It’s always there every time you flip a switch or plug in a cord. We all rely on electricity to keep us going daily, whether it’s boiling water for our morning coffee, using our computer for work or charging our phone. Have you ever asked yourself exactly how electricity gets to your home? Through a complex network, electricity is carried directly to your house. The station where your electricity is generated might be hundreds of miles away! All the poles and wires you see in front of your home and along the highway are called the electrical distribution system or transmission. Today, generating stations across the country are connected through the electrical system (sometimes called the “power grid”).
HOW THE POWER GRID WORKS
The power grid is a multifaceted and vital system. One of the most remarkable engineering achievements of the modern era. It transmits power generated at an assortment of facilities and distributes it to end-users, often over extensive distances. Furthermore, it provides electricity to industrial facilities, buildings, schools, and homes; every minute of every day, all year-round. The National Grid is essential to energy generation because it guarantees that both electricity and gas are transported safely.
It also ensures that the demand and supply of power are well balanced. The purpose of the National Grid is to get the heat, light, and power that customer’s need into their different homes. As significant as the Grid is, it will also have to keep up with the increasing demand it faces in the future with the switch to low carbon sources.
About 40 percent of the energy from all energy resources is used to generate electricity, more than for any other single purpose. Technical and Scientific understanding of energy has allowed us to generate, transmit and use electricity to heat homes, charge phones, light streets and much more. Electricity gets to our homes in three stages; generation, transmission, and distribution. This is an intricate engineering procedure.
The process involves a huge investment and requires experienced manpower. The basics of generating electricity remain the same in all forms of electricity, such as electricity generated using coal, hydro dams, nuclear plants, and renewable energy sources like wind and solar. Now, let’s dive into the details.
ELECTRICITY GENERATION
Electricity starts its journey at the power plant. It’s brought into existence by fossil fuel or renewable resources, ranging from coal and natural gas to hydroelectric and wind power. In most cases, these resources are used to power turbines through the force(s) of gas, steam, wind, water, solar, biomass, geothermal and even nuclear fission.
There are different sources of power, and also different ways power can be generated. The main thing to consider is that electricity is a man-made product, created in an electrical generator. Power generation commences with an energy source that can be controlled and transformed to create electric power and then delivered through electric current via power lines. Power generation is the first step in the delivery of produced power production and distribution.
Renewable Energy
The mass of renewable energy utilized to make up our electricity has been on the rise over the years, with fossil fuels being slowly phased out. Renewable energy comes from several sources: solar, hydro, wind, wave energy, biomass, and marine. After energy is generated through renewable energy sources, it is directed to the grid to be distributed.
Fossil Fuels
Fossil fuels still dominate electricity sources today. They’re made up of natural gas, coal, and oil. They generate energy by burning fossil fuels, such as oil, coal, and gas, which then breaks down the carbon bonds and begins to create energy. Steam is then produced, which drives huge turbines to produce electricity via a high powered, spinning magnet. Coal-burning power plants are recognized to be the worst industrial polluter because of the large volume of carbon emissions, which is a threat to our environment and health.
NUCLEAR POWER
Nuclear power stations are where energy is generated from a nuclear reactor that produces heat from radioactive metals like uranium. Nuclear power remains a much cleaner choice for energy generation compared to fossil fuels, as they produce lower amounts of carbon dioxide. In summary, electricity is generated by turning or rotation of turbines. These turbines can be switched by any means – coal, nuclear energy, steam, renewable energy like solar energy, etc. In different power plants, turbines are rotated by the pressure of steam, which is created by boiling water using burning coal in big boilers. The pressure of steam is such that it turns the turbines, which in turn generates electricity.
Hydroelectricity uses the force of running water downstream a man-made water reservoir dam. The great force of the running water turns the turbines, therefore generating energy.
ELECTRICITY TRANSMISSION
This is the mass transfer of electrical energy from the generating power plants to different electrical substations. Electricity is transported over an extended distance at high voltages, which minimizes the loss of electricity. Transmission lines are sets of wires (called conductors) that carry electric power from generating plants to the substations that deliver the power to customers. All these combined form a network that is known as the “power grid.” This network involves generating facilities, transmission lines, sub-transmission lines, distribution lines, and substations. The process transmitting electricity is described below:
Electricity is generated at a power plant or station. The generator then converts mechanical energy to electrical energy by pushing electrical current to flow through an external circuit. Typically, an electric conductor, like copper, rotates inside a magnetic field to create electricity. The energy used to turn the conductor can come from coal, natural gas, nuclear energy, falling water, and renewable resources like wind and solar energy. At generating stations, electricity is usually produced at less than 30,000 volts (30 kV). Before flowing into the transmission cables/lines, the electricity is “stepped up” to high voltages by transformers (these are devices that increase and also decrease the voltage on a circuit).
The Transmission Lines carry electricity over extended distances, from the generating facility to different areas where they’re needed. The electricity in transmission lines is conveyed at voltages of above 200 kV to amplify efficiency. Voltages of about 220 kV to 500 kV are standard. Furthermore, Transmission lines are usually attached to large lattice steel towers or tubular steel poles.
A Transmission Substation links two or more transmission lines, and it is made up of high-voltage switches that permit lines to be connected or isolated for maintenance. This can also be referred to as a Switching Station. The substation may have transformers to convert between two transmission voltages, or equipment such as regulators to control power flow between two adjacent power systems. A large transmission substation can cover many acres with multiple voltage levels, and a large amount of protection and control equipment (capacitors, relays, switches, breakers, voltage, and current transformers).
Sub-transmission lines carry electricity at voltages less than 200 kV; typically, 66 kV or 115 kV. They’re usually suspended on tall wood or light-weight steel poles. They can also be placed underground.
ELECTRICITY DISTRIBUTION
Electricity is distributed through electric distribution substations. At the substations, the high voltage electricity from the high-voltage transmission lines is channeled through step-down transformers that lower the voltage. The electricity is then transmitted to a network of local electric distribution lines. Before electricity enters a home, the voltage is again lowered using step-down transformers. In most countries, the voltage is 220 V AC or 110 V DC. Electricity is most often distributed through alternating current, although direct current is sometimes used for long-distance, high-voltage transmission.
Alternating current (AC) switches its direction occasionally. A cycle is one full period, where current flows first towards one direction and then in the other. Most transmission lines transport AC power because electricity is generated and used as alternating current, and a transformer can be used to change the voltage where necessary.
Direct current (DC) flows in one direction and is useful to transmit electricity over considerable distances because DC electricity does not cycle, it can be used to connect two grids that are not at the same frequency or synchronized. However, transformers cannot change the voltage of direct current; it must be converted back into alternating current to be stepped down for distribution.
YOUR HOME
In a home, electricity is given to different outlets by a network of electrical wiring. Your electricity passes through the service drop and gets recorded at your meter. The meter tracks how much electricity you use. At your switchboard, your electricity gets divided up into circuits for each area of your house. Finally, the electricity moves through wires behind your walls to power outlets and switches where you operate your lights and appliances
It’s easy to take the electricity used to light your house for granted, but this valuable energy source has traveled a long way through the sophisticated generation and transmission infrastructure to get to your home. Knowing this, you’ll perhaps be more likely to appreciate electricity the next time you switch on the light or turn on the TV.
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