Energy and Fossil Fuels 13.4

Formation of Fossil Fuels A fuel is a material that contains stored potential energy Some of the fuels used today were made from materials that formed hundreds of millions of years ago Fuels, which include coal, petroleum, and natural gas are fossil fuels As organisms died, the remains piled up and were covered by clay and sand and over time pressure and high temperatures turned the remains into coal

Energy From the Sun Energy is conserved so fuels do not create energy Fossil fuels contain energy that came from the sun The sun is the source of energy for most of Earth’s processes During the process of nuclear fusion, nuclear energy is transformed to electromagnetic energy and it reaches the Earth in the form of light

The Sun’s Energy on Earth When the sun’s energy reaches the Earth, certain living things (plants, algae, some bacteria) transform some of it into chemical energy Some of the energy is used for daily needs and the rest is stored An energy transformation takes place when animals eat the plants and use the chemical energy to function

Use of Fossil Fuels Fossil fuels can be burned to release the chemical energy stored millions of years ago The process of burning fossil fuels is combustion

Steps of Combustion Coal is burned producing thermal energy to heat water and produce steam Steam is released to turn the turbines transforming thermal energy to mechanical energy The turbines are connected to generators that produce electricity Chemical energy thermal energy mechanical energy electrical energy