Coal Energy Detailed Study Notes for the UGC-NET Paper 1 Exam

Coal energy, one of the oldest sources of energy, has played a significant role in powering industries and generating electricity for centuries. Coal, a fossil fuel formed from the remains of plants that lived millions of years ago, is abundant and widely available in many parts of the world. The process of burning coal to produce heat or electricity releases energy that has been stored in the form of carbon compounds over millions of years. Despite concerns about its environmental impact, coal remains a major source of energy for electricity generation in many countries, contributing to economic development and energy security.

Coal energy is very crucial for the competitive exams such as the UGC-NET Paper 1 Examinations.

In this article, the readers will be able to know about coal energy along with other related topics in detail.

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What is Coal Energy?

Coal energy refers to the energy generated from burning coal as a fuel source. Coal is a fossil fuel formed from the remains of plants that lived millions of years ago. Over time, layers of dead plants accumulated and were buried under sediment, which subjected them to heat and pressure. This process, known as coalification, transformed the plant material into coal.

When coal is burned, the chemical energy stored in its carbon compounds is released in the form of heat. This heat can be used directly for heating or converted into electricity through a process called combustion. In power plants, coal is burned in a boiler to produce steam, which drives a turbine connected to a generator. The generator converts the mechanical energy from the turbine into electrical energy, which is then transmitted through power lines for distribution to homes, businesses, and industries.

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Coal Energy Source

Coal is a non-renewable energy source that is derived from the remains of plants that lived millions of years ago. As these plants died, they accumulated in swamps and wetlands, where they were buried by sediment over time. The pressure and heat from the overlying sediment caused the plant material to undergo chemical and physical changes, eventually forming coal.

Coal is classified into four main types based on its carbon content and energy density:

• Lignite: Lignite is the lowest quality and least carbon-dense type of coal. It has a high moisture content and low energy density, making it less efficient for energy generation compared to other types of coal.
• Sub-bituminous Coal: Sub-bituminous coal has a higher energy density than lignite but lower than bituminous coal. It is commonly used for electricity generation due to its relatively lower sulfur content and higher heating value.
• Bituminous Coal: Bituminous coal is the most abundant type of coal and is widely used for electricity generation and industrial applications. It has a higher carbon content and energy density than sub-bituminous coal, making it more efficient for energy production.
• Anthracite: Anthracite is the highest quality and most carbon-dense type of coal. It has the highest energy density and lowest moisture content among coal types, making it the most efficient for energy generation. However, anthracite is relatively rare and more expensive to mine than other types of coal.

How is Energy Generated from Coal?

Energy is generated from coal through a process called combustion, which involves burning coal to produce heat. This heat can then be used directly for heating purposes or converted into electricity through a series of steps:

• Coal Mining: The process begins with coal extraction from underground mines or surface mines. Coal is typically mined using various methods, including strip mining, underground mining, and mountaintop removal.
• Coal Preparation: Once mined, coal undergoes a preparation process to remove impurities such as rocks, soil, and debris. This process, known as coal washing or coal beneficiation, ensures that the coal meets quality standards for combustion and reduces environmental impacts during burning.
• Combustion: The prepared coal is then transported to power plants, where it is burned in a furnace or boiler to produce heat. The heat generated by burning coal converts water into steam within the boiler.
• Steam Generation: The high-pressure steam produced during combustion is directed to a steam turbine. As the steam flows through the turbine blades, it causes the turbine to rotate, converting the thermal energy of the steam into mechanical energy.
• Electricity Generation: The rotating turbine is connected to a generator, which converts the mechanical energy from the turbine into electrical energy. This process involves the movement of magnets within coils of wire, inducing an electric current according to Faraday's law of electromagnetic induction.
• Transmission and Distribution: The electricity generated by the generator is transmitted through power lines to homes, businesses, and industries for use. Transformers step up the voltage for efficient long-distance transmission and step down the voltage for safe distribution to consumers.
• Consumption: Finally, the electricity is consumed by various devices and appliances, providing power for lighting, heating, cooling, electronics, and industrial processes.

Conclusion

Coal energy has been a cornerstone of industrial development and energy production for centuries, providing a reliable and affordable source of electricity and heat to power economies worldwide. However, concerns about its environmental impact, including air and water pollution, greenhouse gas emissions, and contribution to climate change, have prompted efforts to transition to cleaner and more sustainable energy sources. While coal continues to play a significant role in the global energy mix, it is essential to explore and invest in alternative energy sources and technologies to mitigate its environmental consequences and ensure a sustainable energy future.

Coal energy is a vital topic as per several competitive exams. It is advisable for the learners to go through other similar topics with the Testbook App.