by parker » Wed Feb 23, 2011 9:03 pm
oal is a fossil fuel formed from the remains of plants, which existed millions of years ago. This was a time when a lot of the parts of earth were covered with colossal swampy forests. Coal is known to be a nonrenewable energy source. This is a nonrenewable energy resource because it takes millions of years to form.
Coal is used to harness energy and this energy comes from plants. Millions of years ago, these living plants had stored energy from the sun. After the plants die, a form of energy is released as the plants decay. But this is a process, which doesn't take place smoothly all the time. In certain conditions, the decay might be interrupted. This results in preventing the release of the stored solar energy.
It takes about a million years for a dead plant to turn into coal. These plants die and end up in the bottom of swamps, decaying for many years and forming a thick layer. Over time, the surface and the climate of the earth changed, as more water and dirt washed in. This halted the decay process. This process created more layers. The weight of the top layers packed down the lower layers of plant matter. Then, the heat and pressure caused chemical and physical changes. This resulted in, pushing out oxygen and leaving hydrocarbon-enriched deposits. In the end, the process gradually changed the plants into coal.