What Is Coal Power Plant and How Does it Work?

What is Coal-Fired Power Plant?

A coal-fired power station or coal power plant is a thermal power station that burns coal to generate electricity. A coal-fired power station is a type of fossil fuel power station. The coal is usually pulverized and then burned in a pulverized coal-fired boiler.

The furnace heat converts boiler water to steam, which is then used to spin turbines that turn generators. Thus, the chemical energy stored in coal is converted successively into thermal energy, mechanical energy, and, finally, electrical energy.

Coal that has been ground into a fine powder by a pulverize is blown into a furnace-like device, called a boiler, and burned. The heat produced converts water, which runs through a series of pipes in the boiler, to steam. The high-pressure steam turns the blades of a turbine, which is connected by a shaft to a generator. The generator spins and produces electricity.

Coal-fired power stations generate a third of the world’s electricity but cause hundreds of thousands of early deaths each year, mainly from air pollution.

Coal-fired power stations emit over 10 Gt of carbon dioxide each year, about one-fifth of world greenhouse gas emissions, so are the single largest cause of climate change. More than half of all the coal-fired electricity in the world is generated in China.

In 2020 the total number of plants started falling as they are being retired in Europe and America although still being built in Asia, almost all in China. Some remain profitable because costs to other people due to the health and environmental impact of the coal industry are not priced into the cost of generation, but there are the risk newer plants may become stranded assets.

The UN Secretary-General has said that OECD countries should stop generating electricity from coal by 2030, and the rest of the world by 2040.

Coal Power Plant Diagram

Coal Plant Works Diagram

How does a Coal Plant Works?

Coal-fired plants produce electricity by burning coal in a boiler to produce steam. The steam produced, under tremendous pressure, flows into a turbine, which spins a generator to create electricity. The steam is then cooled, condensed back into the water, and returned to the boiler to start the process over.

Here’s a real-life example: The Kingston Fossil Plant near Knoxville, Tenn., burns coal to heat its boilers to about 1,000 degrees Fahrenheit to create high-pressure steam. The steam is piped to the turbines at pressures of more than 1,800 pounds per square inch.

The turbines are connected to the generators and spin them at 3,600 revolutions per minute to make alternating current (AC) electricity at 20,000 volts. River water is pumped through tubes in a condenser to cool and condense the steam coming out of the turbines.

The Kingston plant generates about 10 billion kilowatt-hours a year, or enough electricity to supply 700,000 homes. To meet this demand, Kingston burns about 14,000 tons of coal a day, an amount that would fill 140 railroad cars.

Advantages of Coal as Power Plant Fuel

Today, advances in technology have allowed coal to improve living conditions with its current role in meeting man’s fuel needs. Coal has been used extensively in power generation where better technology is employed to ensure that there is a balance between ecology and economics in producing sustainable and affordable energy. Some of its advantages include reliability, affordability, abundance, known technologies, safety, and efficiency.

  • Reliability: One of the greatest advantages of coal-fired plants is reliability. Coal’s ability to supply power during peak power demand either as base power or as off-peak power is greatly valued as a power plant fuel. It is with this fact that advanced pulverized coal-fired power plants are designed to support the grid system in avoiding blackouts.
  • Affordability: Energy produced from coal-fired plants is cheaper and more affordable than other energy sources. Since coal is abundant, it is definitely cheap to produce power using this fuel. Moreover, it is not expensive to extract and mine from coal deposits. Consequently, its price remains low compared to other fuel and energy sources.
  • Abundance: There are approximately 300 years of economic coal deposits still accessible. With this great amount of coal available for use, coal-fired plants can be continuously fueled in many years to come.
  • Known technologies: The production and use of coal as a fuel are well understood, and the technology required in producing it is constantly advancing. Moreover, coal-mining techniques are continuously enhanced to ensure that there is a constant supply of coal for the production of power and energy.

Disadvantages of Coal-Fired Power Plants

On the other hand, there are also some significant disadvantages of coal-fired plants including Greenhouse Gas (GHG) Emissions, mining destruction, the generation of millions of tons of waste, and the emission of harmful substances.

  • Greenhouse gas emissions: It cannot be denied that coal leaves behind harmful byproducts upon combustion. These byproducts cause a lot of pollution and contribute to global warming. The increased carbon emissions brought about by coal-fired plants have led to further global warming which results in climate change.
  • Mining destruction: Mining coal not only results in the destruction of habitat and scenery, but it also displaces humans as well. In many countries where coal is actively mined, many people are displaced in huge numbers due to the pitting of the earth brought about by underground mining. Places near coal mines are unsafe for human habitation as the land could cave in at any time.
  • Generation of millions of tons of waste: Millions of tons of waste products that can no longer be reused are generated from coal-fired plants. Aside from the fact that these waste products contribute to waste disposal problems, they also contain harmful substances.
  • Emission of harmful substances: Thermal plants like coal-fired plants emit harmful substances to the environment. These include mercury, sulfur dioxide, carbon monoxide, mercury, selenium, and arsenic. These harmful substances not only cause acid rain but also are very harmful to humans as well.