Fossil fuels account for about one-third of the world's total energy production, especially for generating electricity, one of the most common sources being coal! Read to find out the process of how coal is converted to electrical power!
According to the World Coal Association, coal is the biggest electrical power source and is predicted to continue being so for the next few decades. Currently, 37% of all the combined electricity being produced globally is generated by coal-fired power plants.
So how are pieces of rock converted to be used for work? To answer this, we will first dive into what coal is.
What is Coal?
You've probably seen coal before, such as in a barbecue grill, and they are black or dark brown in color. Coal contains large amounts of carbon and hydrocarbons, and form over millions of years, making it a nonrenewable energy source, or a source of energy that is not able to be produced as quickly as it is being consumed. As they form, they store the energy from plants that grew on top of them centuries ago, which were turned into coal due to the immense amount of pressure and heat from layers of rock and dirt above.
There are four main types of coal, which are classified by the carbon concentration as well as how much power they are able to produce. This is characterized by how much pressure and heat the plants that they formed from were exposed to over time. From highest to lowest heating value, the ranks of coal are anthracite (86-97% carbon), bituminous coal (45-86%), subbituminous coal (35-45%), and lignite (25-35%).
How Is Electricity Generated From Coal?
There are many steps involved in the process of using coal for power. This is done at power stations, where the coal is first crushed into a fine powder that allows it to burn at a quicker rate when it is moved to the pulverised coal combustion (PCC) systems that are set at a high temperature. Within these systems, tubes of water produce steam from the heat and other hot gases. This high-pressure steam is then moved to steam turbines, which have fast-moving propellers that rotate due to the steam. The turbine is connected to a generator full of wire coils, which generates electricity when they are wounded and rotate quickly in a strong magnetic field.
Once the coal is extracted of all the electricity it is capable of producing, and the electricity has been maximized to its highest voltage to be transmitted through power line grids, the steam is then condensed back into liquid water and moved back to the boiler, where it will be heated again in the next cycle. Once the electricity moves near to locations where electricity is used, such as houses and buildings, the electricity is converted into a lower voltage for safe usage.
Although coal has been effective at powering life and our communities for many years, many scientists, engineers, and researchers are looking for other alternative sources of energy, especially renewable sources. This is because the coal supply will eventually be depleted since it cannot be produced in a short period of time, and other sources of energy such as solar, wind, geothermal, and hydroelectric, are working to be developed, as they are powered by sources that are naturally restored.
Thank you for reading!
References:
“Coal and Electricity.” World Coal Association, 29 Oct. 2021, www.worldcoal.org/coal-facts/coal-electricity.
“Coal Explained.” U.S. Energy Information Administration (EIA), 19 Oct. 2021, www.eia.gov/energyexplained/coal.
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