Final answer:
Coal-fired power plants produce electricity by burning coal to boil water into steam, which drives a turbine connected to a generator. The efficiency of energy conversion is low, with significant heat loss to the environment and a large CO2 emission as one of the main environmental impacts.
Step-by-step explanation:
A coal-fired power plant converts the energy stored in coal into electricity through a multi-step process. First, coal is mined and processed to be suitable for burning. When coal is combusted in the plant, it heats water to turn it into steam. The steam at high pressure then drives a turbine, which is connected to a generator. As the turbine blades turn, they rotate the generator, which converts the kinetic energy into electricity. This process involves significant heat transfer to the surroundings, which is an inherent part of energy production from combustion.
During the energy conversion process, the efficiency of coal power stations is quite low, with only about 42% of the energy being used for electricity generation and the rest being lost as heat transfer to the environment. The chemical reaction during the combustion of coal is C + O2 → CO2, and a significant amount of CO2 is emitted into the atmosphere. This contributes to the warming of our planet, and coal power plants are known for being the least efficient and most CO2-emitting fossil fuel energy sources.