energy. They are “who invented electricity?” and “when was electricity discovered?” The two are proof that there is a misconception that it was invented, which is not the case. Electricity has always existed in nature, which means that it was not created. Scientists only managed to discover and then understand it with time.
The discovery of electricity has a complicated history. Thus, it is difficult to attribute the achievement to one single individual. Despite the complicated history, many people tend to associate the discovery to Benjamin Franklin. The link is because of the kite experiment that he carried out in 1752.
In the test, Franklin wanted to show that lightning was electricity. The experiment involved tying a metal key to a kite, which he flew in a thunderstorm. Franklin wanted the metal key to tap the energy from lightning and transmit it via the kite string to his hands. Eventually, the experiment worked as he had anticipated where he was electrocuted, but the effects were not fatal.
The kite experiment led to increased interest in electricity, something that led to more discoveries and improvements. For instance, after Franklin’s experiment, Alessandro Volta discovered that some chemical reactions also produced this energy.
He then proceeded to invent the Voltaic pile in 1800, which was a form of an electric battery. It is considered to be the first practical method of generating electricity. Other renowned scientists such as Michael Faraday and Nikola Tesla later carried out research and experiments that increased people’s understanding of the energy.
How is Electricity Generated?
There are several methods of generating electricity, which depends on the type of energy source that is in use. There are three categories of energy used to generate electricity. They are fossil fuels, nuclear power, and renewables.
Generation of Electricity Using Fossil Fuels
In fossil fuels power plants, fuels such as coal and natural gas are burnt to produce heat that converts water into steam. The steam is then used to move turbines, which are coupled to generators.
Turbines convert the kinetic energy from the steam into mechanical energy, which rotates the shaft of the connected generator. In response, generators transform the applied mechanical energy into electrical energy, which is then sent to transformers. The transformers step up the generated power to high voltage, which can easily be transmitted across long distances.
The generation of electricity by generators is made possible by the relationship between electric power and magnetism. As was discovered by Michael Faraday, an electric current flows each time a magnet moves inside a wire. Generators adopt this principle but make use of an electromagnet as opposed to a traditional magnet.
Inside each generator, there are coils of wire that are insulated and which make up the cylinder. There is also a rotating electromagnetic shaft within the generator. Thus, when the shaft rotates after a turbine drives it, it induces a current within the wires. The result is the production of electricity. The generated power is then sent to other electrical equipment or devices such as transformers for improvement.
Generation by Nuclear Power Plants
Nuclear power plants apply the same principle as the one used during the generation with fossil fuels. The only difference is that instead of burning fossil fuels, nuclear plants rely on the heat released during a fission reaction.
The heat is then used to convert water into steam, which contains kinetic energy that is converted to mechanical energy by turbines. Generators within the system then end up turning this energy into electrical power
Generation of Electricity from Renewable Sources
There are many types of renewable energy sources. Most of them differ in how they generate electricity.
In solar energy, it is generated by solar panels once they come into contact with energy particles from the sun. The process initiates the photovoltaic effect, which results in the loosening and movement of electrons within the cells.
The produced DC electricity is then utilized directly, taken to a battery bank, or directed to an inverter where it is changed into AC electricity.
In wind energy, the kinetic energy from the blades is turned into mechanical energy by the wind turbine. A generator within the turbine then uses the mechanical energy to generate electricity.
In a geothermal power plant, the hot steam from the ground under high pressure is used to spin turbines. These turbines then drive generators in the same way as nuclear power plants, a process that results in the generation of electricity.
Hydroelectric plants also use turbines. The only difference is that they are driven by water as opposed to steam, which is the case with fossil fuel power plants. Under high pressure, water from a dam spins the turbines, which then rotates the shaft of a generator. The whole process results in the conversion of kinetic energy to mechanical energy and then to electrical power.
Types of Electricity
There are two types of electricity: static and current electricity.
What is Static Electricity?
It is a type of energy that comes to existence when two or more objects are rubbed together. It occurs when there is an imbalance in the positive and negative charges on the surface of a given material. As a result, the charged particles build up on the surface where they remain until they are discharged.
Static electricity cause two objects of opposite charges, positive and negative, to be attracted to each other. In some instances, this type of energy can cause a spark to jump. An example of static electricity is when you rub a balloon against your clothes and then place it on the wall. You will notice that it will stick to the wall. But why does this happen?
Rubbing a balloon increases the number of negative charges or electrons on its surface. Thus, if the wall has more positive charges, it will attract the balloon because opposite charges tend to attract each other. The two objects will remain stuck to each other until the positive and negative charges are released.
Static electricity can be dangerous. For instance, it might cause an electric shock, which can sometimes be fatal. It can also produce a spark that might ignite flammable materials leading to a fire or an explosion. Such accidents occur when flammable fluids such as gasoline pass through a pipe, something that can lead to the production of static electricity.
What is Current Electricity?
Current electricity refers to the flow of electric charge or electrons in a given material. Unlike static energy, where positive and negative charges remain on the surface of an object, current electricity must flow through an object.
It is for such a reason that materials are considered to be excellent or poor conductors of electricity. Good conductors are those which allow current electricity to flow through them and include copper and aluminum. Poor conductors are those that resist the flow of electrons. Examples include rubber and wood.
Current electricity is further divided into direct current (DC) and alternating current (AC). The main difference between the two is that in DC, electrons flow in one direction. However, in AC, they keep switching where they sometimes move in the forward direction and sometimes in reverse.
In the late nineteenth century, when electric power was still being improved, there was a debate over which type of current electricity was the best. The dispute involved the greatest minds in Europe and America, such as Nikola Tesla and Thomas Edison. They argued over which of the two current electricity that is DC and AC was to be adopted as the standard.
Eventually, AC emerged as superior since, unlike DC, it could be transmitted over long distances without significant loss of power. What made this possible is that AC can be stepped up to high voltage levels during transmission. It can later be stepped down to appropriate voltage levels during distribution.
It is for the same reason that many homes, industries, and institutions in the modern world make use of AC power. However, it should be noted that DC electricity is also growing in popularity. It is a progress that can be linked back to advancements in technology, which have improved how it is generated, transmitted, and distributed.
How is Electricity Measured?
The amount of electricity that is being used at any particular moment is measured in watts (W) using an energy meter. Watts is also the unit that is used to measure electrical power.
Power is determined by finding the product of current times the voltage. Thus, a watt is equivalent to one ampere multiplied by one volt. The quantity of electricity used or produced depends on the nature of the appliance or system.
For instance, the electricity at generating plants is measured in Megawatts (MW) since it is very high. In contrast, the power consumed by smaller appliances can be measured in watts or kilowatts.
As noted, the electricity used or generated at any particular moment is measured in watts. However, the energy that is used or generated over a given period is measured in watt-hours. For instance, a 300 watts panel in a solar power system would produce 300 watt-hours of electricity if it received one hour of sunlight.
In the domestic, commercial, and industrial settings, utility companies use electricity meters to measure the energy used by a customer. The readings are then used to come up with electricity bills, which shows the energy consumed in kilowatt-hours (kWh).
There are also advanced meters used to measure electricity. An example is a net meter, a device found in grid-tied and hybrid solar power systems. It is a meter that measures the electric power taken by a home or business from the grid in kWh against what the solar system in place supplies to the national network.
How is Electricity Used?
Electricity is a vital commodity in the modern world. It has many applications in the domestic, commercial, industrial, and transportation sectors.
The energy has a wide range of residential uses. The most common applications include providing power to appliances used for:
- Air conditioning
- Communication and Entertainment such as phones, laptops, radios, and TVs.
In offices, warehouses, hotels, hospitals, and schools, among other commercial institutions, electric power is used for:
- Space and water heating
- Space cooling
- Powering electronic devices such as computers, printers, and X-ray machines.
The energy is key to the successful functioning of industries across the world. In this sector, its uses include:
- Driving machines
- Heating and cooling processes
- Heating boilers
- Air conditioning
- Heating the facilities
The demand for electricity in the transportation sector has grown in the last few decades. It is now considered an alternative to traditional fuels, which have for long been used to operate trains and vehicles.
Currently, it is powering electric trains and cars across the world.