1. Energy and Fossil Fuels
13.4

2. 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

4. 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

5. 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

6. 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

7. 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