The sun is the major source of energy for the earth.

Coal, oil, and natural gas are called fossil fuels because they come from plants and animals that have been buried for millions of years.

The weight of mud and rock over millions of years created pressure and heat that changed the plants and animals into fossil fuels.

These energy sources are considered nonrenewable because they are consumed, they are gone for our lifetimes: it will take millions of years to produce more.

Coal Have you felt the heat energy released during charcoal-grill cooking? Charcoal is like coal, which is a nonrenewable energy source: once all the coal is used up from the place it was found, no more can be mined there or made.

Oil How is the oil lamp an energy source? Heat and light are produced during the burning process.

Oil is also refined to produce gasoline. Oil is a nonrenewable energy source because once all the oil is used up from the place it was found, no more can be found or made.

Natural Gas Natural gas is formed from dead plants and decaying plant and animal life that lived millions of years ago in swampy, warm conditions.

Natural gas is usually piped to homes and is used to light stoves, heat water, and run furnaces.

Gas is a nonrenewable energy source because once all the gas is used up from the place it was found, no more can be found there or made.

Sunlight, moving water, and wind are naturally occurring sources of energy.

Solar energy is captured directly from the sun by plants to make food.

Solar energy can also be converted to electricity by solar cells. The force of moving water and moving air (wind) can also be used to generate electricity.