in this program we're going to learn about coal what is coal coal is a fossil fuel that formed from the remains of plants that died millions of years ago it is a non-renewable resource coal is a combustible dark-colored rock that can be ignited and burned to produce energy 41% of all electricity is produced by coal it is the world's largest source of energy used for the production of electricity in coal burning power plants steam from boiling water spins turbines and generators to create electricity coal was formed from dead plant matter that fell into swampy water it formed a thick layer of decomposing plant material called peat to become coal the peat must be buried by sediment the continued burial and combination of heat time and pressure caused the complex hydrocarbon compounds in the peat to break down and change coal goes through different phases of carbonization over millions of years and can be found at all stages of development in different parts of the world coal is classified into four main types depending on the amount and types of carbon it contains and the amount of heat energy it can produce lignite is the lower rank of coal with the lowest energy content then sub-bituminous coal that contains 35 to 45 percent carbon bituminous coal contains 45 to 86 percent carbon and was formed under high heat and pressure then anthracite anthracite contains 86 to 97 percent carbon and has a heating value slightly higher than bituminous coal one way we get coal from the earth is underground mining where shafts and tunnels are dug down to coal scenes miners are then transported down the shafts to run machines that dig out the coal once the coal is dug out conveyors bring the coal to the surface some coal is dug out from surface mines also called strip mines these are large holes and can be up to hundreds of meters deep in order to get the coal once the dirt is removed equipment is used to remove the coal the coal is often washed at the mine to remove impurities before it is transported to the power plants and other places that use it coal mining and the subsequent burning of coal can have many negative effects on both humans and the environment the burning of coal emits carbon dioxide sulfur dioxide nitrogen dioxide and mercury compounds that pollute the air the mining and burning of coal typically requires the use of water pollutants build up in the water used contaminating bodies of water land resources are affected by coal mining and processing - we've seen that surface mining disturbs large areas of land while the soil at coal-fired power plant sites can also become contaminated with various pollutants from the coal coal is an important energy resource and new technologies are being created to protect human health and the environmental impact of coal energy generation